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.

H0: There will be no difference in ankle plantar flexion strength measured using a handheld dynamometer between patients randomized to achilles tendon decompression and debridement alone (Group 1) and patients randomized to achilles tendon decompression and debridement augmented with FHL transfer (Group 2).

HA: Patients randomized to achilles tendon decompression and debridement alone (Group 1) will have less ankle plantar flexion strength compared to patients randomized to achilles tendon decompression and debridement augmented with FHL transfer (Group 2).

Inclusion Criteria:

• Patients 50 years of age or older
• Patients diagnosed with chronic insertional Achilles tendonitis
• Failed greater than 3 months of conservative treatment (activity and shoe modification, heel lifts, non-steroidal anti-inflammatory medications, stretching exercises, and formal physical therapy)

Exclusion Criteria:

• Patients less than 50 years of age upon presentation
• Females of child-bearing potential
• Patients who have a history of ipsilateral Achilles tendon rupture
• History of infection in the same lower extremity
• Patients unable to undergo MRI scan