TARSAL TUNNEL APPROACH

USES

This approach is used for neurolysis of the posterior tibial nerve and tarsal tunnel syndrome.

ADVANTAGES

This approach comes directly down over the pathology.

DISADVANTAGES

This is a single-use approach. For fracture work you need to be more anterior, and for Achilles tendon work you need to be more posterior. Except for freeing the nerves, it does not make sense to come down directly over them.

STRUCTURES AT RISK

The neurovascular structures are generally centered in the incision and are definitely at risk. Because the whole point of the surgery is generally to free up the nerve, it would be in harm’s way no matter where you put the incision.

TECHNIQUE

An incision is made generally midway between the posterior border of the distal tibia and the Achilles tendon anterior border. Instead of coming around the medial malleolus paralleling the posterior tibialis muscle, as in the posteromedial approach used for fractures, this incision angles more directly toward the arch of the foot and is carried through the subcutaneous tissue to the superficial fascia. This fascia is split. Usually the neurovascular bundle is visible through the fascia, and the splitting should be done along the anterior edge of where that bundle seems to be located. It is better to err by being anterior rather than posterior. The fascia is split down to the abductor hallucis origin. The nerve passes underneath and can be impinged by the sharp fibers of its tendon of origin off of the calcaneus. Because the nerve generally needs to be traced down into the arch of the foot where it splits into the medial and lateral plantar branches, it is usually necessary to release the tendinous portion of the abductor hallucis.

TRICKS