Arthroscopy of the subtalar joint: an experimental approach.

Talocalcaneal articulations are relatively complex and functionally very important because they play a major role in the movements of inversion and eversion of the foot. Few reports on arthrography of the subtalar joints are available in the literature, and, similarly, little attention has been paid by arthroscopists to these joints. This preliminary study briefly defines the normal anatomy of the subtalar joints and describes a new technique of arthroscopic examination of the posterior subtalar joint. The distal lower extremities of six fresh cadavers were used in these experiments. All the subtalar joints were supple. A 2.7-mm arthroscope was used to carry out arthroscopic and anatomic examinations. A technique of examination with one anterior portal and one posterior portal is described in detail. When the anterior portal was used, the egress needle was placed posteriorly; when the posterior portal was used, the converse was true. By using the two portals, the following intraarticular structures could be visualized: a major part of the convex posterior calcaneal facet of the talus and the posterior talar facet of the calcaneus; the synovial lining laterally and posteriorly; the posterior aspect of the interosseous talocalcaneal ligament; and the posterior recess of the joint. The results of this experimental study indicate that arthroscopy of the posterior subtalar joint is technically feasible. Clinically, the possible indications for arthroscopy would include state of the articular cartilage in suspected cases of degenerative arthritis, rheumatoid arthritis, and infection; visualization of the joint after intraarticular fracture to evaluate chronic pain syndrome in the hindfoot; biopsy; management of sinus tarsi syndrome; loose body removal.