The Effect of Stem Stiffness on Femoral Bone Resorption After Canine Porous-Coated Total Hip Arthroplasty

Bobyn, J. D.; Glassman, Andrew H.; Goto, Hisataka; Krygier, Jan; Miller, Joseph E.; Brooks, C.E.

doi:10.1097/00003086-199012000-00022

Cited by 149 publications

(74 citation statements)

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“…When the material of the prosthesis was changed from titanium to a more flexible material with a reduced elastic modulus, the amount of bone resorption after six months was notably less. 13 Similar results were reported by Bobyn et al, 2 who investigated the effects of massive and more flexible hollow hip stems on bone-resorption patterns in the dog. This effect of stem stiffness on the extent of bone resorption was also reported from clinical roentgenographic studies of patients by Engh and Bobyn,8 this time related to the thickness of the stem instead of its elastic modulus.…”

supporting

confidence: 68%

“…In the remodeling analyses, the effects of several factors were studied: (1) the extent of the dead zone in the remodeling rule was reduced from s = 0.75 to s = 0.35 to study the effects of differences in bone reactivity; (2) the stiffness characteristics of the bone were varied from E = Cp3 [equation (i)] to E = C(2p)3, 2p:S 1.73 gr!cm 3 , hence, a thicker cortex and trabecular bone twice as dense, to study the effects of a stiffer bone relative to the implant; and (3) the elastic modulus of the stem was varied from E = 1.1 X 10 5 MPa (titanium) to E = 0.2 X 10 5 MPa, to study the effect of a flexible, isoelastic stem material. In all these cases, a complete remodeling analysis was performed to predict the long-term morphology.…”

Section: Ma Terials and Methodsmentioning

confidence: 99%

“…This indicates a biomechanical effect, for it coincides with the effect on stress shielding. 2,16,18,21 Assuming that the bone-remodeling effects around prostheses are indeed caused by biomechanical adaptation mechanisms, and neglecting other factors, this process can be studied analytically, using strain-adaptive boneremodeling theories. 3,6,18 These theories are quantitative formulations of Wolff's Law, mathematical descriptions of the net bone modeling and remodeling process.…”

mentioning

confidence: 99%

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The Relationship Between Stress Shielding and Bone Resorption Around Total Hip Stems and the Effects of Flexible Materials

Huiskes

Weinans²,

Rietbergen

1992

Clinical Orthopaedics and Related Research

923

636

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supporting

confidence: 68%

Section: Ma Terials and Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

The Relationship Between Stress Shielding and Bone Resorption Around Total Hip Stems and the Effects of Flexible Materials

Huiskes

Weinans²,

Rietbergen

1992

Clinical Orthopaedics and Related Research

923

636

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“…However, the problems of osteolysis due to polyethylene wear particles and bone atrophy because of stress shielding mean that the long-term stability of uncemented THA is still in question [7,14,24]. The length, design, composition, and elasticity of a stem, as well as the extent of its porous coating, have all been pointed out as factors that influence stress shielding postoperatively [1,2,11]. Bone mineral density (BMD) can be measured with a high degree of accuracy by the use of dual-energy X-ray absorptiometry (DEXA) [13,25].…”

Section: Introductionmentioning

confidence: 99%

Changes of bone mineral density after cementless total hip arthroplasty with two different stems

Sano

Ito

Yamamoto

2007

International Orthopaedics (SICO

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Cementless total hip arthroplasty has achieved reliable long-term results since porous coatings were developed, but postoperative changes around the stem remain poorly documented. In this study, changes of the bone mineral density (BMD) were compared between two types of cementless stem. In group B (28 patients with 31 hips), a straight tapered stem with porous plasma spray coating on the proximal 1/4 was used, while group S (24 patients with 26 hips) was given a fluted, tri-slot stem with porous hydroxyapatite coating on the proximal 1/3. In group B, there was an early decrease of BMD, which recovered after 12 months, indicating that stress shielding was minimal. In group S, however, BMD continued to decrease without recovery. The stem shape and radiological findings suggested that the cause of stress shielding in group S was distal fixation.Résumé Les prothèses totales de hanche sans ciment ont de bons résultats à long terme, notamment depuis qu'ont été développées les techniques de revêtement poreux, mais les modifications post opératoires autour de la pièce fémorale, ont été jusqu'à présent peu documentées. Dans cette étude, nous avons souhaité étudier les modifications de la densité osseuse (BMD) en comparant deux types de prothèses sans ciment. Dans le groupe B (28 patients, 31 hanches) une pièce fémorale droite avec un plasma spray proximal pour le groupe S (24 patients, 26 hanches) la pièces fémorale a été recouverte d'hydroxyapatite sur le tiers proximal. Les patients du groupe B ont présenté une diminution précoce de la BMD indiquant un stress shielding minime et dans le groupe S, la BMD diminue sans récupération alors que cette BMB réaugmente dans le groupe B. Ceci nous indique que la cause du stress shielding dans le groupe S est secondaire à la fixation distale.

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“…These findings directly support the canine study by Bobyn, et al that found substantially more bone around the femoral stem with implants made of titanium than with implants made of cobalt-chromium. 10 Through completing this laboratory exercise, the students learned that by applying fundamental principles learned in a sophomore-level engineering class to the design of the total hip replacement, they could have reached the same conclusions that took many years (even decades) for the actual designers to reach by trial and error. Numerous sophisticated computational models of the total hip replacement and large-scale evaluations of clinical results have been completed to confirm what the students in these laboratory sections demonstrated in a few hours.…”

Section: Discussionmentioning

confidence: 98%

Using Stress Shielding in Hip Implants as a Case Study to Teach Loading of Composite Beams

Ashby

Reffeor

2016 ASEE Annual Conference &Amp; Exposition Proceedings

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A laboratory activity was developed in which the students modeled and analyzed the femoral portion of an artificial hip replacement as a composite beam. A historical challenge with artificial hip replacements has been that the stiffer artificial femoral component shields the surrounding bone from stresses during physiological activities. This phenomenon, known as "stress shielding," results in bone resorption that can lead to implant failure. In this activity, the students investigated the extent of stress shielding for femoral implants of varying sizes and material properties for different loading conditions. The students discovered that making the femoral component smaller and of more compliant material minimizes the detrimental effects of stress shielding in hip replacements.The effectiveness of this hip implant activity was studied by comparing it with the traditional laboratory in which the students were tasked with designing a composite beam out of various materials to satisfy rigidity and cost constraints. Students from two laboratory sections completed the traditional composite beams exercise, and students from two laboratory sections completed the hip implant case study. The students from both groups were surveyed before and after the laboratory exercises to determine their confidence in the course material, their interest in the course, and their perception of the real-world relevance of the course.In the post-exercise survey, students were asked all of the questions from the pre-exercise survey as well as questions to determine the effectiveness of the exercise as a teaching tool and the adequacy of the instruction they received. Students consistently felt the hip implant activity was more effective as a teaching tool for the material and were more interested in biomedical engineering than those completing the traditional exercise. The students who completed the hip implant activity expressed greater confidence in their abilities to interpret the results for bending calculations and to design a machine using bending. Overall, the results of the student perception surveys indicate that the hip replacement activity was a better tool for teaching the composite beam theory and had the added benefit of introducing students to biomedical engineering applications of fundamental mechanics principles.

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The Effect of Stem Stiffness on Femoral Bone Resorption After Canine Porous-Coated Total Hip Arthroplasty

Cited by 149 publications

References 0 publications

The Relationship Between Stress Shielding and Bone Resorption Around Total Hip Stems and the Effects of Flexible Materials

The Relationship Between Stress Shielding and Bone Resorption Around Total Hip Stems and the Effects of Flexible Materials

Changes of bone mineral density after cementless total hip arthroplasty with two different stems

Using Stress Shielding in Hip Implants as a Case Study to Teach Loading of Composite Beams

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