Dual-Achilles Reconstruction for Chronic Quadriceps Rupture (DARC) Technique as a Novel Surgical Technique for Chronic Quadriceps Tendon Rupture: A Case Report

Quadriceps tendon ruptures (QTRs) are uncommon injuries that can become challenging to manage when diagnosis is delayed and significant tendon retraction and scarring occur. In chronic cases with significant tendon defects, primary repair is often not feasible, and reconstruction with graft augmentation becomes necessary. Achilles tendon allografts are commonly used in such scenarios; however, obtaining reliable graft incorporation and stable load-sharing remains difficult in patients with large defects, poor tendon quality, or elevated mechanical demand. This report describes a novel dual-layer Achilles tendon allograft reconstruction, referred to as the Dual-Achilles Reconstruction for Chronic Quadriceps Rupture (DARC) technique. This technique is designed to maximize circumferential graft contact, restore tendon bulk, and improve load distribution in a chronic QTR with significant retraction. A 56-year-old man with a body mass index (BMI) of 42.2 presented six weeks after two mechanical falls with persistent pain, recurrent buckling, and loss of active knee extension. Examination revealed a palpable suprapatellar defect, patella baja, and complete extensor mechanism failure. Radiographs demonstrated a Caton-Deschamps index of 0.56, and magnetic resonance imaging confirmed a full-thickness QTR with approximately 8 cm of proximal retraction and a 7 mm hematoma. Because of the chronicity of the injury and poor-quality tendon tissue, primary repair was not suitable. Reconstruction was performed using two Achilles tendon allografts anchored to the medial and lateral thirds of the superior patellar pole, which were then passed through the quadriceps muscle belly. The grafts were circumferentially wrapped around the tendon stump to create an anterior-posterior dual-layer construct intended to enhance graft integration and biomechanical stability. The patient followed a structured rehabilitation protocol. The patient regained full knee extension without extensor lag, achieved 0-120° of flexion, normalized gait by 12 weeks, and returned to unrestricted activity by one year. This favorable recovery is notable given the chronic nature of the rupture, the 8 cm retraction, and the patient's high BMI, all of which typically predict poorer outcomes. This case suggests that dual-layer Achilles tendon allograft reconstruction may offer a viable and structurally robust alternative for chronic QTRs with significant tissue loss where direct repair or single-graft techniques may be insufficient. Further investigation in larger patient cohorts is needed to evaluate the reproducibility, long-term performance, and broader applicability of this technique.