Treatment of Medial Collateral Ligament Injury During Total Knee Arthroplasty With Internal Suture Brace Augmentation: A Cadaveric and Biomechanical Study

Abstract

Intraoperative medial collateral ligament (MCL) injury during total knee arthroplasty (TKA) is a serious complication. External bracing and/or conversion to a constrained implant has previously been studied. The technique of using an internal high-strength suture brace to augment an MCL repair has been evaluated in the nonarthroplasty patient and could provide an alternate solution. The goal of this study was to determine whether MCL repair with internal suture bracing restores stability of the implanted knee joint. A robotic simulator completed laxity testing on 5 cadaveric knee specimens in 4 sequential phases: (1) intact knee, (2) after implantation with TKA, (3) after sectioning of the MCL, and (4) after MCL repair with suture brace augmentation. Laxity was compared between the different test phases throughout range of motion. Subsequently, the internal brace was tested to failure under valgus load. The MCL repair with internal bracing was effective at restoring laxity in varus-valgus, internal-external, and medial-lateral degrees of freedom through midflexion, with limited support at deeper flexion angles and in anterior-posterior laxity. Rotational laxity was not significantly different than intact knee laxity. Generally, medial-lateral translations were less and anterior-posterior translations were greater and were significantly different at 30° to 45° and 90°, respectively. The mean failure moment was 46.4±9.1 Nm, with the primary mode of failure being MCL repair. Primary MCL repair with internal bracing using a high-strength suture augment showed the potential to provide adequate stability and strength to correct MCL incompetence in TKA without the use of an external knee brace or constrained implants. [ Orthopedics . 2022;45(5):e269–e275.]

MCL internal brace does not fully recapitulate normal MCL function in valgus stress

“…The study found that in valgus loading, MCL repair with internal brace augmentation could withstand force similar to the intact MCL state, which was not true for the MCL repair without internal brace state. A study from Frisch et al demonstrated that MCL repair with internal brace augmentation following total knee arthroplasty could withstand similar valgus loads to the intact state [9]. It is unclear why these studies produced different findings than the present study, however, the present study was conducted in otherwise intact knees, while the studies from van Eck et al and Frisch et al were conducted with concomitant procedures.…”

“…Two recent studies have looked at valgus loading of the MCL with concomitant procedures in cadaveric specimens [9, 31]. The study from van Eck et al compared the force generated on the MCL with concomitant ACL reconstruction during 4 states: Intact MCL, Deficient MCL, MCL repair, and MCL repair with internal brace augmentation [31].…”