Femoral tunnel length does not impact outcomes following ACL reconstruction using a single‐bundle quadriceps tendon autograft: A systematic review

PURPOSE: To determine whether femoral tunnel length (FTL) affects clinical or functional outcomes following primary Anterior cruciate ligament reconstruction (ACLR) with single-bundle quadriceps tendon autograft, both with and without a patellar bone block. METHODS: An electronic search of MEDLINE, EMBASE, and Cochrane databases was carried out via OVID. Data pertaining to study characteristics, patient demographics, surgical techniques, femoral tunnel length, and subjective/objective clinical outcomes was abstracted. Studies were stratified into two groups based on FTL; a short femoral tunnel (S-FT) group of ≤25 mm, and a long femoral tunnel (L-FT) group of >25 mm. There was a high degree of heterogeneity between studies, prohibiting meta-analysis. RESULTS: Seven studies comprising 368 total patients with a mean age of 30.3 years (range: 23.4-34 years) were included for analysis. The S-FT group included 126 patients and the L-FT group 242 patients. Both groups demonstrated statistically significant postoperative improvements across both subjective and objective clinical and functional outcomes. Average complication rates were 11.9% (range: 0%-29%) in the S-FT group and 4.5% (range: 1%-14%) in the L-FT group. Ranges of re-rupture rates were 0%-2% and 0%-3% for the S-FT and L-FT groups, respectively (n.s.). CONCLUSION: Both S-FT and L-FT groups demonstrated comparable postoperative outcomes following primary ACLR with single bundle quadriceps tendon autograft. There were slightly superior, although non-significant, outcomes reported with short femoral tunnel length, however, this may have been confounded by the variation in surgical technique used. LEVEL OF EVIDENCE: Level IV.