Successful revision of an infected and challenging knee replacement: A case report

Abstract

Introduction: Internal rotation of the femoral component is detrimental to the functional results of total knee replacement. However, recent concepts test the limits of internal rotation that may be acceptable. We present an unusual case of an early revision of a total knee replacement for severe internal rotation of the femoral component leading to severe restriction of movement, further complicated by infection and gross instability. The case: A 63-year-old diabetic lady with a 4-month old knee replacement had persistent pain, instability, flexion of only 10°, and a seropurulent discharge. She needed a staged revision. Because of a femoral internal rotation of between 30 and 40°, the second stage required a reconstruction of the anteromedial aspect of the femoral condyle using structural bone graft to reproduce external rotation and a hinge for stability. The patient has since recovered well and has regained good function with no recurrence of sepsis 22 weeks post op. Conclusion: We present in this case a rare revision for an unusual amount of severe internal rotation of the femoral component needing a bone graft reconstruction at a location where metal augments are not usually available, further made complex by multiple other complications.

Keywords

• Knee replacement
• Revision
• Component malrotation
• Unstable total knee replacement
• Infected knee revision
• Hinged prosthesis