Displaying all 13 publications

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  1. Hussin MS, Fernandez J, Ramezani M, Kumar P, Kelly PA
    Comput Methods Biomech Biomed Engin, 2020 Mar;23(4):143-154.
    PMID: 31928215 DOI: 10.1080/10255842.2019.1709118
    Osteoarthritis (OA) is a commonly occurring cartilage degenerative disease. The end stage treatment is Total Knee Arthroplasty (TKA), which can be costly in terms of initial surgery, but also in terms of revision knee arthroplasty, which is quite often required. A novel conceptual knee implant has been proposed to function as a reducer of stress across the joint surface, to extend the period of time before TKA becomes necessary. The objective of this paper is to develop a computational model which can be used to assess the wear arising at the implant articulating surfaces. Experimental wear coefficients were determined from physical testing, the results of which were verified using a semi-analytical model. Experimental results were incorporated into an anatomically correct computational model of the knee and implant. The wear-rate predicted for the implant was 27.74 mm3 per million cycles (MC) and the wear depth predicted was 1.085 mm/MC. Whereas the wear-rate is comparable to that seen in conventional knee implants, the wear depth is significantly higher than for conventional knee prostheses, and indicates that, in order to be viable, wear-rates should be reduced in some way, perhaps by using low-wear polymers.
    Matched MeSH terms: Knee Prosthesis*
  2. Chee, E.K., Ewe, T.W.
    Malays Orthop J, 2010;4(2):0-0.
    MyJurnal
    In total knee arthroplasty, mechanical alignment guides have improved the accuracy of implant alignment, but errors are not uncommon. In the present study, an image-free computer-assisted navigation system was used to analyse the accuracy of an extramedullary (tibial) alignment system, which is based on predetermined, fixed anatomical landmarks. Comparisons were made between two surgeons, with different levels of competency in order to determine if experience affected the accuracy of extramedullary tibial jig placement, in either the coronal and sagittal planes or both planes. The results showed that the accuracy of the extramedullary tibial alignment system, in the coronal plane (in up to 80-87% of cases) was much better than for posterior slope, and sagittal plane. Surgeon experience was not a significant factor.
    Matched MeSH terms: Knee Prosthesis
  3. Anuar MA, Todo M, Nagamine R, Hirokawa S
    ScientificWorldJournal, 2014;2014:586921.
    PMID: 25133247 DOI: 10.1155/2014/586921
    The primary objective of this study is to distinguish between mobile bearing and fixed bearing posterior stabilized knee prostheses in the mechanics performance using the finite element simulation. Quantifying the relative mechanics attributes and survivorship between the mobile bearing and the fixed bearing prosthesis remains in investigation among researchers. In the present study, 3-dimensional computational model of a clinically used mobile bearing PS type knee prosthesis was utilized to develop a finite element and dynamic simulation model. Combination of displacement and force driven knee motion was adapted to simulate a flexion motion from 0° to 135° with neutral, 10°, and 20° internal tibial rotation to represent deep knee bending. Introduction of the secondary moving articulation in the mobile bearing knee prosthesis has been found to maintain relatively low shear stress during deep knee motion with tibial rotation.
    Matched MeSH terms: Knee Prosthesis*
  4. Nurhanisah MH, Jawaid M, Ahmad Azmeer R, Paridah MT
    Disabil Rehabil Assist Technol, 2019 07;14(5):513-520.
    PMID: 29933703 DOI: 10.1080/17483107.2018.1479782
    This study describes a newly developed prosthetic leg socket design for a below-knee amputation. Excessive heat and the resulted perspiration within a prosthetic socket were the most common causes for reporting a reduced quality of life for prosthetic users. The product namely AirCirc means air circulation and it has been designed by approach of medical device design process in providing the amputees to maintain the skin temperature inside the socket. This device has been designed to provide the amputees with comfort and ultimate breathable. In order to design the device, the small hole was made in prosthetic socket surface since it has a function as air circulation. Four types of proposed sockets namely P1, P2, P3 and P4 and one control socket were compared on a single patient to determine the best design of prosthetic socket. The result successfully reveals that by using holes can be maintain the temperature inside prosthetic socket. In addition to the eco-friendly material, the woven kenaf was used as material that provides good strength as compared to glass fibre and offer sustainable and biodegradable product yet provides unique and aesthetic surface as came from woven kenaf itself. The objective of this paper is to provide the airflow prosthetic socket design and optimize the use of natural fibre in prostheses field. Thus, with the use of the environmental friendly material, functionality device and heat removal capability make the device suitable for maintaining a comfortable and healthy environment for prosthesis. Implications of Rehabilitation Newly developed prosthetic leg socket design for a below-knee amputation Device has been designed to provide the amputees with comfort and ultimate breathable Woven kenaf was used as material that provides good strength as compared to glass fibre for sustainable and biodegradable product Results show that by using holes can be maintain the temperature inside prosthetic socket.
    Matched MeSH terms: Knee Prosthesis*
  5. Arif M, Makundala V, Choon DSK
    Med J Malaysia, 2005 Jul;60 Suppl C:99-103.
    PMID: 16381292 MyJurnal
    We report on our early experiences with the Press Fit Condylar Rotating Platform (PFC-RP) total knee replacement prosthesis at University Malaya Medical Centre. This new prosthesis was introduced to Malaysia in 2001. It combines the rotating platform technology of Low Contact Stress (LCS) and the modularity of Press Fit Condylar (PFC) system. We performed 18 knee replacements using cruciate retaining prosthesis without patellar resurfacing in 10 patients and followed them up over a period of 16-month. A new operative strategy was developed to match the flexion and extension gaps. The pre- and post-operative assessments were made according to the American Knee Society Scores (AKSS). Post-operative pain relief, range of motion, knee score and functional score showed promising early results. The average knee rating improved from 28 to 91 (range 75-94). Average functional assessment improved from 26 to 82 (range 75-90). The radiographic assessments show correction of an average pre-operative varus of 140 to post-operative valgus of 50 (range 4-70). Early infection occurred in two knees. Both responded to aggressive debridement and antibiotics. Stiffness was encountered in one patient. There were no spinouts of the insert. We are satisfied that the implants are performing well at the one-year mark and will continue monitor this cohort.
    Matched MeSH terms: Knee Prosthesis*
  6. Asif S, Choon DS
    J Orthop Surg (Hong Kong), 2005 Dec;13(3):280-4.
    PMID: 16365492
    To evaluate the midterm results of 50 patients who underwent total knee replacement using Press Fit Condylar (PFC) Sigma system.
    Matched MeSH terms: Knee Prosthesis*
  7. Badrul B, Ruslan G
    Med J Malaysia, 2000 Sep;55 Suppl C:93-6.
    PMID: 11200051
    We report a 64 year old man who developed Candida albicans infection following total knee arthroplasty. A two-stage exchange arthroplasty was performed after an initial swab culture grew Acinobacter sp. A scanty growth of yeast was also found from the tissue culture. Intravenous cefuroxime was instituted for six weeks followed by reimplantation four months after the removal. Three weeks after that revision, the prosthesis became infected and a culture of knee aspirate established the diagnosis of Candida albicans infection. Treatment consisted of thorough debridement of the involved joint and oral fluconazole for a year. Infection was never totally resolved and a secondary infection with methicillin resistant staphylococcus aureus then developed. Excision arthroplasty was done at two and a half years after the initial infection. At five years follow-up the infection was quiescent and he had a range of movement of 30 degrees to 70 degrees. Knee brace was used to control the valgus-varus stability.
    Matched MeSH terms: Knee Prosthesis/microbiology*
  8. Fallahiarezoodar A, Abdul Kadir MR, Alizadeh M, Naveen SV, Kamarul T
    Knee Surg Sports Traumatol Arthrosc, 2014 Dec;22(12):3019-27.
    PMID: 25149643 DOI: 10.1007/s00167-014-3227-7
    PURPOSE: Reproducing the femoral rollback through specially designed mechanism in knee implants is required to achieve full knee function in total knee arthroplasty. Most contemporary implants use cam/post mechanism to replace the function of Posterior Cruciate Ligament. This study was aimed to determine the most appropriate cam and post designs to produce normal femoral rollback of the knee.

    METHODS: Three different cams (triangle, ellipse, and circle) and three different posts (straight, convex, concave) geometries were considered in this study and were analysed using kinematic analyses. Femoral rollback did not occur until reaching 50° of knee flexion. Beyond this angle, two of the nine combinations demonstrate poor knee flexion and were eliminated from the study.

    RESULTS: The combination of circle cam with concave post, straight post and convex post showed 15.6, 15.9 and 16.1 mm posterior translation of the femur, respectively. The use of ellipse cam with convex post and straight post demonstrated a 15.3 and 14.9 mm femoral rollback, whilst the combination of triangle cam with convex post and straight post showed 16.1 and 15.8 mm femoral rollback, respectively.

    CONCLUSION: The present study demonstrates that the use of circle cam and convex post created the best femoral rollback effect which in turn produces the highest amount of knee flexion. The findings of the study suggest that if the design is applied for knee implants, superior knee flexion may be possible for future patients.

    LEVEL OF EVIDENCE: IV.

    Matched MeSH terms: Knee Prosthesis*
  9. Yong CK, Choon DS, Soon HC
    J Orthop Surg (Hong Kong), 2008 Aug;16(2):197-200.
    PMID: 18725672
    To present midterm results of Duracon total knee arthroplasty (TKA) performed between 1991 and 2001.
    Matched MeSH terms: Knee Prosthesis*
  10. Tai CC, Cross MJ
    J Bone Joint Surg Br, 2006 Sep;88(9):1158-63.
    PMID: 16943464
    We carried out a prospective study of 118 hydroxyapatite-coated, cementless total knee replacements in patients who were = 55 years of age and who had primary (92; 78%) or post-traumatic (26; 22%) osteoarthritis. The mean period of follow-up was 7.9 years (5 to 12.5). The Knee Society clinical scores improved from a pre-operative mean of 98 (0 to 137) to a mean of 185 (135 to 200) at five years, and 173 (137 to 200) at ten years. There were two revisions of the tibial component because of aseptic loosening, and one case of polyethylene wear requiring further surgery. There was no osteolysis or progressive radiological loosening of any other component. At 12 years, the overall rate of implant survival was 97.5% (excluding exchange of spacer) and 92.1% (including exchange of spacer). Cementless total knee replacement can achieve excellent long-term results in young, active patients with osteoarthritis. In contrast to total hip replacement, polyethylene wear, osteolysis and loosening of the prosthesis were not major problems for these patients, although it is possible that this observation could change with longer periods of follow-up.
    Matched MeSH terms: Knee Prosthesis*
  11. Zairul-Nizam ZF, Badaruddin BS
    J Orthop Surg (Hong Kong), 2006 Aug;14(2):216-8.
    PMID: 16914793
    Infection following total knee arthroplasty can be devastating. Even with established treatment protocols, eradication of the infection may not be feasible. We report 2 patients who required above-knee amputation to eradicate recalcitrant infection.
    Matched MeSH terms: Knee Prosthesis/adverse effects*
  12. Dhillon KS, Askander A, Doraismay S
    J Bone Joint Surg Br, 1996 May;78(3):427-30.
    PMID: 8636180
    Postoperative deep-vein thrombosis (DVT) is believed to be rare in Asians. We studied 88 consecutive patients in Malaysia who had operations for fracture of the proximal femur or for total hip or knee replacement. No patient had prophylaxis against DVT; bilateral ascending venography was performed between six and ten days after operation. A total of 55 patients (62.5%) showed venographic evidence of DVT. The prevalence was greatest after total knee replacement (76.5%), less after total hip replacement (64.3%) and smallest in the fracture group (50%). One patient developed symptomatic pulmonary embolism. In contrast to other reports from Asia, we found an incidence of postoperative DVT which is similar to that reported in Western populations. This suggests that the present practice of withholding routine prophylaxis against thromboembolism in Asian patients undergoing high-risk orthopaedic procedures should be reconsidered.
    Matched MeSH terms: Knee Prosthesis/adverse effects*
  13. Fong TS, Kim SC, Kim JE, Lee ES, Kim TW, Lee YS
    J Arthroplasty, 2019 09;34(9):1929-1937.
    PMID: 31138501 DOI: 10.1016/j.arth.2019.04.061
    BACKGROUND: This study aimed at assessing the morphometry of resected femurs in Korean patients during total knee arthroplasty (TKA) and comparing these measurements with current Western-designed femoral component dimensions.

    METHODS: This single-blind, prospective, randomized, controlled trial involved intraoperative measurements for 271 femoral component implantations from 3 contemporary TKA systems, with 2 systems offering narrow sizing options. The difference between femoral component dimensions and the resected surface of distal femur was measured in millimeters at 5 distinct zones.

    RESULTS: Overhang of standard femoral component was common in the anterior-medial condyle and anterior-lateral condyle ranging from 50.8% to 99.0% and 21.5% to 88.0%, respectively. With narrow femoral components, the rate of overhang reduced to 21.5%-30.2% and 9.2%-32.1%. Conversely, underhang rates were higher over the anterior flange width, middle medial-lateral and posterior medial-lateral zones. Standard components displayed higher underhang rates at these zones compared to narrow components. The good fit rate for femoral component was low among the 3 systems ranging from 1.0% to 56.0%. System with narrow option sizing increases the underhang rates in males, while improving the component fit among females at similar zones with rate ranging from 5.2% to 52.9%.

    CONCLUSION: Currently available TKA implant designs may not provide a perfect match for the distal femoral shape of the Korean population. The availability of implants with standard and narrow options can substantially improve the optimal fitting of femoral components in the Korean population.

    Matched MeSH terms: Knee Prosthesis
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