Anterior cruciate ligament revision risk is associated with mismatch between hamstring graft size and body size in football players

PURPOSE: To evaluate the association between hamstring autograft diameter and the risk of revision anterior cruciate ligament reconstruction (ACLR) in football players, and to determine whether this relationship differs according to sex and height. METHODS: A nationwide registry-linked cohort was assembled by combining the Swedish Knee Ligament Registry and the Swedish Football Association's competition database. Football players undergoing primary index ACLR with hamstring autograft between 2014 and 2023 were eligible. Graft diameter was categorised ≤7.5, 8.0, 8.5, ≥9.0 mm with ≥9.0 mm as the reference group. Estimated adjusted hazard ratios (HRs) for revision were calculated with Cox models, stratified by sex and predefined height groups, a secondary analysis restricted to players who returned to official match play (RTC) were also performed. RESULTS: A total of 9448 players were included, 6127 (65%) men. During follow-up, 771 revision ACLR occurred (8.2%). Crude revision risk decreased stepwise with increasing graft diameter: 10.4% for ≤7.5 mm, 9.5% for 8.0 mm, 8.5% for 8.5 mm, and 6.2% for ≥9.0 mm. Among men, diameter-related risk differences were concentrated in taller players. In those 176-184 cm, grafts ≤7.5 mm showed a 2.27-fold higher adjusted hazard of revision (95% confidence interval [CI], 1.30-3.94) compared with ≥9.0 mm. In players ≥185 cm, hazards were elevated for both ≤7.5 mm (HR 2.86, 95% CI 1.19-6.85) and 8.0 mm grafts (HR 1.98, 95% CI 1.14-3.42). No significant graft-diameter effect was identified in men ≤175 cm, nor in any height stratum among women. Findings were consistent in the subgroup restricted to players who returned to official competition. CONCLUSION: Smaller hamstring autografts are associated with increased revision ACLR risk in tall male football players, whereas no clear graft-diameter effect is observed in women or shorter men. These findings suggest that graft diameter may be best interpreted in relation to patient height rather than applied as a universal threshold. LEVEL OF EVIDENCE: Level III, retrospective cohort study.