Custom-Made Total Talonavicular Replacement in a Professional Rock Climber: Functional Evaluation With Gait Analysis and 3-Dimensional Medical Imaging in Weightbearing at 5 Years’ Follow-Up

Abstract

With the goal to restore ankle and foot function also in the long term, custom-made prostheses are becoming more frequently possible solutions for severe bone loss and avascular necrosis of the talus. A young professional rock climber was implanted with a custom-made talonavicular prosthesis, and short-term (30 months) assessment has been published. A thorough assessment at the intermediate term (60 months), with state-of-the-art gait and medical imaging analyses, is reported here. Level walking and more demanding motor tasks were analyzed with both a full-body and a multisegment foot protocol on the operated and contralateral limbs. Cone-beam computer-tomography was also used to obtain 3-dimensional (3D) position and orientation of bone models on the operated ankle. These models were also used for a 3D video fluoroscopy analysis, with the ankle in 3 joint positions at the extremes of motion. Distance map analysis was performed to check for possible changes over time of bone morphology and joint contact areas, in all 3 joint positions. Very satisfactory functional results were observed, with large and symmetric joint motion and physiological muscular recruitment even in demanding motor tasks. Distance map analyses revealed that very small morphologic and contact patterns changes occurred in the replaced ankle between 30 and 60 months. Concerns about possible wear of the cartilage in the tibial mortise are not yet supported by experimental evidence.