Rim Fracture of a Tibial Base-Plate Due to Retained Cement as a Cause of Catastrophic Failure of Unicompartmental Knee Arthroplasty: A Case Report

Early Tibial Baseplate Fracture After Medial Unicondylar Knee Arthroplasty: A Report of 2 Cases

CASE

Implant failure after unicondylar knee arthroplasty (UKA) is a rare but well-described complication in the arthroplasty literature. However, there is a paucity of literature regarding rapid catastrophic failure of modern implant designs. This is a case report of 2 patients with early catastrophic failure of the tibial baseplate after UKA with a Stryker Restoris MultiCompartmental Knee System implant using Mako robotic assistance, both requiring revision to total knee arthroplasty.

CONCLUSION

Improved awareness and understanding of early UKA tibial baseplate failure may help identify both patient and surgical risk factors that could help prevent further instances in the future.

Tibial tray fracture in a modern prosthesis with retrieval analysis

Fracture of the tibial tray is a rarely observed complication of total knee arthroplasty (TKA), predominately in implants placed greater than a decade ago. This case highlights a case of baseplate fracture in a contemporary prosthesis. The patient presented 1 year after TKA with medial knee pain consistent with pes bursitis. The implant-cement-bone construct was intact and she was managed with corticosteroids. She had persistent pain, acutely developed new varus deformity, and presented with a tibial tray fracture. Retrieval analysis suggested fatigue fracture as the likely mechanism. At time of revision, necrotic bone was found at the medial plateau, which likely caused cantilever bending relative to the well-supported portion of the tray and resultant failure. The patient continues to do well 5 years after revision TKA.