EARLY REVISION FOR ISOLATED INTERNAL MALROTATION OF THE FEMORAL COMPONENT IN TOTAL KNEE ARTHROPLASTY

Abstract

Aims: In this prospective study, we determined whether corrective surgery for rotational malalignment of femoral prosthesis components would benefit patients that had previously undergone total knee arthroplasty.

Methods: 68 consecutive patients with a painful total knee arthroplasty were screened with computed tomography. All patients were offered plain radiographs, tangential radiographs and stress radiography for valgus/varus stability in 20° and 90° flexion. No patient had signs of infection or loosening. 14 patients were selected that had isolated internal malrotation of the femoral component. No other malpositions could be found. Two patients with mild (≤3°) internal mal-rotation were excluded due to conservative treatment. Revision surgery was performed to replace prosthetic components in 12 patients with internal malrotation ≥ 4° within 3 years of the primary arthroplasty

Results: The corrective surgery resulted in an increase in the average Knee Society Score from 51/65 to 86/86 points and an improvement in the average Hospital for Special Surgery knee score from 64 to 83 points. The mean follow-up was 57 (range 46 to 89) months.

Conclusion: This study showed that correction of isolated internal malrotation of the femoral component will lead to better clinical and functional outcomes.