Jeffrey M Spivak, M.D.

The prevalence of transitional vertebrae in the lumbar spine
Apazidis, Alexios; Ricart, Pedro A; Diefenbach, Christopher M; Spivak, Jeffrey M
2011 Sep;11(9):858-862, Spine journal
BACKGROUND CONTEXT: Lumbosacral transitional vertebrae (LSTVs) are a congenital vertebral anomaly of the L5-S1 junction in the spine. This alteration may contribute to incorrect identification of a vertebral segment, leading to wrong-level spine surgery and poor correlation with clinical symptoms. Although several studies describe the occurrence of this anomaly in back pain populations, investigation of the prevalence in the American general population is lacking. PURPOSE: To establish the prevalence rates for LSTVs in the general population. STUDY DESIGN: Retrospective review. PATIENT SAMPLE: Consecutive kidney-urinary bladder (KUB) radiographs of subjects from the past 2 years (2008-2009). OUTCOME MEASURES: Clinical demographics, number of lumbar vertebrae, L5-S1 transverse process (TP) height, and rib length. METHODS: Consecutive adult KUB studies of adult subjects were queried with clear visibility of the last rib's vertebral body articulation, all lumbar TPs, and complete sacral wings. Exclusion criteria consisted of any radiologic evidence of previous lumbosacral surgery that would obstruct our measurements. A total of 1,100 abdominal films were reviewed, and 211 were identified as being adequate for the measurement of the desired parameters. RESULTS: Two hundred eleven subjects were identified as eligible for the study, and 75 (35.6%) were classified as positive for a transitional lumbosacral vertebra. The most common anatomical variant was the Castellvi Type IA (14.7%). The average age at the time of the KUB study was 59.8 years (18-95 years). One hundred ninety-seven subjects (93.4%) presented five lumbar (nonribbed) vertebrae, and only 14 (6.6%) had six lumbar vertebrae. CONCLUSIONS: The significance of lumbosacral transitional level changes to the establishment of pain, degenerative changes, stenosis, and disc disease have been well documented in symptomatic patients. Although LSTV's role in low back pain remains controversial, our study has shown that, when the same criteria are used for classification, prevalence among the general population and symptomatic patients may be similar
— id: 137894, year: 2011, vol: 11, page: 858, stat: Journal Article,

Prospective, Randomized, Multicenter Food and Drug Administration Investigational Device Exemption Study of the ProDisc-L Total Disc Replacement Compared with Circumferential Arthrodesis for the Treatment of Two-Level Lumbar Degenerative Disc Disease Results at Twenty-four Months
Delamarter, Rick; Zigler, Jack E.; Balderston, Richard A.; Cammisa, Frank P.; Goldstein, Jeffrey A.; Spivak, Jeffrey M.
2011 APR 20 ;93A(8):705-715, Journal of bone & joint surgery (American volume)
Background: Disc replacement arthroplasty previously has been shown to be an effective alternative to spine fusion for the treatment of single-level lumbar degenerative disc disease. The purpose of the present study was to determine the twenty-four-month results of a clinical trial of the ProDisc-L total disc replacement as compared with spinal fusion for the treatment of degenerative disc disease at two contiguous vertebral levels from L3 to Si. Methods: A total of 237 patients were treated in a randomized controlled trial designed as a non-inferiority study for regulatory application purposes. Blocked randomization was performed with use of a 2:1 ratio of total disc arthroplasty to circumferential arthrodesis. Evaluations, including patient self-assessments, physical and neurological examinations, and radiographic examinations, were performed preoperatively, six weeks postoperatively, and three, six, twelve, eighteen, and twenty-four months postoperatively. Results: At twenty-four months, 58.8% (eighty-seven) of 148 patients in the total disc replacement group were classified as a statistical success, compared with 47.8% (thirty-two) of sixty-seven patients in the arthrodesis group; non-inferiority was demonstrated. The mean Oswestry Disability Index in both groups significantly improved from baseline (p < 0.0001); the mean percentage improvement for the total disc replacement group was significantly better than that for the arthrodesis group (p = 0.0282). An established clinical criterion for success, a >= 15-point improvement in the Oswestry Disability Index from baseline, occurred in 73.2% (109) of 149 patients in the total disc replacement group and 59.7% (thirty-seven) of sixty-two patients in the arthrodesis group. The Short Form-36 physical component scores were significantly better for the total disc replacement group as compared with the arthrodesis group (p = 0.0141 at twenty-four months). Visual analog scale scores for satisfaction significantly favored total disc replacement from three to twenty-four months. At twenty-four months, 78.2% (111) of 142 patients in the total disc replacement group and 62.1% (thirty-six) of fifty-eight patients in the arthrodesis group responded 'yes' when asked if they would have the same surgery again. Lumbar spine range of motion on radiographs averaged 7.8 degrees at the superior disc and 6.2 degrees at the inferior disc in patients with total disc replacement. Reduction in narcotics usage significantly favored the total disc replacement group at twenty-four months after surgery (p = 0.0020). Conclusions: Despite the relatively short duration of follow-up and design limitations, the present study suggests that two-level lumbar disc arthroplasty is an alternative to and offers clinical advantages in terms of pain relief and functional. recovery in comparison with arthrodesis. Longer-term follow-up is needed to determine the risks for implant wear and/or degenerative segment changes
— id: 131935, year: 2011, vol: 93A, page: 705, stat: Journal Article,

Outcomes analysis of anterior-posterior fusion for low grade Isthmic spondylolisthesis
Quirno M.; Kamerlink J.R.; Goldstein J.A.; Spivak J.M.; Bendo J.A.; Errico T.J.
2011 ;69(4):316-319, Bulletin of the NYU Hospital for Joint Diseases
Background. Traditional surgical treatment of isthmic spondylolisthesis is posterior-lateral fusion, but the addition of anterior surgery has been explored. The purpose of this study was to evaluate the surgical and clinical outcomes of anterior-posterior surgical treatment for low-grade isthmic spondylolisthesis. Methods. Retrospectively, we enrolled 23 consecutive patients (mean age of 50) who underwent surgical treatment for low grade isthmic spondylolisthesis. The mean follow-up was 10 months. Basic demographic and radiographic data was collected. Pre- and post-surgical clinical surveys (VAS, ODI, and SF-36) were collected. Results. All 23 patients underwent anterior interbody fusion with a femoral ring allograft or ICBG in combination with posterior lumbar decompression and fusion with instrumentation. The average slip percentage decreased from 23.2% to 19.0% (p = 0.24) while slip angle increased from 9.8degree to 17.9degree (p < 0.001) and average disc height decreased from 1.9 cm to 0.80 cm (p < 0.001). VAS scores decreased from 7.1 to 2.4 (p < 0.001), ODI scores decreased from 52.5 to 28.1 (p < 0.001), and SF-36 scores increased in the Physical Component Scale (PCS) from 29.5 to 42.6 (p < 0.001). Conclusion. In our study, patients demonstrated an improvement in the ODI as well the physical component scores of the SF-36, thus having a good clinical outcome
— id: 148750, year: 2011, vol: 69, page: 316, stat: Journal Article,

The Incidence of Potential Candidates for Total Disc Replacement among Lumbar and Cervical Fusion Patient Populations
Quirno, Martin; Goldstein, Jeffrey A; Bendo, John A; Kim, Yong; Spivak, Jeffrey M
2011 Dec;5(4):213-219, Asian spine journal
STUDY DESIGN: Retrospective chart review. PURPOSE: To evaluate the incidence of potential total disc replacement (TDR) candidates among cervical and lumbar fusion patient populations using strict Food and Drug Administration (FDA) criteria and with relative exclusion criteria removed. OVERVIEW OF LITERATURE: Recent studies suggest that the potential percentage of patients that are candidates for TDR ranges from 0-5% in lumbar fusions and 43% in cervical fusions. METHODS: We performed a retrospective chart review of 280 consecutive patients who had lumbar (n = 174) and cervical (n = 106) fusion or TDR performed by one of four independent adult orthopaedic spine surgeons. Charts were screened for investigational device exemption (IDE) inclusion/exclusion criteria and later reanalyzed excluding relative exclusion criteria, such as history of chronic medical illness, twolevel disease (cervical cases), and history of prior fusion surgery in the anatomic region. RESULTS: Of the 174 lumbar surgeries, 10 were TDR with Prodisc-L and 164 were lumbar fusions. The most common TDR exclusion criteria were lytic spondylolisthesis or spinal stenosis (47.7% of patients) and more than 2 level degenerative disc disease (37.9%). 14.9% had no IDE exclusion criteria and would be considered candidates for TDR. After excluding the relative lumbar exclusion criteria, this percentage increased to 25.8%. Of the 106 cervical cases, 3 had a TDR with Prodisc-C and 103 had a cervical fusion. Twenty eight percent had no IDE exclusion criteria and would be considered candidates for cervical TDR. CONCLUSIONS: A larger percentage of cervical fusion candidates are potential candidates for TDR (28%) than lumbar fusion candidates (14.9%) based on the strict IDE criteria
— id: 147694, year: 2011, vol: 5, page: 213, stat: Journal Article,

Biomechanical comparison of translaminar screw versus pedicle screw supplementation of anterior femoral ring allografts in one-level lumbar spine fusion
Razi A.E.; Spivak J.M.; Kummer F.J.; Hersh D.S.; Goldstein J.A.
2011 ;69(4):298-302, Bulletin of the NYU Hospital for Joint Diseases
Pedicle screws (PS) can provide initial stabilization of anterior interbody femoral ring allograft (FRA) lumbar constructs. Translaminar screws (TLS) have also been advocated for this procedure. The objective of this study was to use an in vitro human cadaveric model to compare the stability of one-level anterior interbody lumbar constructs stabilized with PS and those stabilized with TLS. Five human cadaveric spinal motion segments (L4-S2) were biomechanically evaluated in the intact condition and using the following methods of stabilization: anterior interbody fusion with FRA, anterior FRA supplemented with PS, and anterior FRA supplemented with TLS. Stability was determined for each construct by measuring construct displacement as a function of applied load under the following conditions: compression, flexion, extension, lateral bending to each side, and axial torsion. There were no statistically significant differences in construct stability between FRA supplemented with PS and FRA supplemented with TLS under any of the loading conditions. In selected cases, supplementation of anterior femoral ring allograft with translaminar screws is a viable alternative to supplementation with pedicle screws
— id: 148752, year: 2011, vol: 69, page: 298, stat: Journal Article,

Prospective, randomized study of surgical site infections with the use of perioperative antibiotics for 24 hours versus the duration of a drain after spinal surgery
Ricart-Hoffiz P.; Takemoto R.; Park J.; Andres T.; Hoelscher C.; Goldstein J.; Spivak J.; Bendo J.; Errico T.; Lonner B.
2011 ;11(10 SUPPL 1):23S-23S, Spine journal
BACKGROUND CONTEXT: The use of a postoperative spinal drain for spine surgery patients is widely thought to increase the risk of postoperative infection. While antibiotics are commonly given postoperatively to decrease bacterial seeding of the hematoma, the duration of postoperative antibiotics is more debatable, and protocols may vary. PURPOSE: To determine if the continuation of postoperative antibiotics for the duration of the timea spinal drain is in place reduces the risk of acute surgical site infection, in comparison with postoperative antibiotics given for 24 hours only. STUDY DESIGN/SETTING: Prospective, randomized double-blind study. PATIENT SAMPLE: Patients undergoing multilevel thoracolumbar spine surgery in which a drain is used. OUTCOME MEASURES: Surgical site infections were defined as purulent drainage; organisms obtained from an aseptically obtained culture; pain, swelling and redness; and/or diagnosis of infection by a surgeon. METHODS: 315 patients who underwent multilevel thoracolumbar spine surgery requiring a postoperative drain were enrolled and randomized into two groups: one group receiving 24 hours of perioperative antibiotics and one group receiving antibiotics for the duration that the drain was in place. Data collected included demographics, medical co-morbidities, type of spine surgery and surgical site infection. RESULTS: 13/170 (7.6%) in the 24 hours of antibiotic group developed a surgical site infection while 21/145 (14.5%) in the antibiotic for the duration of the drain were found to have a surgical site infection. The differences between each group were significant (p<.05). There were no significant differences between the groups with respect to demographics, surgical time, type of surgery, drain output or length of stay. CONCLUSIONS: Continuing postoperative antibiotics for the entire duration a drain is in place after spine surgery does not decrease the rate of surgical site infections
— id: 139772, year: 2011, vol: 11, page: 23S, stat: Journal Article,

The lumbar facet joint: a review of current knowledge: part 1: anatomy, biomechanics, and grading
Varlotta, Gerard P; Lefkowitz, Todd R; Schweitzer, Mark; Errico, Thomas J; Spivak, Jeffrey; Bendo, John A; Rybak, Leon
2011 Jan;40(1):13-23, Skeletal radiology
We present a two-part review article on the current state of knowledge of lumbar facet joint pathology. This first article discusses the functional anatomy, biomechanics, and radiological grading systems currently in use in clinical practice and academic medicine. Facet joint degeneration is presented within the larger context of degenerative disc disease to enable the reader to better understand the anatomical changes underlying facet-mediated lower back pain. Other less-common, but equally important etiologies of lumbar facet joint degeneration are reviewed. The existing grading systems are discussed with specific reference to the reliability of CT and MR imaging in the diagnosis of lumbar facet osteoarthritis. It is hoped that this discussion will stimulate debate on how best to improve the diagnostic reliability of these tests so as to improve both operative and non-operative treatment outcomes
— id: 114816, year: 2011, vol: 40, page: 13, stat: Journal Article,

The lumbar facet joint: a review of current knowledge: Part II: diagnosis and management
Varlotta, Gerard P; Lefkowitz, Todd R; Schweitzer, Mark; Errico, Thomas J; Spivak, Jeffrey; Bendo, John A; Rybak, Leon
2011 Feb;40(2):149-157, Skeletal radiology
This article is the second article in a two-part review on lumbar facet joint pathology. In this review, we discuss the current concepts and controversies regarding the proper diagnosis and management of patients presenting with presumed facet-mediated lower back pain. All efforts were made to include the most relevant literature from the fields of radiology, orthopaedics, physiatry, and pain management. Our focus in this article is on presenting the evidence supporting or refuting the most commonly employed injection-based therapies for facet-mediated lower back pain
— id: 116219, year: 2011, vol: 40, page: 149, stat: Journal Article,

Analysis of segmental cervical spine vertebral motion after prodisc-C cervical disc replacement
Park, Justin J; Quirno, Martin; Cunningham, Mary R; Schwarzkopf, Ran; Bendo, John A; Spivak, Jeffrey M; Goldstein, Jeffrey A
2010 Apr 15;35(8):E285-E289, Spine
STUDY DESIGN: Retrospective study of patients enrolled in a prospective randomized Food and Drug Administration trial with single level cervical disc replacement (CDR) with the ProDisc-C (Synthes, Paoli, PA). OBJECTIVE: Evaluate the segmental range of motion (ROM) in the cervical spine pre- and postoperative after CDR. SUMMARY OF BACKGROUND INFORMATION: Each cervical level is believed to have its own biomechanical characteristics, ultimately leading to different sagittal and lateral ROM. Our understanding of the factors that influence motion after CDR continues to change and expand. METHODS: One hundred sixty-four patients with single level ProDisc-C arthroplasty were evaluated radiographically using Medical Metrics (QMATM, Medical Metrics, Inc., Houston, TX). Pre- and postoperative disc height and ROM were measured from standing lateral and flexion-extension radiographs. Of these 164 patients, 44 had a CDR at C6/C7, 96 at C5/C6, 18 at C4/C5, and 6 at C3/C4. The mean follow-up was of 24 months. Statistical analysis evaluated the difference in mean ROM between the groups. RESULTS: Before surgery, C4/C5 had more sagittal ROM compared with C3/C4, C5/C6, and C6/C7 (P < 0.001.) Before surgery, C4/C5 also had more lateral ROM compared with C3/C4, C5/C6, and C6/C7 (P = 0.015). After surgery, there were no significant differences in sagittal and lateral ROM between C3/C4, C4/C5, C5/C6, and C6/C7. The delta (difference between pre- and postoperative) proved that the C4/C5 CDR actually lost sagittal ROM (-2.5 degrees ) compared with the other levels, which gained sagittal ROM, C3/C4 (0.9 degrees ), C5/C6 (1.8 degrees ), and C6/C7 (1.6 degrees ); P = 0.037. There was no significant difference in the delta lateral ROM between the segments: C3/C4, C4/C5, C5/C6, and C6/C7. CONCLUSION: CDR approximates the different segmental sagittal and lateral ROM. Although C4/C5 had negative delta ROM in the sagittal and lateral planes, it provided a satisfactory final ROM. Long-term clinical outcome studies are needed to properly evaluate if these differences could ultimately affect the patients everyday life
— id: 109215, year: 2010, vol: 35, page: E285, stat: Journal Article,

Effects of perioperative blood product use on surgical site infection following thoracic and lumbar spinal surgery
Schwarzkopf, Ran; Chung, Christine; Park, Justin J; Walsh, Michael; Spivak, Jeffrey M; Steiger, David
2010 Feb 1;35(3):340-346, Spine
STUDY DESIGN: Retrospective case-control review. OBJECTIVE: This retrospective study explored the hypothesis that the perioperative administration of blood products is an identifiable risk factor of increased surgical site infections (SSIs) after thoracic and lumbar spine surgical procedures. SUMMARY OF BACKGROUND DATA: Surgical site infections are a significant cause of postoperative morbidity and mortality. According to the Center for Disease Control's National Nosocomial Infections Surveillance system, which monitors the rate of hospital-acquired infections in the United States, SSIs represent the third most commonly reported type of nosocomial infection, accounting for 14% to 16% of all nosocomial infections. The incidence of SSIs after spinal surgery is influenced by both preoperative and intraoperative risk factors. The relationship between blood products and SSIs has been a matter of debate for more than 2 decades. Several studies have supported the association between the use of blood products and the development of postoperative surgical site infections. METHODS: A retrospective case-control study was performed. We reviewed the charts of all patients who had undergone thoracic and/or lumbar spinal surgery at the NYU Hospital for Joint Diseases between 2002 and 2007. All patients who had developed surgical site infections following spine surgery in this 5-year period were identified. RESULTS: Data for 61 cases and 71 controls were included in this study. The analysis of the preoperative risk factors was performed for the entire population of patients. Body mass index and blood transfusions were found to be statistically significant risk factors for increased surgical site infections for this population. CONCLUSION: Our findings support current theories that blood transfusions may have modulatory effects on the immune system of the recipients. Our specific study in spine patients may contribute to the expanding literature on allogeneic blood transfusions and the risk of nosocomial infections and encourage surgeons to favor a more restrictive policy with regard to transfusions
— id: 106498, year: 2010, vol: 35, page: 340, stat: Journal Article,

Intervertebral foramen size and volume changes in low grade, low dysplasia isthmic spondylolisthesis
Spivak, Jeffrey M; Kummer, Frederick J; Chen, Deyu; Quirno, Martin; Kamerlink, Jonathan R
2010 Sep 15;35(20):1829-1835, Spine
STUDY DESIGN: Anatomic study. OBJECTIVE: The purpose of this study is to determine the effect of the slip amount, slip angle, and disc height on the geometry of the L5 foramen in low-grade, low-dysplasia isthmic L5 spondylolisthesis using a human cadaveric model. SUMMARY OF BACKGROUND DATA: Radicular pain and varying degrees of nerve root dysfunction are present in many adult isthmic spondylolisthesis patients and can be the result of compression of the L5 root within its foramen. METHODS: The intervertebral foramens of six L5 vertebra and sacrum cadaver specimens had a standardized pars defect created and were mounted on an adjustable frame. Plasticene molds of the foramens were made by varying sagittal translocation (0%, 12.5%, 25%, and 50%), slip angle (kyphotic 10 degrees and lordotic 0 degrees , 10 degrees , 20 degrees , and 30 degrees ), and disc height (0, 5, and 10 mm). The volume of each mold was measured. The surface area was determined by sagittally slicing on a microtome the mold and each section's face was measured by computer image analysis. RESULTS: The area and volume of the foramen at a sagittal slip of 0%, slip angle of 0 degrees , and 0 mm disc height were used as a control. As disc height decreased from 10 to 5 mm, 10 to 0 mm, and 5 to 0 mm, the foramen area and volume significantly decreased (P < 0.05). Incremental slip percentage from 0% to 12.5%, 25%, and 50% produced significantly reduced foramen area and volumes (P < 0.05). As slip angle increased from 10 degrees kyphosis to 0 degrees , 10 degrees , 20 degrees , and 30 degrees lordosis, foramen area and volume decreased (P < 0.05). CONCLUSION: Disc height and slip percentage had the largest effect on intervertebral foramen area and volume in this model of low-grade, low-dysplasia isthmic spondylolisthesis. Slip angle changes affected foramen area to a lesser degree. Surgical treatment strategies should consider restoration of disc height in cases with foraminal stenosis
— id: 112550, year: 2010, vol: 35, page: 1829, stat: Journal Article,

Revision of a lumbar disc arthroplasty following late infection
Spivak, Jeffrey M; Petrizzo, Anthony M
2010 May;19(5):677-681, European spine journal
Anterior removal of a lumbar total disc replacement implant is often a very technically demanding procedure. The anterior retroperitoneal anatomy is prone to scarring, limiting remobilization and making a direct anterior exposure above the L5-S1 level difficult if not impossible to achieve safely. Anterolateral approach strategies can be more safely achieved at L4-L5 and above, but may require vertebral osteotomy in order to remove a keeled prosthesis. Successful conversion to a fusion with implant removal can be achieved, even when osteotomy is needed for implant removal. This Grand Rounds case presentation involves an unusual late retroperitoneal abscess following two-level TDR with direct extension to one of the implants, and the subsequent nonoperative and operative management. Removal of a well-fixed keeled implant at the L4-L5 level following nonoperative treatment of a surrounding retroperitoneal abscess and conversion to fusion represents close to, if not a 'worst-case' scenario for revision TDR. However, with proper preoperative planning and surgical experience, a safe and successful procedure can be the end result
— id: 109198, year: 2010, vol: 19, page: 677, stat: Journal Article,

Outcome analysis of anteriorposterior surgical technique for the treatment of low grade lumbar isthmic spondylolisthesis through standardized surveys
Kamerlink J.; Quirno M.; Goldstein J.; Spivak J.; Bendo J.; Errico T.
2009 ;9:67-68, Pain practice
Introduction: The gold standard for the treatment of isthmic spondylolisthesis is posterior-lateral fusion. Few studies have evaluated the clinical outcomes of circumference fusion in the treatment if isthmic spondylolisthesis. The purpose of this study was to evaluate the surgical and clinical outcomes of anterior-posterior surgical treatment for low-grade isthmic spondylolisthesis. Methods: Retrospectively, 23 consecutive patients were enrolled that underwent surgical treatment for Isthmic Spondylolisthesis Grade 1 or 2. Basic demographic data was collected. Radiographic data that was collected included Meyerding Scale, disc height, and slip angle. Pre and post surgical clinical surveys which included VAS, ODI, and SF-36 surveys were collected. Results: There were 23 patients. All patients underwent anterior interbody fusion with a femoral ring allograft or iliac crest bone graft in addition to posterior lumbar decompression and fusion with instrumentation. The average slip percentage decreased from 23.2% to 19.0% (P = 0.24), slip angle increased from 9.8 to 17.9 (P < 0.001), and disc height decreased from 1.9 cm to 0.80 cm (P < .001). VAS scores decreased from 7.1 to 2.4 (P < 0.001). ODI scores decreased from 52.5 to 28.1 (P < 0.001). SF-36 scores demonstrated a significant increase in the Physical Component Scale (PCS) from 29.5 to 42.6 (P < 0.001). Conclusion: This study demonstrates that patients with isthmic spondylolisthesis that undergo circumferential fusion have a good clinical outcome. Patients demonstrated an improvement in the ODI and the physical component scores of the SF-36. These results demonstrate that patients improved in their physical functioning due to the surgery alone
— id: 111411, year: 2009, vol: 9, page: 67, stat: Journal Article,

Effect of intervertebral disc height on postoperative motion and clinical outcomes after Prodisc-C cervical disc replacement
Peng, Chan W B; Quirno, Martin; Bendo, John A; Spivak, Jeffrey M; Goldstein, Jeffrey A
2009 Jul;9(7):551-555, Spine journal
BACKGROUND CONTEXT: Cervical total disc replacement (TDR) is an emerging technology. However, the factors that influence postoperative range of motion (ROM) and patient satisfaction are not fully understood. PURPOSE: To evaluate the influence of pre- and postoperative disc height on postoperative motion and clinical outcomes. STUDY DESIGN/SETTING: Retrospective review of patients enrolled in prospective randomized Food and Drug Administration (FDA) trial. PATIENT SAMPLE: One hundred sixty-six patients with single-level ProDisc-C arthroplasty performed were evaluated. OUTCOME MEASURES: ROM and clinical outcomes based on Neck Disability Index (NDI) and Visual Analog Scale (VAS) were assessed. METHODS: Preoperative and postoperative disc height and ROM were measured from lateral and flexion-extension radiographs. Student t test and Spearman's rho tests were performed to determine any correlation or 'threshold' effect between the disc height and ROM or clinical outcome. RESULTS: Patients with less than 4mm of preoperative disc height had a mean 1.8 degrees increase in flexion-extension ROM after TDR, whereas patients with greater than 4mm of preoperative disc height had no change (mean, 0 degrees ) in flexion-extension ROM (p=.04). Patients with greater than 5mm of postoperative disc height have significantly higher postoperative flexion-extension ROM (mean, 10.1 degrees ) than those with less than 5mm disc height (mean, 8.3 degrees , p=.014). However, patients with greater than 7mm of postoperative disc height have significantly lower postoperative lateral bending ROM (mean, 4.1 degrees ) than those with less than 7mm disc height (mean, 5.7 degrees , p=.04). It appears that the optimal postoperative disc height is between 5 and 7mm for increased ROM on flexion extension and lateral bending. There was a mean improvement of 30.5 points for NDI, 4.3 points for VAS neck pain score, and 3.9 points for VAS arm pain score (all p<.001). No correlation could be found between clinical outcomes and disc height. Similarly, no threshold effect could be found between any specific disc height and NDI or VAS. CONCLUSION: Patients with greater disc collapse of less than 4mm preoperative disc height benefit more in ROM after TDR. The optimal postoperative disc height range to maximize ROM is between 5 and 7mm. This optimal range did not translate into better clinical outcome at 2-year follow-up
— id: 100606, year: 2009, vol: 9, page: 551, stat: Journal Article,

Vertebral artery injury in cervical spine surgery: anatomical considerations, management, and preventive measures
Peng, Chan W; Chou, Benedict T; Bendo, John A; Spivak, Jeffrey M
2009 Jan-Feb;9(1):70-76, Spine journal
BACKGROUND CONTEXT: Vertebral artery (VA) injury can be a catastrophic iatrogenic complication of cervical spine surgery. Although the incidence is rare, it has serious consequences including fistulas, pseudoaneurysm, cerebral ischemia, and death. It is therefore imperative to be familiar with the anatomy and the instrumentation techniques when performing anterior or posterior cervical spine surgeries. PURPOSE: To provide a review of VA injury during common anterior and posterior cervical spine procedures with an evaluation of the surgical anatomy, management, and prevention of this injury. STUDY DESIGN: Comprehensive literature review. METHODS: A systematic review of Medline for articles related to VA injury in cervical spine surgery was conducted up to and including journal articles published in 2007. The literature was then reviewed and summarized. RESULTS: Overall, the risk of VA injury during cervical spine surgery is low. In anterior cervical procedures, lateral dissection puts the VA at the most risk, so sound anatomical knowledge and constant reference to the midline are mandatory during dissection. With the development and rise in popularity of posterior cervical stabilization and instrumentation, recognition of the dangers of posterior drilling and insertion of transarticular screws and pedicle screws is important. Anomalous vertebral anatomy increases the risk of injury and preoperative magnetic resonance imaging and/or computed tomography (CT) scans should be carefully reviewed. When the VA is injured, steps should be taken to control local bleeding. Permanent occlusion or ligation should only be attempted if it is known that the contralateral VA is capable of providing adequate collateral circulation. With the advent of endovascular repair, this treatment option can be considered when a VA injury is encountered. CONCLUSIONS: VA injury during cervical spine surgery is a rare but serious complication. It can be prevented by careful review of preoperative imaging studies, having a sound anatomical knowledge and paying attention to surgical landmarks intraoperatively. When a VA injury occurs, prompt recognition and management are important
— id: 94850, year: 2009, vol: 9, page: 70, stat: Journal Article,

Inflamatory Spondyloarthropathies
Zavatsky, Joseph; Zarro, Christopher; Lonner, Baron; Spivak, Jeffrey
Surgical management of spinal deformities Philadelphia PA : Saunders/Elsevier, 2009,
— id: 5803, year: 2009, vol: , page: ?, stat: Chapter,

A comparison of two retroperitoneal surgical approaches for total disc arthroplasty of the lumbar spine
Bendo, John A; Quirno, Martin; Errico, Thomas; Spivak, Jeffrey M; Goldstein, Jeffrey
2008 Jan 15;33(2):205-209, Spine
STUDY DESIGN: Retrospective outcome data analysis. OBJECTIVE: To evaluate if there is a significant difference between the midline rectus (MR) and the paramedian lateral rectus (PLR) approaches with regard to implant position for lumbar disc arthroplasty. To establish that a less than optimal implant position may influence clinical outcome. SUMMARY OF BACKGROUND DATA: Little is known about the impact of varying surgical approaches on lumbar artificial disc implant position and clinical outcome. METHODS: Fifty-seven patients were obtained from one center participating Food and Drug Administration study for the evaluation of the lumbar Prodisc-L. Two different surgical access techniques were compared; the MR and left PLR. Two independent evaluators calculated the postoperative radiographical displacement from the midline in the coronal and sagittal planes for each of the surgical techniques. Pre- and postoperative clinical outcomes were evaluated to determine which surgical access technique was associated with better outcomes and if there was a clinical correlation with technical accuracy. RESULTS: The PLR approach was associated with greater malalignment of the prosthesis in both the coronal and sagittal planes compared with the MR approach. However, the difference was significant only in the sagittal plane (P = 0.021). There was no significant difference in clinical outcome for either approach (P = 0.34). Patients with >or=5 mm prosthetic displacement from the midvertebral point had significantly worse Owestry disability index scores than patients with <3 mm malalignment in both the coronal and sagittal planes regardless of the surgical approach employed. CONCLUSION: The finding of a statistically significant more anteriorly displaced position in the sagittal plane of the total disc arthroplasty using the PLR approach may indicate a need to change to the MR approach. This study also demonstrates that patients with >or=5 mm prosthetic deviation from midline in either the coronal or sagittal planes had diminished clinical outcomes regardless of the approach used
— id: 75855, year: 2008, vol: 33, page: 205, stat: Journal Article,

The lumbar spine and low back pain in golf: a literature review of swing biomechanics and injury prevention
Gluck, George S; Bendo, John A; Spivak, Jeffrey M
2008 Sep-Oct;8(5):778-788, Spine journal
BACKGROUND CONTEXT: The golf swing imparts significant stress on the lumbar spine. Not surprisingly, low back pain (LBP) is one of the most common musculoskeletal complaints among golfers. PURPOSE: This article provides a review of lumbar spine forces during the golf swing and other research available on swing biomechanics and muscle activity during trunk rotation. STUDY DESIGN: The role of 'modern' and 'classic' swing styles in golf-associated LBP, as well as LBP causation theories, treatment, and prevention strategies, are reviewed. METHODS: A PubMed literature search was performed using various permutations of the following keywords: lumbar, spine, low, back, therapy, pain, prevention, injuries, golf, swing, trunk, rotation, and biomechanics. Articles were screened and selected for relevance to injuries in golf, swing mechanics, and biomechanics of the trunk and lumbar spine. Articles addressing treatment of LBP with discussions on trunk rotation or golf were also selected. Primary references were included from the initial selection of articles where appropriate. General web searches were performed to identify articles for background information on the sport of golf and postsurgical return to play. RESULTS: Prospective, randomized studies have shown that focus on the transversus abdominus (TA) and multifidi (MF) muscles is a necessary part of physical therapy for LBP. Some studies also suggest that the coaching of a 'classic' golf swing and increasing trunk flexibility may provide additional benefit. CONCLUSIONS: There is a notable lack of studies separating the effects of swing modification from physical rehabilitation, and controlled trials are necessary to identify the true effectiveness of specific swing modifications for reducing LBP in golf. Although the establishment of a commonly used regimen to address all golf-associated LBP would be ideal, it may be more practical to apply basic principles mentioned in this article to the tailoring of a unique regimen for the patient. Guidelines for returning to golf after spine surgery are also discussed
— id: 94851, year: 2008, vol: 8, page: 778, stat: Journal Article,

Effect of intervertebral disc height on postoperative motion and outcomes after ProDisc-L lumbar disc replacement
Yaszay, Burt; Bendo, John A; Goldstein, Jeffrey A; Quirno, Martin; Spivak, Jeffrey M; Errico, Thomas J
2008 Mar 1;33(5):508-512, Spine
STUDY DESIGN: Retrospective study of patients enrolled in prospective randomized Food and Drug Administration trial. OBJECTIVE: To evaluate the influence of pre- and postoperative disc height on postoperative motion and clinical outcomes. SUMMARY OF BACKGROUND DATA: Our understanding of the factors that influence motion and ultimately patient satisfaction after lumbar disc replacement continues to evolve. METHODS: Forty-two patients with a single level ProDisc-L at either the L4/5 or L5-S1 were selected. Pre- and postoperative disc height and range of motion (ROM) were measured from standing lateral and flexion-extension radiographs. Oswestry Disability Index and visual analog scale were also collected. Student t test and Spearman rho tests were performed to determine if there was any correlation or 'threshold' effect between the disc height and ROM or clinical outcome. RESULTS: The mean anterior and posterior disc height significantly increased from 10.8 mm to 17.6 mm and 4.4 mm to 7.9 mm, respectively (P < 0.01). The mean ROM decreased from 7.0 degrees to 5.7 degrees (P = 0.21). Patients with less than 9 mm of preoperative anterior disc height had an increase in their ROM (2.2 degrees) compared with a loss of ROM (-2.2 degrees) in patients with more than 9 mm of preoperative disc height (P = 0.02). Patients with between 16 mm and 18 mm of postoperative anterior disc height have greater ROM (7.5 degrees) than those above or below this range (3.6 degrees and 3.6 degrees respectively, P < 0.05). There was no correlation or threshold effect between clinical outcomes and disc height. CONCLUSION: Patients with greater disc collapse benefit more in ROM from a total disc replacement. The optimal range to maximize ROM for postoperative anterior disc height is 16 mm to 18 mm. This optimal range did not translate into better clinical outcome at 2 years follow-up
— id: 76470, year: 2008, vol: 33, page: 508, stat: Journal Article,

Comparative charge analysis of one- and two-level lumbar total disc arthroplasty versus circumferential lumbar fusion
Levin, David A; Bendo, John A; Quirno, Martin; Errico, Thomas; Goldstein, Jeffrey; Spivak, Jeffrey
2007 Dec 1;32(25):2905-2909, Spine
STUDY DESIGN: This is a retrospective, independent study comparing 2 groups of patients treated surgically for discogenic low back pain associated with degenerative disc disease (DDD) in the lumbosacral spine. OBJECTIVE: To compare the surgical and hospitalization charges associated with 1- and 2-level lumbar total disc replacement and circumferential lumbar fusion. SUMMARY OF BACKGROUND DATA: Reported series of lumbar total disc replacement have been favorable. However, economic aspects of lumbar total disc replacement (TDR) have not been published or studied. This information is important considering the recent widespread utilization of new technologies. Recent studies have demonstrated comparable short-term clinical results between TDR and lumbar fusion recipients. Relative charges may be another important indicator of the most appropriate procedure. We report a hospital charge-analysis comparing ProDisc lumbar disc replacement with circumferential fusion for discogenic low back pain. METHODS: In a cohort of 53 prospectively selected patients with severe, disabling back pain and lumbar disc degeneration, 36 received Synthes ProDisc TDR and 17 underwent circumferential fusion for 1- and 2-level degenerative disc disease between L3 and S1. Randomization was performed using a 2-to-1 ratio of ProDisc recipients to control spinal fusion recipients. Charge comparisons, including operating room charges, inpatient hospital charges, and implant charges, were made from hospital records using inflation-corrected 2006 U.S. dollars. Operating room times, estimated blood loss, and length of stay were obtained from hospital records as well. Surgeon and anesthesiologist fees were, for the purposes of comparison, based on Medicare reimbursement rates. Statistical analysis was performed using a 2-tailed Student t test. RESULTS: For patients with 1-level disease, significant differences were noted between the TDR and fusion control group. The mean total charge for the TDR group was $35,592 versus $46,280 for the fusion group (P = 0.0018). Operating room charges were $12,000 and $18,950, respectively, for the TDR and fusion groups (P < 0.05). Implant charges averaged $13,990 for the fusion group, which is slightly higher than the $13,800 for the ProDisc (P = 0.9). Estimated blood loss averaged 794 mL in the fusion group versus 412 mL in the TDR group (P = 0.0058). Mean OR minutes averaged 344 minutes for the fusion group and 185 minutes for the TDR (P < 0.05) Mean length of stay was 4.78 days for fusion versus 4.32 days for TDR (P = 0.394). For patients with 2-level disease, charges were similar between the TDR and fusion groups. The mean total charge for the 2-level TDR group was $55,524 versus $56,823 for the fusion group (P = 0.55). Operating room charges were $15,340 and $20,560, respectively, for the TDR and fusion groups (P = 0.0003). Surgeon fees and anesthesiologist charges based on Medicare reimbursement rates were $5857 and $525 for the fusion group, respectively, versus $2826 and $331 for the TDR group (P < 0.05 for each). Implant charges were significantly lower for the fusion group (mean, $18,460) than those for 2-level Synthes ProDisc ($27,600) (P < 0.05). Operative time averaged 387 minutes for fusion versus 242 minutes for TDR (P < 0.0001). EBL and length of stay were similar. CONCLUSION: Patients undergoing 1- and 2-level ProDisc total disc replacement spent significantly less time in the OR and had less EBL than controls. Charges were significantly lower for TDR compared with circumferential fusions in the 1-level patient group, while charges were similar in the 2-level group
— id: 75860, year: 2007, vol: 32, page: 2905, stat: Journal Article,

Results of the prospective, randomized, multicenter Food and Drug Administration investigational device exemption study of the ProDisc-L total disc replacement versus circumferential fusion for the treatment of 1-level degenerative disc disease
Zigler, Jack; Delamarter, Rick; Spivak, Jeffrey M; Linovitz, Raymond J; Danielson, Guy O 3rd; Haider, Thomas T; Cammisa, Frank; Zuchermann, Jim; Balderston, Richard; Kitchel, Scott; Foley, Kevin; Watkins, Robert; Bradford, David; Yue, James; Yuan, Hansen; Herkowitz, Harry; Geiger, Doug; Bendo, John; Peppers, Timothy; Sachs, Barton; Girardi, Federico; Kropf, Michael; Goldstein, Jeff
2007 May 15;32(11):1155-1162, Spine
STUDY DESIGN: A prospective, randomized, multicenter, Food and Drug Administration-regulated Investigational Device Exemption clinical trial. OBJECTIVE: To evaluate the safety and effectiveness of the ProDisc-L (Synthes Spine, West Chester, PA) lumbar total disc replacement compared to circumferential spinal fusion for the treatment of discogenic pain at 1 vertebral level between L3 and S1. SUMMARY OF BACKGROUND DATA: As part of the Investigational Device Exemption clinical trial, favorable single center results of lumbar total disc replacement with the ProDisc-L have been reported previously. METHODS: Two hundred eighty-six (286) patients were treated on protocol. Patients were evaluated before and after surgery, at 6 weeks, 3, 6, 12, 18, and 24 months. Evaluation at each visit included patient self-assessments, physical and neurologic examinations, and radiographic evaluation. RESULTS: Safety of ProDisc-L implantation was demonstrated with 0% major complications. At 24 months, 91.8% of investigational and 84.5% of control patients reported improvement in the Oswestry Low Back Pain Disability Questionnaire (Oswestry Disability Index [ODI]) from preoperative levels, and 77.2% of investigational and 64.8% of control patients met the > or =15% Oswestry Disability Index improvement criteria. Overall neurologic success in the investigational group was superior to the control group (91.2% investigational and 81.4% control; P = 0.0341). At 6 weeks and 3 months follow-up time points, the ProDisc-L patients recorded SF-36 Health Survey scores significantly higher than the control group (P = 0.018, P = 0.0036, respectively). The visual analog scale pain assessment showed statistically significant improvement from preoperative levels regardless of treatment (P < 0.0001). Visual analog scale patient satisfaction at 24 months showed a statistically significant difference favoring investigational patients over the control group (P = 0.015). Radiographic range of motion was maintained within a normal functional range in 93.7% of investigational patients and averaged 7.7 degrees. CONCLUSIONS: ProDisc-L has been found to be safe and efficacious. In properly chosen patients, ProDisc-L has been shown to be superior to circumferential fusion by multiple clinical criteria
— id: 94852, year: 2007, vol: 32, page: 1155, stat: Journal Article,

Laminoplasty: a review of its role in compressive cervical myelopathy
Hale, James J; Gruson, Konrad I; Spivak, Jeffrey M
2006 Nov-Dec;6(6 Suppl):289S-298S, Spine journal
BACKGROUND CONTEXT: The currently accepted surgical treatments for compressive cervical myelopathy include both anterior and posterior decompression. Anterior approaches including multilevel discectomy with fusion or vertebral corpectomy with strut grafting, both with and without instrumentation, have enjoyed successful outcomes, but have been associated with select postoperative complications. Laminoplasty has been developed to decompress the spine posteriorly while avoiding the spinal destabilization seen after laminectomy. PURPOSE: The purpose of this article is to provide a review of the various techniques, biomechanical basis, predictive value of imaging modalities, clinical outcomes, and postoperative complications associated with cervical laminoplasty. STUDY DESIGN: A review of the literature. METHODS: A comprehensive literature review using Medline was performed identifying relevant articles that addressed the techniques, clinical outcomes, and complications after cervical laminoplasty, as well as preoperative radiographic predictors of outcome. RESULTS: The various modifications of cervical laminoplasty have generally been associated with excellent clinical outcomes when used for myelopathy secondary to cervical spondylosis or ossification of the posterior longitudinal ligament (OPLL). Recent long-term studies have identified issues with this technique including axial neck pain, canal restenosis, nerve root palsy, diminished cervical motion, and loss of cervical lordotic alignment. CONCLUSIONS: Cervical laminoplasty remains a reliable procedure for posterior decompression of the spine, but the optimal approach to cervical myelopathy must take into account both patient and disease characteristics, as well as the capabilities and experience of the surgeon
— id: 71861, year: 2006, vol: 6, page: 289S, stat: Journal Article,

Embryology of the spine and associated congenital abnormalities
Kaplan, Kevin M; Spivak, Jeffrey M; Bendo, John A
2005 Sep-Oct;5(5):564-576, Spine journal
BACKGROUND CONTEXT: The spine is a complex and vital structure. Its function includes not only structural support of the body as a whole, but it also serves as a conduit for safe passage of the neural elements while allowing proper interaction with the brain. Anatomically, a variety of tissue types are represented in the spine. Embryologically, a detailed cascade of events must occur to result in the proper formation of both the musculoskeletal and neural elements of the spine. Alterations in these embryologic steps can result in one or more congenital abnormalities of the spine. Other body systems forming at the same time embryologically can be affected as well, resulting in associated defects in the cardiopulmonary system and the gastrointestinal and genitourinary tracts. PURPOSE: This article is to serve as a review of the basic embryonic development of the spine. We will discuss the common congenital anomalies of the spine, including their clinical presentation, as examples of errors of this basic embryologic process. STUDY DESIGN/SETTING: Review of the current literature on the embryology of the spine and associated congenital abnormalities. METHODS: A literature search was performed on the embryology of the spine and associated congenital abnormalities. RESULTS: Development of the spine is a complex event involving genes, signaling pathways and numerous metabolic processes. Various abnormalities are associated with errors in this process. CONCLUSION: Physicians treating patients with congenital spinal deformities should have an understanding of normal embryologic development as well as common associated abnormalities
— id: 61843, year: 2005, vol: 5, page: 564, stat: Journal Article,

Percutaneous treatment of vertebral body pathology
Spivak, Jeffrey M; Johnson, Michael G
2005 Jan-Feb;13(1):6-17, Journal of the American Academy of Orthopaedic Surgeons
Percutaneous vertebral body injection procedures currently are used to stabilize and reinforce weakened or fractured bone resulting from metastatic disease and severe osteoporosis. Both vertebroplasty and kyphoplasty can reinforce the structure of a vertebral body and provide pain relief, but the procedures have technical differences. Kyphoplasty improves vertebral height to varying degrees in nearly three quarters of patients. Kyphosis is improved more effectively when the procedure is performed within 3 months from the onset of fracture pain. To date, it is unknown whether vertebroplasty with preprocedure postural reduction can provide similar improvement of deformity. Complications are relatively infrequent with both vertebroplasty and kyphoplasty. Cement leakage from the vertebral body is more likely with vertebroplasty than with kyphoplasty. Leakage is more common in the treatment of pathologic fractures resulting from metastatic disease. Clinical complications caused by cement leakage and neural compression are infrequent. Specific indications for these injection procedures need to be more clearly refined. Long-term outcomes, including the fate of the injected material and the effect on adjacent vertebrae, have yet to be determined
— id: 55602, year: 2005, vol: 13, page: 6, stat: Journal Article,

Degenerative lumbar spinal stenosis: options for aging backs
Chen, Andrew L; Spivak, Jeffrey M
2003 Aug;31(8):25-34, Physician & Sportsmedicine
Degenerative lumbar spinal stenosis commonly disables and functionally limits the aging population. Degenerative changes may constrict the spinal canal, lateral recesses, and neural foramina, compressing the neural elements. Clinicians can make an earlier, more accurate diagnosis by using advanced imaging techniques. Nonoperative management is the mainstay of treatment, although surgery is indicated in patients who have progressive neurologic decline or when nonoperative measures have failed to adequately address symptoms
— id: 106288, year: 2003, vol: 31, page: 25, stat: Journal Article,

Somatosensory evoked potential monitoring of lumbar pedicle screw placement for in situ posterior spinal fusion
Gundanna, Mukund; Eskenazi, Mark; Bendo, John; Spivak, Jeffrey; Moskovich, Ronald
2003 Sep-Oct;3(5):370-376, Spine journal
BACKGROUND CONTEXT: Somatosensory evoked potentials (SSEP) are commonly used to monitor the spinal cord and nerve roots during operative procedures that put those structures at risk. The utility of SSEPs to evaluate cauda equina and nerve root function during posterior spinal arthrodesis with pedicular fixation for degenerative lumbar disease has been reported anecdotally and remains controversial. PURPOSE: An institution-wide review of the ability of SSEP readings to monitor nerve function during posterior lumbar spinal arthrodeses with transpedicular fixation for degenerative lumbar spinal disorders was undertaken. STUDY DESIGN/SETTING: A retrospective review was undertaken. Patient history, preoperative physical examination, intraoperative anesthesia, SSEP records and the postoperative course were reviewed. METHODS: A total of 186 consecutive arthrodeses as described above were reviewed. Patients who had anterior procedures, spondyloreduction or scoliosis correction were excluded from the study. There were 76 male and 110 female patients. Five fellowship-trained spine surgeons placed a total of 888 pedicle screws. Sixty-five percent of the patients had a principal preoperative diagnosis of spinal stenosis with degenerative spondylolisthesis. Other common diagnoses were isthmic spondylolisthesis and degenerative scoliosis. Ninety-three percent of the cases involved decompressive laminectomy. Eight percent had posterior interbody fusions. All pedicle screws were placed without the assistance of fluoroscopy or stereotactic computer-assisted guidance. Screw position was evaluated intraoperatively with standard posteroanterior and lateral radiographs.Anesthetic agents compatible with SSEP monitoring were used in all patients. SSEP baseline readings were obtained in all patients in the operating room soon after induction of general anesthesia. An acute and sustained loss of 50% of the SSEP amplitude and/or increase by 10% of latency from baseline was considered to be pathologic. RESULTS: None of the 186 patients had significant SSEP changes. There were, however, 5 patients with postoperative radiculopathies distinct from their preoperative presentations. Early postoperative plain radiographs and computed assisted tomography (CAT) scans revealed malpositioned pedicle screws. Consequently, eight pedicle screws were either revised or removed. All patients had partial or full recovery of their new deficits after revision surgery. CONCLUSION: We conclude that the use of SSEPs in evaluating pedicle screw placement during lumbar arthrodesis is limited. In this setting, if monitoring is required, alternative methods with greater sensitivity and efficacy should be explored
— id: 42647, year: 2003, vol: 3, page: 370, stat: Journal Article,

Vertebroplasty: weighing the benefits and the risks
Spivak, Jeffrey M
2002 Aug 15;66(4):565-565, American family physician
— id: 94853, year: 2002, vol: 66, page: 565, stat: Journal Article,

Augmentation of anterior vertebral body screw fixation by an injectable, biodegradable calcium phosphate bone substitute
Bai B; Kummer FJ; Spivak J
2001 Dec 15;26(24):2679-2683, Spine
STUDY DESIGN: A biomechanical study to evaluate the effects of a biodegradable calcium phosphate (Ca-P) bone substitute on the fixation strength and bending rigidity of vertebral body screws. OBJECTIVES: To determine if an injectable, biodegradable Ca-P bone substitute provides significant augmentation of anterior vertebral screw fixation in the osteoporotic spine. SUMMARY OF BACKGROUND DATA: Polymethylmethacrylate (PMMA) augmented screws have been used clinically; however, there is concern about thermal damage to the neural elements during polymerization of the PMMA as well as its negative effects on bone remodeling. Injectable, biodegradable Ca-P bone substitutes have shown enhanced fixation of pedicle screws. METHODS: Sixteen fresh cadaveric thoracolumbar vertebrae were randomly divided into two groups: control (no augmentation) (n = 8) and Ca-P bone substitute augmentation (n = 8) groups. Bone-screw fixation rigidity in bending was determined initially and after 10(5) cycles, followed by pullout testing of the screw to failure to determine pullout strength and stiffness. RESULTS: The bone-screw bending rigidity for the Ca-P bone substitute group was significantly greater than the control group, initially (58%) and after cyclic loading (125%). The pullout strength for Ca-P bone substitute group (1848 +/- 166 N) was significantly greater than the control group (665 +/- 92 N) (P < 0.01). Stiffness in pullout for the Ca-P bone substitute groups (399 +/- 69 N/mm) was significantly higher than the control group (210 +/- 51 N/mm) (P < 0.01). CONCLUSION: This study demonstrated that augmentation of anterior vertebral body screw fixation with a biodegradable Ca-P bone substitute is a potential alternative to the use of PMMA cement
— id: 65808, year: 2001, vol: 26, page: 2679, stat: Journal Article,

Use of hydroxyapatite in spine surgery
Spivak JM; Hasharoni A
2001 Oct;10 Suppl 2(10):S197-S204, European spine journal
Hydroxyapatite- (HA-)based ceramics have been evaluated for a variety of applications in spinal surgery, utilizing in vivo animal models and human clinical series. In vivo animal studies have shown efficacy for these materials as a bone graft substitute in interbody fusions and as a bone graft extender or bioactive osteoinductive material carrier in posterolateral lumbar fusions. Clinically, HA ceramic has been shown to be effective as a bone graft extender in posterior spinal fusion surgery for childhood scoliosis, and as a structural bone graft substitute in anterior cervical spine fusions. As an osteoconductive material, it appears to function best as a bone graft extender or carrier for an osteoinductive bone growth factor rather than as a stand-alone bone graft substitute in nonstructural clinical applications. Injectable HA ceramics also hold promise as biocompatible and bioresorbable materials for use in spinal screw fixation strength augmentation and in minimally invasive vertebral body strength augmentation either following fracture or prophylactically in osteoporotic vertebrae
— id: 27272, year: 2001, vol: 10 Suppl 2, page: S197, stat: Journal Article,

Instrumented posterior arthrodesis of the lumbar spine in patients with diabetes mellitus [In Process Citation]
Bendo JA; Spivak J; Moskovich R; Neuwirth M
2000 Aug;29(8):617-620, American journal of orthopedics (Belle Mead, NJ)
The existence of diabetes mellitus has been postulated to have a deleterious effect on the outcome following lumbar spine surgery. We retrospectively examined the records and radiographs of 32 diabetic patients (mean age, 60 years) who underwent posterior lumbar fusions using transpedicular instrumentation and iliac crest autograft. Ten patients were insulin-dependent and 22 required oral hypoglycemic agents for at least 1 year prior to surgery. The minimum follow-up time was 2 years after surgery (mean, 2.5 years). Surgical indications included herniated lumbar disk, lumbar spinal stenosis, thoracolumbar trauma, and lumbar pseudarthrosis. Clinical results were evaluated by chart review and/or interview by using Odom's criteria. At follow-up, 75% of patients were graded as excellent or good, and 25% as fair or poor. Twenty-five of 32 patients (78%) had improvement of back pain. Twenty of 27 (74%) patients had improvement of leg pain. Eight of 15 (53%) patients had improvement in motor strength, and 6 of 11 (54%) had improvement in light-touch sensation. Insulin dependence and the presence of polyneuropathy were associated with a poorer outcome. The average time to radiographic fusion was 5 months. Twenty-nine of 32 patients (91%) developed solid fusion by strict radiographic criteria. The three patients with a pseudarthrosis had persistent back pain and a poor result. Ten of 32 (31%) of the patients experienced perioperative complications, including prolonged wound drainage (n = 5), deep wound infection (n = 1), superficial wound infection (n = 1), atrial fibrillation (n = 1), ruptured cerebral aneurysm (n = 1), and ulnar nerve neuropathy (n = 1). We conclude that posterolateral lumbar spinal fusion with internal fixation in diabetic patients yields clinical results comparable to those of nondiabetic patients, with similar risks of perioperative complications
— id: 11532, year: 2000, vol: 29, page: 617, stat: Journal Article,

Internal fixation of cervical trauma following corpectomy and reconstruction. The effects of posterior element injury
Spivak JM; Bharam S; Chen D; Kummer FJ
2000 ;59(1):47-51, Bulletin (Hospital for Joint Diseases)
Although biomechanical data indicates that anterior fixation alone in unstable cervical injuries may not provide adequate stability, reports of clinical series indicate general success with this method of treatment. The specific contribution of posterior column injury to overall stability following reconstruction has not been evaluated. This study examined the biomechanical stability of anterior and/or posterior plate fixation following anterior corpectomy and reconstruction for unstable cervical injuries with varying degrees of posterior element injury. The C4-C6 motion segments of ten fresh frozen bovine cervical spines were used. After mounting, nondestructive mechanical testing in axial compression, torsion, flexion, extension, and lateral bending was done as an intact control. A C5 corpectomy with reconstruction using a synthetic bone graft was performed and the posterior ligaments sectioned at the C5-C6 level. Each specimen was sequentially instrumented with anterior and posterior plating alone and in combination and each construct was mechanically retested. The specimens were then further destabilized by bilateral facetectomies at C5-C6 and again tested with the same instrumentation combinations. In comparison to the controls, the spines with a C5 corpectomy/bone graft and posterior ligament rupture with anterior plating demonstrated significantly increased stiffness in flexion, extension, and lateral bending; posterior plating increased stiffness in only flexion and lateral bending. In axial compression and torsion, anterior or posterior plating demonstrated stiffness similar to the controls. Further destabilization by facetectomy significantly decreased stiffness of the instrumented construct (less than control) in torsion with anterior or posterior plate fixation alone. Combined plating showed increased stability compared to controls in all loading conditions for both patterns of instability. Anterior plating alone was able to restore the stability of the cervical spines with posterior ligamentous injury after corpectomy, but it failed to do so with the addition of bilateral facetectomies. For the unstable cervical spine with significant bilateral loss of posterior bony contact, anterior or posterior plating alone may not provide sufficient stabilization in the absence of any additional external immobilization. Combined plating should be considered, which may obviate the need for external immobilization
— id: 65810, year: 2000, vol: 59, page: 47, stat: Journal Article,

The use of an injectable, biodegradable calcium phosphate bone substitute for the prophylactic augmentation of osteoporotic vertebrae and the management of vertebral compression fractures
Bai B; Jazrawi LM; Kummer FJ; Spivak JM
1999 Aug 1;24(15):1521-1526, Spine
STUDY DESIGN: A biomechanical study comparing two materials for augmentation of osteoporotic vertebral bodies and vertebral bodies after compression fracture. OBJECTIVES: To compare an injected, biodegradable calcium phosphate bone substitute with injected polymethylmethacrylate bone cement for strengthening osteoporotic vertebral bodies and improving the integrity of vertebral compression fractures. SUMMARY OF BACKGROUND DATA: Injection of polymethylmethacrylate bone cement into fractured vertebral bodies has been used clinically. However, there is concern about thermal damage to the neural elements during polymerization of the polymethylmethacrylate bone cement as well as its negative effects on bone remodeling. Biodegradable calcium phosphate bone substitutes have been studied for enhancement of fixation in fractured vertebrae. METHODS: Forty fresh osteoporotic thoracolumbar vertebrae were used for two separate parts of this study: 1) injection into osteoporotic vertebrae: intact control (n = 8), calcium phosphate (n = 8), and polymethylmethacrylate bone cement (n = 8) groups. Each specimen then was loaded in anterior compression until failure; 2) injection into postfractured vertebrae: calcium phosphate (n = 8) and polymethylmethacrylate bone cement (n = 8) groups. Before and after injection, the specimens were radiographed in the lateral projection to determine changes in vertebral body height and then loaded to failure in anterior bending. RESULTS: For intact osteoporotic vertebrae, the average fracture strength was 527 +/- 43 N (stiffness, 84 +/- 11 N/mm), 1063 +/- 127 N (stiffness, 157 +/- 21 N/mm) for the group injected with calcium phosphate, and 1036 +/- 100 N (stiffness, 156 +/- 8 N/mm) for the group injected with polymethylmethacrylate bone cement. The fracture strength and stiffness in the calcium phosphate bone substitute group and those in the polymethylmethacrylate bone cement group were similar and significantly stronger than those in intact control group (P < 0.05). For the compression fracture study, anterior vertebral height was increased 58.5 +/- 4.6% in the group injected with calcium phosphate and 58.0 +/- 6.5% in the group injected with polymethylmethacrylate bone cement as compared with preinjection fracture heights. No significant difference between the two groups was found in anterior vertebral height, fracture strength, or stiffness. CONCLUSION: This study demonstrated that the injection of a biodegradable calcium phosphate bone substitute to strengthen osteoporotic vertebral bodies or improve vertebral compression fractures might provide an alternative to the use of polymethylmethacrylate bone cement
— id: 6183, year: 1999, vol: 24, page: 1521, stat: Journal Article,

The effect of locking fixation screws on the stability of anterior cervical plating
Spivak JM; Chen D; Kummer FJ
1999 Feb 15;24(4):334-338, Spine
STUDY DESIGN: Current anterior cervical plate systems were tested with locked and unlocked fixation screws and with unicortical and bicortical fixation screws to determine fixation rigidity and pull-off strengths. OBJECTIVES: To evaluate the effects of screw-plate locking and screw length on fixation strength and stability of anterior cervical plates. SUMMARY OF BACKGROUND DATA: New plate systems provide for rigid locking of the screw-plate interface, theoretically increasing construct rigidity, allowing unicortical fixation, and preventing screw back-out. There are few data on the effects of locking screws on the stability of anterior cervical plating. METHODS: Eighty fresh lamb vertebrae (C3-T1) were used. Test systems included: Cervical Spine Locking Plate (CSLP; Synthes, Paoli, PA, Orion plate (Sofamor-Danek, Memphis, TN), and Acroplate (AcroMed, Cleveland, OH). The CSLP and Orion plates were tested with fixation screws, locked and unlocked, and the AcroMed plate with unicortical and bicortical screw purchase. Biomechanical testing of the screw-plate constructs was performed to determine the initial bone-plate rigidity and pull-off strength. A 2.5-Nm cyclic bending moment was then applied to additional constructs for 10(5) cycles, and these constructs retested. RESULTS: Locked CSLP and Orion constructs were more rigid than all unlocked unicortical systems initially and after cyclic loading (P < 0.05). After cycling, the rigidity of all unlocked unicortical constructs decreased significantly (P < 0.05). There was no significant difference in pull-off strengths between the CSLP, the Orion, and the unicortical AcroMed plate. However, all had significantly less pull-off strength than the AcroMed plate with bicortical screws. A negative correlation was observed between initial pull-off strength and sagittal vertebral body diameter. CONCLUSIONS: Locking screws significantly increased the rigidity of the tested screw-plate systems initially and after cyclic loading. Because pull-off strength was affected by the vertebral body diameter, use of longer unicortical screws may be clinically beneficial in the patient with larger cervical vertebrae
— id: 6053, year: 1999, vol: 24, page: 334, stat: Journal Article,

Orthopaedics : a study guide
Spivak, Jeffrey M. (Jeffrey Michael)
New York : McGraw Hill, Health Professions Division, c1999,
— id: 699, year: 1999, vol: , page: , stat: ,

Optimal selection and preparation of fresh frozen corticocancellous allografts for cervical interbody spinal fusion
Kummer FJ; Chen D; Spivak JM
1998 Nov 1;23(21):2295-2298, Spine
STUDY DESIGN: Iliac crest corticocancellous allografts for anterior interbody fusion were harvested from six cadavers. The grafts were cut sequentially from left and right crests and randomly assigned to tricortical or bicortical preparations. Their compression strengths then were determined and compared by matched pair analysis. OBJECTIVES: To quantify the failure strength of the grafts from different iliac locations and determine the optimal type of preparation of the grafts for anterior interbody fusion. SUMMARY OF BACKGROUND DATA: Iliac crest corticocancellous autografts and allografts commonly are used for interbody cervical fusions. However, graft strengths for specific sites have not been determined fully. METHODS: Six paired, fresh frozen, iliac crests were sectioned using a customized miter box into multiple 1-cm-thick grafts 1.5 cm in depth to simulate cervical interbody grafts. The left and right sides of each pair were randomly assigned to tricortical and bicortical preparations. The samples were tested by applying a compressive load to failure using a specialized fixture to simulate vertebral body loading. RESULTS: The grafts closer to the anterosuperior iliac spine had significantly higher failure loads and failure strengths than those closer to the posterosuperior iliac spine. The strengths of the bicortical grafts were 72 +/- 14% of the strengths of the tricortical grafts (P < 0.001). CONCLUSIONS: Anterior iliac crest grafts were stronger in compression, even after removal of one cortical surface, than posterior iliac crest grafts
— id: 7378, year: 1998, vol: 23, page: 2295, stat: Journal Article,

Optimal selection and preparation of fresh frozen corticocancellous allografts for anterior interbody lumbar spinal fusion
Chen D; Kummer FJ; Spivak JM
1997 Dec;10(6):532-536, Journal of spinal disorders
To determine the effect of graft preparation on graft strength, corticocancellous grafts suitable for anterior interbody fusion were obtained from six cadavers using five different donor bone sites with different graft sectioning orientations and locations. Graft compression strength was determined in simulated physiological loading. The distal tibia and femoral head lumbar interbody grafts are significantly stronger than grafts prepared from other corticocancellous donor sites. Graft fabrication by cutting perpendicular to the long axis and closer to the long bone ends results in increased graft strength
— id: 65811, year: 1997, vol: 10, page: 532, stat: Journal Article,

Flexion failure of posterior cervical lateral mass screws. Influence of insertion technique and position
Choueka J; Spivak JM; Kummer FJ; Steger T
1996 Feb 15;21(4):462-468, Spine
STUDY DESIGN. The strength of posterior cervical lateral mass fixation was evaluated in a cadaver model for two techniques of screw insertion. OBJECTIVE. To compare the flexion failure strengths of posterior cervical plate fixation for two techniques of screw placement at the superior and inferior screw hole positions, and to evaluate the effect of bone mineral density on fixation strength. SUMMARY OF BACKGROUND DATA. Biomechanical analyses of various screw insertion techniques for posterior cervical lateral mass fixation have never evaluated the effect of screw position along the plate. METHODS. Individual C3-C6 segments of 24 human cadaveric cervical spines were used. The spinous process and lamina were removed to simulate a postlaminectomy situation. Vertebral body bone mineral density for each specimen was determined by dual-energy radiograph absorption scanning. In each lateral mass, a bicortical 3.5-mm screw was placed using either the Magerl or Roy-Camille insertion technique through an end hole of a titanium bone plate. For 'superior' screws, the plate was directed caudally; for 'inferior' screws, the plate was directed cranially. Screw violation of the surrounding facet joint was noted. An increasing flexion moment was applied by loading the plate 4 cm from the screw head at a rate of 10 cm/min using a servohydraulic testing machine until screw failure. RESULTS. For the superior screw hole position, the Magerl screw sustained a significantly higher average moment to failure (190.2 Ncm) than the Roy-Camille screw (138.7 Ncm; P < 0.05). For the inferior screw hole position, there was no significant difference in flexion failure strength between the two techniques (Magerl screws, 287.7 Ncm; Roy-Camille screws, 308.2 Ncm). For each insertion technique, inferior screws were nearly twice as strong as superior screws (P < 0.01). Violation of the inferior articular process occurred with 53% of Roy-Camille screws and with none of the Magerl screws. Lateral mass fracture on screw insertion occurred with 6% of the Roy-Camille screws and with 7% of the Magerl screws. Significant correlation between screw path length and load to failure was found only at the superior screw hole position. Correlation with vertebral body bone mineral density was significant at both positions. CONCLUSIONS. The Magerl technique has advantages over the Roy-Camille technique for placing the end screws when performing posterior cervical lateral mass plate fixation, providing greater strength superiorly and not violating unfused facet joints inferiorly. Evaluation of bone mineral density by dual-energy radiographic absorption scanning is predictive of failure strength for both test modes
— id: 65817, year: 1996, vol: 21, page: 462, stat: Journal Article,

An anatomic evaluation of L5 nerve stretch in spondylolisthesis reduction
Petraco DM; Spivak JM; Cappadona JG; Kummer FJ; Neuwirth MG
1996 May 15;21(10):1133-1138, Spine
STUDY DESIGN. Lumbosacral spondylolisthesis was simulated using four embalmed human spines, and the path of the L5 nerve was studied. OBJECTIVES. To quantify the change in length of the L5 nerve root associated with reduction of spondylolisthesis, correction of slip angle, and changing disc height. SUMMARY OF BACKGROUND DATA. Stretch injury to the lumbar nerves remains a complication of spondylolisthesis reduction. To date, no anatomic studies have been performed to quantify this effect of reduction on the lumbar nerves. METHODS. The L5 vertebral body and the sacrum of four embalmed human spines were constrained in an adjustable jig, and the length of a simulated nerve was determined for various position variables--sagittal translation (0-100% slip), slip angle (-40 degrees to +20 degrees), and disc height (5 or 10 mm). Two standard points of reference were chosen to represent fixed points along the path of the L5 nerve. An inelastic cord was used to measure the path length between these points as L5 was reduced from 100% to 0% slip. Testing was performed using a 5-mm and a 10-mm disc height. The effect of varying slip angle alone was also studied. RESULTS. The effect of spondylolisthesis reduction and slip angle correction on nerve length varied depending on the location of L5 with respect to the sacrum. There was an increasing effect of partial reduction on nerve length as L5 approached full reduction. Initially, little strain was produced in the L5 nerve as L5 was reduced in higher grade slips. However, as L5 approached full reduction, the strain per increment of reduction increased rapidly. On average, the mean nerve strain was 4.0% for the first 50% of reduction and 10.0% for the second half of reduction. Increasing lordosis relaxed the nerve in high-grade slips and stretched the nerve in fully reduced slips. At 100% slip, the mean nerve excursion decreased 5.1 mm (nerve slackening) when L5 was rotated from +20 degrees to -40 degrees. At 0% slip, the mean nerve excursion increased 3.1 mm (nerve stretch). Increasing disc height directly stretched the L5 nerve. However, given a larger disc height, the strain on the nerve per increment of reduction was less than for the smaller height. CONCLUSION. The findings suggest that the risk of stretch injury to the L5 nerve with reduction of a high-grade spondylolisthesis is not linear; with 71% of the total L5 nerve strain occurring during the second half of reduction, partial reduction may be a significantly safer treatment approach for high-grade spondylolisthesis than complete reduction. Correction of lumbosacral kyphosis in high-grade spondylolisthesis may be protective of the L5 nerve
— id: 65815, year: 1996, vol: 21, page: 1133, stat: Journal Article,

Determination of the mineral phases and structure of the bone-implant interface using Raman spectroscopy
Leung Y; Walters MA; Blumenthal NC; Ricci JL; Spivak JM
1995 May;29(5):591-594, Journal of biomedical materials research
The bone-implant interface formed in a canine distal femur was examined by means of a Raman microprobe using an implant model designed to test calcium phosphate surface coatings. By using the 960 cm-1 band of calcium phosphate to characterize the interface and adjacent mineral, we obtained spatial and compositional information about the attachment of bone to the synthetic calcium phosphate coating on a titanium support. The interface between bone and the synthetic calcium phosphate is approximately 30-40 microns in width
— id: 35926, year: 1995, vol: 29, page: 591, stat: Journal Article,

Thoracolumbar Spine Trauma: I. Evaluation and Classification
Spivak JM; Vaccaro AR; Cotler JM
1995 Nov;3(6):345-352, Journal of the American Academy of Orthopaedic Surgeons
A timely and thorough evaluation of thoracolumbar injuries and rational treatment based on a complete understanding of the mechanism of bone, soft-tissue, and nerve injury is essential for maximizing the patient's neurologic and functional recovery and minimizing associated complications, the time to recovery, and the problems of long-term pain and deformity. The initial evaluation includes both clinical and radiologic assessment. Clinical evaluation includes the general trauma examination as well as a detailed spinal and neurologic examination to determine the level (or levels) of spinal injury. Radiologic evaluation includes both plain radiography and the appropriate use of advanced imaging modalities. A review of the evolution of thoracolumbar injury classifications is presented
— id: 11728, year: 1995, vol: 3, page: 345, stat: Journal Article,

Thoracolumbar Spine Trauma: II. Principles of Management
Spivak JM; Vaccaro AR; Cotler JM
1995 Nov;3(6):353-360, Journal of the American Academy of Orthopaedic Surgeons
The care of patients with thoracolumbar spine trauma with or without neurologic deficits has evolved dramatically over the past 20 years with the emergence of tertiary-care spinal injury centers and the development of more effective spinal instrumentation and anesthesia techniques. Despite these advances, the majority of patients with thoracolumbar injuries are still treated nonoperatively with cast or brace immobilization and early ambulation. More aggressive treatment is guided by the use of classification systems that detail the mechanism of injury, the degree of compromise of spinal structures, and the potential for late mechanical instability or neural injury. The goal of treatment remains attainment of spinal stability with protection or improvement of the patient's neurologic status, allowing rapid and maximal functional recovery
— id: 11727, year: 1995, vol: 3, page: 353, stat: Journal Article,

Hydroxyapatite enhancement of posterior spinal instrumentation fixation
Spivak JM; Neuwirth MG; Labiak JJ; Kummer FJ; Ricci JL
1994 Apr 15;19(8):955-964, Spine
STUDY DESIGN. The ability of hydroxyapatite (HA) materials to enhance the fixation strength of posterior spinal instrumentation was examined in 19 adult mongrel dogs. METHODS. Sixteen dogs underwent bilateral placement of lumbar transpedicular screws from L1 to L6, sacral alar screws, and posterior iliac rods. The six transpedicular screw test groups included standard and plasma-sprayed HA-coated screws with the recommended insertion technique, standard and HA-coated screws with a poor initial fit insertion technique using an oversized pilot hole, and HA-grout augmentation of standard and HA-coated screws with a poor initial fit. The sacral alar screws and posterior iliac rods were either uncoated or HA-coated. Six dogs were killed immediately; ten dogs were killed at 6 weeks, and the fixation elements were mechanically tested or histologically examined. Three additional dogs and synthetic bone material were used for additional baseline mechanical testing. RESULTS. The strength of standard screws with recommended insertion did not change after 6 weeks in vivo. HA-coated screws were initially 13% less resistant to pull out than standard screws, but this difference was not significant at 6 weeks. Screws inserted with a poor initial fit technique were significantly weaker initially; at 6 weeks, pull-out strength was similar to the standard screws properly inserted. The HA-grout material significantly enhanced pull-out strength for both screw types at 6 weeks. Sacral alar screw pull-out strength was not significantly different between standard and HA-coated screws initially or at 6 weeks. HA-coated rods were initially twice as resistant to pull out than standard rods and became stronger after 6 weeks in vivo, whereas standard rods became significantly weaker. Histologically, the quantity and morphology of bone around all implants was similar, with HA-coated rods and screws demonstrating regions of direct attachment to bone. An osteoconductive response and new bone formation was observed within the HA-grout material. Scanning electron microscopic observation of mechanically tested implants revealed a shear failure of surrounding bone (and HA if present) at the screw outer thread margin or at the bone-metal or HA-metal interfaces for the posterior iliac rods. CONCLUSIONS. The strength of poorly inserted transpedicular screws was significantly enhanced in vivo by the resorbable HA-grout material. The lower strength of HA-coated screws was attributed to screw geometry changes resulting from the coating process, and modifications of screw coating are recommended
— id: 35928, year: 1994, vol: 19, page: 955, stat: Journal Article,

Demineralized bone matrix. Enhancement of spinal fusion
Frenkel SR; Moskovich R; Spivak J; Zhang ZH; Prewett AB
1993 Sep 15;18(12):1634-1639, Spine
A study was conducted to determine the ability of demineralized bone matrix gel to act as an osteoconductive/osteoinductive material to enhance canine spinal fusion. Seven dogs underwent posterior spinal fusion. Four-level fusions were performed with one of four procedures at each level: decortication alone, with gel added, with autograft, or with both gel and autograft. Dogs were killed at 6 weeks and early histologic response was studied. At untreated control sites, little bone formation was evident. Gel-filled sites showed abundant osteoid, with 60% of demineralized particles fused to or surrounded by new bone. Sites filled with autograft had more new bone, but there was more osteoid at gel-treated sites. Autograft augmented with gel showed the most vigorous response, with extensive bridging between demineralized particles, host bone, autograft, and new bone. Significantly less autograft was needed to induce a similar amount of new bone formation when gel was added. Use of the gel as an autograft extender may improve the chance for successful spinal fusion
— id: 35852, year: 1993, vol: 18, page: 1634, stat: Journal Article,

Evaluation of a low-temperature calcium phosphate particulate implant material: physical-chemical properties and in vivo bone response
Ricci JL; Blumenthal NC; Spivak JM; Alexander H
1992 Sep;50(9):969-978, Journal of oral & maxillofacial surgery
A study was conducted to evaluate the osteoconductive ability of a particulate, low-temperature hydroxylapatite (HA(LT)) material (OsteoGen; Impladent, Holliswood, NY). An implantable chamber model was used to determine the ability of this material to encourage bone ingrowth into channels lined with either rough-surfaced titanium or rough-surfaced plasma-sprayed hydroxylapatite. The HA(LT) material increased bone ingrowth into the titanium-lined channels comparable with that in plasma-sprayed hydroxylapatite-coated channels. It was incorporated into ingrowing bone without intervening soft tissue, with the bone bonding directly to the material surface in much the same fashion as it bonds at the plasma-sprayed hydroxylapatite surface. Mechanical testing of the ingrown bone showed no weakness because particles were incorporated. At 12 weeks, the particles began to show signs of dissolution. It was concluded that the HA(LT) material is a biocompatible, osteoconductive material that conducts bone ingrowth in much the same way as high-temperature particulate hydroxylapatite ceramics. This material has the additional desirable property of being slowly resorbable, a beneficial characteristic for many bone-filling applications
— id: 35930, year: 1992, vol: 50, page: 969, stat: Journal Article,

Hexamethylene bisacetamide in myelodysplastic syndrome: effect of five-day exposure to maximal therapeutic concentrations
Rowinsky, E K; Conley, B A; Jones, R J; Spivak, J L; Auerbach, M; Donehower, R C
1992 Jun;6(6):526-534, Leukemia
The efficacy of hexamethylene bisacetamide (HMBA), a potent polar-planar solvent which is capable of differentiating leukemias and solid tumors in vitro at clinically achievable concentrations, was studied in 16 patients with severe myelodysplastic syndromes (MDS). An adaptive control dosing algorithm was used to maintain HMBA steady-state concentrations (Css) within a narrow therapeutic window (1-2 mM) for five days every four weeks. Despite achieving the target HMBA Css during at least two courses in each of 15 patients, HMBA did not produce clinically relevant improvements in blood cell counts nor in other functional indices. Instead, HMBA induced cytopenias in the majority of these patients, most of whom had preexisting cytopenias and limited hematopoietic reserves. These disappointing results correlated with concurrent in vitro bone marrow studies from these patients in which both the HMBA concentrations that were optimal for differentiation in vitro (2-5 mM) and the HMBA Css that were achieved in this study (1-2 mM) substantially inhibited the growth of granulocyte-macrophage colony-forming units and erythroid burst-forming units. Although the mechanism responsible for the anti-proliferative effects of HMBA on hematopoietic progenitors (cytotoxicity versus terminal differentiation) could not be determined, the induction of cytopenias and lack of significant clinical improvements suggest that HMBA is cytotoxic and will not be useful alone as a differentiating agent on this schedule of administration in the treatment of MDS
— id: 144372, year: 1992, vol: 6, page: 526, stat: Journal Article,

Fatigue failure of the sliding screw in hip fracture fixation: a report of three cases
Spivak JM; Zuckerman JD; Kummer FJ; Frankel VH
1991 ;5(3):325-331, Journal of orthopaedic trauma
Hardware failure of the sliding screw system used in hip fracture fixation is rare. The fatigue failure of the sliding screw is always related clinically to nonunion or refracture along the path of the screw. In both situations, cyclic loading of the implant exceeds its endurance limit, and failure can ensue. Three cases of failure of the sliding screw are presented: a nonunion of a basicervical fracture, a nonunion secondary to stress fracture at the plate-barrel junction, and a refracture through the femoral neck after healing of an intertrochanteric fracture. A biomechanical analysis of the stresses on the sliding screw focuses on design features such as the internal threaded region used for the compression screw or the barrel length that creates increased stresses in the screw, thus lowering the number of cycles to failure. Based on this analysis, recommendations are made concerning implant design and surgical technique
— id: 44614, year: 1991, vol: 5, page: 325, stat: Journal Article,

Molecular structure at the bone-implant interface: a vibrational spectroscopic characterization
Walters MA; Blumenthal NC; Leung Y; Wang Y; Ricci JL; Spivak JM
1991 May;48(5):368-369, Calcified tissue international
Test implant plates surgically retrieved from distal femurs of dogs were studied by Raman spectroscopy in order to characterize the bone-implant interface. The implant surface consisted of phosphate mineral, plasma sprayed on a titanium substrate. On the basis of its spectroscopic signature, the phosphate mineral of bone and the implant surface formed a mixed phase in the interface
— id: 35931, year: 1991, vol: 48, page: 368, stat: Journal Article,

Effects of the differentiating agent hexamethylene bisacetamide on normal and myelodysplastic hematopoietic progenitors
Rowinsky, E K; Donehower, R C; Spivak, J L; Burke, P J; Griffin, C A; Jones, R J
1990 Dec 19;82(24):1926-1931, Journal of the National Cancer Institute
Hexamethylene bisacetamide (HMBA; NSC 95580) is a potent polar-planar differentiating agent of leukemia and solid tumor cell lines in vitro at clinically achievable concentrations. HMBA is currently being studied in patients with myelodysplastic syndrome. Previous phase I trials have demonstrated that HMBA produces hematologic toxicity in morphologically normal bone marrows of patients with solid tumors. Because of concern that HMBA may produce more severe myelotoxicity in patients with myelodysplastic syndrome since these patients have limited hematopoietic reserves, we studied the effects of HMBA on myelodysplastic and normal hematopoietic progenitors in vitro. HMBA concentrations that are optimal for differentiation in vitro (2 to 5 mmol/L) and HMBA concentrations that are being achieved in clinical trials (1 to 2 mmol/L) inhibited the growth of granulocyte-macrophage colony-forming units and erythroid burst-forming units from all 15 patients with myelodysplastic syndrome and all 4 normal subjects, HMBA did not induce proliferation of myelodysplastic or normal progenitors at any concentration; rather, it produced nearly identical inhibition of normal and myelodysplastic hematopoietic progenitors. HMBA also produced quantitatively similar inhibition of clonogenic leukemic growth of two myeloid leukemia cell lines. For a differentiating agent to be effective, it will likely have to either produce both differentiation and proliferation of abnormal hematopoietic progenitors or show selective inhibitory effects on abnormal as compared with normal progenitors. Although the mechanisms responsible for the antiproliferative effects of HMBA cannot be determined from this study, similar inhibitory effects of HMBA on normal and abnormal hematopoietic progenitors suggest that HMBA may be of limited utility in producing and sustaining elevations of peripheral blood cell counts in patients with myelodysplastic syndrome
— id: 144382, year: 1990, vol: 82, page: 1926, stat: Journal Article,

A new canine model to evaluate the biological effects of implant materials and surface coatings on intramedullary bone ingrowth
Spivak JM; Blumenthal NC; Ricci JL; Alexander H
1990 Jul;11(9):79-82, Biomaterials
A new animal model for examining the intramedullary bone response to various implant materials and surfaces is presented, utilizing an implantable chamber with multiple bone ingrowth channels placed through a cortical defect in the lateral aspect of the distal femur. Twelve adult mongrel dogs received bilateral implants containing channels lined by smooth-surfaced coupons of titanium, titanium alloy, sputter-hydroxyapatite-coated titanium alloy, and UHMW polyethylene. A pattern was detected for all test groups of early initial bone ingrowth by two weeks, which became maximal at six to twelve weeks, followed by remodelling to a more mature lamellar bone and later resorption by 24 weeks, with fibrous tissue interfaces covering the smooth test coupons of all groups at all times. Significantly increased bone ingrowth in the sputter-HA coated group was found only at six weeks
— id: 35934, year: 1990, vol: 11, page: 79, stat: Journal Article,

A new canine model to evaluate the biological response of intramedullary bone to implant materials and surfaces
Spivak JM; Ricci JL; Blumenthal NC; Alexander H
1990 Sep;24(9):1121-1149, Journal of biomedical materials research
A new canine model utilizing an implantable chamber with multiple bone ingrowth channels has been used to study the response of intramedullary bone to various implant materials and surfaces. The first group of dogs received implants containing channels lined by smooth-surfaced coupons of titanium, titanium alloy, sputter-hydroxyapatite-coated (HA-coated) titanium alloy, and polyethylene. A pattern of early initial bone ingrowth by 2 weeks, becoming maximal at 6 to 12 weeks with remodeling to a more mature lamellar bone, and later resorption by 24 weeks was seen for all test groups, with fibrous tissue interfaces covering the smooth test coupons at all time points. Significantly increased bone ingrowth in the sputter-HA coated group was found only at 6 weeks. The second group of dogs received implants with channels lined by surface-roughened coupons of either titanium or plasma-HA-coated titanium, half of which were also packed with a crystalline-HA grouting at the time of surgery. At both 6 and 12 weeks, bone ingrowth was greatly enhanced by the presence of the plasma-HA coating or the crystalline-HA grouting as compared to the uncoated titanium channels. Histologically, bone was seen to bond directly to the plasma-HA coating and the crystalline-HA grouting. A thin fibrous tissue layer was noted between bone and the titanium in most areas, but evidence of direct bone contact to the metal surface was seen. Mechanical testing in tension of intact coupon-bone-coupon units revealed significant strength of the bone-plasma-HA bond, with failure initiating at the metal-HA interface with forces of 15.3 N at 6 weeks, increasing to 44.8 N at 12 weeks. Plasma-HA-lined channels with crystalline-HA packing required similar forces for failure. No significant adhesion strength was noted for the titanium channels at 6 weeks, and only the crystalline-HA-filled channels displayed measurable strength of the bone-titanium interface at 12 weeks, with a force of 9 N needed for failure
— id: 35933, year: 1990, vol: 24, page: 1121, stat: Journal Article,

Hydroxyapatite ceramics and the nature of the bone-ceramic interface
Ricci JL; Spivak JM; Alexander H; Blumenthal NC; Parsons JR
1989 Fall;49(2):178-191, Bulletin of the Hospital for Joint Diseases Orthopaedic Institute
Hydroxyapatite ceramics have been used as bone implants in a number of experimental systems and clinical applications. We have developed a unique experimental model that allows study of the interface between bone and implant materials. A comparison of titanium and hydroxyapatite materials, using this model, has demonstrated the osteoconductive nature of hydroxyapatite and its ability to bond directly to bone
— id: 35937, year: 1989, vol: 49, page: 178, stat: Journal Article,