Limited correlation between clinical failure and MRI graft status in the setting of revision anterior cruciate ligament reconstruction

PURPOSE: To investigate whether clinically failed anterior cruciate ligament (ACL) reconstructions can be accurately identified using magnetic resonance imaging (MRI). METHODS: This prospective case series included 81 patients (mean age 33.5 ± 11.9 years, 50.6% male) with clinically failed ACL reconstructions defined by Lachman ≥ Grade 2, Pivot-shift ≥ Grade 2 and/or anterior tibial translation side-to-side difference (ATT SSD) > 5 mm measured using a Rolimeter (Aircast®). MRI graft status was assessed using the anterior cruciate ligament Osteoarthritis Score (ACLOAS) and categorized into: Status 0/1 (regular/hyperintense), Status 2 (thinned/elongated) and Status 3 (ruptured). Secondary measures comprised MRI meniscus and cartilage status, alongside baseline clinical and functional assessments, including the International Knee Documentation Committee (IKDC), Lysholm and Tegner score. RESULTS: Graft status was classified as Status 3 (ruptured) in 51 (63.0%) cases, while 30 (37.0%) were intact (18 [22.2%] Status 0/1; 12 [14.8%] Status 2). Meniscus and cartilage were unremarkable in 30 (37.0%) and 31 (38.3%) cases, respectively, without significant correlation to graft status (p = 0.135 and p = 0.846). Mean ATT SSD was 6.6 ± 1.6 mm without significant group differences (p = 0.163). Lachman Grade 2+ predominated in Status 0/1 (14 [77.8%]), whereas Lachman Grade 3+ was more frequent in Status 2 (9 [75.0%]) and Status 3 (28 [54.9%]). Status 2 grafts showed a significant excess of Lachman Grade 3+ over Grade 2+ (p = 0.011). Grade 2 pivot-shift was found in majority of cases (highest in Status 0/1 with 12 [66.7%]), while Status 2 showed the highest proportion of Grade 3 instability (4 [44.4%]). Between-group differences were not statistically significant (p = 0.185). Tegner was significantly lower in Status 3 (p = 0.014), while IKDC (44.5 ± 15.9, p = 0.786) and Lysholm (52.2 ± 21.2, p = 0.547) showed no significant group differences. CONCLUSIONS: Clinical failure following ACL reconstruction correlates only in 63.0% of cases with MRI-based graft status. The findings indicate that clinical assessment should guide diagnosis, while MRI remains most valuable for identifying associated intra-articular lesions. LEVEL OF EVIDENCE: Level IV, prospective case series design.