Purpose: To compare patient-reported outcome 5-9 years after anterior cruciate ligament (ACL) reconstruction in patients with and without a concomitant full-thickness [International Cartilage Repair Society (ICRS) grade 3-4] cartilage lesion.
Methods: This is a prospective follow-up of a cohort of 89 patients that were identified in the Norwegian National Knee Ligament Registry and included in the current study in 2007, consisting of 30 primary ACL-reconstructed patients with a concomitant, isolated full-thickness cartilage lesion (ICRS grade 3 and 4) and 59 matched controls without cartilage lesions (ICRS grade 1-4). At a median follow-up of 6.3 years (range 4.9-9.1) after ACL reconstruction, 74 (84 %) patients completed the Knee Injury and Osteoarthritis Outcome Score (KOOS), which was used as the main outcome measure. Secondary outcomes included radiographic evaluation according to the Kellgren-Lawrence criteria of knee osteoarthritis (OA).
Results: At follow-up, 5-9 years after ACL reconstruction, no statistically significant differences in KOOS were detected between patients with a concomitant full-thickness cartilage lesion and patients without concomitant cartilage lesions. Radiographic knee OA of the affected knee, defined as Kellgren and Lawrence ≥2, was significantly more frequent in subjects without a concomitant cartilage lesion (p = 0.016).
Conclusion: ACL reconstruction performed in patients with an isolated concomitant full-thickness cartilage lesion restored patient-reported knee function to the same level as ACL reconstruction performed in patients without concomitant cartilage lesions, 5-9 years after surgery. This should be considered in the preoperative information given to patients with such combined injuries, in terms of the expected outcome after ACL reconstruction and in the counselling and decision-making on the subject of surgical treatment of the concomitant cartilage lesion.
Level of evidence: Prognostic; prospective cohort study, Level I.
Keywords: Anterior cruciate ligament; Cartilage lesion; KOOS; Outcome; Reconstruction.