Aims. Flexor hallucis longus (FHL) tendon transfer is a well-recognized technique in the treatment of the neglected tendo Achillis (TA) rupture. Patients and Methods. We report a retrospective review of 20/32 patients who had undergone transtendinous FHL transfer between 2003 and 2011 for chronic TA rupture. Their mean age at the time of surgery was 53 years (22 to 83). The mean time from rupture to surgery was seven months (1 to 36). The mean postoperative follow-up was 73 months (29 to 120). Six patients experienced postoperative wound complications. Results. The mean postoperative Achilles tendon Total Rupture Score (ATRS) was 83 (40 to 100) and the mean American Orthopaedic Foot & Ankle Society (AOFAS) score was 94.3 (82 to 100). Tegner scoring showed a mean reduction of one level from the pre-injury level of activity. There was a mean reduction of 24% (4 to 54) in dynamometer-measured strength of ankle plantarflexion, in comparison with the non-operated side. The hallux had a mean of only 40% (2 to 90) strength of plantarflexion in comparison with the contralateral side. Conclusion. We conclude that transtendinous FHL transfer for neglected TA ruptures, with a long harvest to allow reattachment of the triceps surae, provides reliable long-term function and good ankle plantarflexion strength. Despite the loss of strength in hallux plantar flexion, there is little comorbidity from the FHL harvest. Cite this article: Bone Joint J 2018;100-B:584–9

Aims

The traditional transosseus flexor hallucis longus (FHL) tendon transfer for patients with Achilles tendinopathy requires two incisions to harvest a long tendon graft. The use of a bio-tenodesis screw enables a short graft to be used and is less invasive, but lacks supporting evidence about its biomechanical behaviour. We aimed, in this study, to compare the strength of the traditional transosseus tendon-to-tendon fixation with tendon-to-bone fixation using a tenodesis screw, in cyclical loading and ultimate load testing.

We studied a cohort of 26 diabetic patients with chronic ulceration under the first metatarsal head treated by a modified Jones extensor hallucis longus and a flexor hallucis longus transfer. If the first metatarsal was still plantar flexed following these two transfers, a peroneus longus to the peroneus brevis tendon transfer was also performed. Finally, if ankle dorsiflexion was < 5° with the knee extended, a Strayer-type gastrocnemius recession was performed.

The mean duration of chronic ulceration despite a minimum of six months’ conservative care was 16.2 months (6 to 31). A total of 23 of the 26 patients were available for follow-up at a mean of 39.6 months (12 to 61) after surgery. All except one achieved complete ulcer healing at a mean of 4.4 weeks (2 to 8) after surgery, and there was no recurrence of ulceration under the first metatarsal.

We believe that tendon balancing using modified Jones extensor hallucis longus and flexor hallucis longus transfers, associated in selected cases with a peroneus longus to brevis transfer and/or Strayer procedure, can promote rapid and sustained healing of chronic diabetic ulcers under the first metatarsal head.

Chronic infections and ulceration around the tendo Achillis are difficult to manage. Split-skin grafts do not survive even on healthy exposed tendon. Refractory cases may require plastic surgical intervention with the use of free flaps. Patients with significant vascular disease are not suitable for such techniques. Flexor hallucis longus tendon transfer is an established treatment for chronic ruptures of the tendo Achillis.

We report the successful treatment of an infected tendo Achillis with excision and reconstruction with flexor hallucis longus transfer. The muscle belly of this tendon allowed later skin grafting while the tendon transfer provided good functional recovery.