Tarsal Tunnel Syndrome: Can A Minimally Invasive Release Be Advantageous?
The medial calcaneal nerve should be visible beneath the cut fascia and is usually located within a bed of adipose. Trace the nerve distally to its bifurcation into posterior and descending branches. The posterior branch innervates the skin of the postero-inferior area of the heel while the descending branch pierces the superficial fascia of the abductor and gives off perforators that innervate the medial and plantar surfaces of the heel. The foramina where these branches perforate the fascia are points of compression and require release.
Then release the fascia over the anterior end of the incision all the way to the sheath of the flexor digitorum longus. The upper edge of the abductor should be free. Grasp the superior edge of the common fascia of the abductor with an Allis clamp and pull the muscle outward. Doing so exposes the anterior and posterior compartments, and the intervening septae. Cauterize the septae with a bipolar cautery. The septae serve as conduits for nerve and vascular pedicles to the muscle. Then cut the septae.
Then remove the deep fascia of the abductor hallucis along with the superficial end of the septum. At this point, the medial and lateral neurovascular bundles are surrounded by the muscle bellies of the abductor hallucis and the quadratus plantae. To ensure an adequate distal release, insert a finger into the porta pedis and lyse any remaining fibers of the septae in the sole of the foot.
Key Tips On Wound Closure And Post-Op Care
Release the pneumatic tourniquet and obtain hemostasis. Close the wound in a single layer with sutures or staples. Apply a non-adherent compression dressing from the toes to the knee. Patients may bear weight on the foot immediately but should have crutches for support.
Remove the compression dressing between the fifth and the seventh postoperative day, and apply a large Band-Aid. The patient should wear a short leg compression stocking for the next two weeks. The patient may wear clogs or any other shoe that does not irritate the incision. Have the patient begin physical therapy at this time as well. Encourage the patient to avoid limping and to go through a normal heel-toe gait progression without shifting his or her weight to the outer border of the foot. Remove sutures or staples between the 14th and 21st days post-op.
A minimally invasive approach to the tarsal tunnel has an advantage over traditional incisions in that it limits the contact of the resultant scar and the neurovascular bundle to one specific point. In addition, by limiting the soft tissue injury, it permits an earlier return to function. Finally, this technique places the incision within both Langer’s and the relaxed skin tension lines, reducing both the amount of scarring and injury to the lymphatic system.
Applying these principles to release of the posterior tibial nerve and its branches significantly improves patient outcomes, reduces the period of disability and reduces the risk of post-op complications.1,2
Dr. Jolly is a Clinical Professor of Surgery at the Temple University School of Podiatric Medicine. He is also a Clinical Professor of Surgery at the Des Moines University School of Podiatric Medicine. He is a Fellow and Past President of the American College of Foot and Ankle Surgeons.
Dr. Burks is a Fellow of the American College of Foot and Ankle Surgeons, and is board-certified in foot and ankle surgery. He is in private practice in Little Rock, Ark.