Intercondylar notch width index and graft failure after ACL reconstruction: A retrospective cohort study

Graft failure following anterior cruciate ligament reconstruction (ACL-R) is a significant complication. A smaller Notch Width Index (NWI) has been proposed as a potential risk factor, although there is conflicting evidence regarding smaller notch morphology and the risk of graft failure. This study aimed to determine whether NWI is associated with graft failure following ACL-R and to identify additional risk factors of graft failure.

A retrospective review of 452 patients undergoing primary ACL-R between 2012 and 2024 was performed. NWI was measured on preoperative coronal MRI with interobserver reliability assessed using intraclass correlation coefficients (ICC). Graft failure was defined as revision ACL-R. Univariate and multivariable analyses were performed to identify factors associated with failure.

Interobserver reliability for NWI measurement was high (ICC = 0.865). 19 graft failures (4.2%) were identified. NWI was not associated with graft failure (p = 0.237). Sex (p = 0.483) and graft type (p = 0.536) were also not associated. Younger age (p = 0.008) and smaller tibial graft diameter (p = 0.049) were associated with failure. Multivariable analysis identified younger age (OR 0.91, 95% CI 0.84-1.00) and smaller graft diameter (OR 0.48, 95% CI 0.23-1.00) as independently associated factors. No failures occurred in patients undergoing concomitant lateral extra-articular tenodesis (n = 18).

In this study, NWI was not significantly associated with graft failure following ACL-R. Younger age and smaller graft diameter were identified as independently associated factors. Adequately sized grafts should be considered alongside adjunctive procedures, such as LEAT, in selected, high-risk patients.