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.