A New Total Knee Arthroplasty Technique for Valgus Knees that preserves the deep layer of the medial collateral ligament.

OBJECTIVE

The aim of this study was to assess the outcomes and complications, such as tibiofemoral instability and recurrence of valgus deformity, of total knee arthroplasty for valgus knees with a new technique preserving the deep layer of the medial collateral ligament.

METHODS

In this study 33 (4 male and 29 female) patients, and a total of 36 (26 knees with osteoarthritis and 10 with rheumatoid arthritis) knees with a standing femorotibial angle (FTA) of <170° were included. Posterior Stabilized (PS) implants were used in 34 knees, rotating hinged knee implants were used in 2 knees. The procedures were carried out by a single surgeon protecting the deep layer of the medial collateral ligament. The patients' average age at the time of the operation was 67.6 ± 12 years, and the average follow-up period was 9.0 ± 3 years (range, 4-15 years). The Japanese Orthopaedic Association (JOA) knee score, range of motion (ROM) (extension/flexion; measured in degrees), FTA (measured in degrees) and complications were investigated.

RESULTS

The Japanese Orthopaedic Association knee score significantly improved from an average of 51 ± 12 points before the operation to 86 ± 9 points after the operation (P <0.001). The extension ROM and flexion ROM improved from, -13 ± 13° to a postoperative average of -2 ± 4°, and 115 ± 25° to a postoperative average of 125 ± 18° respectively (P <0.001). The standing FTA significantly improved from 158 ± 9° to an average of 173 ± 2° after the operation (P <0.001). Thirty-four knees with severe valgus deformity were operated on using pos- terior stabilised implants, while only two knees required constrained implants. During follow-up, no complications, such as tibiofemoral instability, recurrence of valgus deformity, patellar necrosis, deep infection, wound problems, or peroneal nerve paralysis were observed.

CONCLUSION

This study has shown us that after performing TKA while preserving the d-MCL for valgus knee deformity good clinical results were obtained and no complications were observed.

LEVEL OF EVIDENCE: Level IV, Therapeutic Study.