Displaying publications 1 - 20 of 40 in total

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  1. Nagentrau M, Mohd Tobi AL, Jamian S, Otsuka Y, Hussin R
    J Mech Behav Biomed Mater, 2021 10;122:104657.
    PMID: 34246851 DOI: 10.1016/j.jmbbm.2021.104657
    Present research aims to develop a finite element computational model to examine delamination-fretting wear behaviour that can suitably mimic actual loading conditions at HAp-Ti-6Al-4V interface of uncemented hip implant femoral stem component. A simple finite element contact configuration model based on fretting fatigue experimental arrangement subjected to different mechanical and tribological properties consist of contact pad (bone), HAp coating and Ti-6Al-4V substrate are developed using adaptive wear modelling approach adopting modified Archard wear equation to be examined under static simulation. The developed finite element model is validated and verified with reported literatures. The findings revealed that significant delamination-fretting wear is recorded at contact edge (leading edge) as a result of substantial contact pressure and contact slip driven by stress singularity effect. The delamination-fretting wear behaviour is promoted under higher delamination length, lower normal loading with higher fatigue loading, increased porous (cancellous) and cortical bone elastic modulus with higher cycle number due to significant relative slip amplitude as the result of reduced interface rigidity. Tensile-compressive condition (R=-1) experiences most significant delamination-fretting wear behaviour (8 times higher) compared to stress ratio R=0.1 and R=10.
    Matched MeSH terms: Hip Prosthesis*
  2. Sun C, Lee WG, Ma Q, Zhang X, Zhao Z, Cai X
    J Orthop Surg Res, 2023 Aug 08;18(1):586.
    PMID: 37553600 DOI: 10.1186/s13018-023-04023-w
    BACKGROUND: The positioning of implant components for total hip arthroplasty (THA) is essential for joint stability, polyethylene liner wear, and range of motion. One potential benefit of the direct anterior approach (DAA) for THA is the ability to use intraoperative fluoroscopy for acetabular cup positioning and limb-length evaluation. Previous studies comparing intraoperative fluoroscopy with no fluoroscopy during DAA have reported conflicting results. This meta-analysis aimed to evaluate whether intraoperative fluoroscopy improves component positioning compared to no fluoroscopy during direct anterior total hip arthroplasty.

    METHODS: A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted. We searched Web of Science, EMBASE, PubMed, Cochrane Controlled Trials Register, Cochrane Library, Highwire, CBM, CNKI, VIP, and Wanfang database in May 2023 to identify studies involving intraoperative fluoroscopy versus no fluoroscopy during direct anterior total hip arthroplasty. Finally, we identified 1262 hips assessed in seven studies.

    RESULTS: There were no significant differences in terms of acetabular cup inclination angle (ACIA, P = 0.21), ACIA within safe zone rate (P = 0.97), acetabular cup anteversion angle (ACAA, P = 0.26); ACAA within safe zone rate (P = 0.07), combined safe zone rate (P = 0.33), and limb-length discrepancy (LLD, P = 0.21) between two groups.

    CONCLUSION: Even though intraoperative fluoroscopy was not related to an improvement in cup location or LDD. With fewer experienced surgeons, the benefit of intraoperative fluoroscopy might become more evident. More adequately powered and well-designed long-term follow-up studies were required to determine whether the application of the intraoperative fluoroscopy for direct anterior total hip arthroplasty will have clinical benefits and improve the survival of prostheses.

    Matched MeSH terms: Hip Prosthesis*
  3. Soliman MM, Islam MT, Chowdhury MEH, Alqahtani A, Musharavati F, Alam T, et al.
    J Mater Chem B, 2023 Nov 15;11(44):10507-10537.
    PMID: 37873807 DOI: 10.1039/d3tb01469j
    The UK's National Joint Registry (NJR) and the American Joint Replacement Registry (AJRR) of 2022 revealed that total hip replacement (THR) is the most common orthopaedic joint procedure. The NJR also noted that 10-20% of hip implants require revision within 1 to 10 years. Most of these revisions are a result of aseptic loosening, dislocation, implant wear, implant fracture, and joint incompatibility, which are all caused by implant geometry disparity. The primary purpose of this review article is to analyze and evaluate the mechanics and performance factors of advancement in hip implants with novel geometries. The existing hip implants can be categorized based on two parts: the hip stem and the joint of the implant. Insufficient stress distribution from implants to the femur can cause stress shielding, bone loss, excessive micromotion, and ultimately, implant aseptic loosening due to inflammation. Researchers are designing hip implants with a porous lattice and functionally graded material (FGM) stems, femur resurfacing, short-stem, and collared stems, all aimed at achieving uniform stress distribution and promoting adequate bone remodeling. Designing hip implants with a porous lattice FGM structure requires maintaining stiffness, strength, isotropy, and bone development potential. Mechanical stability is still an issue with hip implants, femur resurfacing, collared stems, and short stems. Hip implants are being developed with a variety of joint geometries to decrease wear, improve an angular range of motion, and strengthen mechanical stability at the joint interface. Dual mobility and reverse femoral head-liner hip implants reduce the hip joint's dislocation limits. In addition, researchers reveal that femoral headliner joints with unidirectional motion have a lower wear rate than traditional ball-and-socket joints. Based on research findings and gaps, a hypothesis is formulated by the authors proposing a hip implant with a collared stem and porous lattice FGM structure to address stress shielding and micromotion issues. A hypothesis is also formulated by the authors suggesting that the utilization of a spiral or gear-shaped thread with a matched contact point at the tapered joint of a hip implant could be a viable option for reducing wear and enhancing stability. The literature analysis underscores substantial research opportunities in developing a hip implant joint that addresses both dislocation and increased wear rates. Finally, this review explores potential solutions to existing obstacles in developing a better hip implant system.
    Matched MeSH terms: Hip Prosthesis*
  4. Oshkour AA, Abu Osman NA, Davoodi MM, Yau YH, Tarlochan F, Wan Abas WA, et al.
    Int J Numer Method Biomed Eng, 2013 Dec;29(12):1412-27.
    PMID: 23922316 DOI: 10.1002/cnm.2583
    This study focused on developing a 3D finite element model of functionally graded femoral prostheses to decrease stress shielding and to improve total hip replacement performance. The mechanical properties of the modeled functionally graded femoral prostheses were adjusted in the sagittal and transverse planes by changing the volume fraction gradient exponent. Prostheses with material changes in the sagittal and transverse planes were considered longitudinal and radial prostheses, respectively. The effects of cemented and noncemented implantation methods were also considered in this study. Strain energy and von Mises stresses were determined at the femoral proximal metaphysis and interfaces of the implanted femur components, respectively. Results demonstrated that the strain energy increased proportionally with increasing volume fraction gradient exponent, whereas the interface stresses decreased on the prostheses surfaces. A limited increase was also observed at the surfaces of the bone and cement. The periprosthetic femur with a noncemented prosthesis exhibited higher strain energy than with a cemented prosthesis. Radial prostheses implantation displayed more strain energy than longitudinal prostheses implantation in the femoral proximal part. Functionally graded materials also increased strain energy and exhibited promising potentials as substitutes of conventional materials to decrease stress shielding and to enhance total hip replacement lifespan.
    Matched MeSH terms: Hip Prosthesis*
  5. Choudhury D, Ay Ching H, Mamat AB, Cizek J, Abu Osman NA, Vrbka M, et al.
    J Biomed Mater Res B Appl Biomater, 2015 Jul;103(5):1002-12.
    PMID: 25220737 DOI: 10.1002/jbm.b.33274
    Diamond like carbon (DLC) is applied as a thin film onto substrates to obtain desired surface properties such as increased hardness and corrosion resistance, and decreased friction and wear rate. Microdimple is an advanced surface modification technique enhancing the tribological performance. In this study, DLC coated microdimples were fabricated on hip prosthesis heads and their mechanical, material and surface properties were characterized. An Electro discharge machining (EDM) oriented microdrilling was utilized to fabricate a defined microdimple array (diameter of 300 µm, depth of 70 µm, and pitch of 900 µm) on stainless steel (SS) hip prosthesis heads. The dimpled surfaces were then coated by hydrogenated amorphous carbon (a-C:H) and tetrahedral amorphous carbon (Ta-C) layers by using a magnetron sputtering technology. A preliminary tribology test was conducted on these fabricated surfaces against a ceramic ball in simulated hip joint conditions. It was found that the fabricated dimples were perpendicular to the spherical surfaces and no cutting-tools wear debris was detected inside the individual dimples. The a-C:H and Ta-C coatings increased the hardness at both the dimple edges and the nondimpled region. The tribology test showed a significant reduction in friction coefficient for coated surfaces regardless of microdimple arrays: the lowest friction coefficient was found for the a-C:H samples (µ = 0.084), followed by Ta-C (µ = 0.119), as compared to the SS surface (µ = 0.248).
    Matched MeSH terms: Hip Prosthesis*
  6. Hafizh M, Soliman MM, Qiblawey Y, Chowdhury MEH, Islam MT, Musharavati F, et al.
    Biosensors (Basel), 2023 Jan 02;13(1).
    PMID: 36671914 DOI: 10.3390/bios13010079
    In this paper, a surface acoustic wave (SAW) sensor for hip implant geometry was proposed for the application of total hip replacement. A two-port SAW device was numerically investigated for implementation with an operating frequency of 872 MHz that can be used in more common radio frequency interrogator units. A finite element analysis of the device was developed for a lithium niobate (LiNBO3) substrate with a Rayleigh velocity of 3488 m/s on COMSOL Multiphysics. The Multiphysics loading and frequency results highlighted a good uniformity with numerical results. Afterwards, a hip implant geometry was developed. The SAW sensor was mounted at two locations on the implant corresponding to two regions along the shaft of the femur bone. Three discrete conditions were studied for the feasibility of the implant with upper- and lower-body loading. The loading simulations highlighted that the stresses experienced do not exceed the yield strengths. The voltage output results indicated that the SAW sensor can be implanted in the hip implant for hip implant-loosening detection applications.
    Matched MeSH terms: Hip Prosthesis*
  7. Ab Shukor NS, Abdullah R, Abdul Aziz MZ, Samson DO, Musarudin M
    Appl Radiat Isot, 2023 Jun;196:110751.
    PMID: 36871495 DOI: 10.1016/j.apradiso.2023.110751
    The present study was conducted to elucidate the effects of hip prostheses in 192Ir HDR brachytherapy and determine dose uncertainties introduced by the treatment planning. A gynaecological phantom irradiated using Nucletron 192Ir microSelectron HDR source was modeled using MCNP5 code. Three hip materials considered in this study were water, bone, and metal prosthesis. According to the obtained results, a dose perturbation was observed within the medium with a higher atomic number, which reduced the dose to the nearby region.
    Matched MeSH terms: Hip Prosthesis*
  8. Sivananthan, K., Drabu, K.J.
    Malays Orthop J, 2009;3(1):42-45.
    MyJurnal
    The number of hip replacement procedures in the United States is expected to increase four-fold by 2030. Younger patients, those under 65 years old, are expected to account for 53% of hip replacements in 2030, compared to 44% in 2005. As midterm review results are becoming available worldwide now, the problem that perplexes surgeons is the alteration of limb length which has been an ancillary goal of Total Hip Replacements. The lack of modularity in neck lengths and offsets in resurfacing arthroplasty clearly limits the change in limb lengths achievable for the hip. The goal of this study is to scrutinize the various parameters that affect implant seating in resurfacing arthroplasty and to determine the alteration of limb length achievable during surgery.
    Matched MeSH terms: Hip Prosthesis
  9. Surinder S, George P
    Med J Malaysia, 2017 02;72(1):71-72.
    PMID: 28255148 MyJurnal
    Fracture of hip prostheses is a rare occurrence. A case of bilateral hip prostheses fracture is described here. The need to follow-up and remain vigilant post hip replacement is highlighted.
    Matched MeSH terms: Hip Prosthesis
  10. Oshkour AA, Talebi H, Seyed Shirazi SF, Yau YH, Tarlochan F, Abu Osman NA
    Artif Organs, 2015 Feb;39(2):156-64.
    PMID: 24841371 DOI: 10.1111/aor.12315
    This study aimed to assess the performance of different longitudinal functionally graded femoral prostheses. This study was also designed to develop an appropriate prosthetic geometric design for longitudinal functionally graded materials. Three-dimensional models of the femur and prostheses were developed and analyzed. The elastic modulus of these prostheses in the sagittal plane was adjusted along a gradient direction from the distal end to the proximal end. Furthermore, these prostheses were composed of titanium alloy and hydroxyapatite. Results revealed that strain energy, interface stress, and developed stress in the femoral prosthesis and the bone were influenced by prosthetic geometry and gradient index. In all of the prostheses with different geometries, strain energy increased as gradient index increased. Interface stress and developed stress decreased. The minimum principal stress and the maximum principal stress of the bone slightly increased as gradient index increased. Hence, the combination of the femoral prosthetic geometry and functionally graded materials can be employed to decrease stress shielding. Such a combination can also be utilized to achieve equilibrium in terms of the stress applied on the implanted femur constituents; thus, the lifespan of total hip replacement can be prolonged.
    Matched MeSH terms: Hip Prosthesis*
  11. Baharuddin MY, Salleh ShH, Suhasril AA, Zulkifly AH, Lee MH, Omar MA, et al.
    Artif Organs, 2014 Jul;38(7):603-8.
    PMID: 24404766 DOI: 10.1111/aor.12222
    Total hip arthroplasty is a flourishing orthopedic surgery, generating billions of dollars of revenue. The cost associated with the fabrication of implants has been increasing year by year, and this phenomenon has burdened the patient with extra charges. Consequently, this study will focus on designing an accurate implant via implementing the reverse engineering of three-dimensional morphological study based on a particular population. By using finite element analysis, this study will assist to predict the outcome and could become a useful tool for preclinical testing of newly designed implants. A prototype is then fabricated using 316L stainless steel by applying investment casting techniques that reduce manufacturing cost without jeopardizing implant quality. The finite element analysis showed that the maximum von Mises stress was 66.88 MPa proximally with a safety factor of 2.39 against endosteal fracture, and micromotion was 4.73 μm, which promotes osseointegration. This method offers a fabrication process of cementless femoral stems with lower cost, subsequently helping patients, particularly those from nondeveloped countries.
    Matched MeSH terms: Hip Prosthesis/economics*
  12. Choudhury D, Lackner JM, Major L, Morita T, Sawae Y, Bin Mamat A, et al.
    J Mech Behav Biomed Mater, 2016 06;59:586-595.
    PMID: 27085502 DOI: 10.1016/j.jmbbm.2016.04.004
    This study investigates the durability of functional diamond-like carbon (DLC) coated titanium alloy (Ti-6Al-4V) under edge loading conditions for application in artificial hip joints. The multilayered (ML) functional DLC coatings consist of three key layers, each of these layers were designed for specific functions such as increasing fracture strength, adapting stress generation and enhancing wear resistance. A 'ball-on-disk' multi-directional wear tester was used in the durability test. Prior to the wear testing, surface hardness, modulus elasticity and Raman intensity were measured. The results revealed a significant wear reduction to the DLC coated Ti-6Al-4V disks compared to that of non-coated Ti-6Al-4V disks. Remarkably, the counterpart Silicon Nitride (Si3N4) balls also yielded lowered specific wear rate while rubbed against the coated disks. Hence, the pairing of a functional multilayered DLC and Si3N4 could be a potential candidate to orthopedics implants, which would perform a longer life-cycle against wear caused by edge loading.
    Matched MeSH terms: Hip Prosthesis*
  13. Alkhatib SE, Tarlochan F, Mehboob H, Singh R, Kadirgama K, Harun WSBW
    Artif Organs, 2019 Jul;43(7):E152-E164.
    PMID: 30805945 DOI: 10.1111/aor.13444
    The mismatch between stiffness of the femoral dense stem and host bone causes complications to patients, such as aseptic loosening and bone resorption. Three-dimensional finite-element models of homogeneous porous (HGP) and functionally graded porous (FGP) stems incorporating body-centered cubic (BCC) structures are proposed in this article as an alternative to the dense stems. The relationship between the porosity and strut thickness of the BCC structure was developed to construct the finite-element models. Three levels of porosities (20%, 50%, and 80%) were modeled in HGP and FGP stems. The porosity of the stems was decreased distally according to the sigmoid function (n = 0.1, n = 1 and n = 10) with 3 grading exponents. The results showed that FGP stems transferred 120%-170% higher stresses to the femur (Gruen zone 7) as compared to the solid stem. Conversely, the stresses in HGP and FGP stems were 12%-34% lower than the dense stem. The highest micromotions (105-147 µm) were observed for stems of 80% overall porosity, and the lowest (42-46 µm) was for stems of 20% overall porosity. Finally, FGP stems with a grading exponent of n = 10 resulted in an 11%-28% reduction in micromotions.
    Matched MeSH terms: Hip Prosthesis*
  14. Choudhury D, Vrbka M, Mamat AB, Stavness I, Roy CK, Mootanah R, et al.
    J Mech Behav Biomed Mater, 2017 08;72:192-199.
    PMID: 28500998 DOI: 10.1016/j.jmbbm.2017.05.011
    Coefficient of friction (COF) tests were conducted on 28-mm and 36-mm-diameter hip joint prostheses for four different material combinations, with or without the presence of Ultra High Molecular Weight Polyethylene (UHMWPE) particles using a novel pendulum hip simulator. The effects of three micro dimpled arrays on femoral head against a polyethylene and a metallic cup were also investigated. Clearance played a vital role in the COF of ceramic on polyethylene and ceramic on ceramic artificial hip joints. Micro dimpled metallic femoral heads yielded higher COF against a polyethylene cup; however, with metal on metal prostheses the dimpled arrays significantly reduced the COF. In situ images revealed evidence that the dimple arrays enhanced film formation, which was the main mechanism that contributed to reduced friction.
    Matched MeSH terms: Hip Prosthesis*
  15. Raj JJ, Thompson M, Whitehouse SL, Jaiprakash A, Varughese I, Crawford RW
    Proc Inst Mech Eng H, 2023 Mar;237(3):368-374.
    PMID: 36734414 DOI: 10.1177/09544119231152351
    Standard practice for acetabular component placement in total hip arthroplasty (THA) is to medialise the acetabular component. Bone preservation techniques during primary THA are beneficial for possible future revisions. The goal of this study is to examine the effect of downsizing and minimising medialisation of the acetabular component on bone resection volume. The volume of bone resected during acetabular preparation for different sizes of components was calculated and the volume of bone preserved by downsizing the cup was determined. Minimising medialisation of the acetabular component by 1-3 mm from the true floor was calculated. Absolute values and percentage of bone volume preserved when acetabular components are downsized or less medialised is presented. Downsizing the acetabular component by one size (2 mm) preserves between 2.6 cm3 (size 40 vs 42) and 8.4 cm3 (size 72 vs 74) of bone volume and consistently reduces resected bone volume by at least 35% (range 35.2%-37.5%). Similarly, reducing medialisation of a 56 mm acetabular cup (as an example of a commonly implanted component) by 3 mm reduces bone loss by 5.9 cm3- 44% less bone volume resection. Downsizing and minimising medialisation of the cup in THA substantially preserves bone which may benefit future revision surgeries. Surgeons could consider implanting the smallest acceptable acetabular shell to preserve bone without compromising on head size.
    Matched MeSH terms: Hip Prosthesis*
  16. Mohd Syafiq Mohd Suri, Nor Liyana Safura Hashim, Ardiyansyah Syahrom, Mohd Juzaila Abd. Latif, Muhamad Noor Harun
    MyJurnal
    Introduction: The lubricant thickness in clearance between bearing surfaces for metallic hip implants are currently incapable of accommodating the motion experienced (high load and low entraining motion) in hip walking cycle. Thus, micro-dimpled surfaces were introduced onto surfaces of metallic acetabular cups to improve lubricant thick- ness. Micro-dimpled surface is a method of advanced surface improvement to increase the lubricant thickness in various tribological applications, such as hip implants. However, the application of micro-dimpled surfaces in hip implants has not yet been explored adequately. Therefore, this study aims to identify the influence of micro-dimpled depth on lubricant thickness elastohydrodynamically for metallic hip implants using Fluid-Structure Interaction (FSI) approach. Methods: Fluid-Structure Interaction (FSI) approach is an alternative method for analysing characteristics of lubrication in hip implant. Dimples of radius 0.25 mm and various depths of 5μm, 45μm and 100μm were applied on the cup surfaces. The vertical load in z-direction and rotation velocity around y-axes representing the average load and flexion-extension (FE) velocity of hip joint in normal walking were applied on Elastohydrodynamic lubri- cation (EHL) model. Results: The metallic hip implants with micro-dimpled surfaces provided enhanced lubricant thickness, namely by 6%, compared to non-dimpled surfaces. Furthermore, it was suggested that the shallow depth of micro-dimpled surfaces contributed to the enhancement of lubricant thickness. Conclusion: Micro-dimpled sur- faces application was effective to improve tribological performances, especially in increasing lubricant thickness for metallic hip implants.
    Matched MeSH terms: Hip Prosthesis
  17. Solehuddin Shuib, Sahari, B.B., Wong, Shaw Voon, Arumugam, Manohar, Halim Kadarman, A.
    MyJurnal
    Bone is a living tissue. It continuously reproduces its structure and its growth depends partly upon the applied mechanical load. After an implant is inserted, the load equilibrium is disturbed, leading to bone resorption and the stress shielding phenomena. Aseptic loosening is the main contributor for hip prosthesis failure. The purpose of the study is to determine the effect of bone resorption on the stress values and hence obtain a better understanding of the behavior of the stress adaptive bone-remodeling. The bone material used for the analysis was assumed to be isotropic and linearly elastic, and the external loads applied comprised of a femoral head load and an abductor load. A Finite element computer program for evaluating the changes in bone's density and modulus was developed. The values of stress for bone, cement mantle in medial, and lateral positions of Total Hip Replacement (THR) are presented. The failure mechanisms of THR with bone resorption observed the implant loosening since stress is reduced.
    Matched MeSH terms: Hip Prosthesis
  18. Krishnan, H., Yoon, T.R., Park, K.S.
    Malays Orthop J, 2010;4(1):26-31.
    MyJurnal
    This retrospective study was undertaken to analyze perioperative parameters, functional outcomes and complications of cemented versus uncemented bipolar hemiarthroplasty in elderly patients presenting with displaced intracapsular femoral neck fracture. The authors reviewed 17 patients that underwent cemented bipolar hemiarthroplasty and 21 patients that underwent uncemented bipolar hemiarthroplasty. The mean follow-up duration in the cemented and uncemented group was 29.9 and 30.5 months respectively. Intraoperative and postoperative blood loss was higher in the cemented group. On the last follow-up the mean HHS was 74.7 in the cemented group and 84.2 in the uncemented group. No statistically significant difference was evident in the pain score. In summary, bipolar hemiarthroplasty was found to be a good option for displaced intracapsular femoral neck fractures, and overall outcome was marginally better in the uncemented group in terms of postoperative of blood loss and functional outcome at last follow up.
    Matched MeSH terms: Hip Prosthesis
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