Results of revision knee replacement for patients with isolated fixed flexion deformity after primary or revision knee replacement

Postoperative fixed flexion deformity is a known complication of knee replacement surgery. We present our results of revision surgery for treatment of isolated fixed flexion deformity after knee replacement.

32 patients had revision knee replacement for fixed flexion deformity and were included in this retrospective study. Minimum follow up period was 28 months.

Two different surgical interventions had been done in these patients.

Group 1 (15 patients) had revision of the femoral component, posterior capsular release and tibial component was not revised. Group 2 (18 Patients) had revision of both femoral and tibial components. One patient was included in both groups as she had both interventions.

The extent of preoperative flexion deformity in group 1 was from 15 to 40 deg (mean 20.6 deg). Postoperative range of extension was 0 to 20 deg (mean 8.2 deg). In group 2, preoperative flexion deformity was 10 to 25 deg (mean 16.9 deg) and postoperative flexion deformity was 0 to 20 deg (mean 4.2 deg). The difference in improvement between the two groups was not statistically significant on Mann Whitney U test (two tailed p value 0.181) for non normal distribution. Improvement in Oxford knee score following surgery was only 1 point in both groups.

Revision for isolated fixed flexion deformity leads to improvement in range of extension, but improvement in clinical score is marginal. The choice of preservation or revision of the tibial component did not make a significant difference to the outcome.