Displaying publications 1 - 20 of 95 in total

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  1. Chan CY, Kwan MK, Saw LB
    Surg Radiol Anat, 2011 Jan;33(1):19-25.
    PMID: 20848102 DOI: 10.1007/s00276-010-0726-1
    Pedicle screw instrumentation has superior biomechanical as well as clinical outcome. Thoracic pedicles show great variation in different population groups, particularly in Asians who have been shown to have smaller pedicle dimensions. Although plain radiographs are widely performed prior to spine surgery, no studies have been done so far to investigate whether the thoracic pedicle profile on plain radiographs affect thoracic pedicle screw insertion. Therefore, this is a cadaveric study aimed to determine the relationship between plain radiographic thoracic pedicle profile in Asians and the outcome of pedicle screw insertion in the thoracic spine.
    Matched MeSH terms: Bone Screws*
  2. Harna B, Dutt DD, Sabat D
    Malays Orthop J, 2020 Nov;14(3):174-176.
    PMID: 33403081 DOI: 10.5704/MOJ.2011.028
    Hoffa fractures are rare and difficult fractures to manage. Hoffa fracture involves a coronal plane fracture of posterior femoral condyle. Non-union in Hoffa fracture is further difficult to manage. The surgical management for such nonunion includes open reduction with recon/LCP plate or screw fixation with bone grafting. The problem with plates is the difficulty in contouring the plates according to the shape of posterior femoral condyles. We describe a new technique with 2 L shaped neutralisation plates placed in a circular fashion. This technique provides a more rigid construct and gives better holding strength of screws in Hoffa fragment. This enhances union and mobilisation can be started early.
    Matched MeSH terms: Bone Screws
  3. Nadzirah Mohamad Radzi, Zafri Azran Abdul Majid
    MyJurnal
    Carabiner is one of Personal Protective Equipment (PPE), which is used to protect the users from hazards by reducing any chance of serious injury. Thus, it is very important to detect even a small
    defect on the component before it becomes worse that could give harm to the users. The aim of this paper is to find out the appropriate imaging technical factors of steel carabiner by using computed radiography (CR). Methods: Radiographic images of carabiner were obtained by manipulating the values of kVp and mAs with respect to contrast and density. A preliminary study was carried out to determine the exposure factor combination in order to produce perceptible visual quality of radiographic images. Positioning techniques applied in this study were whole view (open-gate and close-gate position) and screw view (open-gate and close-gate position). An assessor was invited to evaluate the radiographs by using Image Quality Criteria Scoring (ICS) adapted from European Guidelines on Quality Criteria for Diagnostic Radiographic Images. Results: Findings showed that the optimum values of kVp and mAs in imaging whole view (open-gate and close-gate) carabiner were 133 kVp and 28 mAs while, for screw view (opengate and close-gate) the range of kVp and mAs preferred were 121 kVp to 133 kVp and 28 mAs to 36 mAs respectively. Conclusion: This study has found that the use of medical CR to expose metal steel such as
    carabiner is accepted. By manipulating the imaging parameters, CR can produce a good quality image of carabiner.
    Matched MeSH terms: Bone Screws
  4. Ramlee MH, Seng GH, Ros Felip A, Abdul Kadir MR
    Injury, 2021 Aug;52(8):2131-2141.
    PMID: 33745700 DOI: 10.1016/j.injury.2021.03.017
    An external fixator is a promising medical device that could provide optimum stability and reduce the rate of complications in treating bone fracture during intervention period. It is noted that the biomechanics behaviour of device can be altered by introducing more features such as material suitability and additional components. Therefore, this study was conducted via finite element method to investigate the effects of additional hollow cylinder coated with external fixator screws in treating Type III pilon fracture. Finite element models which have been validated with experimental data were used to simulate stresses at the pin-bone interface and relative micromovement at interfragmentary fractures during swing (70 N load) and stance phases (350 N load). All bones and external fixators were assigned with isotropic material properties while the cartilages were simulated with hyper-elastic. For the hollow cylinder, polyethylene was assigned due to its properties which are equivalent to the bone. From the results, it is found that stresses at the pin-bone interface for the coated screws were reduced to 54% as compared to the conventional fixator. For the micromovement, there was no difference between both models, whereby the value was 0.03 mm. The results supported previously published literature, in which high stresses are unavoidable at the interface, fortunately, those stresses did not exceed the ultimate strength of bone, which is safe for treating patients. In conclusion, if patients are allowed to bear weight bearing, the external fixator with coated screws is a more favourable option to be fixed into the bone to avoid complications at the interface.
    Matched MeSH terms: Bone Screws
  5. Yan L, Zhang M, Wang M, Guo Y, Zhang X, Xi J, et al.
    J Nanosci Nanotechnol, 2020 03 01;20(3):1504-1510.
    PMID: 31492313 DOI: 10.1166/jnn.2020.17350
    This research has been accomplished using the advanced selective laser melting (SLM) technique as well as HIP post-treatment in order to improve mechanical properties and biocompatibility of Mg- Ca-Sr alloy. Through this research it becomes clearly noticeable that the Mg-1.5Ca-xSr (x = 0.6, 2.1, 2.5) alloys with Sr exhibited better mechanical properties and corrosion potentials. This is more particular with the Mg-1.5Ca-2.5Sr alloy after HIP post-treatment allowing it to provide a desired combination of degradation and mechanical behavior for orthopedic fracture fixation during a desired treatment period. In vivo trials, there was a clear indication and exhibition that this Mg-1.5Ca-2.5Sr alloy screw can completely dissolve in miniature pig's body which leads to an acceleration in growth of bone tissues. Mg-Ca-Sr alloy proved potential candidate for use in orthopedic fixation devices through Our results concluded that Mg-Ca-Sr alloy are potential candidate for use in orthopedic fixation devices through mechanical strength and biocompatibility evaluations (in vitro or In vivo).
    Matched MeSH terms: Bone Screws
  6. Lee, C.K., Kwan, M.K., Chua, Y.P.
    Malays Orthop J, 2009;3(1):85-87.
    MyJurnal
    Removal of plates is a procedure commonly performed by orthopaedic surgeons and stripped screws are probably the most common problem encountered during this procedure. Stripped screws are caused by slippage between the screwdriver and the screw. Due to the inherent difficulty in removing such screws, surgeons should be knowledgeable in techniques for their removal and should be equipped with the proper instruments to expedite the procedure. There are few published articles about such techniques. This report describes a technique for removal of plates with stripped screws. The tip of a stripped screw is approached from the far cortex and then reamed with a trephine reamer in the direction of the screw until both cortices are cleared. The plate is then removed with stripped screws attached. All the removals utilizing this technique to date have been successful with no complications, and this method is safe, efficient and technically easy to learn.


    Matched MeSH terms: Bone Screws
  7. Nik Alyani Nik Abdul Adel, Mohd Shukrimi bin Awang, Zamzuri bin Zakaria
    MyJurnal
    Anterior cruciate ligament (ACL) reconstruction has evolved during past
    decade. All inside technique is introduced aiming for less invasive procedure, bone stock
    preservation, preservation of tendon at its donor site, better graft positioning and
    fixation technique. This study is conducted to compare the outcomes of this new
    technique to the previous biotransfix screw. (Copied from article).
    Matched MeSH terms: Bone Screws
  8. Yasim-Anuar TAT, Ariffin H, Norrrahim MNF, Hassan MA, Andou Y, Tsukegi T, et al.
    Polymers (Basel), 2020 Apr 17;12(4).
    PMID: 32316664 DOI: 10.3390/polym12040927
    Two different liquid assisted processing methods: internal melt-blending (IMB) and twin-screw extrusion (TWS) were performed to fabricate polyethylene (PE)/cellulose nanofiber (CNF) nanocomposites. The nanocomposites consisted maleic anhydride-grafted PE (PEgMA) as a compatibilizer, with PE/PEgMA/CNF ratio of 97/3/0.5-5 (wt./wt./wt.), respectively. Morphological analysis exhibited that CNF was well-dispersed in nanocomposites prepared by liquid-assisted TWS. Meanwhile, a randomly oriented and agglomerated CNF was observed in the nanocomposites prepared by liquid-assisted IMB. The nanocomposites obtained from liquid-assisted TWS exhibited the best mechanical properties at 3 wt.% CNF addition with an increment in flexural strength by almost 139%, higher than that of liquid-assisted IMB. Results from this study indicated that liquid feeding of CNF assisted the homogenous dispersion of CNF in PE matrix, and the mechanical properties of the nanocomposites were affected by compounding method due to the CNF dispersion and alignment.
    Matched MeSH terms: Bone Screws
  9. Ahmad Sobri S, Whitehead D, Mohamed M, Mohamed JJ, Mohamad Amini MH, Hermawan A, et al.
    Polymers (Basel), 2020 Oct 23;12(11).
    PMID: 33114223 DOI: 10.3390/polym12112461
    Carbon fibre-reinforced polymer (CFRP) composite materials play an increasingly important role in modern manufacturing, and they are among the more prominent materials used in aircraft manufacturing today. However, CFRP is highly prone to delamination and other damage when drilled due to it being extremely strong with a good strength-to-weight ratio and high thermal conductivity. Because of this problem and CFRP's growing importance in aircraft manufacture, research has focused on the entry and exit holes as indicators of damage occurrence during drilling of screws, rivets, and other types of holes. The inside of the hole was neglected in past research and a proper way to quantify the internal side of a hole by combining the entry and exit hole should be included. To fill this gap and improve the use of CFRP, this paper reports a novel technique to measure the holes by using the extension of the adjusted delamination factor (SFDSR) for drilling thick CFRP composites in order to establish the influence of machining input variables on key output measures, i.e., delamination and other damages. The experimental results showed a significant difference in interpretation of the damage during the analysis. Improvement was made by providing better perspectives of identifying hole defects.
    Matched MeSH terms: Bone Screws
  10. Caracelli I, Hino CL, Zukerman-Schpector J, Biaggio FC, Tiekink ER
    Acta Crystallogr E Crystallogr Commun, 2015 Aug 1;71(Pt 8):o558-9.
    PMID: 26396795 DOI: 10.1107/S2056989015012670
    In the title compound, C10H11NO2, two independent but virtually superimposable mol-ecules, A and B, comprise the asymmetric unit. The heterocyclic ring in each mol-ecule has a screw-boat conformation, and the methyl-hydroxyl group occupies a position to one side of this ring with N-C-C-O torsion angles of -55.30 (15) (mol-ecule A) and -55.94 (16)° (mol-ecule B). In the crystal, O-H⋯O and N-H⋯O hydrogen bonding leads to 11-membered {⋯HNCO⋯HO⋯HNC2O} heterosynthons, involving three different mol-ecules, which are edge-shared to generate a supra-molecular chain along the a axis. Inter-actions of the type C-H⋯O provide additional stability to the chains, and link these into a three-dimensional architecture.
    Matched MeSH terms: Bone Screws
  11. Yong CK, Tan CN, Penafort R, Singh DA, Varaprasad MV
    Malays Orthop J, 2009;3(1):13-18.
    MyJurnal
    Dynamic hip screw (DHS) fixation is considered standard treatment for most intertrochanteric fractures. However, excessive sliding at the fracture site and medialisation of femoral shaft may lead in fixation failure. In contrast, fixed-angled 95° condylar blade plate (CBP) has no effective dynamic capacity and causes little bone loss compared to DHS. We compared the outcome of 57consecutive unstable intertrochanteric fragility fractures treated with these two fixation methods. CBP instrumentation is more difficult requiring longer incision, operating time and higher surgeon-reported operative difficulty. The six month post-operative mortality rate is 16%. Post-operative Harris hip scores were comparable between the two methods. Limb length shortening more than 20 mm was 6-fold more common with DHS. In elderly patients with unstable intertrochanteric fragility fractures, fixed angled condylar blade plate appears to be a better choice than dynamic hip screws for preventing fixation failures.
    Matched MeSH terms: Bone Screws
  12. Khoo, C. C. H., Amber Haseeb, Vivek Ajit Singh
    Malays Orthop J, 2014;8(2):14-21.
    MyJurnal
    Cannulated screw fixation is a widely accepted surgical method for management of fractures of the neck of femur especially in patients with poor premorbid conditions, minimally displaced fractures and those from a younger age group. A five year retrospective study was carried out in 53 consecutive patients between 2006 to 2010 to determine the pattern of injuries, management, outcomes and the associated predictive factors.All the patients underwent cannulated screw fixation, with 37 (69.8%) having had surgery within 24 hours and the remaining 16 (30.2%) 24 hours after the initial injury. All patients were followed up to union of fractures and complications thereafter if any. Good outcome was observed in 43 (81.1%) patients leaving only 10 (18.9%) patients with a poor outcome, of whom nine developed avascular necrosis (90%) and one non-union (10%). We found no significant relationship between the incidence of avascular necrosis and age of patient, fracture displacement, numbers of cannulated screws used, fracture reduction acceptability and anatomical location of the fracture. The time interval from injury to surgery and the presence of posterior comminution did seem to influence the rate of avascular necrosis but due to the small number of patients, was not statistically significant.We conclude that cannulated screw fixation is a viable option of treatment for fractures of the neck of femur.
    Matched MeSH terms: Bone Screws
  13. Nor Azura Abdul Rahim, Zulkifli Mohamad Ariff, Azlan Ariffin
    MyJurnal
    A study of kaolin addition in polypropylene (PP-kaolin) melt was carried out to characterize its flow behaviour and viscoelasticity at different temperatures. The compound of 20 wt% kaolin was prepared by melt mixing using two roll-mill heated at 185°C, while the compounded composites were put through a single screw extruder to evaluate its melt flow properties. The prepared PPKaolin composites exhibited a shear thinning behaviour and appeared to be strongly dependent on temperature. Moreover, it was also found that the power law index was constantly increased as the temperature increased. Meanwhile, a similar trend was observed for swelling ratio, whereby it also increased with increasing temperature. It was also observed that changes in the die temperatures would result in the formation of obvious bubble like surface morphology, and it became more prominent when the temperature was lowered.
    Matched MeSH terms: Bone Screws
  14. Soo SY, Silikas N, Satterthwaite J
    Materials (Basel), 2019 Jun 23;12(12).
    PMID: 31234580 DOI: 10.3390/ma12122009
    A single paragraph of about 200 words maximum. For research articles, abstracts should give a pertinent overview of the work. We strongly encourage authors to use the following style of structured abstracts, but without headings: (1) Background: Place the question addressed in a broad context and highlight the purpose of the study; (2) Methods: Describe briefly the main methods or treatments applied; (3) Results: Summarize the article's main findings; and (4) Conclusions: Indicate the main conclusions or interpretations. The abstract should be an objective representation of the article, it must not contain results which are not presented and substantiated in the main text and should not exaggerate the main conclusions. Please add in this section. The aim of the study was to investigate the fracture behaviour of four different groups of zirconia abutments with internal and external connections: (A) Astra Tech ZirDesign™ abutment on Astra Tech Implants, (B) Procera® Esthetic abutment on Nobel Biocare MK III Groovy Implants, (C) IPS e.max® on Straumann Implants, and (D) ZiReal® Posts on Biomet 3I implants. The load was applied on the assemblies using a Zwick universal testing machine: the initial and final failure loads and amplitude were recorded using acoustic emission technique. Mean initial and final failure force was found to be significantly different in each group (P < 0.001). IPS e.max® Straumann abutments exhibited the highest resistance to final fracture force compared to other abutment types. Acoustic emission can be used as one of the methods to detect fracture behaviour of implant abutments. There were no significant differences in fracture loads between the internal and externally connected zirconia abutments studied. However, externally connected abutments demonstrated screw loosening and some deformations.
    Matched MeSH terms: Bone Screws
  15. Buzayan MM, Yunus NB
    J Indian Prosthodont Soc, 2014 Mar;14(1):16-23.
    PMID: 24604993 DOI: 10.1007/s13191-013-0343-x
    One of the considerable challenges for screw-retained multi-unit implant prosthesis is achieving a passive fit of the prosthesis' superstructure to the implants. This passive fit is supposed to be one of the most vital requirements for the maintenance of the osseointegration. On the other hand, the misfit of the implant supported superstructure may lead to unfavourable complications, which can be mechanical or biological in nature. The manifestations of these complications may range from fracture of various components in the implant system, pain, marginal bone loss, and even loss of osseointegration. Thus, minimizing the misfit and optimizing the passive fit should be a prerequisite for implant survival and success. The purpose of this article is to present and summarize some aspects of the passive fit achieving and improving methods. The literature review was performed through Science Direct, Pubmed, and Google database. They were searched in English using the following combinations of keywords: passive fit, implant misfit and framework misfit. Articles were selected on the basis of whether they had sufficient information related to framework misfit's related factors, passive fit and its achievement techniques, marginal bone changes relation with the misfit, implant impression techniques and splinting concept. The related references were selected in order to emphasize the importance of the passive fit achievement and the misfit minimizing. Despite the fact that the literature presents considerable information regarding the framework's misfit, there was not consistency in literature on a specified number or even a range to be the acceptable level of misfit. On the other hand, a review of the literature revealed that the complete passive fit still remains a tricky goal to be achieved by the prosthodontist.
    Matched MeSH terms: Bone Screws
  16. Khoo C, Haseeb A, Ajit Singh V
    Malays Orthop J, 2014 Jul;8(2):14-21.
    PMID: 25279087 DOI: 10.5704/MOJ.1407.010
    Cannulated screw fixation is a widely accepted surgical method for management of fractures of the neck of femur especially in patients with poor premorbid conditions, minimally displaced fractures and those from a younger age group. A five year retrospective study was carried out in 53 consecutive patients between 2006 to 2010 to determine the pattern of injuries, management, outcomes and the associated predictive factors.All the patients underwent cannulated screw fixation, with 37 (69.8%) having had surgery within 24 hours and the remaining 16 (30.2%) 24 hours after the initial injury. All patients were followed up to union of fractures and complications thereafter if any. Good outcome was observed in 43 (81.1%) patients leaving only 10 (18.9%) patients with a poor outcome, of whom nine developed avascular necrosis (90%) and one non-union (10%). We found no significant relationship between the incidence of avascular necrosis and age of patient, fracture displacement, numbers of cannulated screws used, fracture reduction acceptability and anatomical location of the fracture. The time interval from injury to surgery and the presence of posterior comminution did seem to influence the rate of avascular necrosis but due to the small number of patients, was not statistically significant.We conclude that cannulated screw fixation is a viable option of treatment for fractures of the neck of femur.
    Matched MeSH terms: Bone Screws
  17. Teh KH, Ruben JK, Chan CK, Abbas AA
    Malays Orthop J, 2020 Jul;14(2):134-137.
    PMID: 32983389 DOI: 10.5704/MOJ.2007.022
    Avascular necrosis and non-union are two most dreaded complications of femoral neck fracture fixations. Hip replacement seems to be a simple solution for this complex problem. However, the long-term efficacy of prosthetic replacement in the young population with higher functional demand is still questionable. Femoral head preserving valgus subtrochanteric osteotomies in properly selected cases have strong support from literature. The conventional technique of valgus subtrochanteric osteotomy involves lateral based wedge resection. Alternatively, a simpler sliding oblique subtrochanteric osteotomy without any wedge removal can also be performed. We hereby describe a successful case of sliding subtrochanteric osteotomy with 135° dynamic hip screw (DHS) plate fixation in treating non-union neck of femur fracture in a young gentleman.
    Matched MeSH terms: Bone Screws
  18. Sath S
    Malays Orthop J, 2020 Nov;14(3):184-187.
    PMID: 33403084 DOI: 10.5704/MOJ.2011.031
    Complications in the form of esophageal injury, tracheal injury, injury to carotids, implant failure, loosening of screws, etc do occur after anterior cervical surgeries. Although intra-operative esophageal injuries are as such rare, there have been few reports of delayed esophageal perforation as well after anterior cervical surgeries. We report a very rare case of migration of missing screw from anterior cervical plate after anterior cervical corpectomy and plating, which had ultimately migrated down to colon and had to be removed via colonoscopy. Along with removal of migrated screw from colon, revision of failed anterior cervical surgery was done wherein plate and screws were removed with mesh cage left in-situ as it was snug-fit while pharyngeophageal perforation was explored and was found to be spontaneously healing, with addition of posterior Bohlman's interspinous wiring for added stability. Migration of screw from the anterior cervical plate into the colon although very rare, should be always kept in mind and its potentially serious complications. We also conclude that particular attention should be given to elderly people with poor bony quality who have high chances of implant failure, along with attention to proper cage size, screw position and proper locking of the screw to further lessen the chances of implant failure.
    Matched MeSH terms: Bone Screws
  19. Sureisen M, Saw LB, Wei Chan CY, Singh DA, Kwan MK
    Indian J Orthop, 2011 Nov;45(6):504-7.
    PMID: 22144742 DOI: 10.4103/0019-5413.87118
    BACKGROUND: Various lateral mass screw fixation methods have been described in the literature with various levels of safety in relation to the anterior neurovascular structures. This study was designed to radiologically determine the minimum lateral angulations of the screw to avoid penetration of the vertebral artery canalusing three of the most common techniques: Roy-Camille, An, and Magerl.

    MATERIALS AND METHODS: Sixty normal cervical CT scans were reviewed. A minimum lateral angulation of a 3.5 mm lateral mass screw which was required to avoid penetration of the vertebral artery canal at each level of vertebra were measured.

    RESULTS: The mean lateral angulations of the lateral mass screws (with 95% confidence interval) to avoid vertebral artery canal penetration, in relation to the starting point at the midpoint (Roy-Camille), 1 mm medial (An), and 2 mm medial (Magerl) to the midpoint of lateral mass were 6.8° (range, 6.3-7.4°), 10.3° (range, 9.8-10.8°), and 14.1° (range, 13.6-14.6°) at C3 vertebrae; 6.8° (range, 6.2-7.5°), 10.7° (range, 10.0-11.5°), and 14.1° (range, 13.4-14.8°) at C4 vertebrae; 6.6° (range, 6.0-7.2°), 10.1° (range, 9.3-10.8°), and 13.5° (range, 12.8-14.3°) at C5 vertebrae and 7.6° (range, 6.9-8.3°), 10.9° (range, 10.3-11.6°), and 14.3° (range, 13.7-15.0°) at C6 vertebrae. The recommended lateral angulations for Roy-Camille, Magerl, and An are 10°, 25°,and 30°, respectively. Statistically, there is a higher risk of vertebral foramen violation with the Roy-Camille technique at C3, C4 and C6 levels, P < 0.05.

    CONCLUSIONS: Magerl and An techniques have a wide margin of safety. Caution should be practised with Roy-Camille's technique at C3, C4, and C6 levels to avoid vertebral vessels injury in Asian population.

    Matched MeSH terms: Bone Screws
  20. Goh, K.L., Zamzuri, Z., Mohd Ariff, S., Mohamed Azril, M.A.
    MyJurnal
    Introduction: Application of dynamic hip screw (DHS) implant for the treatment of unstable intertrochanteric fractures continues to raise concern related to risk of lag screw cut-out with or without subsequent damage to the acetabulum. Measurement of tip-apex distances (TAD) has been recommended to guide the optimal placement of lag screw and to predict subsequent risk of screw cut-out. In this study, the value of TAD was evaluated to verify its usefulness.
    Methods: This is a retrospective study of 33 consecutive patients with intertrochanteric fracture treated with DHS. Demographic data of the patients were traced from their case notes. Post-operative radiographs were reviewed by focusing on measurement of TAD on anteroposterior and lateral radiographs. Radiographs at one year follow-up were reviewed to depict any fixation-related failure or complication.
    Results: Fifty two percent of patients did not achieved the recommended TAD of ≤ 25mm. The mean post-operative TAD was 25.9mm and elderly patients were likely to achieve TAD of ≤ 25mm. The overall complication rate of 6% was attributed to screw cut-out in two cases. The unstable left-sided fracture was identified to be a potential risk for screw cut-out or migration.
    Conclusion: TAD is a valuable measurement to guide optimal placement of lag screw during DHS fixation of intertrochanteric fracture.
    KEYWORDS: Intertrochanteric fracture, dynamic hip screw, tip-apex distance, screw cut-out
    Matched MeSH terms: Bone Screws
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