Tony Chen1,2, Caroline Brial1, Moira McCarthy3, Russell F Warren2,3, Suzanne A Maher1,2. 1. Department of Biomechanics, Hospital for Special Surgery, New York, New York, USA. 2. Orthopedic Soft Tissue Research Program, Hospital for Special Surgery, New York, New York, USA. 3. Sports Medicine and Shoulder Service, Hospital for Special Surgery, New York, New York, USA.
Abstract
BACKGROUND: Although polyvinyl alcohol (PVA) implants have been developed and used for the treatment of femoral osteochondral defects, their effect on joint contact mechanics during gait has not been assessed. PURPOSE/HYPOTHESIS: The purpose was to quantify the contact mechanics during simulated gait of focal osteochondral femoral defects and synthetic PVA implants (10% and 20% by volume of PVA), with and without porous titanium (pTi) bases. It was hypothesized that PVA implants with a higher polymer content (and thus a higher modulus) combined with a pTi base would significantly improve defect-related knee joint contact mechanics. STUDY DESIGN: Controlled laboratory study. METHODS: Four cylindrical implants were manufactured: 10% PVA, 20% PVA, and 10% and 20% PVA disks mounted on a pTi base. Devices were implanted into 8 mm-diameter osteochondral defects created on the medial femoral condyles of 7 human cadaveric knees. Knees underwent simulated gait and contact stresses across the tibial plateau were recorded. Contact area, peak contact stress, the sum of stress in 3 regions of interest across the tibial plateau, and the distribution of stresses, as quantified by tracking the weighted center of contact stress throughout gait, were computed for all conditions. RESULTS: An osteochondral defect caused a redistribution of contact stress across the plateau during simulated gait. Solid PVA implants did not improve contact mechanics, while the addition of a porous metal base led to significantly improved joint contact mechanics. Implants consisting of a 20% PVA disk mounted on a pTi base significantly improved the majority of contact mechanics parameters relative to the empty defect condition. CONCLUSION: The information obtained using our cadaveric test system demonstrated the mechanical consequences of femoral focal osteochondral defects and provides biomechanical support to further pursue the efficacy of high-polymer-content PVA disks attached to a pTi base to improve contact mechanics. CLINICAL RELEVANCE: As a range of solutions are explored for the treatment of osteochondral defects, our preclinical cadaveric testing model provides unique biomechanical evidence for the continued investigation of novel solutions for osteochondral defects.
BACKGROUND: Although polyvinyl alcohol (PVA) implants have been developed and used for the treatment of femoral osteochondral defects, their effect on joint contact mechanics during gait has not been assessed. PURPOSE/HYPOTHESIS: The purpose was to quantify the contact mechanics during simulated gait of focal osteochondral femoral defects and synthetic PVA implants (10% and 20% by volume of PVA), with and without porous titanium (pTi) bases. It was hypothesized that PVA implants with a higher polymer content (and thus a higher modulus) combined with a pTi base would significantly improve defect-related knee joint contact mechanics. STUDY DESIGN: Controlled laboratory study. METHODS: Four cylindrical implants were manufactured: 10% PVA, 20% PVA, and 10% and 20% PVA disks mounted on a pTi base. Devices were implanted into 8 mm-diameter osteochondral defects created on the medial femoral condyles of 7 human cadaveric knees. Knees underwent simulated gait and contact stresses across the tibial plateau were recorded. Contact area, peak contact stress, the sum of stress in 3 regions of interest across the tibial plateau, and the distribution of stresses, as quantified by tracking the weighted center of contact stress throughout gait, were computed for all conditions. RESULTS: An osteochondral defect caused a redistribution of contact stress across the plateau during simulated gait. Solid PVA implants did not improve contact mechanics, while the addition of a porous metal base led to significantly improved joint contact mechanics. Implants consisting of a 20% PVA disk mounted on a pTi base significantly improved the majority of contact mechanics parameters relative to the empty defect condition. CONCLUSION: The information obtained using our cadaveric test system demonstrated the mechanical consequences of femoral focal osteochondral defects and provides biomechanical support to further pursue the efficacy of high-polymer-content PVA disks attached to a pTi base to improve contact mechanics. CLINICAL RELEVANCE: As a range of solutions are explored for the treatment of osteochondral defects, our preclinical cadaveric testing model provides unique biomechanical evidence for the continued investigation of novel solutions for osteochondral defects.
Authors: Asheesh Bedi; Tony Chen; Thomas J Santner; Saadiq El-Amin; Natalie H Kelly; Russell F Warren; Suzanne A Maher Journal: Proc Inst Mech Eng H Date: 2013-06-26 Impact factor: 1.617
Authors: Joshua D Harris; Kraig K Solak; Robert A Siston; Alan Litsky; Jason Richards; David C Flanigan Journal: Orthopedics Date: 2011-01-01 Impact factor: 1.390
Authors: Ronald A Sismondo; Frederick W Werner; Nathaniel R Ordway; Allen O Osaheni; Michelle M Blum; Matthew G Scuderi Journal: Clin Biomech (Bristol, Avon) Date: 2019-04-25 Impact factor: 2.063