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

Official title

Medial Displacement Calcaneal Osteotomy and FDL- Transfer - a Prospective Comparative Study Between Metal/Bio-Tenodesis Screw (Arthrex) and the Human, Allogeneic Cortical Bone Screw (Shark Screw®️, Surgebright-GmbH)

Overview

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.

Detailed description

Symptomatic flatfoot deformity in adults often occurs as a result of dysfunction of the Tibialis posterior tendon (TPTD), with a prevalence of 3.3%. Structured non-surgical treatment programs with orthotics and physiotherapy can achieve a high level of long-term subjective and functional satisfaction, with surgery being avoided in 70-89% of cases. Surgical intervention is indicated for progressive or uncontrolled symptoms. Flexible flatfoot deformity, stage II classified by Johnson and Strom, can be treated with a joint-preserving strategy, which usually includes a medializing calcaneal osteotomy, debridement of the tibialis posterior tendon, and transfer of the flexor digitorum longus (FDL) tendon. 87% satisfaction after ten years was observed in both pain relief and foot function and alignment.

Metal screws have been used for decades to treat bone fractures. The removal is the major disadvantage of conventional osteosyntheses and requires a second operation, with all the resulting risks of complications for each patient. The use of the bone screw from allogeneic cortical bone would reduce costs substantially, with a significant reduction in the average complication rate to 0.3%.

The idea of stabilizing fractures using compact bone instead of metal is not new. Obwegeser published the clinical use of 796 screw implants of allogeneic bone and reported that the only complication was the fracture of 6 screws (\<1%) and three screw loosening (\<0,5%).

Since 2016, the human, allogeneic cortical bone screw(Shark Screw®) has been used by two tissue banks, the Austrian Austrian tissue bank Surgebright-GmbH and the German Institute for Cell and Tissue Replacement (DIZG). The Shark Screw® graft was approved by the competent Austrian authority (AGES) in 2016. The bone graft immediately creates a solid, purely bony connection. This leads to bone remodeling, bone incorporation and optimal reparation in the surgical area. Depending on the loads and requirements, the bone connection adapts for the future. The bone grafts undergo a certified sterilization procedure at the DIZG, which was developed in 1985 at the Berlin Charité.

Due to the lack of further systematic investigations to objectively confirm the theoretically given and subjectively experienced product advantages, this observational study is now being conducted.

The aim of the present study is to evaluate the application of the human allogeneic cortical bone screw (Shark Screw®) and the metal/Bio-Tenodesis screw in the surgical treatment (medializing calcaneus osteotomy with FDL transfer) of symptomatic flatfoot and to systematically document corresponding clinical and radiological parameters before and after surgery.

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 tendo
• 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

Primary outcome measures

• x-ray qualitative evaluation of changes in bony union of calcaneus osteotomy [Time frame: 6 weeks, 6 months, 1 year, 2 years]
• CT-scan qualitative evaluation of changes in bony union of calcaneus osteotomy [Time frame: 6 months, 1 year]

Secondary outcome measures (7)

• changes in AOFAS score in comparison to presurgery [Time frame: 6 months, 1 year and 2 years]
• changes in Foot and Ankle Outcome Score (FOAS) score in comparison to presurgery [Time frame: 6 months, 1 year and 2 years]
• changes in FFI score in comparison to presurgery [Time frame: 6 months, 1 year and 2 years]
• changes in Vas-Pain score in comparison to presurgery [Time frame: 6 weeks, 6 months, 1 year and 2 years]
• complications [Time frame: during surgery, 6 weeks, 6 months, 1 year and 2 years]
• reoperations [Time frame: during surgery, 6 weeks, 6 months, 1 year and 2 years]
• pseudoarthrosis [Time frame: during surgery, 6 months, 1 year and 2 years]

Eligibility criteria

Inclusion criteria

• Indication for the use of a metal/Bio-Tenodesis screw or human bone screw in medializing calcaneus osteotomy with FDL transfer.
• BMI< 40 kg/m²

Exclusion criteria

• Insufficient knowledge of German
• Alcohol and drug abuse
• Pregnant woman or nursing mother
• Foreseeable compliance problems
• Neoplastic diseases, malignant bone tumors, rheumatoid arthritis
• Active osteomyelitis
• History of foot surgery
• Advanced osteoarthritis of the lower ankle joint
• Ulcerations in the skin of the surgical area
• Immunosuppressive medications that cannot be discontinued
• BMI >40

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model

Case-control

Study locations

Austria · 1 center

• Abteilung für Kinderorthopädie und Fußchirurgie Orthopädisches Spital Speising — Vienna

Publications

• Pastl K, Pastl E, Flory D, Borchert GH, Chraim M. Arthrodesis and Defect Bridging of the Upper Ankle Joint with Allograft Bone Chips and Allograft Cortical Bone Screws (Shark Screw(R)) after Removal of the Salto-Prosthesis in a Multimorbidity Patient: A Case Report. Life (Basel). 2022 Jul 11;12(7):1028. doi: 10.3390/life12071028. PMID 35888116
• Pastl K, Schimetta W. The application of an allogeneic bone screw for osteosynthesis in hand and foot surgery: a case series. Arch Orthop Trauma Surg. 2022 Oct;142(10):2567-2575. doi: 10.1007/s00402-021-03880-6. Epub 2021 Apr 8. PMID 33834287
• Brcic I, Pastl K, Plank H, Igrec J, Schanda JE, Pastl E, Werner M. Incorporation of an Allogenic Cortical Bone Graft Following Arthrodesis of the First Metatarsophalangeal Joint in a Patient with Hallux Rigidus. Life (Basel). 2021 May 24;11(6):473. doi: 10.3390/life11060473. PMID 34073841
• Johnson KA, Strom DE. Tibialis posterior tendon dysfunction. Clin Orthop Relat Res. 1989 Feb;(239):196-206. PMID 2912622
• Obwegeser JA. [Absorbable and bioconvertible osteosynthesis materials in maxillofacial surgery]. Mund Kiefer Gesichtschir. 1998 Nov;2(6):288-308. doi: 10.1007/s100060050077. German. PMID 9880999
• Hanslik-Schnabel B, Flory D, Borchert GH, Schanda JE. Clinical and Radiologic Outcome of First Metatarsophalangeal Joint Arthrodesis Using a Human Allogeneic Cortical Bone Screw. Foot Ankle Orthop. 2022 Jul 29;7(3):24730114221112944. doi: 10.1177/24730114221112944. eCollection 2022 Jul. PMID 35924004
• Amann P, Pastl K, Neunteufel E, Bock P. Clinical and Radiologic Results of a Human Bone Graft Screw in Tarsometatarsal II/+III Arthrodesis. Foot Ankle Int. 2022 Jul;43(7):913-922. doi: 10.1177/10711007221081533. Epub 2022 Apr 2. PMID 35373594
• Sailer S, Lechner S, Flossmann A, Wanzel M, Habeler K, Krasny C, Borchert GH. Treatment of scaphoid fractures and pseudarthroses with the human allogeneic cortical bone screw. A multicentric retrospective study. J Orthop Traumatol. 2023 Feb 10;24(1):6. doi: 10.1186/s10195-023-00686-7. PMID 36765020

Identifiers

NCT: NCT05643079 · FDLTransferSharkScrew

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗