Search
Biomechanics
Evaluating New Surgical Devices and Techniques
Target Condition: Intertrochanteric hip fractures
Traditional Approach: Sliding hip screw fixation
New Approach: Medoff plate fixation: buttress plate augmentation
Progress: Superior stability ahs been demostrated in the laboratory
Investigator Dr. Fred Kummer
More than one hundred laboratory and clinical studies have been conducted in our Mechanical Testing Laboratory to evaluate new orthopaedic devices and surgical techniques. The goals of this work have been to improve patient care by determining the best device for a particular problem (e.g., hip fracture), the optimal surgical technique for its application, and objective measures of patient outcomes.
One such recent study tested the ability of a new device to stabilize intertrochanteric hip fractures—fractures just below the neck of the femur. The new device, the Medoff Sliding Plate, was compared to the “gold standard” of treatment, the sliding hip screw. Because the Medoff plate can slide in two directions (the sliding hip screw slides in only one), it permits greater fracture consolidation and improves healing. The study, employing cadaver femurs, quantified the stability and strength of hip fracture fixation by subjecting it to repeated stresses that simulate physiologic conditions. The results of testing showed that the Medoff plate provides improved fixation strength with less displacement of the fracture. Further studies have shown that the Medoff plate provides a degree of fixation in high subtrochanteric fractures equivalent to that obtained with standard intramedullary nailing.
In a related study, we evaluated the effect of augmenting a standard sliding hip screw with a buttress plate. Tests in our laboratory showed that this configuration provides greater stability to intertrochanteric hip fractures than the sliding hip screw alone. This new construct promises to shorten healing time and is now undergoing clinical trials.
Evaluating New Surgical Devices and Techniques
Target Condition: Intertrochanteric hip fractures
Traditional Approach: Sliding hip screw fixation
New Approach: Medoff plate fixation: buttress plate augmentation
Progress: Superior stability ahs been demostrated in the laboratory
Investigator Dr. Fred Kummer
More than one hundred laboratory and clinical studies have been conducted in our Mechanical Testing Laboratory to evaluate new orthopaedic devices and surgical techniques. The goals of this work have been to improve patient care by determining the best device for a particular problem (e.g., hip fracture), the optimal surgical technique for its application, and objective measures of patient outcomes.
One such recent study tested the ability of a new device to stabilize intertrochanteric hip fractures—fractures just below the neck of the femur. The new device, the Medoff Sliding Plate, was compared to the “gold standard” of treatment, the sliding hip screw. Because the Medoff plate can slide in two directions (the sliding hip screw slides in only one), it permits greater fracture consolidation and improves healing. The study, employing cadaver femurs, quantified the stability and strength of hip fracture fixation by subjecting it to repeated stresses that simulate physiologic conditions. The results of testing showed that the Medoff plate provides improved fixation strength with less displacement of the fracture. Further studies have shown that the Medoff plate provides a degree of fixation in high subtrochanteric fractures equivalent to that obtained with standard intramedullary nailing.
 |
 |
| Traditional sliding hip screw shown here disassembled (left) and in its assembled configuration (center). Right: Medoff Sliding Plate. Both the plate and the screw can slide to consolidate a fractured hip. | Improving fracture fixation The x-rays show paired femurs after testing; the buttress plate (right) provides greater stability of the intertrochanteric hip fractures than the sliding hip screw alone (left). |
In a related study, we evaluated the effect of augmenting a standard sliding hip screw with a buttress plate. Tests in our laboratory showed that this configuration provides greater stability to intertrochanteric hip fractures than the sliding hip screw alone. This new construct promises to shorten healing time and is now undergoing clinical trials.
 |
 Testing implants Laboratory setup for testing hip fracture fixation devices. Cadaveric specimens are subjected to controlled stresses in a testing machine to determine the stability of fracture repairs using various fixation devices. |