Evaluation of Flexor hallucis tendon transfer in chronic insertional Achilles tendinopathy in over 50-year-old population using validated ankle scores

Purpose: Chronic insertional Achilles tendinopathy is a common pathology in the over 50 years old population. Patients not relieved with conservative treatment had to undergo surgical intervention for the management. This study evaluates the clinical outcome of FHL transfer in such patients using validated ankle functional scores.

Method: It is a retrospective study including 20 patients of either gender managed with debridement of the distal degenerative remnant Achilles tendon fibers either at the insertion site or the distal end of the torn tendon, resection of Haglund deformity with FHL transfer, and reattachment of Achilles tendon. The average age of the patients was 56.55 + 11 years (50-77 years) followed by over 35.6 months (Range 22-48months). The preoperative FAAM, FADI, SF 36, VAS, and AOFAS scores were calculated and followed every 6 months. The plantarflexion and dorsiflexion of the ankle were also recorded preoperatively and at follow-up visits.

Results: All the patients were operated on by a single surgeon (MS) with the same surgical technique, implant, and rehabilitation protocol. All the patients were followed for an average of 35.6 months (Range 22-48 months). All the ankle scores, FAAM, FADI, SF36, VAS, and AOFAS improved in follow-ups. The mean plantarflexion and dorsiflexion were 39.30⁰+ 4.9⁰ and 12.5⁰+ 4.7⁰ respectively. Three patients had minor wound complications. All the patients returned to activities of daily living.

Conclusion: FHL transfer in elderly patients with insertional Achilles tendinopathy improves the validated ankle functional scores and decreases pain significantly. Furthermore, randomized studies with a larger study population and longer follow-ups may ascertain the beneficial effects.