Brad Miles1, William L Walter2, Elizabeth Kolos1, Tim Waters2, Richard Appleyard3, R Mark Gillies4,5, Shane Donohoo6, Andrew J Ruys1. 1. Biomedical Engineering, AMME, University of Sydney, Sydney, NSW, Australia. 2. Specialist Orthopedic Group, Sydney, NSW, Australia. 3. The Australian School of Advanced Medicine, Macquarie University, Sydney, NSW, Australia. 4. Medical Device Research Australia, Sydney, NSW, Australia. 5. Murray Maxwell Biomechanics Laboratory, Kolling Institute, Sydney University, Sydney, NSW, Australia. 6. WorelyParsons Advanced Analysis, Sydney, NSW, Australia.
Abstract
BACKGROUND: The design of femoral component used in total hip arthroplasty is known to influence the incidence of periprosthetic femoral fractures (PFFs) in cementless hip arthroplasty. OBJECTIVE: This study was undertaken to determine if 2 potential changes to an existing ABG II-standard cementless implant - addition of a roughened titanium plasma-sprayed proximal coating (ABG II-plasma) and lack of medial scales (ABG II-NMS) could decrease the risk of PFF in the intraoperative and early postoperative periods. METHODS: Six pairs of human cadaveric femurs were harvested and divided into 2 groups, each receiving either of the altered implants and ABG II-standard (control). Each implant was tested in a biomechanical setup in a single-legged stance orientation. Surface strains were measured in intact femurs, during implant insertion, cyclic loading of the bone with the implant, and loading to failure. Strains with the ABG II-standard and the altered implants were compared. FINDINGS: ABG II-plasma showed better load-bearing capacity, with an average 42% greater failure load than that of ABG II-standard. The cortical hoop, axial and mean strains ABG II-plasma were less than those of ABG II-standard, demonstrating decreased tensile behaviour and better load transfer to the proximal femur. The final residual hoop strains in ABG II-plasma were closer to those of intact bone as compared to the standard stem. No differences in strains were observed between the standard stem and ABG II-NMS. CONCLUSION: The increased load-bearing capacity and decreased proximal surface strains on femurs implanted with ABG II-plasma stem should reduce the risks of intraoperative and early postoperative PFF.
BACKGROUND: The design of femoral component used in total hip arthroplasty is known to influence the incidence of periprosthetic femoral fractures (PFFs) in cementless hip arthroplasty. OBJECTIVE: This study was undertaken to determine if 2 potential changes to an existing ABG II-standard cementless implant - addition of a roughened titanium plasma-sprayed proximal coating (ABG II-plasma) and lack of medial scales (ABGII-NMS) could decrease the risk of PFF in the intraoperative and early postoperative periods. METHODS: Six pairs of human cadaveric femurs were harvested and divided into 2 groups, each receiving either of the altered implants and ABG II-standard (control). Each implant was tested in a biomechanical setup in a single-legged stance orientation. Surface strains were measured in intact femurs, during implant insertion, cyclic loading of the bone with the implant, and loading to failure. Strains with the ABG II-standard and the altered implants were compared. FINDINGS:ABG II-plasma showed better load-bearing capacity, with an average 42% greater failure load than that of ABG II-standard. The cortical hoop, axial and mean strains ABG II-plasma were less than those of ABG II-standard, demonstrating decreased tensile behaviour and better load transfer to the proximal femur. The final residual hoop strains in ABG II-plasma were closer to those of intact bone as compared to the standard stem. No differences in strains were observed between the standard stem and ABGII-NMS. CONCLUSION: The increased load-bearing capacity and decreased proximal surface strains on femurs implanted with ABG II-plasma stem should reduce the risks of intraoperative and early postoperative PFF.
Authors: Antonio Klasan; Martin Bäumlein; Philipp Dworschak; Christopher Bliemel; Thomas Neri; Markus D Schofer; Thomas J Heyse Journal: Bone Joint Res Date: 2019-11-02 Impact factor: 5.853
Authors: Jonathan N Lamb; Oliver Coltart; Isaiah Adekanmbi; Hemant G Pandit; Todd Stewart Journal: Proc Inst Mech Eng H Date: 2022-05-21 Impact factor: 1.763