Ankle arthritis is ranked as debilitating as end-stage kidney disease. It often strikes at an earlier age than other arthritic joints, frequently due to after-effects of trauma, and is extremely painful. Previously arthrodesis, or ankle joint fusion, was the primary treatment to help stop the pain. But ankle fusion was not a great long-term answer because it additionally caused further joint break down and significantly limited function, such as walking, because the ankle bones no longer moved. Unlike ankle joint fusion, ankle joint replacement allows for a more natural walking pattern and thus allows for people to do more following replacement.
Thanks to technological advances, there are now two types of total ankle joint options, a mobile joint and a fixed joint. The mobile implant has a ball-bearing type function that allows for improved ankle motion and increased walking speeds. The hardware shows promising survival rates up to 10 years. The fixed joint replacement allows for lesser movement from side to side than the mobile implants. There is less research surrounding this type of joint replacement but the replacements are associated with improved function and a return at the 2-year mark to “moderate exertional activities.”
Ninety patients with end-stage ankle arthritis participated in a recent study, comparing these two implant types. Authors collected gait analysis, performed a physical exam, x-rays, and functional tests prior to surgery, and at both one and two years following surgery. Participants also filled out several questionnaires self-assessing their function and satisfaction with their surgical outcomes throughout this time period. Forty-nine participants received the mobile bearing implant and forty-one receive the fixed-bearing implant. Results found both of the implants to either maintain or improve function. The fixed-bearing implants had better walking qualities than the mobile implant group, however the mobile implant group reported better improvements in pain. Authors concluded that the implants can be rated as equal when choosing ankle joint replacement type and prove a better option than ankle fusion.