This study aimed to identify whether a delay of greater than three months between reinjury and subsequent revision anterior cruciate ligament reconstruction (ACLR) influences outcomes.
A retrospective chart review was conducted to identify patients who underwent revision ACLR at an academic institution between 2004 and 2018. The following information was collected: age at surgery; gender; body mass index (BMI); date of first ACL reinjury; date of first revision ACLR; graft utilized; patient-reported outcomes (Knee Injury and Osteoarthritis Outcome Scores [KOOS] and Marx activity scores); Outerbridge cartilage grades at time of first revision ACLR; concomitant meniscus injuries at time of first revision ACLR; revision ACLR graft tears; and time to follow-up. Patients who underwent revision ACLR within three months of documented reinjury were defined as the Early Revision Group, and patients who underwent revision ACLR at least three months after reinjuring their knee and patients with chronic ACL deficiencies were defined as the Late Revision Group. Intra-operative findings (cartilage and meniscus status), subsequent graft failure risk, and patient-reported outcomes were compared between the groups.
A total of 62 patients met inclusion criteria. Patients in the Late Revision Group were more likely to have Outerbridge cartilage grades of 2-4 in the patella (p = 0.005), trochlea (p < 0.001), medial tibial plateau (p = 0.038), lateral femoral condyle (p = 0.049), and lateral tibial plateau (p = 0.005). No significant differences in medial meniscus injury (70.7% vs 52.4%, p=0.081) or lateral meniscus injury (53.7% vs 76.2%, p=0.051) were noted. No significant differences were noted in KOOS Pain (89.4 vs. 83.8, p=0.12), Symptom (81.3 vs. 79.5, p=0.66), ADL (93.6 vs. 89.5, p=0.23), Sports/Rec (76.1 vs 67.6, p=0.22), QOL (60.1 vs. 57.2, p=0.66), and Marx Activity Score (6.7 vs 5.1, p=0.20) between the groups. Similar re-injury risk was noted in the Early (12.2%) and Late (9.5%) Revision Groups (p=0.32).
Patients who undergo revision ACLR more than three months after graft tear demonstrate more severe articular cartilage damage in the patella, trochlea, medial tibial plateau, lateral femoral condyle, and lateral tibial plateau than those who undergo reconstruction within three months of re-injury. Further work with larger numbers is required to evaluate the impact of these findings on outcomes following revision ACL surgery.