The Outcome of a Combined Lateral Extra-Articular Reconstruction and Anterior Cruciate Ligament Reconstruction: A Systematic Review of the Literature

BACKGROUND: The resurgence in recent attention given to the Anterolateral Ligament has fuelled debate regarding its potential role in knee kinematics, injury, and the need for repair or reconstruction. Surgeons have long recognised that a laterally based extra-articular reconstruction (LEAR) offers a powerful tool to control rotation of the knee. The principle subsequently emerged that combining extra- and intra-articular reconstructions was less likely to fail than either technique performed in isolation. Although successful in reducing anterolateral instability, LEAR fell out of favour when reports emerged about its unpredictability and unsatisfactory results in some cases. AIM: The purpose of this study was to systematically review the current literature on the clinical outcomes following primary anterior cruciate ligament reconstruction (ACLR) with a LEAR. A secondary aim was to compare the clinical outcomes of combined ACLR and LEAR with ACLR alone. METHODOLOGY: Systematic Review. Relevant articles were identified by two independent reviewers following a search of seven electronic databases. The inclusion criteria was all published peer-reviewed studies including randomized controlled trials, nonrandomized comparative studies, cohort studies, and case series (> 10 patients) with outcome data following primary ACLR with a LEAR with more than two years follow-up. The exclusion criteria included extra-articular procedures performed in isolation, synthetic ACLR or LEAR, cases with greater than two surgically treated knee ligaments or combined alignment knee surgery, ACL repair, reports on guidelines, technical notes, reviews or systematic reviews. Methodological quality assessment was performed using the MINORS criteria. Data was obtained using a data-extraction form developed specifically for this review. The outcomes of interest included postoperative clinical examination, objective, subjective, functional and radiographic evaluation. A meta-analysis was performed using a random effects model on available data. RESULTS: The literature search yielded 363 articles. After titles and abstracts were reviewed, 125 articles were selected for full-text review, of which 32 studies met the inclusion criteria (11 comparative studies 21 non-comparative studies). Of the 11 comparative studies, 5 recommended a combined LEAR and ACLR, 5 were in favour of the ACLR alone, and 1 was equivocal. Meta-analysis demonstrated a statistically significant difference for the pivot-shift test in favour of a combined LEAR and ACLR. All but 2 of the non-comparative groups reported a satisfactory outcome with combined ACLR and LEAR at a minimum of two years. Three long-term studies (>10 years) found there was no increased rate of lateral compartment osteoarthrosis with LEAR. CONCLUSIONS: A meta-analysis of data acquired from studies comparing ACLR to a combined ACLR with a LEAR, revealed a significantly reduced the post-operative pivot shift with LEAR. Review of the recommendations of 11 comparatives studies reached an equivocal verdict as to effectiveness of a LEAR in conjunction with ACLR. A number of studies advocated that a LEAR was not necessary when treating an acutely rupture ACLR in the primary setting, however, in the chronic setting it may have greater utility. Based on the available radiographic data, long term follow-up of ACLR with LEAR, there was no evidence of an increased incidence of lateral compartment osteoarthrosis.