The purpose of this study is to determine whether Achilles tendon debridement and decompression augmented with flexor hallucis longus (FHL) tendon transfer results in improved clinical and functional outcome as measured by ankle plantar flexion strength and American Orthopedic Foot and Ankle Society (AOFAS) score compared to debridement and decompression alone in patients over 50 years of age with chronic insertional Achilles tendinosis.