Influences of Prosthesis Stem Lengths in Cementless Total Hip Arthroplasty

2011 ◽  
Vol 52-54 ◽  
pp. 2088-2093 ◽  
Author(s):  
Abdul Halim Abdullah ◽  
Emmi Farisa Jaafar ◽  
Nursalbiah Nasir ◽  
Eli Nadia Abdul Latip ◽  
Giha Tardan
Keyword(s):  
Stress Distribution ◽  
Hip Arthroplasty ◽  
Maximum Stress ◽  
Stress Shielding ◽  
Primary Stability ◽  
Middle Region ◽  
Cementless Total Hip Arthroplasty ◽  
Calculated Stress ◽  
Long Stem ◽  
Stability Issues

Stress shielding phenomenon is an important issues in considering the primary stability of the cementless hip arthroplasty. Stress shielding occurs when there is a mismatch in the elastic modulus of two materials perfectly bonded to each other, such as the prosthesis stem and the bone. In this study, influences of different prosthesis stem lengths on stress distribution in cementless THA are examined using finite element method. The calculated stress distribution is discussed with respect to stress shielding and primary stability issues in THA femur cases. Results show that similar pattern in stress distribution for intact and THA femur but differs in magnitudes. The stress level increases from the neck to the middle region and peaks at locations coinciding with the tip of the prosthesis. The maximum stress for intact femur is 55.5 MPa, THA with short stem is defined up to 112 MPa, while with medium and long stem are 204 MPa and 278 MPa, respectively.

scholarly journals Preventing Loss of Femoral Periprosthetic Bone Mineral Density in Cementless Total Hip Arthroplasty Using a Tapered Wedge Stem in Patients With Osteoporosis Treated With Denosumab: a Retrospective, Cohort Study

2021 ◽  
Author(s):  
Keiji Kamo ◽  
Hiroaki Kijima ◽  
Koichiro Okuyama ◽  
Tetsuya Kawano ◽  
Nobutoshi Seki ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Total Hip Arthroplasty ◽  
Bone Mineral ◽  
Hip Arthroplasty ◽  
Stress Shielding ◽  
Control Group ◽  
Mineral Density ◽  
Total Hip ◽  
Cementless Total Hip Arthroplasty ◽  
Periprosthetic Bone Mineral Density

Abstract Background: Bone mineral density (BMD) of the proximal femur around the stem decreases due to stress shielding after cementless total hip arthroplasty (THA). When severe stress shielding occurs, the risk of periprosthetic femoral fractures increases, and this bone loss can also increase the difficulty of future revision THA. Denosumab is known to improve the quality and strength of cortical bone in the proximal femurs of patients with osteoporosis. The purpose of this study was to investigate whether denosumab prevents loss of proximal femoral periprosthetic BMD in cementless THA using a tapered wedge stem in patients with osteoporosis.Methods: Sixty-three consecutive patients who had undergone unilateral primary THA using a tapered wedge stem were included in this retrospective study. Twenty-four patients who received denosumab for osteoporosis were the denosumab group, and the 39 without denosumab were the control group. At 2 weeks, 6 months, and 12 months after THA, bone turnover markers and femoral periprosthetic BMD were measured.Results: BMD in zone 1 was significantly increased from baseline at both 6 and 12 months after THA in the denosumab group and significantly decreased in the control group. BMD in zone 7 was significantly decreased compared to baseline at both 6 and 12 months after THA in the control group, but not in the denosumab group. The use of denosumab for THA patients with osteoporosis was independently related to preventing loss of periprosthetic BMD of the femur at 12 months after surgery in zones 1 and 7 on multivariate analysis.Conclusions: Denosumab significantly increased proximal femoral periprosthetic BMD in zone 1 and prevented loss of BMD in zone 7 in patients with osteoporosis after cementless THA using a tapered wedge stem at both 6 and 12 months after surgery.

Effects of Prosthesis Stem Materials on Stress Distribution of Total Hip Replacement

2010 ◽  
Vol 129-131 ◽  
pp. 343-347 ◽  
Author(s):  
Abdul Halim Abdullah ◽  
Alias Mohd Saman ◽  
Mohd Asri Mohd Nor ◽  
Ishkrizat Taib ◽  
Giha Tardan
Keyword(s):  
Finite Element Method ◽  
Material Properties ◽  
Hip Replacement ◽  
Stress Shielding ◽  
Distal Region ◽  
Stress Distributions ◽  
Middle Region ◽  
Femur Bone ◽  
Calculated Stress ◽  
Intact Femur

Bone loss and bone thickening phenomenon occurred due to different stiffness of the implant and femur. Implant with stiffer materials than the bone carries majority of the load and it transferred down along the implant till the distal tip of the stem. Both phenomenons contribute to stress shielding and loosening of the prosthesis stem. In this study, the stress distributions in intact femur and THR femur are established using finite element method. The THR femur model consists of cemented hip Ti6Al4V and CoCrMo prosthesis stem implanted inside the femur bone. Effects of different material properties of the prosthesis stem on the resulting stress distributions are investigated. Results shows that the largest discrepancy in stress values between intact and THR femur is predicted along the middle region at both lateral and medial planes. The distal region shows that the calculated stress for both THR femur experienced higher stress magnitude than that of intact femur. The higher stress in THR femur leads to bone thickening at the particular region. The corresponding stress magnitude saturates at 25 MPa for THR femur while intact femur is slightly lower at 22 MPa.

Evaluation of Stress Shielding for Three Types of Implanted Femurs Based on Stress Distribution

2013 ◽  
Vol 459 ◽  
pp. 524-529
Author(s):  
Koki Ouchi ◽  
Gang Deng ◽  
Go Yamako ◽  
Etsuo Chosa ◽  
Tsutomu Nakanishi
Keyword(s):  
Total Hip Arthroplasty ◽  
Stress Distribution ◽  
Hip Arthroplasty ◽  
Stress Shielding ◽  
Stress Distributions ◽  
The Finite Element Method ◽  
Gruen Zone ◽  
Total Hip ◽  
Method Analysis ◽  
Thrust Plate Prosthesis

This research investigates the stress distribution of the three types of implanted femurs using the finite element method analysis. The comparisons of the stress distribution between the implanted femursand the healthy femur were performed and the characteristics in the stress shielding of each casewere clarified. Since the load is transferred on the contact surface between the implant and the inner surface of the femur in the case of the total hip arthroplasty, the stress in the intertrochanteric zone (Gruen zone 7) become very small, and the phenomenon of the stress shielding is confirmed obviously. The stress distributions of the femurs afterthe resurfacing hiparthroplasty and the thrust plate prosthesis are about the same with that of the healthy femur, so, the possibility of the stress shielding is considered lower compared with the femur after the total hip arthroplasty. However, considering the stress concentration thatwill increase the risk of femoral fracture caused by the screws for the fixation of the implant in the thrust plate prosthesis, the resurfacing hiparthroplastymay beconcluded as the best method among these three types of implants to avoid stress shielding.

scholarly journals Periprosthetic fragility fracture of the femur after primary cementless total hip arthroplasty

2021 ◽  
Author(s):  
Masanobu Hirao ◽  
Kazumasa Miyatake ◽  
Ryohei Takada ◽  
Tetsuya Tachibana ◽  
Atsushi Okawa ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Fragility Fracture ◽  
Survival Rates ◽  
Stress Shielding ◽  
Epidemiological Data ◽  
Total Hip ◽  
Cementless Total Hip Arthroplasty ◽  
End Point ◽  
Significant Difference

ABSTRACT Objectives Periprosthetic bone fragility due to stress shielding (SS) can be a risk factor of periprosthetic fracture after cementless total hip arthroplasty (THA). We aimed to obtain epidemiological information on periprosthetic fragility fracture of the femur (PPFF) after THA. Methods We retrospectively reviewed the medical records of 1062 hips that had undergone cementless THA. We evaluated the epidemiological data as well as the features of PPFFs. Results Of the 1062 hips, 8 (0.8%) were diagnosed with PPFFs. The survival rates, with the occurrence of PPFF as the end point, were 99.2% and 97.6% at 10 and 16 years postoperatively, respectively. When patients were classified as having either mild or severe SS on radiographs 5 years postoperatively, there was no significant difference in the survival rate, with PPFF as the end point. Conclusions In our cases, the incidence of PPFF after cementless THA was 0.8%.

Average Periosteal Stress of the Proximal Femur Before and After Cementless Total Hip Arthroplasty

2009 ◽  
Author(s):  
Joseph D. Yutzy ◽  
Erik R. Bardy
Keyword(s):  
Total Hip Arthroplasty ◽  
Hip Arthroplasty ◽  
Stress Shielding ◽  
Stress Distributions ◽  
Stress Concentrations ◽  
Total Hip ◽  
Cementless Total Hip Arthroplasty ◽  
Before And After ◽  
Hip Replacements ◽  
Neck Fracture

Cementless Total Hip Arthroplasty (THA) is a standard surgical technique for the treatment of several types of joint diseases and damages including, but not limited to, osteoarthritis and femoral neck fracture [1]. An estimated one half to one million total hip replacements are performed each year [2]. Two drawbacks to THA are (1): micromotions as a result of improper implant fit in the bone cavity [1], and (2): stress shielding due to unnatural stress concentrations near the implant [3]. The latter causes bone resorption in other areas found in the bone-implant interface [1]. Therefore, the geometry and size of the implant is a major factor in determining cortical stress distributions and stress shielding [4].

Sign in / Sign up

Export Citation Format

Share Document