Retrieval analysis of nonmodular constrained tibial inserts after primary total knee replacement.

Large angular deformities can be a challenge when performing primary total knee replacement. Some investigators have advocated the use of increased component constraint in these settings. The goal of this study was to determine the location and extent of damage to a consecutive series of retrieved constrained tibial inserts used in primary arthroplasty. There was significant post and articular damage in retrieved implants. Reliance on the polyethylene post for implant stability was associated with post and articular surface damage and may be a potential source of failure. Attempts to achieve implant stability using soft tissue techniques seem justified.