Management of Medial Collateral Ligament Injury During Primary Total Knee Arthroplasty: A Systematic Review

Medial collateral ligament injury during primary total knee arthroplasty is a recognised complication potentially resulting in valgus instability, suboptimal patient outcomes and a higher rate of revision or reoperation. Options for management include primary repair with or without augmentation, reconstruction or immediate conversion to prosthesis with greater constraint, in conjunction with various postoperative rehabilitation protocols. Inconsistent recommendations throughout the orthopaedic literature have made the approach to managing this complication problematic. The objective of this study was to review the available literature to date comparing intraoperative and postoperative management options for primary total knee arthroplasty complicated by recognised injury to the medial collateral ligament. This systematic literature review was prospectively registered with PROSPERO (#CRD42014008866) and performed in accordance with PRISMA guidelines including a PRISMA flow diagram. Five articles satisfied the inclusion criteria. Each was a retrospective, observational cohort or case series with small numbers reported, inconsistent methodology and incompletely reported outcomes. Four of the five studies managing medial collateral ligament injury during total knee arthroplasty (47/84 patients) with direct repair with or without autograft augmentation reported good outcomes with no revision or reoperation required for symptomatic instability over a follow-up period of 16 months to almost 8 years. The fifth study with a follow-up to 10 years and a high rate of conversion to unlinked semi constrained total knee arthroplasty implant (30/37 patients) reported a greater incidence of revision due to instability, in patients in whom the medial collateral ligament injury was directly repaired without added constraint. Overall balance of evidence is in favour of satisfactory outcomes without symptomatic instability following direct repair with or without augmentation of an medial collateral ligament injury recognised intraoperatively during total knee arthroplasty. An implant with greater constraint may have reduced longevity in younger, more active patients through aseptic loosening. In elderly or less mobile patients, and in situations where the medial collateral ligament repair is deemed poor quality or incomplete, an implant with greater constraint would seem prudent. In patients where direct repair with or without augmentation was used, a period of 4-6 weeks of unrestricted rehabilitation in a hinged knee brace should be followed.