Timing of anterior cruciate ligament reconstructive surgery and risk of cartilage lesions and meniscal tears: a cohort study based on the Norwegian National Knee Ligament Registry.

BACKGROUND There is inadequate evidence to determine when to perform surgery on anterior cruciate ligament-deficient knees. PURPOSE To study the association between timing of anterior cruciate ligament reconstruction and the risk of having meniscal tears and cartilage lesions. STUDY DESIGN Cohort study (prognosis); Level of evidence, 2. METHODS All patients registered in the Norwegian National Knee Ligament Registry who had undergone primary anterior cruciate ligament reconstruction from 2004 and throughout 2006 were reviewed. Logistic regression analyses were used to estimate the relationship between time from injury until anterior cruciate ligament surgery and the risk of meniscal tears or cartilage lesions. RESULTS Of a total of 3475 patients, there were 909 patients (26%) with cartilage lesions, 1638 patients (47%) with meniscal tears, and 527 patients (15%) with both cartilage and meniscal lesions. The odds of a cartilage lesion in the adult knee (>16 years) increased by 1.006 (95% confidence interval, 1.003-1.010) for each month that elapsed from injury to surgery. The cartilage in young adults (17-40 years) deteriorated further with an increase in odds of 1.03 (95% confidence interval, 1.02-1.05) related to the aging in years of the patient. The odds for meniscal tears in young adults increased by 1.004 (95% confidence interval, 1.002-1.006) for each month that elapsed since injury. The presence of 1 degenerative lesion increased the odds of having the other degenerative lesion by between 1.6 and 2.0 in all patient groups. CONCLUSION The odds of a cartilage lesion in the adult knee increased by nearly 1% for each month that elapsed from the injury date until the surgery date and that of cartilage lesions were nearly twice as frequent if there was a meniscal tear, and vice versa.