Steroid injections can be used to diagnose and treat nerve compression in the wrist and foot. Carpal tunnel syndrome (CTS) can cause burning pain, numbness, and/or tingling in the thumb and first two fingers.
Pressure on the median nerve as it goes through the carpal tunnel is the underlying problem. The carpal tunnel is a space between the bones of the wrist and the retinaculum ligament across the wrist. There is usually enough room for the nerves to pass through this area undisturbed.
A similar problem called tarsal tunnel syndrome (TTS) can occur in the ankle and foot. Pressure on the tibial nerve can also cause ankle pain and pain, numbness, or tingling along the bottom of the foot.
Corticosteroid injection can bring relief from the symptoms. It is both a pain reliever and an antiinflammatory. Injections serve as a treatment and a diagnostic tool. If the wrist or ankle symptoms are eliminated by injection, then the problem was most likely nerve compression.
The authors review supplies needed for the procedure. They present surface anatomy to help the surgeon find the tunnel and locate the nerve. The patient’s position is important. Once the patient is placed in the best position, the skin is numbed and the injection is given.
Specific steps are included such as proper sterilization, angle of needle insertion, and proper length to advance the needle. Injection of the tendon can be avoided using proper patient positioning and stopping if there is any pain, numbness, or resistance.
If problems occur, the needle can be pulled back out and redirected. Patients should be told that their symptoms may get worse at first. This doesn’t last. It’s caused by the extra fluid of the steroid that has been pumped into the tunnel area.
This article was one of a dozen in a series describing the most commonly injected joints and bursae. Eight more of these procedural reviews will be presented in future publications of this journal.