Degeneration of the knee joint in skeletally immature patients with a diagnosis of an anterior cruciate ligament tear: is there harm in delay of treatment?

BACKGROUND: In skeletally immature patients with an anterior cruciate ligament (ACL) tear and significant growth remaining, the risk of inducing a growth disturbance with early reconstruction must be balanced against the risk of further intra-articular damage by delaying treatment until closer to skeletal maturity.

HYPOTHESIS: Increased time from injury to ACL reconstruction in children ≤14 years of age will be associated with increased meniscal and chondral injuries at the time of reconstruction.

STUDY DESIGN: Cohort study; Level of evidence, 3.

METHODS: With institutional review board approval, the records of a consecutive series of patients 14 years of age and younger who underwent ACL reconstruction between 1991 and 2005 were reviewed. Demographic, magnetic resonance imaging (MRI), and intraoperative findings were analyzed. Meniscal and articular cartilage injuries were graded. Logistic regression models using both univariable and multivariable regression procedures were used to identify factors independently associated with intra-articular lesions. Fisher exact test and Kaplan-Meier analysis were used to test for differences in intra-articular injuries by time from injury to surgery.

RESULTS: Seventy patients were identified. Twenty-nine patients (41%) underwent reconstruction more than 12 weeks from the time of injury. Logistic regression analysis revealed time to surgical reconstruction (odds ratio, 4.1) and a history of a sense of knee instability (odds ratio, 11.4) to be independently associated with medial meniscal tears. Time to surgical reconstruction was also independently associated with medial and lateral compartment chondral injuries (odds ratios, 5.6 and 11.3, respectively). Testing time as a continuous variable, survivorship analysis also confirmed a significant association of time to reconstruction with medial meniscal injury as well as lateral and patellotrochlear cartilage injuries. When present, a delay in treatment of over 12 weeks (29 patients) was associated with an increase in the severity of medial meniscal tears (P = .011) and higher grade lateral and patellotrochlear chondral injuries (P = .0014 and P = .038, respectively).

CONCLUSION: Young patients who underwent surgical reconstruction of an acute ACL tear >12 weeks after the injury were noted to have a significant increase in irreparable medial meniscal tears and lateral compartment chondral injuries at the time of reconstruction. When a subjective sense of knee instability was present, this association was even stronger.