Early postoperative results of endoscopic transfer of the flexor hallucis longus muscle for the treatment of chronic Achilles tendon rupture

Abstract

Objective: Chronic lesions of the Calcaneal Tendon (CT) involve proximal retraction of the tendon, and have poorer functional results than those observed in acute ruptures. Transfer of the Flexor Hallucis Longus (FHL) muscle is a well-established treatment option, usually performed by open surgery. The objective of this work is to report a series of chronic ruptures/re-ruptures of the CT, treated through endoscopic transfer of the FHL. Methods: Six patients with chronic lesions or re-ruptures of the AT were treated with endoscopic transfer of the FHL - four men and two women, with an average age of 50 years. All the lesions were located in zone 2 of the AT (2-6cm proximal to its insertion). The mean follow-up time was nine months (5-12 months). Three patients underwent an associated procedure for repair of a preexisting gap in the AT, through the minimally invasive surgery technique. The average surgery time was 56 minutes. Results: All the patients presented good improvement in Achilles Tendon Rupture Score (ATRS), with a mean of 17.8 in the pre- and 83.3 in the postoperative period. All the patients were capable of standing on tiptoe, without limitation. None of the patients reported loss of functional strength of the hallux during daily activities. Conclusion: In this case series, the endoscopic transfer of the FHL proved a safe and viable option for the treatment of chronic lesions of the CT. Other studies are needed, to compare this technique with the open procedure, which is still the gold standard.