Comparison of Ankle Joint Visualization Between the 70° and 30° Arthroscopes: A Cadaveric Study.

Ankle arthroscopy is an important diagnostic and therapeutic tool. Arthroscopic ankle surgery for anterior ankle impingement or osteochondral lesions (OCLs) is mostly performed with a 30° arthroscope; however, visualization of lesions is sometimes difficult. This study sought to compare ankle joint visualization between 70° and 30° arthroscopes and clarify the effectiveness of 70° arthroscopy. Standard anterolateral and anteromedial portals were placed with 4-mm 70° or 30° angled arthroscopes in a fresh 77-year-old male cadaveric ankle. The medial ligament and surrounding tissue were dissected via a medial malleolar skin incision. Kirschner wires were inserted into the distal tibia anterior edge; 5-mm diameter OCLs were created on the medial talar gutter anteriorly, midway, and posteriorly. The talar dome and distal tibia anterior edge were visualized using both arthroscopes. The 70° arthroscope displayed the anterior edge of the distal tibia immediately in front of the arthroscope, allowing full visualization of the posterior OCL of the medial talar gutter more clearly than the 30° arthroscope. This study revealed better ankle joint visualization with the 70° arthroscope, and may enable accurate, safe, and complete debridement, especially in treatment of medial talar gutter posterior OCLs and removal of anterior distal tibial edge bony impediments. LEVELS OF EVIDENCE: Level IV, Anatomic study.