Subtalar arthroscopy using a 2.4-mm zero-degree arthroscope: indication, technical experience, and results

The subtalar joint is complex. With the advent of smaller diameter arthroscopes, subtalar arthroscopy has become an important diagnostic and therapeutic tool for subtalar joint disorders. The objective of this study was to evaluate the outcome of patients who underwent arthroscopy for subtalar joint disorders using a 2.4-mm zero-degree arthroscope. In this prospective study, 6 patients who underwent subtalar arthroscopy from September 2008 to January 2009 in the authors' institution were included. The American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot scores were recorded preoperatively and at 3 and 6 months postoperatively. Mean +/- SD age was 45.5 +/- 16.2 years (range, 27.5-63.2). Postoperative diagnosis included arthrofibrosis, osteoarthritis, and osteochondral disease of the subtalar joint. Mean +/- SD AOFAS scores improved from 49.67 +/- 18.83 (range, 22-76) to 67.33 +/- 14.92 (range, 53-91) at 3 months (P = .03) and 75 +/- 19.74 (range, 54-100) at 6 months (P = .004). Subtalar arthroscopy using the 2.4-mm zero-degree arthroscope shows promising results in the diagnosis and treatment of subtalar pathologies. Patients have a significant improvement in their AOFAS hindfoot scores as early as 3 months and continue to improve subsequently. Usage of the zero-degree arthroscope allows the "instrumentation hand" to maneuver more easily in space and perform the operative procedure without getting in the way of the "camera hand." It can also save on inventory costs for centers that already have the zero-degree arthroscope. The role of specialized imaging is still unclear. Diagnosis of sinus tarsi syndrome should be historical with direct visualization of the joint revealing exact etiology.