Incidence and strategies for prevention of adjustable loop suspensory fixation maldeployment in multiligament knee reconstruction.

INTRODUCTION/

OBJECTIVES

Adjustable loop suspensory (ALS) fixation offers the ability to re-tension grafts in complex multiligament knee reconstruction. A frequent complication of adjustable loop fixation is implant maldeployment. This study's primary objective was to determine the incidence of implant maldeployment associated with ALS fixation in a cohort of patients who underwent multiligament knee reconstruction and to identify the most at-risk tunnel(s). Our secondary objective was to determine the clinical impact of implant maldeployment.

METHODS

Demographic, radiological, and clinical data were collected from adult patients who underwent multiligament knee reconstruction using ALS fixation between January 1, 2018, and January 1, 2020. The primary outcome measure was the incidence of implant maldeployment, as defined by radiologic soft-tissue interposition of >5 mm or radiologic intraosseous button flip. Secondary outcomes were the rate of reoperation, postoperative Lysholm and Tegner scores, and postoperative knee range of motion. Statistical analyses were conducted using univariate logistic regression, and odds ratio (OR) with 95% confidence interval (CI) were reported.

RESULTS

A total of 241 ALS buttons were included in 56 patients, predominantly male patients (N = 39, 70%), with a median age of 32 [26.0-42.0] years. The incidence of ALS implant maldeployment was 5% (N = 11/241). Soft-tissue interposition maldeployment only occurred for the femoral medial collateral ligament (MCL) and the femoral posterior cruciate ligament posteromedial bundle fixation (PCL PM). Reoperation occurred in five out of nine (56%) patients with maldeployment, and six out of 34 (18%) in patients with well deployed implants (OR 6.8, 95% CI 1.1 to 49, p = 0.022). Maldeployment did not appear to impact postoperative knee patient reported outcomes or range of motion (p ≥ 0.05). The median follow-up duration was 9.1 [7.4-13.6] months.

CONCLUSION

This cohort demonstrates a 5% incidence of maldeployment when using ALS fixation. Despite maldeployment, ALS fixation demonstrated similarly favorable clinical outcomes, but a higher rate of reoperation. In multiligament reconstructions, surgeons should be particularly attentive to femoral ALS button deployment for PCL and MCL grafts.

LEVEL OF EVIDENCE: IV.