Bone anchored hearing aid (Baha) implant is an option for patient with canal atresia, single sided deafness(SSD) and chronically discharging ears despite treatments. This retrospective study was conducted from 2001 to 2011 to evaluate the surgical outcome of Baha implant surgery. Thirty-three patients were identified during this study period. Their age at implantation ranged from 5 to 40 years. Of 33 patients, 29 (87.9 %) patients had bilateral microtia and canal atresia, 3 (9.1 %) patients had unilateral microtia and canal atresia and 1 (3.0 %) patients have SSD following labyrinthitis. One patient (3.2 %) had major complication which is lost of implant due to failure of osseointegration. Soft tissue reactions were seen 7 patients (21.1 %). Of these 7 patients, 4 patients required 3-4 procedures as day care operation for excision of the skin overgrowth surrounding the abutment. Recurrent antibiotic treatment was required in 3 patients (9.7 %). None of our patient had history of intraoperative or peri-operative complication following Baha surgery. The commonest complications are local infection and inflammation at the implant site. None of our patient had history of intraoperative or peri-operative complication following Baha implant surgery.
This paper is concerned with the existence, types and the cardinality of the integral solutions for
diophantine equation
4 4 3
x y z + = where x , y and z are integers. The aim of this paper was to
develop methods to be used in finding all solutions to this equation. Results of the study show the
existence of infinitely many solutions to this type of diophantine equation in the ring of integers
for both cases, x y = and x y ¹ . For the case when x y = , the form of solutions is given by
3 3 4
( , , ) (4 , 4 ,8 ) x y z n n n = , while for the case when x y ¹ , the form of solutions is given by
3 1 3 1 4 1
( , , ) ( , , )
k k k
x y z un vn n
- - -
= . The main result obtained is a formulation of a generalized method to find
all the solutions for both types of diophantine equations.
In recent years, fiber Bragg gratings (FBGs) are becoming increasingly attractive for sensing applications in biomechanics and rehabilitation engineering due to their advantageous properties like small size, light weight, biocompatibility, chemical inertness, multiplexing capability and immunity to electromagnetic interference (EMI). They also offer a high-performance alternative to conventional technologies, either for measuring a variety of physical parameters or for performing high-sensitivity biochemical analysis. FBG-based sensors demonstrated their feasibility for specific sensing applications in aeronautic, automotive, civil engineering structure monitoring and undersea oil exploration; however, their use in the field of biomechanics and rehabilitation applications is very recent and its practicality for full-scale implementation has not yet been fully established. They could be used for detecting strain in bones, pressure mapping in orthopaedic joints, stresses in intervertebral discs, chest wall deformation, pressure distribution in Human Machine Interfaces (HMIs), forces induced by tendons and ligaments, angles between body segments during gait, and many others in dental biomechanics. This article aims to provide a comprehensive overview of all the possible applications of FBG sensing technology in biomechanics and rehabilitation and the status of ongoing researches up-to-date all over the world, demonstrating the FBG advances over other existing technologies.
Implanted medical devices are very important electronic devices because of their usefulness in monitoring and diagnosis, safety and comfort for patients. Since 1950s, remarkable efforts have been undertaken for the development of bio-medical implanted and wireless telemetry bio-devices. Issues such as design of suitable modulation methods, use of power and monitoring devices, transfer energy from external to internal parts with high efficiency and high data rates and low power consumption all play an important role in the development of implantable devices. This paper provides a comprehensive survey on various modulation and demodulation techniques such as amplitude shift keying (ASK), frequency shift keying (FSK) and phase shift keying (PSK) of the existing wireless implanted devices. The details of specifications, including carrier frequency, CMOS size, data rate, power consumption and supply, chip area and application of the various modulation schemes of the implanted devices are investigated and summarized in the tables along with the corresponding key references. Current challenges and problems of the typical modulation applications of these technologies are illustrated with a brief suggestions and discussion for the progress of implanted device research in the future. It is observed that the prime requisites for the good quality of the implanted devices and their reliability are the energy transformation, data rate, CMOS size, power consumption and operation frequency. This review will hopefully lead to increasing efforts towards the development of low powered, high efficient, high data rate and reliable implanted devices.
A normally restored orbital structure after reconstructive surgery would accelerate the return of orbital function. The aim of the present study was to compare the outcomes of 2 orbital implants: autogenous grafts and porous polyethylene (Medpor).
The relationship between orthopaedic surgeons and the device industry is one that is mutually beneficial and productive. However there are skeletons in the closet. The financial implications of this relationship have come under intense scrutiny. The sponsorships and the financial benefits of this symbiotic relationship have been found to cross the boundaries considered acceptable to ethical practice of the profession. In India, the ethical transgressions resulting from unhealthy associations between the orthopaedic surgeon and the industry have yet to be given due importance. Adequate rules and regulations are yet to be enforced and self-regulation is practically non-existent. It is essential to deal with the problem and potential implications that can arise from this kind of misconduct at the organisational level and enforce them for compliance.
Tumour surgery for locally extensive malignant neoplasms of the extremity will sometimes result in extensive composite soft tissue defect. Local flaps are usually inadequate to cover these large defects. More than one tissue flap might be required to cover any exposed neurovascular structures, bone or prosthesis. We present two cases where two composite flaps were simultaneously used to cover extensive surgical defects after ablative tumour resections in the extremity. These resulted in uncomplicated wound healing and limb salvage.
Upon implantation or insertion into patient's body for exerting the intended purpose like salvage of normal functions of vital organs, the medical devices are unfortunately becoming the sites of competition between host cell integration and microbial adhesion. Moreover, since there is an increased use of implanted medical devices, the incidence of biofilm-and medical devices-related nosocomial infections is also increasing progressively. To control microbial colonization and subsequent biofilm formation of the medical devices, different approaches either to enhance the efficiency of certain antimicrobial agents or to disrupt the basic physiology of the pathogenic microorganisms including novel small molecules and antipathogenic drugs are being explored. In addition, the various lipid-and polymer-based drug delivery carriers are also investigated for applying antibiofilm coating of the medical devices especially over catheters. The main intention of this review is therefore to summarize the major and/breakthrough inventions disclosed in patent literature as well as in research papers related to microbial colonization of medical devices and novel preventive strategies. This review starts with an overview of the preventive strategies followed by a short description about the potential of different lipidic-and polymeric-drug delivery carriers in eradicating the biofilm-associated infections from the medical devices.
Matched MeSH terms: Prostheses and Implants/microbiology*
The stress shielding effect is an event in which the replacement implant limits the load transferred to bone and the ineffective stress in the vertebrae causes bony growth to cease. In the present study, a 3D finite element L4-L5 model was developed and subjected to a 1200 N compression preload. Five groups of muscle forces were applied on L4 under flexion-extension, lateral bending and axial rotation. Topology optimisation was employed for reducing the stress shielding effect by removing the ineffective material from the design domain. The optimised design was designed with polyaryletheretherketone (PEEK) titanium and cortical materials to encounter the shielding response. The stress responses show that the new design increased the stress magnitude by at least 17.10, 18.11 and 18.43% in 4 Nm of flexion-extension, lateral bending and axial rotation, respectively. In conclusion, the material factor did not significantly alter the stress magnitude, but volume was the key factor in reducing the stress shielding effect.
D-serine has been implicated as a brain messenger, promoting not only neuronal signalling but also synaptic plasticity. Thus, a sensitive tool for D-serine monitoring in brain is required to understand the mechanisms of D-serine release from glia cells. A biosensor for direct fixed potential amperometric monitoring of D-serine incorporating mammalian D-amino acid oxidase (DAAO) immobilized on a Nafion coated poly-ortho-phenylenediamine (PPD) modified Pt-Ir disk electrode was therefore developed. The combined layers of PPD and Nafion enhanced the enzyme activity and biosensor efficiency by approximately 2-fold compared with each individual layer. A steady state response time (t(90%)) of 0.7+/-0.1s (n=8) and limit of detection 20+/-1 nM (n=8) were obtained. Cylindrical geometry showed lower sensitivity compared to disk geometry (61+/-7 microA cm(-2) mM(-1), (n=4), R(2)=0.999). Interference by ascorbic acid (AA), the main interference species in the central nervous system and other neurochemical electroactive molecules was negligible. Implantation of the electrode and microinjection of D-serine into rat brain striatal extracellular fluid demonstrated that the electrode was capable of detecting D-serine in brain tissue in vivo.
The objective of this study was to regenerate the tracheal epithelium using autologous nasal respiratory epithelial cells in a sheep model. Respiratory epithelium and fibroblast cells were harvested from nasal turbinates and cultured for 1 week. After confluence, respiratory epithelium and fibroblast cells were suspended in autologous fibrin polymerized separately to form a tissue-engineered respiratory epithelial construct (TEREC). A 3 × 2 cm² tracheal mucosal defect was created, and implanted with TEREC and titanium mesh as a temporary scaffold. The control groups were divided into 2 groups: polymerized autologous fibrin devoid of cells (group 1), and no construct implanted (group 2). All sheep were euthanized at 4 weeks of implantation. Gross observation of the trachea showed minimal luminal stenosis formation in the experimental group compared to the control groups. Macroscopic evaluation revealed significant mucosal fibrosis in control group 1 (71.8%) as compared to the experimental group (7%). Hematoxylin and eosin staining revealed the presence of minimal overgrowth of fibrous connective tissue covered by respiratory epithelium. A positive red fluorescence staining of PKH26 on engineered tissue 4 weeks after implantation confirmed the presence of cultured nasal respiratory epithelial cells intercalated with native tracheal epithelial cells. Scanning electron microscopy showed the presence of short microvilli representing immature cilia on the surface of the epithelium. Our study showed that TEREC was a good replacement for a tracheal mucosal defect and was able to promote natural regenesis of the tracheal epithelium with minimal fibrosis. This study highlighted a new technique in the treatment of tracheal stenosis.
The PROSTALAC (PROSThesis Antibiotic Loaded Acrylic Cement) functional spacer is made with antibiotic-loaded acrylic cement. We use it as an interim spacer in two-stage exchange arthroplasty in cases of infected total knee or total hip replacement. PROSTALAC allows continuous rehabilitation between stages as it maintains good alignment and stability of the joint with a reasonable range of movement. It also helps to maintain the soft-tissue planes, thereby facilitating the second-stage procedure. We report here early outcomes of the use of PROSTALAC in 5 patients - 3 in total knee replacements, 1 in a total hip replacement and 1 in a bipolar hemiarthroplasty.
Objective: To evaluate the early results of patients in a single institution who underwent total knee arthroplasty using an implant system. Methods: We retrospectively reviewed 76 total knee replacements using the Genesis II prosthesis (Smith and Nephew, Memphis) in 60 patients (16 were bilateral cases) performed between February 2005 andFebruary 2008. Patient related outcomes and clinical evaluations were done by an independent observer. Knee function and patient satisfaction were evaluated using the American Knee Society (ASK) score and the Western Ontario and Mac Master University Osteoarthritis Index (WOMAC). Results: The mean age of the patients at the time of operation was 63.5years. The mean follow up period was 1 year 5 months. At the final follow up, the mean Knee Society Knee Score was 87.9 with 77.3% (58 knees) rated excellent, 21.3% (16 knees) rated good and1.3% (1 knee) rated fair; none were rated poor. The mean Function Score was 87.1 with 64% (48 knees) rated excellent, 29.3% (22 knees) rated good, 6.7% (5 knees) rated fair, no knee was rated poor. The mean WOMAC Score was 94.4 (standard deviation 6.59). Conclusion: Most patients treated for knee osteoarthritis with total knee replacement showed high rates of excellence and good early functional outcomes.
The consequence of postoperative infections associated with orthopaedic or biomaterial-associated implants is devastating to both the patients and the surgeons. Bacterial microcolonies adhere to the surface of implants, forming biofilms and then detaching part of itself into free-floating planktonic forms may be the cause of recurrent and persistent infections. These bacteria are very resistant towards antibiotics and require a higher drug concentration than usual in order to eradicate them. Quorem-sensing is regarded as one mechanism of communication or integration between these microorganisms in the biofilm and may even be in the transfer of resistant genes. Disruption of this pathway is regarded as one method of inhibiting its growth and formation. Implant design, technique and stability of fixation as well as the surface characteristics, the material and its biocompatibility may also influence bacterial adhesion. It has been suggested that multi-prong strategies such as prevention and disruption of biofilm formation, parenteral antibiotics, use of antibiotic-impregnated construction materials and altering the intrinsic properties of the implant surface may help to eradicate this menace.
We describe herein a modified technique for reconstruction of chronic rupture of the quadriceps tendon in a patient with bilateral total knee replacement and distal realignment of the patella. The surgery involved the application of a Dacron graft and the ‘double eights’ technique. The patient achieved satisfactory results after surgery and we believe that this technique of reconstruction offers advantages over other methods.
Since the establishment of implant in dentistry, the use of removable partial denture in replacing missing teeth apparently becomes less popular. The situation is made worse by the renowned limitations of removable partial denture. One of the obvious limitations of removable partial denture, especially in replacing missing anterior teeth is the unsightly view of metal used for retentive clasp. This case report describes the use of spring loaded plunger attachments as an alternative way to achieve retention and at the same time improving the aesthetic of the prosthesis.
Priapism is a urological emergency. The treatment for ischaemic priapism is usually cavernosal aspiration with or without cavernosal irrigation. Some patients may need surgical intervention -the various shunt procedures. We report a 21-year-old man with priapism secondary to chronic myeloid leukemia who needed a combined medical and surgical management. He underwent a spongiocavernosal shunt as well as cytoreductive chemotherapy to achieve complete detumescence. Therefore, cytoreductive chemotherapy is an adjunct in difficult cult to treat priapism associated with chronic myeloid leukemia.
This is to report on the use of growing endoprosthesis, also known as lengthening prosthesis in the management of four patients in the paedriatic age group in the Orthopaedic Oncolgy Unit at University Malaya Medical Centre. These are custom made prosthesis, designed and made in India based on measured roentrograms. The ages of these patients vary from 6 to 13 years old. These are cases of Osteosarcoma and Ewing's sarcoma around the knee. This is the first time these custom made prosthesis have ever been used in Malaysia. We feel that this is a feasible option for limb salvage in the treatment of primary bone tumours in growing children.
This clinical case report details the clinical sequence of a 78-year-old male receiving prosthetic rehabilitation using an implant-supported screwretained fixed partial denture. Despite the limitations imposed, the aesthetic and functional demands of the patient were fulfilled by this prosthetic rehabilitation. The importance of detailed prosthetic planning and evaluation prior to implant surgery is essential, therefore ideally, it should be done by the same operator or a team of operators working together. Problems can arise when the construction of the prosthesis is performed by other people who are not involved in the planning stage.
We conducted a prospective study in order to audit our experience of repairing cranial defects using Methyl methacrylate. This included a total of 49 patients undergoing cranioplasty using methyl methacrylate, of which 45 were males and 4 females. The age of patients at the time of surgery ranged from 16 to 40 years old, with an average of 24 years. Malays were the majority (67%), followed by Chinese (23%) and Indian (10%). Cranial defects were mainly caused by motor vehicle accident (94%), while gunshot wounds, industrial accidents and tumours, each contribute 2%. Bone flaps were commonly removed during previous surgery related to traumatic subdural haemorrhage (33%), contusion (21%) and intracerebral haemorrhage (14%). The size of cranial defects ranged from 28 cm2 to 440 cm2, with an average of 201 cm2. Most had right sided (55%) and lateral defects [temporoparietal (52%) followed by temporal (16%), frontal (16%), frontotemporal (14%) and occipital (2%)]. Duration of surgery ranged from 70 to 275 minutes, with an average of 135 minutes. Nine of 12 patients (75%) with neurological disability had some improvement while 85% of symptomatic patients had symptoms improvement after cranioplasty. The infection rate in this series was 4%.