Timing of anterior cruciate ligament reconstruction and its effect on associated chondral damage and meniscal injury: a prospective observational study

Background: Following an anterior cruciate ligament (ACL) tear, associated injuries in the knee involving menisci and articular cartilage increase with time. This study was performed to assess the distribution of secondary injuries after an ACL tear with time and identify a suitable timing for the reconstruction surgery. Methods: 74 patients with an ACL tear were divided into three groups based on time since injury- less than six months, six months to one year, and greater than one year. The odds of finding each lesion in every group were calculated and tested for statistical significance. Receiver operating characteristic curves (ROC) were drawn to predict individual lesions with time since injury. The diagnostic performance and statistical significance of these tests were identified. Results: The odds of finding all lesions were greater than one after a year of ACL tear but only chondral damage was statistically significant (p=0.025). Poor diagnostic accuracy was observed for medial meniscal injury even after three years of an ACL tear. Chondral injury showed a good area under the curve (0.817) which predicted chondral damage with a sensitivity of 62% at a cut-off of three years after the ACL injury. Conclusions: After three years of ACL tear, meniscal injuries could not be accurately predicted. However, a significant rise in chondral injuries could be seen and predicted accurately with good sensitivity. There could be a role of MRI or arthroscopy to assess the extent of injury of articular cartilage in patients who do not undergo ACL reconstruction after this time.