Clinical photograph and radiograph demonstrate Haglund's deformity and calcifications consistent with insertional achilles tendonopathy. Failure of conservative management and loss of function are indications for surgical management. Given the large Haglund's deformity on radiograph, calcaneal exostectomy is preferable to tendon debridement alone.
Hartog et al reviews a series of 29 cases of chronic achilles tendinosis treated surgically including supplementation with FHL transfer. Good to excellent clinical results were reported with no major complications.
McGarvey reviewed the clinical results of 22 insertional achilles tendonopathy treated surgically finding a clinical satisfaction rate of 82%. Hartog reports on 29 cases of FHL augmentation of chronic achilles tendonosis finding excellent or good results in 26 of 29 and no report of functional deficit or deformity of the hallux.
Kolodziej conducted a cadaveric study to evaluate the integrity of the insertion of the achilles tendon. The greatest margin of safety was found to be offered by a superior to inferior resection (better than medial/lateral and oblique) and that as much as 50% of the tendon could be resected without sacrificing significant strength to failure.
Den Hartog BD. Flexor hallucis longus transfer for chronic Achilles tendonosis. Foot Ankle Int. 2003 Mar;24(3):233-7. PubMed PMID: 12793486.
PMID:12793486 (Link to Abstract)
Kolodziej P, Glisson RR, Nunley JA. Risk of avulsion of the Achilles tendon after partial excision for treatment of insertional tendonitis and Haglund's deformity: a biomechanical study. Foot Ankle Int. 1999 Jul;20(7):433-7.
PMID:10437926 (Link to Abstract)
McGarvey WC, Palumbo RC, Baxter DE, Leibman BD. Insertional Achilles tendinosis: surgical treatment through a central tendon splitting approach. Foot Ankle Int. 2002 Jan;23(1):19-25.
PMID:11822688 (Link to Abstract)