Early vs Delayed Weightbearing After Surgical Fixation of Unstable Ankle Fractures With Syndesmosis Disruption

Overview

No study has prospectively compared a traditional post-operative non-weightbearing protocol versus early post-operative weightbearing as tolerated for unstable ankle injuries after surgical fixation of the syndesmosis. This prospective study will attempt to determine if early weightbearing can improve functional outcomes, result in a quicker return to work, and monitor differences in rates of adverse events. It will exclude the most severe ankle injuries and patients with excluding comorbidities.

Fractures of the ankle are common injuries reported at around 10% of all fractures, with an incidence between 71-187/100,000 people/year. Rupture of the distal tibiofibular syndesmosis may occur alone or in association with ankle fractures. It is evident in approximately 10-23% of all patients with ankle fractures and approximately 20% of patients requiring internal fixation. Approximately 15/100,000 people sustain syndesmosis injuries each year, which can be associated with a variable degree of trauma to the soft-tissue and/or osseous structures that play an important role in ankle joint stability. With syndesmotic injury, the goal of management is to restore and maintain the normal tibiofibular relationship to allow healing of the ligamentous structures of the syndesmosis. If syndesmotic injury is not detected nor treated long term, residual displacement of the ankle mortise will lead to persistent pain and early arthritis. Although most indications for surgical intervention for syndesmotic injuries are clear, certain elements of the post-operative protocol remain controversial. There is still controversy regarding using screws vs suture buttons to fix the syndesmosis, with studies showing similar functional outcomes and post-operative complications. However, screws have a significantly lower initial implant cost but inconclusive results on long term cost-effectiveness. For surgeons who use screws, two screws are better than one and recent literature shows that there is no need to remove screws routinely unless symptomatic. A recent systematic review shows there is little difference in functional outcome scores between immobilization versus early motion of surgically treated ankle fractures with syndesmotic injury. However, postoperative care in respect to when to initiate weightbearing still remains controversial. Conventional postoperative care in regards to when to allow weightbearing varies by surgeon. Some prefer to keep the patient non-weightbearing for 6-12 weeks +/- immediate to early ankle motion, after which the patient begins protected weight bearing in a short leg walking cast for 2 weeks, followed by use of a soft ankle brace for 4-8 weeks. Others allow only touch toe weightbearing immediately postoperatively and only advance to full weight bearing once the syndesmosis screws have been removed, usually at 6 to 12 weeks. There is still no well-done evaluation to guide post op weightbearing. A recent metanalysis of outcomes of early (EWB) versus delayed (DWB) postoperative weightbearing in patients undergoing surgical fixation of ankle fractures included seven randomized control trials, one quasi randomized trial, one prospective cohort study with retrospective matches, and one retrospective matched cohort study reported 10-point improvement in OMA scores at 6 weeks post-operatively for patients in the EWB group compared to the DWB group (p=0.02). With regards to time off work, there was a trend towards reduction of 15 days in the EWB group (p=0.08). Complication rates were similar, with no difference in rates of nonunion, malunion, or wound complications. Another systematic review does suggest that EWB after surgically treated ankle fractures would be appropriate for patients with good bone stock, minimal commination, and anatomical reduction, and may facilitate quicker rehabilitation and early return to work. Results show no significant difference in overall complication rates, including hardware failure, malunion, or nonunion. However, EWB may increase risk of superficial wound infection, but the studies had no statistical comparison. There have been few studies to show outcomes of early protected weightbearing in patients who underwent surgical screw fixation of the syndesmosis. A recent retrospective review with 42 patients shows that EWB on a fixed syndesmosis appears to be safe, with no measurable clinical or radiographic consequences regarding ankle joint function. Even with screw breakage and loosening, loss of reduction was seldom observed. Another retrospective review was conducted on 89 patients who underwent open reduction internal fixation with syndesmotic stabilization using syndesmotic screws. The results showed maintenance of fracture reduction on all patients at 12 months and a complication rate of 11.7%, which is similar to previous early weightbearing trials on ankle fractures without syndesmotic stabilization. No study has prospectively compared a traditional post-operative non-weightbearing protocol allowing ankle range of motion to early post-operative weightbearing as tolerated allowing ankle range of motion for unstable ankle injuries after surgical fixation of the syndesmosis. We will exclude the most severe injuries, including tibial plafond fractures with articular impaction and high-grade open ankle fractures. Implications of this study will be far reaching. Safe, early weightbearing will not only facilitate rehabilitation but it has been shown that early weightbearing reduces the time to return to work thus decreasing cost to the healthcare system and society.