Medial Patellar Instability Following Total Knee Arthroplasty

Although lateral patellar instability has been discussed as a complication following total knee arthroplasty (TKA), there are no published reports of medial patellar instability. We present a case of a 72-year-old female patient with a remote history of medializing tibial tubercle osteotomy who underwent TKA complicated by a medial dislocation of the patella. Management consisted of lateral retinaculum imbrication, revision of the patellar component, and lateralizing tibial tubercle osteotomy in the setting of appropriate rotation of the tibial and femoral components. It is important to be aware of medial patellar instability as well as potential treatment options as this is a rare complication that can occur following TKA.