Five-Year Functional Outcomes and Gait Analysis Following Anterior Cruciate Ligament Reconstruction with Peroneus Longus Tendon Autograft

The peroneus longus tendon (PLT) is an increasingly used autograft for anterior cruciate ligament reconstruction (ACLR). Several studies have reported donor site morbidity, gait, muscle strength, and long-term safety. This study provides additional 5-year outcome data, including pedorthist-led gait and foot posture assessment. This study aimed to evaluate 5-year gait symmetry, foot posture, and patient-reported outcomes following ACLR using a PLT autograft. Seventeen patients underwent assessment 5 years after ACLR with PLT autograft. Pedorthist-led gait analysis using pressure-mapping technology measured stance time, midfoot force, center-of-pressure (COP) excursion, and gait force differential. Foot posture was classified as planus, cavus, or neutral. Patient-reported outcomes included the Foot and Ankle Disability Index (FADI) and Tegner Activity Scale. The pedorthist, blinded to the operative side, attempted to identify the reconstructed limb. Statistical analysis used paired <i>t</i>-tests, Spearman correlation, and chi-square testing. At 5 years, no significant differences were detected in stance time, midfoot force, or COP excursion between operated and non-operated limbs. Gait force differentials were similar (<i>p</i> = 0.75). Foot posture was not associated with the operated side (<i>p</i> = 0.183), and FADI scores did not differ by foot type. The pedorthist correctly identified the operative limb in 23.5% of cases. PLT harvest was not associated with detectable differences in gait symmetry or arch morphology at 5 years. Findings are consistent with a favorable biomechanical profile; however, the small sample size, lack of preoperative baseline data, and the absence of a control group limit the strength of these inferences. Larger, controlled studies are needed to confirm long-term safety. The level of evidence was IV-retrospective case series with prospective biomechanical follow-up.