Endoscopic Peroneus Longus Transfer for Chronic Achilles Tendon Rupture: A Novel Surgical Technique

Background Chronic Achilles tendon rupture (CATR) is a debilitating condition affecting activities such as walking and jumping. Surgical reconstruction remains preferred for larger defects, with local tendon transfers including the flexor hallucis longus (FHL) and peroneus brevis (PB). However, these techniques carry risks of donor-site morbidity and neurovascular injury, particularly in high-risk patients. Objectives This article describes a novel minimally invasive endoscopic technique and reports 3 cases of CATR reconstruction using peroneus longus (PL) tendon transfer as an alternative. Methods This technique employs standard posterolateral and posteromedial hindfoot portals without requiring additional peroneal tendoscopy portals. A small incision is made near the calcaneocuboid joint to perform tenodesis between PB and PL tendons, with the foot in maximum eversion to maximize tendon harvest. The PL tendon is then pulled through the posterolateral portal with the aid of the tag sutures, then passed through a calcaneal tunnel, and secured using an interference screw under fluoroscopic guidance. Results The procedure was performed in 3 patients with complete CATR (2 insertional, 1 noninsertional). At 1-year follow-up, all patients demonstrated clinical improvement in American Orthopaedic Foot & Ankle Society (AOFAS) and Achilles tendon Total Rupture Score (ATRS) measurements, with no gross clinical weakness in ankle eversion or lateral instability. One patient developed localized plantar heel hypoesthesia, while no major neurovascular complications or lateral ankle instability were observed. Conclusion Endoscopic PL transfer was feasible in 3 patients with CATR and was associated with improved short-term clinical scores. This technique may be considered a potential alternative or salvage option when FHL transfer is unsuitable. However, larger comparative studies are needed before definitive conclusions can be made regarding this technique. Levels of Evidence: Therapeutic studies, Level IV: Case series