Delayed Anterior Cruciate Ligament Reconstruction Increases the Risk of Abnormal Pre-Reconstruction Laxity, Cartilage and Medial Meniscus Injuries.

PURPOSE To determine the association between a delay in anterior cruciate ligament reconstruction (ACLR), age, gender, body mass index (BMI) and cartilage injuries, meniscus injuries, meniscus repair, and abnormal pre-reconstruction laxity. METHODS Patients who underwent primary ACLR at our institution from January 2005 to March 2017, with no associated ligament injuries, were identified. Logistic regression analyses were used to evaluate whether delay in ACLR, age, gender and BMI were risk factors for cartilage and meniscus injuries, meniscus repair, and abnormal (side-to-side difference > 5 mm) pre-reconstruction laxity. RESULTS A total of 3,976 patients (mean age 28.6 ± 10.6 years, range 10-61 years) were included. The risk of cartilage injury increased with a delay in ACLR (12-24 months: odds ratio [OR], 1.20; 95% confidence intervals [CI],1.05-1.29; P=.005; and > 24 months: OR,1.20; 95% CI, 1.11-1.30; P 24 months: OR,1.22; 95% CI, 1.13-1.30; P 3 months and age ≥ 30 years (OR, 0.75; 95% CI, 0.66-0.85; P 24 months: OR, 0.61; 95% CI, 0.52-0.72; P 6 months and MM injury (OR, 1.52; 95% CI, 1.16-1.97; P=.002), whereas it decreased with a BMI of ≥ 25 kg/m2 (OR, 0.68; 95% CI, 0.52-0.89; P=.006). CONCLUSIONS A delay in ACLR of > 12 months increased the risk of cartilage and MM injuries, while a delay of > 6 months increased the risk of abnormal pre-reconstruction laxity and reduced the likelihood of MM repair. To reduce meniscus loss and the risk of jeopardizing knee laxity, ACLR should be performed within 6 months after the injury. LEVEL OF EVIDENCE Level III, retrospective therapeutic comparative study.