Background: Silicone is still the gold standard implant in metacarpophalangeal arthroplasty. Whereas the clinical results are acceptable, in follow-ups with >10 years, high rates of implant fracture are common, and 5 to 7% of implants required revision. This work's purpose is to analyse the hypothesis that the joint flexion amplitude has a relevant effect on bone strain level, implant stress and bone-implant micromotion, which can reflect an increase in the risk of bone resorption/fatigue failure, implant fracture and osteolysis.
Methods: To experimentally predict the cortical loading behaviour, composite metacarpals and proximal phalanges were used in intact and implanted states. A finite element model was developed to evaluate the structural behaviour of cancellous bone and implant. This model was validated by comparing cortical strain and load-displacement curve with experimental measurements.
Findings: Bone strain changes between the intact and the implanted states showed a load transfer effect from the cortical to the cancellous bone that increases significantly with the flexion's amplitude rise. The peak implant stress occurred in the flexion amplitudes further away from the implant neutral angle. The highest implant pistoning motion and the highest phalanx cancellous-bone strain occurred simultaneously at the maximum flexion amplitude.
Interpretation: Limiting joint flexion range will be helpful to reduce the strain-shielding effect on cortical bone, minimizing the overload effect on cancellous bone and decreasing the stress levels and the pistoning motion on the implant, ultimately contributing to the longevity of silicone arthroplasty.
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http://dx.doi.org/10.1016/j.clinbiomech.2023.106120 | DOI Listing |
Open Vet J
November 2024
Department of Veterinary Surgery, College of Veterinary Medicine, Chungbuk National University, Cheongju, Republic of Korea.
Background: Distal radius fractures are prevalent in small and toy-breed dogs, presenting significant treatment challenges due to complications such as delayed union or non-union. These complications are often exacerbated by reduced vascular density at the distal diaphyseal-metaphyseal junction of the radius, which is vital for bone healing, particularly in toy and small breed dogs. Circular external fixation (CEF) is known for its effectiveness in managing acute and chronic fractures and providing temporary stabilization in humans.
View Article and Find Full Text PDFOpen Vet J
November 2024
Orthopedics Unit, "Dr. Victor Popescu" Emergency Military Hospital, Timisoara, România.
Background: Cancellous bone mechanical properties are directly linked to structural integrity, which is a result of bone quantity, the quality of its bone matrix, and its microarchitecture. Several studies highlighted the bone behavior under specific loads, contributing to understanding risk factors and developing more effective therapeutic strategies. The anatomy and stability of iliac bone fractures, providing insight into pelvic trauma management.
View Article and Find Full Text PDFBMC Musculoskelet Disord
December 2024
Department of Anatomy, Guangdong Provincial Key Laboratory of Digital Medicine and Biomechanics, Guangdong Engineering Research Center for Translation of Medical 3D Printing Application, National Virtual & Reality Experimental Education Center for Medical Morphology, School of Basic Medical Sciences, Southern Medical University, No.1023, South Shatai Road, Baiyun District, Guangzhou, Guangdong, 510515, China.
Background: This study investigated the impact of higher interfragmentary compression force (IFCF) on the stability of locking plate fixation in lateral tibial plateau fractures.
Methods: Biomechanical experiments and finite element analysis (FEA) were employed to compare the performance of the AO cancellous lag screw (AOCLS) and a newly developed combined cancellous lag screw (CCLS).
Results: The results demonstrated that the CCLS provided a higher IFCF without the risk of over-screwing, significantly improving fixation stability.
Cureus
November 2024
Aerospace Engineering, Universiti Putra Malaysia, Kuala Lumpur, MYS.
Introduction Spinal fusion surgery with pedicle screws is commonly performed to stabilize the spine of osteoporotic patients. However, securing a strong screw fixation in osteoporotic bone presents significant challenges due to the reduced bone density. This study aimed to compare the biomechanical performance in an osteoporotic bone model of pedicle screws inserted using two different techniques, the Jamshidi needle technique and the pedicle probe technique, as well as the influence of tapping on both these techniques.
View Article and Find Full Text PDFBioact Mater
April 2025
Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
Human long bones exhibit pore size gradients with small pores in the exterior cortical bone and large pores in the interior cancellous bone. However, most current bone tissue engineering (BTE) scaffolds only have homogeneous porous structures that do not resemble the graded architectures of natural bones. Pore-size graded (PSG) scaffolds are attractive for BTE since they can provide biomimicking porous structures that may lead to enhanced bone tissue regeneration.
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