Flexor Hallucis Longus Tendon Transfer VS Gastrocnemius Augmented Flexor Hallucis Longus Tendon Transfer in Management of Achilles Tendon Defect

The Achilles tendon (AT) is the largest and strongest tendon in the human body, yet it is also one of the most commonly ruptured tendons, with an annual incidence of about 18 cases per 100,000 people. Around 75% of Achilles tendon ruptures (ATR) occur in middle-aged patients during sports activity or following trauma. These injuries typically happen in a region 2 to 6 cm above the tendon's attachment to the heel, an area that has a relatively poor blood supply, that reducing the probability of the healing of the tendon by conservative management. Because of the absence of significant pain and the ability to partially maintain plantar flexion, it has been reported that around 10-25% of Achilles tendon rupture (ATR) cases are overlooked or misdiagnosed during the initial medical assessment. The delaying of the diagnosis and by the way the treatment results in a greater separation between the tendon ends, with scar tissue filling the gap leading to lengthening to the gastrocnemius muscle decreasing its tensile forces. This makes the surgical intervention for repair of chronic tendo Achillis rupture necessary to restore normal leg function. Various surgical procedures such as reconstruction with V-Y advanced flap, gastrocnemius turn-down flap, local tendon transfer augments (Flexor hallucis longus (FHL) or peroneus brevis), semitendinosus autograft, free tissue transfer including synthetic grafts and allografts to bridge the gap have been described. Some techniques have been combined, such as tissue advancement and tendon transfer. Multiple studies have been done comparing two or more of the mentioned techniques, but to our knowledge there is no randomized controlled study comparing the isolated FHL tendon transfer to gastrocnemius augmented flexor hallucis longus (GAFHL) tendon transfer.

Inclusion criteria

• Age range: Adolescents and adults with skeletally mature feet (above 12 y in females and 14 years in males).
• Achilles Tendon defects more than 4 cm resulted from acute or chronic rupture, post-debridement defects in case of neglected insertional tendinopathy, spontaneous ruptures due to tendinosis or after tumor resection.

Exclusion criteria

• General medical contraindications to surgical interventions
• Calcaneal Fracture, subtalar fusion
• infection or previous surgery in the ipsilateral hindfoot or ankle
• Systemic disease including seronegative inflammatory diseases, spondyloarthropathies or sarcoidosis.