The last stage of a supination-external rotation ankle fracture involves either transverse fracture of the medial malleolus or rupture of the deltoid ligament. When the deltoid ligament ruptures, a “bimalleolar equivalent” ankle fracture occurs, and the surgeon is presented with several diagnostic and therapeutic challenges. In the native ankle, the deltoid ligament provides restraint to eversion and external rotation of the talus on the tibia. In bimalleolar equivalent ankle fractures, there is often gross medial instability even after fibular reduction. Retraction of the deltoid with subsequent healing in a nonanatomic position theoretically may cause instability, persistent medial gutter pain, and loss of function with risk of early arthritis. In mild cases, deltoid injury may not be obvious, and potential diagnostic techniques include preoperative and intraoperative stress radiography, MRI, and ultrasonography. The most common injury pattern is avulsion from the medial malleolus, and most current repair techniques involve direct repair of the capsular and deltoid injuries involving suture anchors in the medial malleolus and imbrication of the superficial and deep deltoid fibers. To date, there is limited evidence of superior clinical outcomes with the addition of deltoid repair compared with open reduction and internal fixation of the fibula alone.
From the Department of Orthopaedic Surgery, Rush University Medical Center, Chicago, IL.
Dr. Lee or an immediate family member serves as a board member, owner, officer, or committee member of the American Orthopaedic Foot and Ankle Society. Dr. Lin or an immediate family member has received research or institutional support from Arthrex and has received nonincome support (such as equipment or services), commercially derived honoraria, or other non–research-related funding (such as paid travel) from Medwest. Neither of the following authors nor any immediate family member has received anything of value from or has stock or stock options held in a commercial company or institution related directly or indirectly to the subject of this article: Dr. Hamid and Dr. Bohl.
Received July 04, 2018
Accepted October 16, 2018