Patello-femoral synostosis: A rare complication after total knee arthroplasty: A case report

Abstract

Introduction: A painful, stiff knee after TKA affects the outcome. Various causes have been identified, including heterotrophic ossification (HO), but there is no documented evidence of bone formation between the patella and intercondylar notch of the distal femur in HO. Case report: We present the case of an elderly gentleman who presented with a painful stiff knee after revision TKA due to extensive HO leading to the formation of a bone bridge between the patella and femur. He was treated with repeat revision TKA using a rotating hinge prosthesis and achieved a painless, well-functioning knee at 3 years follow-up. Conclusion: Severe HO following TKA necessitating revision surgery is rare. In most cases, HO is minor and confined to the anterior distal femur without causing any functional compromise. In some cases, it can be widespread and affect all the tissues around the knee joint, causing severe restriction of movement.

Keywords

• Patellofemoral synostosis
• Painful stiff knee
• Heterotrophic ossification
• PCL ossification
• Arthrofibrosis