Higher Incidence of Complete Lateral Meniscal Root Tears in Revision Compared With Primary Anterior Cruciate Ligament Reconstruction

PURPOSE: To evaluate the incidence of complete lateral meniscal posterior root tears (LMPRTs) repaired at revision as compared with primary anterior cruciate ligament (ACL) reconstruction (PACLR) and to determine whether other demographic or surgical characteristics were associated with LMPRTs needing repair. METHODS: A chart review was performed to identify the PACLR and revision ACL reconstruction (RACLR) cohorts. Demographic and surgical characteristics were recorded. Cases with concurrent lateral meniscal posterior root repair were identified. Cases were classified as acute (<5 months) or chronic (>5 months) based on the time from reported injury to surgery. Tunnel malposition in revision cases was recorded if either tunnel or both tunnels were malpositioned on radiographs and magnetic resonance imaging. RESULTS: Data from 167 cases, 140 PACLR and 27 RACLR cases, were included. The cohorts had similar demographic characteristics including age, sex, and lateral meniscal injury. The overall incidence of lateral meniscal root repair in ACL reconstruction patients was 12.6% (21 of 167 patients). The incidence of LMPRT repair was 7.1% (10 of 140 patients) in the PACLR cohort versus 40.7% (11 of 27 patients) in the RACLR cohort. The revision cohort was significantly more likely to have a chronic injury (66.7% [18 of 27 patients] vs 31.4% [44 of 140 patients]). The most significant predictor of concurrent lateral meniscal posterior root repair was RACLR versus PACLR for both univariate and multivariate logistic regression analyses (χ(2) = 20.603; P < .0001; odds ratio, 13.887; 95% confidence interval, 1.531-125.993). Analysis of tunnel positions for the revision group revealed that PACLR tunnel malposition was a significant predictor of LMPRTs (χ(2) = 4.91, P = .027). CONCLUSIONS: Complete LMPRTs warranting repair are encountered with a significantly greater frequency at RACLR as compared with PACLR. The overall incidence of LMPRT repair at RACLR is high. In this cohort, LMPRT repair in RACLR cases was associated with tunnel malposition of the PACLR. LEVEL OF EVIDENCE: Level III, retrospective cohort study.