Abstract
BACKGROUND: Failed anterior cruciate ligament (ACL) reconstruction (ACLR) can lead to reduced quality of life because of recurrent episodes of instability, restrictions in level of activity, and development of osteoarthritis. A profound knowledge of the causes of a failed surgery can ultimately help improve graft survival rates. PURPOSE: To investigate the patient-related risks of inferior outcomes leading to revision surgery after ACLR. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: From a prospective cohort of primary ACLRs performed at a single center, patients who required later revision surgery were matched with a control group of uneventful primary ACLRs. Patient characteristics, data from the preoperative examinations, KT-1000 arthrometer laxity testing, Tegner activity scale, International Knee Documentation Committee subjective score, Knee injury and Osteoarthritis Outcome Score, and perioperative data from the initial surgery were included. RESULTS: A total of 100 revision cases and 100 matched controls, with a median follow-up time of 11 years, were included in the study. Those who had undergone revision surgery were younger at the time of reconstruction and had a shorter time from injury to surgery than their matched controls (P = .006). The control group-of uneventful ACLRs-had a higher incidence of meniscal repair at reconstruction (P = .024). Also, the revision group more frequently experienced later failure of the previous meniscal repair (P = .004). Surgeon experience was not found to affect the risk of revision ACL surgery. Those who had undergone ACL revision surgery had more frequently received a hamstring tendon graft size of <8 mm (P = .018) compared with the controls. CONCLUSION: The current study demonstrated that failed meniscal repair and a hamstring tendon graft size of <8 mm were associated with primary ACLR failure. Also, younger age at the time of surgery and shorter time from injury to surgery were found to affect the risk of undergoing revision ACL surgery.