Extra-articular Deformity Correction via Clamshell Osteotomy of the Tibia With Simultaneous Bilateral Total Knee Arthroplasty.

Total knee arthroplasty (TKA) aims to alleviate severe pain and functional impairment in advanced knee arthritis. However, extra-articular deformities must be addressed preoperatively to ensure optimal implant positioning and soft tissue balancing. We present a case of a 58-year-old man with a history of a right tibial malunion and left femoral shaft fracture, who developed progressive bilateral knee osteoarthritis. He underwent simultaneous bilateral TKA with a right tibial clamshell osteotomy to correct a 17° varus deformity and left femoral hardware removal to accommodate a long stem implant. At one year follow-up, the patient had satisfactory functional outcomes with restoration of mechanical alignment and bony union at the osteotomy site. This case demonstrates the utility of the clamshell osteotomy in correcting tibial malunion to facilitate TKA with long stems, reducing the degree of intra-articular correction required.