Significant Increase in the Rate of Meniscal and Chondral Injuries Between Primary and Revision Anterior Cruciate Ligament Reconstruction. (188)

OBJECTIVES: Anterior cruciate ligament (ACL) injuries are often associated with meniscal and chondral lesions. Meniscal lesions are present in up to 50% of ACL injured knees, and chondral lesions occur with an incidence of 20% to 40% in acute ACL-injured knees. The major importance of this lies in the fact that menisectomy and severe chondral damage are important predictors of poor outcomes including the subsequent development of knee osteoarthritis. Furthermore, patient reported outcomes following revision ACL reconstruction remain inferior to primary ACL reconstruction and this may, at least in part, be due to an increased incidence and severity of meniscal and chondral injuries. Although multiple studies have demonstrated that meniscal and chondral lesions are generally present at a higher rate at the time of revision ACL reconstruction when compared to primary ACL reconstruction, large studies following individual patients through primary and revision ACL reconstruction and tracking the change in the occurence of these injuries are scarce. The primary objective of this study was to determine the proportion of patients with meniscal and chondral injuries at the time of primary ACL reconstruction and determine how this rate changed by the time they underwent revision ACL reconstruction. The hypothesis was that the proportion of patients with meniscal and/or chondral lesions would be significantly greater at revision ACL reconstruction when compared to the primary procedures. METHODS: Consecutive patients who underwent primary and then revision ACL reconstruction between March 1999 and February 2018 were identified using a single center registry. Patient characteristics, and intraoperative data from each procedure were collected and analyzed. This specifically included the occurrence and type of meniscal and chondral pathology. Descriptive statistics were used to evaluate the study sample using medians, descriptive data analysis was conducted depending on the nature of the criteria. Comparison between variables were assessed with student’s t test for quantitative variables and Mcnemar test for categorical variables. Statistical significance was set a t p<0.05. RESULTS: 213 consecutive patients underwent both primary ACL reconstruction and then revision surgery during the study period. The average time from primary ACLR to Revision was 46.8 ± 36.6 months (range 5-181).The mean age of patients at primary ACLR was 22.21±7.21 years. The mean age of patients at revision ACLR 26.1 ± 8.3 years. The mean IKDC for the entire population was 85.53 ± 11.59, The mean ACL-RSI score was 71.89 ± 23.95. The mean Lysholm score was 91.77±10.24. The proportion of patients with chondral lesions significantly increased from 7% at primary ACL to 15.5% at revision ACL (p < 0.05). Meniscal lesions also significantly increased from 44.6 % at primary ACLR to 70% at revision ACLR (p < 0.05). There was no significant difference in the rate of lateral meniscal lesions (11.7 vs 13.1, p > 0.05). However, the proportion of patients with a medial meniscus lesion (25.4 vs 36.2, p < 0.05) and bimeniscal lesions (7.5 vs 20.7, p < 0.05) increased significantly at revision ACL reconstruction. CONCLUSIONS: The proportion of patients with meniscal and//or chondral injuries at the time of revision ACL reconstruction is significantly higher than at the time of primary ACL reconstruction. Specifically, the rate of medial meniscus and bimeniscal injuries is significantly higher in patients undergoing revision ACL reconstruction