Background: Chronic Achilles tendon ruptures are uncommon and increase long-term morbidity when untreated. There is no standard treatment for this condition. Methods: Chronic Achilles tendon rupture was repaired in 10 patients by harvesting the flexor hallucis longus tendon (FHL) using a minimally invasive technique. It was then transferred to the calcaneus and the remnant used to bridge the gap for reconstructing the Achilles tendon itself. The patients were assessed using the American Orthopaedic Foot and Ankle Score (AOFAS) Ankle-Hindfoot Scale. Results: Patients were evaluated postoperatively to assess pain, function, and alignment of the ankle and hindfoot. Average follow-up time was 30.9 months (range = 17-43 months). The average postoperative AOFAS score was 78.5 (range = 54-94). The average postoperative score for pain was 33.5 out of 40; for function, 38.7 out of 50; and for alignment, 6.3 out of 10. A single surgical site infection requiring Incision and Drainage (I&D) was the only operative complication noted. No patient developed a significant deformity of the hallux after transfer. Conclusions: FHL transfer using a minimally invasive harvest for the treatment of chronic Achilles tendon ruptures produces good to excellent outcome measures as judged by an AOFAS score of 75 or greater while minimizing risk to the medial neurovascular bundle. Levels of Evidence: Case series, Level IV: Retrospective.
Keywords: Achilles tendon; FHL transfer; chronic Achilles rupture; flexor hallucis longus; tendon rupture.