(Injection, Trigger Point)
A trigger point is a painful area in a muscle. It may feel like there is “knot” in the muscle or an area of tightness. When pressure is applied to the trigger point, the pain spreads out to other areas of the body.
A trigger point injection is a shot that is given in this painful spot.
If you have a trigger point in the thigh muscle, the doctor can give an injection to relieve pain.
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Reasons for the Procedure
Trigger point injections are given to reduce pain and increase physical functioning so that you can participate in a physical therapy program.
Complications are rare. But, no procedure is completely free of risk. If you are planning to have this injection, your doctor will review a list of possible complications, which may include:
- Tenderness, bruising, or bleeding at the injection site
- Allergic reaction to the local anesthetic or medicine
- Damage to organs, such as the lung (rare)
- The need for other treatments if this injection is not effective
Factors that may increase the risk of complications include:
You should not have this injection if you:
- Have allergies to the local anesthetic or medicines being used
- Have a current infection
- Have a bleeding disorder
- Are pregnant
What to Expect
Prior to the Procedure
Your doctor may:
- Do a physical exam and ask you about your medical history
- Have tests done (eg, x-rays , MRI scan )
- Ask you about any allergies that you may have to the anesthetic, pain medicine, or latex
Talk to your doctor about your medicines. You may have to stop taking some medicines up to one week before the procedure, like:
- Aspirin and other nonsteroidal anti-inflammatory drugs (eg, ibuprofen , naproxen )
- Blood-thinning drugs, such as warfarin
- Anti-platelet drugs, such as clopidogrel
Depending on where your trigger point is, you may need someone to drive you home after the procedure.
You will typically remain awake during the procedure. A local anesthetic may be used to numb the area where the injection will be given.
Description of the Procedure
First, the skin around the painful area will be cleansed with an antiseptic. Next, the doctor will locate the trigger point. This may be done by feeling for the painful area with his fingers. Once the trigger point in found, a thin needle containing medicine will be injected. The injection may contain a long-acting pain reliever, a water solution, or a corticosteroid to reduce inflammation. Botulinum toxin is also sometimes used for trigger point injections associated with muscle contraction. Sometimes the doctor will simply put the needle into the trigger point and not inject any medicine. This is all done to break the pain cycle at the trigger point. If you have more than one trigger point, you may need several injections.
Some doctors may use needle-guided electromyography (EMG) to locate the trigger point. With this approach, a needle will send information to a monitor, which will allow the doctor to make sure he has located the right spot.
How Long Will It Take?
The injection takes a few minutes.
Will It Hurt?
When the doctor feels for the trigger point, you will have discomfort. You will also feel a pinching sensation when the needle goes through your skin. You may have pain, which should not last long.
Post Procedure Care
At the Care Center
The hospital staff will apply pressure to the injection site and place a bandage there. You will be observed for a short time to make sure you do not have any poor reactions to the injection. Then, you will be able to go home or return to work.
Take these steps to help ensure a smooth recovery:
- To reduce soreness, apply ice or a cold pack to the affected area for 15-20 minutes, four times a day. You may want to do this for several days. Wrap the ice in a towel. Do not apply it directly to your skin.
- Take over-the-counter pain medicine as recommended by your doctor. The soreness should go away in a couple of days.
- Follow your doctor’s instructions for doing physical therapy. You may need to meet with your physical therapist soon after the injection to take advantage of the pain relief in your muscles.
You may have pain relief for weeks or even months. In some cases, though, you may need to have more than one trigger point injection. Talk to your doctor about how often you will need this treatment.
Call Your Doctor
After you arrive home, contact your doctor if any of the following occurs:
- Signs of infection, including fever and chills
- Redness, swelling, increasing pain, bleeding, or discharge from the injection site
- Numbness, tingling, pain, or weakness
- Any new or unexplained symptoms
Last reviewed March 2013 by Teresa Briedwell, DPT, OCS
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.