Background: Anterior cruciate ligament (ACL) tears are commonly associated with meniscal and chondral injuries. Although lateral meniscal tears are commonly associated with acute ACL injuries, the chronically ACL-deficient knee is associated with an increased rate of medial meniscal injury. These associations have been described in the adult knee literature.
Purpose: To evaluate the relationship of elapsed time from injury with the incidence of meniscal and chondral injuries noted at the time of surgical treatment for ACL tears in pediatric patients. The effect of age, gender, weight, and mechanism of injury was also evaluated.
Study design: Cross-sectional study; Level of evidence, 3.
Methods: A retrospective chart review of pediatric patients undergoing primary arthroscopic ACL reconstruction between January 2005 and January 2011 was performed. The presence of meniscal tear, chondral injury, number of days from injury to treatment, age, weight, gender, and mechanism of injury were recorded. The data were analyzed for associations between elapsed time before surgery as well as patient-specific factors with rates of meniscal and chondral injuries.
Results: Three hundred seventy pediatric patients who underwent primary ACL reconstruction were included. Two hundred forty-one were treated ≤150 days (early) from injury, and 129 were treated >150 days (delayed) from injury. Ninety-one (37.8%) patients in the early treatment group and 69 (53.5%) patients in the delayed treatment group had medial meniscal tears (MMTs) (P = .014; odds ratio [OR], 1.8; 95% confidence interval [CI], 1.12-2.83). Lateral meniscal tear (LMT) rates were similar (56.0% and 57.4%) in each group. Age >15 years also influenced the presence of MMTs (P = .033; OR, 1.6; CI, 1.04-2.54). Increased patient weight was associated with an increased rate of MMTs and LMTs. Fifty-four of 170 (31.8%) patients weighing ≤65 kg and 106 of 200 (53%) weighing >65 kg had MMTs (P < .001; OR, 2.2; CI, 1.36-3.42). Eighty-two of 170 (48.2%) patients weighing ≤65 kg and 127 of 200 (63.5%) weighing >65 kg had LMTs (P < .018; OR, 1.7; CI, 1.10-2.68). The presence of chondral injury was significantly associated with the presence of meniscal tear in the same compartment of the knee.
Conclusion: Pediatric patients treated >150 days after injury for ACL tears have a higher rate of MMT than those treated ≤150 days after injury. Increased age and weight are independently associated with a higher rate of MMT. Patients with ACL tears and an MMT or LMT are more likely to have a chondral injury in that particular compartment than those without meniscal tears.