Anterolateral Arthroscopic Posterior Subtalar Arthrodesis: The Surgical Technique

Abstract

The effectiveness of subtalar arthrodesis has been well documented in treating degenerative subtalar joint disease. The arthroscopic subtalar approach for arthrodesis has also been proved to give excellent results in terms of bone fusion rates and reduction of wound-related pain and complications. To date, the main concerns about arthroscopy have regarded incision-related neurologic complications such as lesions of the tibial, fibular, and sural nerves. In this context, we present a 2-portal lateral (anterior and middle) approach to arthroscopic subtalar arthrodesis, recently documented in the literature, that provides similar excellent access to the joint with a lower risk of nerve damage.

Fig 1

External anatomy of portal placement during arthroscopic left posterior subtalar arthrodesis. The main landmarks are identified as the lateral malleolus (1), the base of the fifth metatarsal bone (2), the sinus tarsi (3), the calcaneocuboid joint (4), and the sural nerve skin projection (5). The anatomic locations of the subtalar arthroscopy portals are also marked (6 and 7).

Fig 2

Placement of anterior portal to perform ALAPSTA (anterolateral arthroscopic left posterior subtalar arthrodesis). After the introduction of the arthroscope in the first (more posterior) lateral portal, a needle is used to control the position of the second (more anterior) portal and to determine the correct orientation of the shaver that will replace the needle. The needle's placement in the lateral space defined by the talus (upper) and calcaneus (inferior) is arthroscopically verified, as shown in the inset.

Fig 3

ALAPSTA (anterolateral arthroscopic posterior subtalar arthrodesis) of left hindfoot in a patient with severe idiopathic subtalar arthritis. The patient is placed in the lateral position. Visualization is performed through the posterior portal in A, B, and D and through the anterior portal in C. The sequence shows the different phases of cartilage debridement in the posteromedial (A), posterior (B), and posterolateral area of the subtalar joint; a curette is generally used to remove the residual cartilage (D).

Fig 4

ALAPSTA (anterolateral arthroscopic posterior subtalar arthrodesis) of left hindfoot in a patient with severe idiopathic subtalar arthritis. The patient is placed in the lateral position, and visualization is performed through the anterior portal. At the end of cartilage debridement, an arthroscopic check is performed to assess the correct exposure of the subchondral bone in the whole joint before arthrodesis fixation. Although cartilage has to be removed as far as possible, the small irregularities of the subchondral bone must be left in place because they contribute to augmenting the total contact surface, thus helping the healing process. (FHL, flexor hallucis longus tendon.)