Quadriceps Tendon Graft Leads to Stronger Flexion and Weaker Extension of the Knee Than Hamstring Graft Post-ACLR: study

The optimal autograft for restoring knee strength and expediting return-to-sport following anterior cruciate ligament reconstruction (ACLR) remains debated. Brandon A. Young et al conducted a systematic review and meta-analysis comparing isokinetic strength and patient-reported outcomes after ACLR using quadriceps tendon (QT), hamstring tendon (HT), or bone–patellar tendon–bone (BTB) autografts to determine graft-specific recovery patterns.

PubMed, Cochrane Library, EMBASE, and Google Scholar were systematically searched for comparative studies evaluating isokinetic strength following primary ACLR using QT, HT, or BTB autografts. Non-English, unavailable fulltext, animal/cadaveric, and physeal-sparing studies were excluded. MINORS and Detsky evaluated bias risk. Key findings were quantified, and subgroup meta-analyses were performed on limb symmetry index (LSI) values (significance: p < 0.05).

The key findings of the study were:

• Seventeen studies (1,705 patients: QT = 765, HT = 725, BTB = 215) with follow-ups through 48 months were included. Due to data heterogeneity, four to six studies qualified for each meta-analysis.

• Among 13 QT vs. HT studies, QT grafts demonstrated weaker extensor strength in nine (56.3%) and greater flexor strength in six (37.5%).

• No differences were reported in extensor or flexor strength in four (25.0%) and seven (43.8%) studies, respectively.

• For QT vs. BTB, two studies (12.5%) showed similar extensor strength, whereas two reported conflicting results.

• QT had greater flexor strength in one (6.3%) and similar strength in three (18.8%) studies.

• Postoperative pain was comparable between QT and HT.

The authors concluded – “Our data supports our hypothesis that ACLR using QT grafts results in greater extensor strength deficits than HT grafts in the first 12 postoperative months. In addition, QT grafts led to similar or better flexor strength results than HT between 4 and 24 months postoperatively, and lower anterior knee pain than BTB. Rehabilitation targeting early strength deficits following QT and HT grafting may decrease the time of return-to-sport. Further research is needed to evaluate postoperative isokinetic strength differences between QT and BTB graft types, as current comparisons are based on limited and inconsistent evidence.”

Level of evidence: IV.

Further reading:

Quadriceps Tendon Graft Leads to Stronger Flexion and Weaker Extension of the Knee Than Hamstring Graft Post-ACLR: Systematic Review and Meta-Analysis

Brandon A. Young et al

Indian Journal of Orthopaedics (2025) 59:2026–2038

https://doi.org/10.1007/s43465-025-01545-9