Anatomic basis for a minimally invasive approach to the subtalar joint

An isolated arthrodesis of the talocalcaneonavicular joint is a common indication in cases of pain and post-traumatic arthroses.

Because of the high infection rate after surgery with the lateral incision, the authors decided to evaluate an alternative, minimally invasive procedure. Joint destruction was carried out via a posterolateral access after the insertion of two guidewires. For an evaluation of the risk for vessel and nerve structures, 102 ankle joint specimens preserved in formalin/alcohol were examined. Additionally, the minimally invasive access was evaluated in ten ankle joint specimens.

Neither in the specimen nor during evaluation of the minimally invasive access could injuries of vessels or nerve structures larger than 1 mm in diameter be found. The authors did not encounter any problems when drilling open the articular surface with a destruction of 65% of the overall surface and when performing the following arthrodesis using a plug technique. Using a posterolateral, minimally invasive access between the Achilles tendon and lateral malleolus, it is possible to resect about 65% of the subtalar articular surface for arthrodesis without impact on major vessels and nerves. Postoperative complications such as sensitive and sensory failure as well as wound healing impairment at the lateral side of the foot are not to be expected when choosing the minimally invasive access.

It has to be said, however, that this technique does not offer the opportunity of performing a corrective arthrodesis as the hindfoot cannot be displayed during surgery. As the result of this study was positive, clinical evaluation was started.