Medial Displacement Calcaneal Osteotomy and FDL- Transfer - With a Human, Allogeneic Cortical Bone Screw

Summary

The goal of this observational study is to compare the use of a screw made of human bone (Shark-Screw®, Surgebright-GmbH) with the metal/Bio-Tenodesis screw (Arthrex) in the treatment of the symptomatic flatfoot using the medializing calcaneus osteotomy with flexor digitorum longus transfer (FDL) in adult patients. The advantage of the human bone screw is that after surgery no hardware removal is necessary. The screw is transformed from the body to normal bone.

The main questions it aims to answer are:

* Can the human bone screw achieve union rates like the metal/Bio-Tenodesis screw?
* Is the time to union similar between the different screws?
* Is the complication rate similar between the different screws?
* Are the activity scores American Orthopaedic Foot and Ankle Society (AOFAS), Foot and Ankle Outcome Score (FAOS) and Foot Function Index (FFI) after surgery similar in the compared patient groups?

Participants will have

* the surgery
* follow-ups at 6 weeks, 6 months, 1 and 2 years.
* X-rays are performed at each follow up.
* CT-scans are performed after 6 months.
* activity scores are collected at the follow up after 6 months, 1 year and 2 years.

Conditions

• Flat Feet
• Flexor Tendon Rupture
• Tibialis Posterior Dysfunction
• Deformity, Foot

Interventions

PROCEDURE

medializing calcaneal osteotomy and/or transfer of the flexor digitorum longus tendon (FDL) with metal/Bio-Tenodesis screws

The calcaneus osteotomy is performed dorsal proximal to plantar distal with caution of the peroneal tendons and sural nerve. After mobilization the dorsal fragment is displaced medially by\~10mm. Thereafter, a guide wire is placed from plantar-lateral into the ventral portion of the calcaneus under fluoroscopic control. After stab incision and length measurement, the osteotomy is fixed with a Metal/Bio-Tenodesis screw(MBS). The lateral projection of the edge is straightened. Opening of the tendon sheath of the FDL muscle and dissection distally to Henry's node. Settling of the tendon and arming with a "shuttle suture". Tendon diameter measurement. Place a guide wire at os naviculare directed from plantar to dorsal in 20°proximal guidance. Pull through the FDL tendon from plantar to dorsal and fixation with an MBS in 20°of pointed foot position and inversion with appropriate desired tension. The tendon is then sutured to the stump of the tibialis posterior tendon, retinaculum sutures.

PROCEDURE

medializing calcaneal osteotomy and/or transfer of the flexor digitorum longus tendon (FDL) with Shark Screws®

The calcaneus osteotomy is performed dorsal proximal to plantar distal with caution of the peroneal tendons and sural nerve. After mobilization the dorsal fragment is displaced medially by approx.10mm. Thereafter, a guide wire is placed from plantar-lateral into the ventral portion of the calcaneus under fluoroscopic control. After stab incision and length measurement, the osteotomy is fixed with a Shark Screw®. The lateral projection of the edge is straightened. Opening of the tendon sheath of the FDL muscle and dissection distally to Henry's node. Settling of the tendon and arming with a "shuttle suture". Tendon diameter measurement. Place a guide wire at os naviculare directed from plantar to dorsal in 20°proximal guidance. Pull through the FDL tendon from plantar to dorsal and fixation with the Shark Screw® in 20°of pointed foot position and inversion with appropriate desired tension. The tendon is then sutured to the stump of the tibialis posterior tendon, retinaculum sutures.

Sponsors & Collaborators

• Orthopedic Hospital Vienna Speising

  lead OTHER

Principal Investigators

• Florian Wenzel-Schwarz, MD · Abteilung für Kinderorthopädie und Fußchirurgie Orthopädisches Spital Speising, Vienna, Austria

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2022-02-10

Primary Completion

2027-02-28

Completion

2028-02-29

Countries

• Austria

Study Locations