Comparison of Clinical and Functional Outcomes in Anterior Cruciate Ligament Reconstruction Using Peroneus Longus Tendon Versus Hamstring Tendon Autograft: A Prospective Comparative Study.

Background Anterior cruciate ligament (ACL) reconstruction is among the most commonly performed knee procedures worldwide. Hamstring tendon autografts remain a popular graft choice but are associated with donor-site morbidity and postoperative thigh muscle weakness. The peroneus longus tendon has recently emerged as a promising alternative due to its favorable biomechanical strength and reportedly low ankle morbidity. However, detailed evidence comparing early functional recovery between these two graft options remains limited. Objective This study aims to compare the clinical and functional outcomes of ACL reconstruction using the peroneus longus tendon autograft versus the hamstring tendon autograft over a 6-month postoperative period. Materials and methods This prospective comparative study was conducted at a tertiary care center in India and included 50 patients with isolated ACL tears requiring primary single-bundle arthroscopic reconstruction. Participants were divided into two groups: Group A (peroneus longus autograft, n=25) and Group B (hamstring autograft, n=25) based on shared decision-making. Outcome measures included International Knee Documentation Committee (IKDC) scores, Lysholm scores, American Orthopaedic Foot and Ankle Society (AOFAS) scores, thigh circumference, ankle range of motion, and clinical knee stability tests. Assessments were performed preoperatively and at 1, 2, 3, and 6 months postoperatively. Statistical analyses utilized independent t-tests, paired t-tests, and chi-square tests or Fisher's exact test with significance set at p<0.05. Results All 50 participants completed the 6-month follow-up. Both groups demonstrated excellent and comparable functional outcomes at 6 months, with significant improvements in IKDC and Lysholm scores, and knee stability outcomes showed grade 0 in ≥92% (≥46/50) of participants. The peroneus longus grafts showed a 14.7% greater mean diameter (8.94 mm vs. 7.79 mm; p<0.001). Thigh muscle preservation was significantly better in Group A, with 45.1% less thigh atrophy at 6 months (p<0.0001). AOFAS scores and ankle mobility were preserved equally in both groups at 6 months, and no graft failures occurred. One patient experienced mild knee stiffness, but no major complications were observed. Conclusion Peroneus longus autograft provides functional outcomes equivalent to hamstring autograft while offering a larger graft diameter and significantly better thigh muscle preservation, without compromising ankle function. These findings support its use as a safe and effective alternative, particularly advantageous for athletes or high-demand patients and in patients concerned about postoperative hamstring weakness.