Management of Medial Collateral Ligament Insufficiency During Total Knee Arthroplasty with a Screw and Rectangular Spiked Washer: A Case Series of 14 Patients.

OBJECTIVE

To describe the technique of primary repair of medial collateral ligament (MCL) insufficiency using a screw and rectangular spiked washer in a case series of 14 patients.

METHODS

Fourteen patients undergoing MCL repair by a screw and rectangular spiked washer during TKA between March 2018 and March 2019 were retrospectively reviewed. Among them, half injuries were avulsion of the femoral origin, and the other half were MCL laxity. There were 12 women and two men included in the study, with an average age of 63.6 years (range, 49-79 years) at the time of surgery. This series were followed up with a focus on range of motion (ROM), coronal alignment, Hospital for Special Surgery (HSS) knee scores, their subjective sense of joint instability, and related complications. At the last follow-up, function of the MCL was assessed by manually applying a valgus stress to the knee at both 0° and 30° of knee flexion.

RESULTS

The mean follow-up time for all patients was 15.6 months (range, 13-20 months). Repair of the MCL was successful in all patients. ROM improved from a mean of 70.7° ± 35.1° before surgery to 103.9° ± 6.8° at latest follow-up (P = 0.001). All patients were able to perform a half squat easily, but none were able to do full squatting. The mean preoperative HSS score was 43.6 ± 13.4 and increased to a mean of 85.6 ± 3.8 postoperatively (P < 0.001). The femorotibial angle improved from a mean of -3.22° ± 9.47° before surgery to a mean of 5.16° ± 3.14° at the final follow-up (P = 0.006). At the time of final follow-up, no patient required revision and manipulation under anesthesia following the index arthroplasty. No radiolucencies or migration were observed in association with the knee prostheses. No displacement of the screw and rectangular spiked washer was found. There were no clinical complications. No patient reported subjective instability of the knee. Upon physical examination, no patient was found to have laxity in the coronal plane in either 30° of flexion or full extension.

CONCLUSIONS

The screw and rectangular spiked washer is a simple and effective method for treating MCL sufficiency in TKA, and a study with a larger cohort and extended follow-up is requisite to claim its role in preventing coronal instability and component failure.