The Effect of Collagen Scaffold Augmentation in Achilles Tendon Rupture Repair

This study is a prospective multi-center randomized controlled trial investigating the effects of collagen scaffold augmentation in surgical repair of acute Achilles tendon ruptures. The research builds upon existing clinical experience and literature suggesting that while surgical techniques have improved mechanical stability of repaired tendons, biological healing remains a limiting factor in recovery. The trial will compare two treatment approaches: one group will receive standard surgical repair augmented with a collagen scaffold, while the control group will undergo conventional repair without scaffold augmentation.

A total of 48 participants will be recruited from five hospitals and randomly assigned to either group with a 1:1 allocation ratio. The surgical procedure involves end-to-end tendon repair using non-absorbable sutures, with the intervention group additionally receiving a bioinductive collagen scaffold placed over the repair site. All participants will follow the same standardized rehabilitation protocol divided into four phases: protection, early loading, strengthening, and return to function.

Intervention Group:

Participants in the intervention group will undergo Achilles tendon repair with Collagen Scaffold Augmentation.

Upon diagnosis of an Achilles tendon rupture, the participant will receive a temporary slab and surgical repair will be scheduled, and the operation will be performed under general anaesthesia with the patient lying prone. The ruptured ends of the right Achilles tendon will be marked, and a 3 cm longitudinal skin incision will be made along the medial border of the tendon. A standardized end-to-end direct surgical repair using non-absorbable sutures in a 2-strand core in a krackow locking fashion will be performed. The bioinductive collagen scaffold will be placed over the repair site and secured with soft tissue anchors. The surgical site will be closed in layers using 3-0 vicryl and 4-0 ethilon.

The patient will be discharged the following day and will follow a standardized rehabilitation plan by physiotherapist. The rehabilitation is split into 4 phases: the protection phase, early loading phase, strengthening phase and return to function phase. This plan includes non-weight-bearing walking for 2 weeks, partial weight-bearing walking for 4 weeks, then full weight-bearing walking.

Control Group:

Participants in the control group will undergo Achilles tendon repair using the same method as the intervention group, only without the additional collagen scaffold augmentation. The rehabilitation protocol will also be identical to the intervention group.

The primary outcome measure is the Victorian Institute of Sports Assessment-Achilles (VISA-A) score, which evaluates pain, function, and sporting activity. Secondary outcomes include surgical complications, Foot and Ankle Outcome Score (FAOS), ultrasound measurements of tendon thickness and neovascularity, shear wave elastography for tendon elasticity, Achilles tendon resting angle, calf muscle strength, ankle range of motion, and photoacoustic imaging of tendon oxygen saturation. Participants will be assessed at baseline, 6 weeks, 3 months, 6 months, and 12 months post-surgery.

• Surgical complications [Срок оценки: During surgery]
• Foot and Ankle outcome scores (FAOS) [Срок оценки: 6 weeks and 3, 6, 12 months]
• Ultrasound measure of tendon thickness [Срок оценки: 6 weeks and 3, 6. 12 months]
• Ultrasound measurement of tendon neovascularity [Срок оценки: 6 weeks and 3, 6 ,12 months]
• Ultrasound measurement of tendon elasticity [Срок оценки: 6 weeks and 3, 6, 12 months]
• Achilles tendon resting angle [Срок оценки: 6 weeks and 3, 6, 12 months]
• Calf muscle strength [Срок оценки: 6 weeks and 3, 6, 12 months]
• Ankle range of motion [Срок оценки: 6 weeks; 3, 6, 12 months]
• Jump test [Срок оценки: 6 weeks; 3, 6, 12 months]
• Tendon oxygenation and vascularity [Срок оценки: 6 weeks; 3, 6, 12 months]
• Thermographic tendon temperature [Срок оценки: 6 weeks; 3, 6, 12 months]
• Achilles Tendon Total Rupture Score [Срок оценки: 6 weeks; 3, 6, 12 months]