Introduction

The FHL transfer is a well-established method of treating chronic Achilles tendon ruptures and in some cases it can be used in insertional or non insertional AT pathologies.

An open technique presents wound complications in more than10% of the patients, and it can reach up to 42.1% in those patients with risk factors such as steroid use, diabetes, or smokers. The endoscopic assisted technique is an excellent option to minimize wound complications, especially in older patients with increased risk of postoperative wound breakdown and infection.

Minimally invasive surgical approach methods may provide some advantages when compared to open surgery for treating AT pathologies. These include keeping the tendon healing in a “closed environment”, lesser dissection to the traumatized tendon, potentially reducing the incidence of neurovascular complications, minimizing skin healing issues (including noncosmetic scarring) and additionally the possibility for a lower infection rate.

Endoscopic technique is attractive for its advantages as a minimally invasive procedure, however, the surgeon should keep in mind the potential complications associated with the FHL tendon harvesting, tunnel drilling, or screw fixation and should pay attention to technical details to avoid them.

The main disadvantage is the use of other normal tendon of the foot.

Indications

Chronic AT ruptures especially in the older non-athletic population.

AT insertional injuries with a compromise > 50% of the insertion of the tendon and in which the AT tendon is degenerative > 50% of its anterior-posterior diameter

AT Re-Ruptures in the older non-athletic population

Literature

Endoscopic Flexor Hallucis Longus Transfer for Chronic Noninsertional Achilles Tendon Rupture. Vega J, Vilá J, Batista J, Malagelada F, Dalmau-Pastor M. Foot Ankle Int. 2018 Dec;39(12):1464-1472. doi: 10.1177/1071100718793172. Epub 2018 Aug 19. PMID:30124070

Lui TH, Chan WC, Maffulli N. Endoscopic flexor hallucis longus tendon transfer for chronic Achilles tendon rupture. Sports Med Arthrosc. 2016;24:38-41.

De Carbo W, Hyer CF. Interference screw fixation for flexor hallucis longus tendon transfer for chronic Achilles tendonopathy. J Foot Ankle Surg. 2008;47(1):69-72.

Carmont M, Jordi V, Batista J, et al. Endoscopic Flexor Hallucis tendon transfer. In: Thermann H et al. (eds.) The Achilles Tendon.103-109. ISBN 978-3-662-54073-2.2017.  

Wilcox D, Bohay D, Anderson J. Treatment of chronic achilles tendon disorders with flexor hallucis longus tendon transfer/augmentation. Foot Ankle Int.21(12):1004-1010.2000.

Maffulli N, Oliva F, Costa V, et al. Management of chronic rupture of the Achilles tendon: minimally invasive peroneous brevis tendon transfer. Bone Joint J.97-B(3):353-357.2015