Medial Malleolus Fractures in Total Ankle Arthroplasty: A Preventable Complication?

by Vince Vacketta, DPM

Medial malleolar fractures (MMF) remain a significant and well-recognized complication of total ankle arthroplasty (TAA), impacting recovery and implant success. A multicenter retrospective review looked at 159 patients who underwent TAA, focusing on iatrogenic MMF – both intraoperative and postoperative – without the use of prophylactic medial malleolus (MM) fixation.

What the numbers reveal

The study found that MMF occurred in roughly 7% of cases. Patients who experienced fractures had a narrower MM, averaging 9.43 millimeters, compared to 11.2 millimeters in those without fractures. Notably, about 54% of the MMF cohort occurred in patients who received the Cadence prosthesis. However, the study did not assess implant positioning or preoperative deformity.

Rethinking risk and prevention

Prophylactic fixation of the MM seems to offer more benefit than risk. The are multiple fixation options available – both metal and non-metal – for potential obviation of MMF, particularly when considering joint loading and overall biomechanics.

That said, MM width alone should not guide decision-making. Final implant position and preoperative deformity are critical factors. Patients with varus deformity have a higher risk and fixation of MM is recommended, though further studies are needed. In contrast, valgus deformity presents a lower risk, often accompanied by compromised medial ligaments. In such cases, MM fixation should be avoided to prevent further trauma to the medial soft tissues.