Randomized Controlled Trial Comparing Early Mobilization vs Six Weeks of Immobilization in a Walking Cast Following Total Ankle Replacement

Rehabilitation for patients after total ankle replacement traditionally involves weeks of immobilization in a plaster cast followed by progressive mobilization. Using a small randomized trial, we compared outcomes after implantation of a three-component cementless, unconstrained, mobile-bearing prosthesis for patients who had initial immobilization in a plaster cast for six weeks and patients who instead had early mobilization. Gait, clinical, patient-reported, and radiologic outcomes were measured. The study included 20 patients, 10 in the plaster cast group and 10 in the early mobilization group, and the demographics of the groups did not differ significantly. All patients were followed for 24 months. There were no significant differences between the two groups two years after surgery in ankle dorsiflexion, spatiotemporal gait characteristics, AOFAS ankle-hindfoot scores, Timed Up and Go Test times, WOMAC (pain, stiffness, function) scores, SF-36 (quality-of-life) scores, or patient satisfaction (pain relief, daily-living, recreational activities, and overall) (all P>0.05). Bone mineral density decrease of the medial malleolus and increase at middle tibia, calculated with DEXA scans, was significantly better in early mobilization than plaster cast group at one and two years postoperatively, but this was also the case preoperatively. The lack of differences in outcomes suggest that early ankle mobilization may be a safe and reliable method to enhance recovery following ankle arthroplasty with a three-component cementless, unconstrained, mobile-bearing prosthesis. Compared to traditional plaster casting, patients who are engaged in early mobilization after arthroplasty may enjoy similar functional, mobility, quality-of-life, pain relief, activity level, and satisfaction outcomes.