Eendoscopic Versus Open Flexor Hallucis Longus Transfer in Managing Various Tendon Achilles Disorders

Summary

* A well-established protocol for the treatment or augmentation a wide range of Achilles disorders including chronic Achilles tendon (AT) rupture, Achilles insertional tendinopathy, Haglund syndrome and among others, is a Flexor hallucis longus (FHL) tendon transfer (1-4).
* Long incisions are required for open surgical procedures, which increase the risk of skin breakdown and wound infection. These factors have contributed to the increased use of endoscopy in the surgical treatment of different Achilles pathologies. Compared to open methods, endoscopic techniques provided the advantage of managing pathology with a low risk of soft-tissue complications(4-7).
* It has been recommended to use an FHL transfer. (8-10) Its anatomic proximity prevents iatrogenic lesions of the neurovascular bundle, it fires in phase with the gastrocnemius-soleus complex, it is a stronger plantar flexor, and its axis of contractile force more closely looks similar to that of the AT. It is plantar flexion strength reinforcement, which is almost always compromised with fascial advancement alone(11). Regarding the nature of the AT's vascularization, the FHL muscle belly reaches distally into its avascular zone, which allows the repaired AT to be recruitment of an increased blood supply. Moreover, by moving muscles that perform the same function, FHL transfer preserves the ankle's natural muscular balance. (8) A recent study using magnetic resonance imaging evaluation revealed that in 60% of patients, the FHL tendon had fully integrated, and in 80% of patients, there was hypertrophy of the tendon above 15%.
* This study tends to compare the outcomes of both open and endoscopic FHL transfer in different parameters like functional outcome, wound complication, and accelerated rehabilitation.
* This is a Prospective, randomized control trial. The study will be conducted on 30 patients complaining of chronic Achilles tendon rupture, Achilles insertional tendinopathy, Haglund syndrome planned for FHL transfer in Assiut university hospital. Patients will be randomized to two groups one group endoscopic FHL will be conducted in other hand second group open FHL will be conducted.

The PICOT algorithm was preliminarily pointed out:

* P (Problem): Different Achilles disorders such as chronic Achilles tendon (AT) rupture, Achilles insertional tendinopathy, Haglund syndrome and among others.
* I (Intervention): Endoscopic FHL Transfer.
* C (Comparison): open FHL tendon transfers.
* O (Outcomes): Clinical outcomes, complications, and return to sport.
* T (Timing): ≥6 months of follow-up.

Preoperative assessment:

A- Detailed history and examination:

* Detailed history for patient complains and previous trauma or surgery.
* Physical examination for FHL, AT, any foot and ankle deformities, functional Achilles pathology or ankle range-of-motion deficits.
* VAS score, Achilles tendon Total Rupture Score - ATRS, American Orthopaedic Foot \& Ankle Society (AOFAS) hindfoot score and ankle plantarflexion strength will be assessed preoperatively and at the latest follow-up (minimum of 1 year after the procedure).

Research outcome measures:

a. Primary (main): Functional outcome of endoscopic versus open FHL transfer in various TA pathology (American Orthopaedic Foot \& Ankle Society (AOFAS) ankle-hindfoot score), Achilles tendon Total Rupture Score - ATRS, ankle plantarflexion strength.

.Secondary (subsidiary):

* Wound complication, skin dehiscence and infection rate.
* Expected time to complete return to sports activities or return to previous levels of activity.
* Accelerated rehabilitation.

Conditions

• Tendon Tear
• Tendinopathy
• Achilles Tendon Ruptures
• Achilles Injuries Tendon
• Achilles Tendon Surgery
• Achilles Tendinopathy
• Achilles Tendon Repairs/Reconstructions
• Haglund's Deformity

Interventions

PROCEDURE

Endoscopic Flexor Hallucis longus tendon transfer to tendon achilles

The endoscopic FHL tendon transfer is usually performed with the scope introduced through the posterolateral portal and instruments through the posteromedial portal. The FHL tendon must be identified during hindfoot working area creation. First, the calcaneoplasty is completed as described. Next, the FHL tendon is harvested. A tunnel was created into calcenous the tendon is introduced into the tunnel and the tendon is secured with an interference screw of same size than the tunnel

PROCEDURE

Open Flexor Hallucis longus transfer to tendon achilles

The FHL tendon can be approached through the posterior longitudinal incision The FHL is confirmed by digital retraction of the tendon, watching for flexion of the hallux. Dissection of the FHL tendon is followed to the posterior talus and FHL tunnel, remaining lateral to avoid the neurovascular bundle. Release of the fibro-osseous tunnel along the posterior talus is necessary to gain length. With the hallux and ankle plantar flexed, the FHL tendon is transected as distally as possible. The tendon is fixed to the calcaneus just anterior to the Achilles stump insertion by an interference screw.

Sponsors & Collaborators

• Assiut University

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2026-04-04

Primary Completion

2028-03-01

Completion

2028-10-01

Countries

• Egypt

Study Locations