Variable fixation promotes callus formation: an experimental study on transverse tibial osteotomies stabilized with locking plates

Autor: Karina Klein, Katrin Planzer, Pascal Behm, Stephen J. Ferguson, Michael Plecko, Dirk Wähnert, Stefano Brianza, Brigitte von Rechenberg, Vincent A. Stadelmann
Přispěvatelé: University of Zurich, Brianza, Stefano
Jazyk: angličtina
Rok vydání: 2020
Předmět:
lcsh:Diseases of the musculoskeletal system
medicine.medical_treatment
Non-unions
2745 Rheumatology
Bone Screws
Fracture healing
Osteotomy
Locking plate
Variable fixation
Fracture Fixation
Internal

0302 clinical medicine
Medicine
Orthopedics and Sports Medicine
030212 general & internal medicine
Bony Callus
Fixation (histology)
Orthodontics
030222 orthopedics
Fracture complications
food and beverages
musculoskeletal system
10226 Department of Molecular Mechanisms of Disease
Biomechanical Phenomena
Variable fixation locking screw
Female
VFLS
Bone Plates
Research Article
medicine.medical_specialty
Callus formation
Bone healing
Delayed unions
03 medical and health sciences
2732 Orthopedics and Sports Medicine
Rheumatology
Fracture dynamization
Animals
Humans
Tibia
Sheep
business.industry
fungi
Tibial Fractures
Callus
Orthopedic surgery
570 Life sciences
biology
lcsh:RC925-935
business
Zdroj: BMC Musculoskeletal Disorders
BMC Musculoskeletal Disorders, Vol 21, Iss 1, Pp 1-13 (2020)
BMC Musculoskeletal Disorders, 21 (1)
ISSN: 1471-2474
DOI: 10.5167/uzh-201738
Popis: Background A new locking screw technology, named variable fixation, has been developed aiming at promoting bone callus formation providing initial rigid fixation followed by progressive fracture gap dynamisation. In this study, we compared bone callus formation in osteotomies stabilized with standard locking fixation against that of osteotomies stabilized with variable fixation in an established tibia ovine model. Methods A 3 mm tibial transverse osteotomy gap was stabilized in three groups of six female sheep each with a locking plate and either 1) standard fixation in both segments (group LS) or 2) variable fixation in the proximal and standard fixation in the distal bone segment (group VFLS3) or 3) variable fixation in both segments (group VFLS6). The implantation site and fracture healing were compared between groups by means of radiologic, micro tomographic, biomechanical, and histological investigations. Results Compared to LS callus, VFLS3 callus was 40% larger and about 3% denser, while VFLS6 callus was 93% larger and its density about 7.2% lower. VFLS3 showed 65% and VFLS6 163% larger amount of callus at the cis-cortex. There wasn’t a significant difference in the amount of callus at the cis and trans-cortex in groups featuring variable fixation only. Investigated biomechanical variables were not significantly different among groups and histology showed comparable good healing in all groups. Tissues adjacent to the implants did not show any alteration of the normal structure in all groups. Conclusions Variable fixation promoted the formation of a larger amount of bone callus, equally distributed at the cis and trans cortices. The histological and biomechanical properties of the variable fixation callus were equivalent to those of the standard fixation callus. The magnitude of variable fixation had a biological effect on the formation of bone callus. At the implantation site, the usage of variable fixation did not raise additional concerns with respect to standard fixation. The formation of a larger amount of mature callus suggests that fractures treated with variable fixation might have a higher probability to bridge the fracture gap. The conditions where its usage can be most beneficial for patients needs to be clinically defined.
BMC Musculoskeletal Disorders, 21 (1)
ISSN:1471-2474
Databáze: OpenAIRE
Popis
Abstrakt:Background A new locking screw technology, named variable fixation, has been developed aiming at promoting bone callus formation providing initial rigid fixation followed by progressive fracture gap dynamisation. In this study, we compared bone callus formation in osteotomies stabilized with standard locking fixation against that of osteotomies stabilized with variable fixation in an established tibia ovine model. Methods A 3 mm tibial transverse osteotomy gap was stabilized in three groups of six female sheep each with a locking plate and either 1) standard fixation in both segments (group LS) or 2) variable fixation in the proximal and standard fixation in the distal bone segment (group VFLS3) or 3) variable fixation in both segments (group VFLS6). The implantation site and fracture healing were compared between groups by means of radiologic, micro tomographic, biomechanical, and histological investigations. Results Compared to LS callus, VFLS3 callus was 40% larger and about 3% denser, while VFLS6 callus was 93% larger and its density about 7.2% lower. VFLS3 showed 65% and VFLS6 163% larger amount of callus at the cis-cortex. There wasn’t a significant difference in the amount of callus at the cis and trans-cortex in groups featuring variable fixation only. Investigated biomechanical variables were not significantly different among groups and histology showed comparable good healing in all groups. Tissues adjacent to the implants did not show any alteration of the normal structure in all groups. Conclusions Variable fixation promoted the formation of a larger amount of bone callus, equally distributed at the cis and trans cortices. The histological and biomechanical properties of the variable fixation callus were equivalent to those of the standard fixation callus. The magnitude of variable fixation had a biological effect on the formation of bone callus. At the implantation site, the usage of variable fixation did not raise additional concerns with respect to standard fixation. The formation of a larger amount of mature callus suggests that fractures treated with variable fixation might have a higher probability to bridge the fracture gap. The conditions where its usage can be most beneficial for patients needs to be clinically defined.<br />BMC Musculoskeletal Disorders, 21 (1)<br />ISSN:1471-2474
ISSN:14712474
DOI:10.5167/uzh-201738