Anatomic Feasibility Study of Posterior Arthroscopic Tibiotalar Arthrodesis.

Abstract

Operative indications for an anterior arthroscopic tibiotalar arthrodesis are well defined. A posterior approach with the patient in a prone position may be indicated when the anterior approach is precluded by the soft tissue condition or for a 1-step procedure associated with posterior approach subtalar fusion. An anatomic study assessed the feasibility of posterior arthroscopic tibiotalar fusion and sought to determine arthroscopy entry points, mortise cartilage freshening quality, and the risk of osseous, tendinous, vascular, and neural complications. Twenty-two zones of the fibular tibiotalar mortise were mapped from 10 specimens. Medial and lateral para-Achilles arthroscopic portals were used with a 4 mm 30-degree arthroscope. Chondral resection was performed with a motorized burr, curette, and osteotome. The entire plafond of the tibia could be debrided in all cases, whereas the talar dome was debrided in its entirety in 20% of cases; in 80%, only the posterior two-thirds could be treated with the anterior portion approaching the neck of the talus being poorly accessible. More than 50% of the area of the malleolar grooves was debrided. There was 1 medial malleolar fracture and 1 peroneal artery lesion. The technique was shown to be feasible if there was no frontal hindfoot deformity or tibiotalar equinus preventing satisfactory resection of the posterior and anterior talar cartilage. This study demonstrated that a posterior approach arthroscopic ankle fusion would lead to adequate joint preparation. This procedure reduces the risk of nerve damage.