• Ankle Osteoarthritis Scale scores [ Time Frame: Two years ] [ Designated as safety issue: No ]
  
• CT data to measure cartilage distribution over the articular surface and synovial fluid markers of biosynthetic/degradative activity and oxidative stress in response to treatment and comparison to clinical and radiographic changes [ Time Frame: Two years ] [ Designated as safety issue: No ]
  
• Improved joint function [ Time Frame: Two Years ] [ Designated as safety issue: No ]
  

Little work has been done on the pathogenesis and prevention of post-traumatic OA. The human ankle joint provides a unique opportunity for the study of post-traumatic OA because of the low risk of primary OA and the relatively high risk of post-traumatic OA. This study involves a multidisciplinary approach utilizing both laboratory and clinical research to improve understanding of OA and to develop innovative approaches for preventing and treating this disease. Mechanical distraction involves operative placement of specialized pins and rods to hold the joint in place. Some distraction allows for limited motion of the joint, while other distraction holds the joint immobile. The purpose of this study is to elucidate the mechanical factors that lead to restoration of a cartilaginous articular surface, decreased pain, and improved joint function after mechanical distraction of osteoarthritic joints.

Participants in this study will be randomly assigned to one of two treatment groups. Group A will be treated with mechanical distraction with motion; Group B will be treated with mechanical distraction without motion. Participants will be followed for 28 months and will have 11 study visits. Most of the study visits will occur during the first half of the study. State-of-the-art techniques for clinical assessment, articular surface imaging, biomechanical modeling, and biochemical testing will be used in this study.