An Outcome Study of Chronic Achilles Tendinosis After Excision of the Achilles Tendon and Flexor Hallucis Longus Tendon Transfer

Abstract

Background: A number of operative techniques, including decompression with debridement and flexor hallucis longus (FHL) tendon augmentation, have been described for chronic degenerative Achilles tendinosis. Decompression with debridement has been shown to be effective; however, pain and functional limitation can persist in individuals with more severe tendon involvement. Augmentation with the FHL tendon can add mechanical support; however, difficulty in achieving proper tendon tensioning and the potential to leave behind painful diseased tendon are disadvantages of the technique. The purpose of this study was to present the results of a modified technique in which the Achilles tendon is completely excised and the FHL tendon is transferred. Methods: Fifty-six surgeries using this modified technique were done between October, 1994, and March, 2002, for patients with chronic degenerative Achilles tendinosis. Forty-four patients with and average age of 58.2 (SD 10.1) years and an average time of followup of 3.4 (SD 1.9) years were available for testing. All subjects were mailed a packet of standardized questionnaire information that included the Self-Reported Health Related Quality of Life measures Short Form (SF-36) and the subjective component of the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle and Hindfoot Score. Nineteen patients returned to the clinic for objective assessment. Statistical analysis tested for a difference in the SF-36 scores between our subjects and the general United States population and for a difference in strength and range of motion between the involved and uninvolved lower extremities. Results: Pain decreased in 95.5% ( n = 42) patients, and 86.4% ( n = 38) patients were satisfied with the result. There was no significant difference ( p >.05) between the SF-36 scores obtained by our sample compared to the general United States population. The average AOFAS score for the 19 patients was 91.6 (SD 7.7). Dorsiflexion range of motion was not significantly different ( p = 0.17); however, significant deficits were found in plantarflexion range of motion ( p = 0.001) and plantarflexion strength ( p < 0.025). Strength deficits were 30% on average; however, all but one patient could do a heel raise. Conclusion: Complete Achilles tendon excision reduces pain while preserving functional status. Although strength deficits persisted, these deficits did not seem to affect the functional status in this sample of patients.