Effect of Concomitant Cartilage Lesions on Patient-Reported Outcome After ACL-Reconstruction-A Nationwide Cohort Study from Norway and Sweden of 8470 Patients With 5-Year Follow-Up

OBJECTIVES: To evaluate (1) the effect of concomitant partial-thickness (International Cartilage Repair Society [ICRS] grades 1-2) and full-thickness (ICRS grades 3-4) cartilage lesions on patient-reported outcome 5 years after Anterior Cruciate Ligament Reconstruction (ACLR), and (2) the effect of debridement or microfracture (MF) compared with no treatment of concomitant full-thickness cartilage lesions on patient-reported outcome 5 years after ACLR. METHODS: All patients that underwent unilateral primary ACLR registered in the Norwegian and Swedish National Knee Ligament Registries from 2005 through 2008 (n = 15,783) were included the study. At the 5-year follow-up, 8470 (54%) patients completed The Knee Injury and Osteoarthritis Outcome Score (KOOS). A subgroup of all patients with concomitant full-thickness cartilage lesions (n = 644), treated with debridement (n = 129), or MF (n = 164), or no surgical treatment (n = 351) at the time of ACLR, was included in the treatment component of the study. At the 5-year follow-up, 368 (57%) patients completed the KOOS. Linear regression models were used to estimate the effect of concomitant focal cartilage lesions on the patient-reported outcome (KOOS) 5 years after ACLR, and to estimate the effect of surgical debridement or MF of concomitant full-thickness cartilage lesions, on patient-reported outcome 5 years after ACLR. RESULTS: Of the 8470 patients available for follow-up at 5 years, 2248 (27%) had 1 or more concomitant cartilage lesions at the time of ACLR, comprised of 1685 (20%) patients with 1 or more partial-thickness cartilage lesions and 563 (7%) patients with 1 or more full-thickness cartilage lesions. Of the 368 patients available for the 5-year follow-up in the treatment component of the study, 203 (55%) patients received no surgical treatment to their full-thickness cartilage lesion at the time of ACLR, 70 (19%) were treated with debridement and 95 (26%) with MF. In the adjusted analyses, partial-thickness cartilage lesions showed significant associations with inferior KOOS scores at follow-up in all subscales. Full-thickness cartilage lesions were significantly associated with inferior KOOS scores in all subscales, both in the unadjusted and the adjusted analyses. With no treatment of the concomitant cartilage lesion as the reference, no significant effects of debridement or MF were detected in the unadjusted or adjusted regression analyses in any of the KOOS subscales at the 5-year follow-up. However, there was a trend in both the unadjusted and adjusted analyses towards negative effects of MF in the KOOS subscales Sport/Rec and QoL with regression coefficient (β) of -5; 95% CI, -12.3-2.2 and -5.7; 95% CI, -12.5-1.1, respectively. CONCLUSION: ACL-injured patients with concomitant full-thickness cartilage lesions reported worse outcomes and less improvement than those without cartilage lesions 5 years after ACLR. Compared to leaving concomitant full-thickness cartilage lesions untreated at the time of ACLR, debridement and MF showed no effect on patient-reported outcome at 5-year follow-up.