Bilateral Distal Femoral Flexion Deformity After Total Knee Arthroplasty in a Patient with Rheumatoid Arthritis

Rheumatoid arthritis is an autoimmune systemic disease with predominant peripheral polyarthritis, often leading to severe joint destruction. This is a case report of an 81-year-old woman with longstanding severe rheumatoid arthritis requiring multiple orthopaedic operations for joint destruction since 2000. These operated joints improved her functional mobility until recently, when she found that her knees were fixed at around 70 degrees of flexion with limited motion. There was chronic progressive flexion deformity of bilateral distal femurs, which was an extremely rare complication of total knee arthroplasty.