A Case of Varus Collapse and Bone Defects in Revision Total Knee Arthroplasty, after 12 Years of Primary Total Knee Replacement: Surgical Challenge and Bailout.

Introduction: The failure of total knee arthroplasties (TKA) due to aseptic implant loosening is now the most common cause of long-term failure. Patients with varus alignment of the tibial or femoral component with additional bone collapse are a specific subset. It is unclear, however, whether implant fixation fails first or if bone collapse occurs first. Case Report: A 70-year-old lady with 12-year post-primary total knee arthroplasty presented with limping gate with radiological evidence of medial femoral bone collapse and implant loosening. After appropriate pre-operative planning, intraoperatively, after the removal of loose femoral implant which had additional bone loss and careful removal of a well-fixed tibial implant and to prevent collapse due to bone loss, Stryker LCCK implant with long stems on both sides was used. Additional screws on the medial femoral end, along with cement to fill the gap. After 5 years of follow-up, the patient is doing well with a painless full range of movement of the knee joint. Conclusion: Preoperatively one should always evaluate for bone loss and infection and compare with the other side. In case of aseptic collapse of bones, the use of thicker stems is a good way as these act as weight-sharing implants, and proper cementation during revision TKA is essential.