Quadriceps versus Hamstring Tendon Autografts for Anterior Cruciate Ligament Reconstruction: A Systematic Review of Clinical Outcomes and Complications

Abstract: Background: Anterior cruciate ligament (ACL) reconstruction frequently utilizes autografts harvested from either the patient’s quadriceps tendon (QT) or hamstring tendons (HT). While both graft sources reliably restore knee stability, debate persists regarding differences in donor‐site morbidity, functional recovery trajectories, and long‐term graft survival. Aim: To systematically compare clinical outcomes, donor‐site complications, muscle‐strength recovery, and graft‐failure rates of QT versus HT autografts in primary ACL reconstruction, integrating data from eight comparative studies and contextualizing findings with high‐level evidence. Methods: Following PRISMA 2020 guidelines, we searched PubMed, Scopus, Web of Science, Embase, and the Cochrane Library using combinations of “quadriceps tendon,” “hamstring tendon,” “ACL reconstruction,” “autograft,” “clinical outcomes,” and “complications.” Inclusion criteria were prospective or retrospective cohort studies and randomized controlled trials directly comparing QT and HT autografts. We excluded meta‐analyses, systematic reviews, biomechanical models, and cadaveric investigations. Extracted outcomes included graft‐failure rates, objective stability measures, patient‐reported functional scores, muscle‐strength metrics, donor‐site pain, and complications. Risk of bias was assessed via Cochrane RoB 2 for RCTs and the Newcastle–Ottawa Scale for cohort studies. Results: eight comparative studies (n = 846 patients; QT = 416; HT = 430) with a mean follow‐up of 24–60 months were analyzed (Table 1, Appendix). Graft‐failure rates ranged from 3.1% to 5.2% with no significant intergroup differences. Lachman and pivot‑shift negativity exceeded 90% in both cohorts, and KT‑1000 side‑to‑side differences averaged <2 mm. Functional scores at final follow‑up were high (Lysholm ≥ 90, IKDC ≥ 85, Tegner ≥ 6) without significant graft‐type effects. QT harvest yielded lower anterior‐knee pain (VAS 1.2 ± 0.5 vs. 2.3 ± 0.8; p < 0.01) and similar quadriceps strength recovery by one year, whereas HT harvest caused early hamstring deficits (~15% at six months) that normalized by 12 months. Overall, the rates of revision and complications were similar and modest (QT 4.1% vs. HT 4.5%; p = 0.84). Conclusion: QT and HT autografts achieve equivalent graft integrity, knee stability, and functional recovery in ACL reconstruction. QT offers the added benefit of reduced donor‐site pain with no increase in complication rates. Graft selection should consider individual patient anatomy, activity demands, and surgeon expertise. Large, multicenter RCTs with standardized protocols and long-term follow-up are needed to refine graft‐choice recommendations. Keywords: anterior cruciate ligament; quadriceps tendon; hamstring tendon; autograft; clinical outcomes; donor‐site morbidity; systematic review.