Are soft tissue releases sufficient to correct moderate to severe flexion contractures during total knee replacement? Role of hamstring tenotomy and horizontal capsular release.

BACKGROUND

Performing total knee arthroplasty (TKA) in arthritic knees with persistent flexion deformities is a challenging task because secondary tightening of surrounding soft tissues makes it difficult to achieve appropriate ligament balancing. In this study, we shared our algorithm for correction of flexion contractures of moderate to severe grade while performing TKA as well as their outcomes with 1 year of follow up.

METHODS

Forty-three patients (61 knees) having knee arthritis with moderate to severe flexion contractures (Lombardi classification) were included in the study. We followed a stepwise algorithm of soft tissue releases for correction of flexion contracture, which included: removal of posterior osteophytes, release of posterior capsule, gastrocnemius release, horizontal capsular release, and hamstring tenotomy. Patients were followed up at 15 days, 6 weeks, 3 months and 1 year, and assessed clinically for residual flexion deformity (FFD), range of motion (ROM), New Knee Society (New KSS) score and Hospital for Special Surgery (HSS) score.

RESULTS

Pre-operative mean FFD 29.07 ± 18.04 standard deviation (SD) was corrected to 0.77 ± 2.93 SD at 1 year follow up. Pre-operative mean ROM 71.37 ± 22.18 increased to 107.7 ± 10.38 at 1 year follow up. There was statistically significant improvement in mean New KSS score and reduction in number of cases with poor HSS score at 1 year follow up.

CONCLUSIONS

Moderate flexion contractures can be corrected with soft tissue releases without distal femoral over-resection. In severe deformities, horizontal release of posterior capsule and hamstring tenotomy are crucial, and residual contractures of up to 20° can be well corrected by postoperative physiotherapy and extension bracing.