44 patients at least 50 years old with chronic insertional Achilles tendinopathy for whom nonoperative treatments have failed, were randomized to Achilles debridement and ostectomy alone or with flexor hallucis longus (FHL) tendon augmentation. The purpose was to determine whether the augmentation would be more effective than the surgery alone. Results at 1 year revealed that although no significant differences were found between groups with respect to clinical outcomes, augmentation with FHL provided significantly greater ankle plantarflexion strength.