Abstract
BACKGROUND: Failure after anterior cruciate ligament (ACL) reconstruction occurs in 3% to 30% of all patients. However, not all failures necessitate a revision surgery. Revision ACL reconstruction (ACLR) presents significant challenges for both the surgeon and the patient, and limited research has been conducted regarding long-term functional outcomes and the potential increased risk of osteoarthritis (OA). PURPOSE/HYPOTHESIS: This study evaluates the long-term radiographic and clinical outcomes after revision ACLR compared with those of primary ACLR. It was hypothesized that revision ACLR results in a higher incidence of OA and inferior functional and patient-reported outcomes. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A retrospective follow-up compared patients with revision ACLR to a matched group of primary reconstruction (matched by sex, age, and surgery date). After a median of 9.7 years, OA was assessed using the Kellgren-Lawrence (K-L) classification.Clinical outcome assessment included Patient-Reported Outcome Measures and knee laxity testing. RESULTS: A total of 273 patients were included, 140 ACL revisions and 133 primary ACLRs. Radiographic evidence of OA (K-L grade ≥2) was present in 67% of the revision group versus 33% in the primary ACL group (P < .001). A longer time from injury to follow-up, meniscal injury, and a high body mass index (BMI) at the index surgery independently increased the odds of developing OA. Although significant improvements in knee laxity measurement were seen in both groups, these were greater in the primary reconstruction group. Improvements well above the minimal important clinical change were observed for both the International Knee Documentation Committee subjective score and the Knee Injury and Osteoarthritis Outcome scores in both groups, with a higher proportion of patients meeting the patient-acceptable symptom state in the primary group. CONCLUSION: Patients undergoing revision ACLR exhibit worse long-term functional outcomes and a higher prevalence of OA compared with patients undergoing primary ACLR. A longer time from injury to follow-up, meniscal injury, and a high BMI at the index surgery independently increased the odds of developing OA. Despite the inferior results, patients undergoing revision reconstruction experience significant improvements in both subjective scores and clinical findings, and report a high level of satisfaction.