Different Types Of Prostheses Research Articles

Wyniki leczenia otosklerozy z uwzględnieniem różnych typów protez

Surgery is the most effective method of improving hearing in patients with otosclerosis. The level of improvement depends on the stage of the disease and the chosen surgical method.is to present hearing results in patients treated surgically by means of different types of prostheses and methods of vestibule sealing.230 cases (160 men, 70 women) between the age of 21 and 64 (median 36 years) treated for the first time in the Department of Otolaryngology of Medical University in Gdańsk underwent epidemiologic and clinical analysis. The researches took into account the level of hearing improvement based on the reduced air-bone reserve for frequencies 0.5, 1.0, 2.0 i 4.0 kHz in groups with where prostheses type 1 and 2 were used.230 stapedotomies were performed. In 110 patients prosthesis type 1 was used (PTFE) and in 120 type 2 (piston PTFE with platinum tape). Each vestibule was sealed with homogenic fat tissue or fibrin sponge. After 6 weeks from the operation the air-bone reserve was reduced by 5 to 30 dB, the reserve existed after one year from the operation in some patients. 35% of the patients presented with vertigo after the operation and 5% with tinnitus.Stapedotomy is a method of hearing improvement in patients with otosclerosis. Best results are achieved when prosthesis type 2 is used and homogenic fat tissue serves to seal the vestibule. Broad opening of the vestibule may be the cause for vertigo and lack of hearing improvement occurrence.

Current Concepts of Hip Arthroplasty for Radiologists: Part 1, Features and Radiographic Assessment

This article will systematically review radiographic assessment of hip arthroplasty including classifications based on different types and techniques of hip arthroplasty, terminology for prosthetic designs and materials, surgical techniques, and initial and follow-up radiographic assessments. Assessment of postoperative hip arthroplasty radiographs is extremely important. It is well known that patients with complications may be asymptomatic, and for this reason, routine radiographic follow-up is recommended for all patients with hip arthroplasty. The foundation of radiologic interpretation of hip arthroplasty is knowledge of the normal appearance of the many different types of prostheses. A standard approach to radiologic reporting should be undertaken.

Cholesteatoma: Long‐term Follow‐up in Romanian Patients

Objective: Cholesteatoma is an abnormal destructive growth of squamous epithelium in middle ear and mastoid. The presence of cholesteatoma requires surgical intervention and the main goal is to achieve a safe, dry ear and to improve hearing. The extension of surgery depends on the size of the cholesteatoma. Method: A total of 875 patients were treated for cholesteatoma in our department between 2001 and 2010, 213 pediatric patients. We performed both open and closed and technique, depending on disease extension, bone erosion, and complications, followed by second-look surgery in most of the closed-technique cases. Results: The closed technique was the treatment of choice in 69.2% cases, most of them uncomplicated cholesteatomas. In 30.6% we performed open technique for different reasons. Second look surgery was done in 57.3% of cases after 1.5 or 2 years. A total of 27.1% of patients were lost to the follow-up program after the first years. Residual cholesteatomas were noticed in 17% of the cases and the recurrent cholesteatomas were operated in 32% of the cases. After surgery the air-bone gape improved in 67.1% of the cases because of tympanoplasty with autologous graft or different types of prosthesis. In some cases we used the BAHA prosthesis. Conclusion: Cholesteatoma is a serious condition which needs surgical treatment. Second-look control in closed technique should be done after one-one and a half year. Closed technique is recommended in order to restore the function of the ear which is very important for a proper development and a good quality of life.

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Injection Molding Technique for Fabrication of Flexible Prosthesis from Flexible Thermoplastic Denture base Materials

ABSTRACT Purpose To know properties, step-by-step procedure for fabrication and insertion of flexible prosthesis. Background Flexible denture base materials were introduced to dentistry by the name of Valplast and Flexiplast in 1950's. Injection molding technique is used for fabrication of various types of prostheses from these materials and fluid resins. Pryor used injection molding technique for introducing unpolymerized acrylic resin into the mold. In the mid 1970's Ivoclar introduced an injection molding system which used an acrylic resin modified for the injection molding process. Recently, numbers of dental manufacturing companies have introduced injection molding systems. Materials and methods The flexible denture base materials are superpolyamides which are available in the form of granules in cylinders of different sizes. These materials are thermoplastic in nature and needed to be converted into fluid form before pouring into mold under pressure. Each cylinder should be plasticized for 15 to 20 minutes at 550 to 560°F in an electric cartridge furnace before injecting the material into the flask. While injecting, the cylinder should be aligned with opening of flask and the levers of the press should be turned rapidly to apply firm pressure until the springs of the press are fully compressed. The pressure should be maintained for 3 to 5 minutes and the flask should be allowed to bench cool for 15 to 20 minutes before opening. Conclusion This technique can be used for fabrication of different types of prostheses from flexible denture base materials and fluid resins. How to cite this article Singh K, Gupta N. Injection Molding Technique for Fabrication of Flexible Prosthesis from Flexible Thermoplastic Denture base Materials. World J Dent 2012;3(4):303-307.

High Rate of Infection Control with One-stage Revision of Septic Knee Prostheses Excluding MRSA and MRSE

The rate of infection control for one-stage revision of infected knee arthroplasties is unclear as are the factors influencing infection control. Such factors include duration of infection and the type of infected prosthesis. We therefore determined: (1) the rate of infection control with one-stage revision of septic knee prostheses, (2) the clinical knee scores that can be achieved, (3) whether the duration of infection or the type of prosthesis influence the level of infection control, and (4) whether different types of prostheses influence the knee scores. We retrospectively reviewed prospectively collected data from 63 patients who underwent one-stage revisions of septic knee endoprostheses (six unicondylar, 37 primary total knee replacement prostheses, and 20 hinged knee endoprostheses) between 2004 and 2006. All were treated locally and systemically with microorganism-specific antibiotics. For this study we excluded patients with Methicillin-resistant Staphylococcus aureus and Methicillin-resistant Staphylococcus epidermidis or unknown microorganisms. The patients were examined for infection every 3 months and Oxford and Knee Society scores were assessed at the same time. The minimum followup was 24 months (mean followup, 36 months; range, 24-70 months). None of the patients with replacement unicondylar and primary total knee replacement prostheses had recurrence of infection. Three of the 20 patients with the hinged infected knee prostheses had recurrences; these three patients had chronic infections and had undergone two to three revision operations during at least a 5-year period. The likelihood of infection control was influenced by the duration of infection. The mean Knee Society knee score 24 months after surgery was 72 points (range, 20-98 points), the Knee Society function score was 71 points (range, 10-100 points), and the Oxford-12 knee score was 27 points (range, 13-44 points). One-stage revision of septic knee prostheses achieved an infection control rate of 95% and higher knee scores than reported for two-stage revisions. Higher rates of recurrent infection appeared to be associated with long-term chronic infections of hinged prostheses.

Schulterendoprothetik bei primären Synovialkrankheiten

Shoulder arthroplasty has become an essential component of the standard surgical repertoire for the treatment of severe primary and secondary glenohumeral arthritis and has been shown to provide reliable long-term pain relief with satisfactory functional results. In most cases, in particular in patients with rheumatoid arthritis (RA), the indications for arthroplasty are primarily based on pain, which often includes severe pain at rest. Despite poor bone stock and impaired soft tissue quality in RA which frequently results in massive, irreparable rotator cuff tears, shoulder arthroplasty has been shown to be an effective means of improving shoulder function. Several different types of prostheses are now available for different indications determined by age, functional demand, etiology and structural deficits. For optimal outcome, the most suitable type of prosthesis needs to be selected by an experienced shoulder surgeon who is familiar with the entire spectrum of treatment options.

Ergebnisse der Radiusköpfchenprothese von Judet bei nicht rekonstruierbaren Radiusköpfchenfrakturen

With regard to the treatment of non-reconstructable radial head fractures, both the resection and the implantation of a prosthesis are considered. Various studies have shown poor results concerning the resection of the radial head with accompanying osteoligamentous injuries. Due to these experiences, different types of prosthesis have been developed. However, the majority of them were not convincing. Judet developed a type of a bipolar prosthesis which had been modeled on the anatomy of the radial head. The aim of our retrospective study consists in examining the results of the Judet prosthesis. Between 1995 and 2007, 50 patients were treated with an arthroplasty. These were, corresponding to the classification by McKee and Jupiter, 19 type III and 31 type IV fractures. Thirty patients were available for a follow-up after 2.5 years on average. According to the Morrey Score, 16 very good, 7 good, 3 fair and 4 bad results could be obtained. Following the criteria of Radin and Riseborough, 17 patients achieved a good, 9 a fair and 4 a bad result. The complications which appeared were: one patient with aseptic loosening, one patient with luxation of a prosthesis, one persistent radial joint instability, three patients with heterotopic ossification and four patients with protrusion relative to the capitulum humeri.

Comparison of Whole-Blood Metal Ion Levels in Four Types of Metal-on-Metal Large-Diameter Femoral Head Total Hip Arthroplasty: The Potential Influence of the Adapter Sleeve

Metal-on-metal bearings, as used in total hip arthroplasty prostheses that have a large-diameter femoral head, were proposed as an option for treating young and active patients with degenerative hip disorders. Despite the theoretical improved performance of large metal articulations with regard to wear, metal ion levels produced by total hip arthroplasty prostheses in which a large-diameter femoral head is used have not been thoroughly evaluated. From 173 eligible patients, 144 patients were allocated to undergo a unilateral total hip arthroplasty with use of metal-on-metal components and a large-diameter femoral head. The purpose of this study was to compare the amount of metal ion release (chromium, cobalt, and titanium) from four different types of prostheses from four different implant manufacturers (Biomet, DePuy, Smith & Nephew, and Zimmer). For cobalt ion levels, a significant difference was found between the different types of total hip arthroplasty prostheses with a large-diameter femoral head at three, six, twelve, and twenty-four months, but only in male patients or patients with a femoral head size of 50 mm or greater. The highest mean cobalt levels at all follow-up periods were observed with the Zimmer implant and the lowest with the Biomet implant. Titanium ion levels were highest in the Zimmer group at all follow-up periods, whereas no difference between groups was found for chromium. At the most recent follow-up, one hip was revised after the development of an adverse local tissue reaction. Of concern was the observation at the time of revision surgery of black metallic deposits inside the adapter sleeve and on the prosthetic femoral neck. This investigation revealed that metal ion release differs greatly between various total hip arthroplasty implants with a large-diameter femoral head. The sources of metal ion production are numerous, but it is hypothesized that wear and corrosion at the junction between the adapter sleeve and the femoral stem in some patients may be responsible for the elevated cobalt ion levels that were found in the Zimmer group. On the other hand, an adapter sleeve made of titanium, such as the one used with the Biomet large-diameter-head total hip arthroplasty, is an unlikely contributor to the release of cobalt ions. Current technology or design of some total hip arthroplasty systems that make use of a large-diameter femoral head may not yet allow the use of modular large heads with a metal-on-metal articulation, especially in young, active male patients whose activities generate high loads at the hip joint. Further research is needed to better understand the favorable design characteristics of modular junctions in metal-on-metal total hip arthroplasty implants that make use of large-diameter femoral heads.

Difference in Occurrence of Heterotopic Ossification According to Prosthesis Type in the Cervical Artificial Disc Replacement

Retrospective study of the difference of heterotopic ossification (HO) occurrence according to 3 different types of prosthesis. This study was designed to investigate the difference of HO occurrence according to different type of prosthesis. HO is defined as formation of the bone outside the skeletal system. Reported HO occurrence rate in cervical artificial disc replacement (ADR) was unexpectedly high and varied. But the influencing factors of HO in cervical ADR have not been elucidated well. The prosthesis-related factors for making difference of HO occurrence were investigated in this study. A total of 170 patients undergoing cervical arthroplasty with the Bryan cervical disc prosthesis (Medtroic Sofamor Danek, Memphis, TN), Mobi-C disc prosthesis (LDR Medical, Troyes, France), and ProDisc-C (Synthes, Inc., West Chester, PA) were included. Cervical lateral radiographs obtained before and after surgery were used to identify HO. Occurrence rate, occurrence-free period, location, and grade of HOs were investigated according to the different prosthesis. Each prosthesis group included patients as follows: Bryan disc, 81 patients; Mobi-C, 61 patients; and ProDisc-C, 28 patients. Overall HO rate was 40.6% (69 of 170 patients). Each HO occurrence rate by prosthesis was as follows: the Bryan disc group, 21.0%; Mobi-C group, 52.5%; and the ProDisc-C group, 71.4%. In the survival analysis, all patients showed 27.1 +/- 3.7 months as the median survival. The Bryan disc group showed statistically longer survival (48.4 +/- 7.4 months) than the other groups. Occurrence of HO is an inevitable postoperative complication after cervical ADR. The occurrence rate of HO was higher than our expectation. Moreover, definite differences in occurrence rate according to the prosthesis type were identified by this study.

Clinical and Microbiologic Features of Multivalvular Endocarditis

Multivalvular endocarditis accounts for 15% of all endocarditis. The mechanisms of spread of the infection differs whether endocarditis is only left-sided (involving both the mitral and aortic valves) or bilateral. In left-sided bivalvular endocarditis, it is often a secondary mitral lesion following a primary aortic endocarditis. Multivalvular endocarditis often results in severe and extensive cardiac lesions, well described at echocardiography and frequently responsible for severe heart failure. Patients often need surgery, which consists of radical debridement of all the infected tissue with reconstruction using different types of prostheses; therefore, the surgery may be very complex. The goal should be an early diagnosis of endocarditis to avoid spread of the infection to more than one valve, to improve the prognosis for those patients.

Tooth Autotransplantation in Orthodontic Patients

The aims of this report are to present three cases of autotransplantation along with a review of the indications, selection criteria for patient donor and recipient sites, and the major steps in the surgical procedure. Autogenous tooth transplantation, or autotransplantation, is the surgical movement of a tooth from one location in the mouth to another in the same individual. It can be a good treatment option in many cases if the dentist knows the implications, indications, and contraindications. Three cases with different treatment indications and plans are presented. All showed autotransplantation of teeth as part of orthodontic treatment. It emphasized the benefits of this treatment modality such as new bone formation and lower costs. One case, a rare example of multiple congenitally missing teeth treated by autotransplantation, also was presented. As shown in these case reports, there are instances where the autotransplantation of teeth is appropriate and may possibly simplify future planned orthodontic or prosthodontic treatment. Tooth autotransplantation is an easy and good treatment option, applicable in a lot of cases, substituting different types of prostheses, including dental implants.

HS13P TOTAL WRIST ARTHROPLASTY‐A REVIEW OF PATIENTS WITH DYSFUNCTIONAL WRISTS

Background: The wrist is essential for augmentation of fine motor control of the hand and fingers. The normal wrist motion involves a complex interaction of articulations from the radius, ulna and carpal bones. Hence, when a disease process disrupts any one of these elements, a painful, deformed and dysfunctional wrist arises. Total wrist arthroplasty is considered an alternative surgical option to wrist fusion for the management of advanced wrist arthritic diseases. Though less commonly performed in comparison to lower‐limb arthroplasty, wrist arthroplasty has its role as a salvage procedure to alleviate pain and preserve function in the wrists.Method: Four patients were collected from the Centre of Hand Surgery, Sydney. Medical records of these patients were reviewed. The patient's pre‐and post‐operative functional status via clinical and radiographic assessments were closely followed over an average period of five years to ensure the continuity of progress. A table was formulated to provide an objective survey of both quantitative and qualitative improvement of a patient's wrist function.Result: The four patients received different types of prostheses. This is an indication of a lack of universal acceptance of wrist anatomy and biomechanics. Regardless, all patients in this study had improved functional outcomes. Pain‐relief was the most successful aspect of wrist arthroplasty during post‐operative follow‐ups. The successful outcome of these patients has proven that total wrist arthroplasty can provide pain relief and an improvement in hand function through appropriate patient selections, careful peri‐operative planning, sound operative technique and well‐designed post‐operative hand therapy.

Handgelenksendoprothetik: Erfahrungen nach Implantation von 41 Prothesen

The advantage of wrist arthroplasty remains controversial, primarily due to the high complication rate. For this reason it seems sensible to monitor the results of different types of prostheses even with small numbers of cases. We were particularly interested to see if wrist joint arthroplasty is a useful alternative for patients with rheumatoid arthritis, and which of the types we used shows the best results. In our hospital, 41 wrist joint prostheses (15 Meuli, 16 BIAX and 10 Universal 2) were implanted in 36 patients from 1992 until 2005 (follow-up 1 to 14 years, mean 5.3 years). 33 patients had rheumatic destruction of the wrist, two had osteoarthritis following fracture of the scaphoid, and one pseudarthrosis after failed arthroplasty and arthrodesis for Kienböck's disease. Mean age was 54 years, ranging from 34 to 73 years. 14 patients had had surgery on this wrist before. The patients were sent a questionnaire including the DASH score, and a clinical evaluation and X-rays were performed. 33 patients with 38 wrist arthroplasties answered the questionnaire, 34 wrist joint prosthesis of 29 patients could be evaluated. 6 prostheses had to be removed because of complications (3 arthrodeses were performed after removal, 3 prostheses were exchanged). There were 4 dislocations (3 times with the Meuli type, once with the BIAX type). There was one case of CRPS type I. But subjectively, in answering our questionnaire, 31 of 38 patients claimed to be very satisfied or satisfied with the result of the operation, only 6 were less satisfied or not satisfied at all. An improvement of pain was found by all but one patient. An increase in strength or range of movement was found more rarely. The mean postoperative DASH score was 61 points. Mean wrist joint mobility was 50 degrees for extension/flexion, and 20 degrees for radial- and ulnar abduction. The result of total wrist joint arthroplasty depends very much on a careful patient selection. A preoperative bony malposition of the wrist and a tendon dysfunction seem to be responsible for a bad result. High expectations with regard to range of movement and strength should be avoided. A good reduction of pain can be achieved but the risk of complication is still higher than in arthrodesis.

Troca valvar aórtica com diferentes próteses: existem diferenças nos resultados da fase hospitalar?

To analyze intraoperative data and possible differences in clinical evolution during postoperative hospital phase for aortic valve replacement surgery using different types of prosthesis. Analysis of 60 patients divided into three groups. Valve replacement with bioprosthesis (20), mechanical prosthesis (20) and homologous valve (20). The mean age was 51.1, 60% were male and 40% female patients; 86.7 % were in NYHA II or III; 63.3% presented arterial hypertension and 18.3% had diabetes. Aetiology of valve disease was degenerative for 39%, rheumatic for 36% and endocarditis for 15%. The hospital mortality was 5%; there were no differences in the incidence of septic or cardiogenic shock, acute renal failure, rhythms disorders during surgery or intensive care, neither for total time in intensive care and mechanical ventilation. However, there was statistical differences as regards the cardiopulmonary bypass total time (P=0.02) and the aortic clamping time (P<0.0001) unfavorable to homograft valve group. The ward admission time was greater for mechanical valve group (P=0.05) as well as for total admission time, but without statistical significance. It was observed that patients with preoperative hematocrit smaller than 38.1% used 2.73 units of blood components, and with postoperative hematocrit smaller than 32% used 1,79 units of blood components. Echocardiography control showed minimal evolutional differences. The use of different types of prosthesis for this study does not cause differences in the results of postoperative hospital phase. The use of homograft valve is a feasible option with good clinical applicability.

Simulation of the fluid dynamics in artificial aortic roots: comparison of two different types of prostheses

As a consequence of the growing number of elderly people, the incidence of degenerative aortic diseases continues to increase. Often, artificial aortic roots are needed to replace the native tissue. Some physical characteristics of the artificial aortic root, however, are quite different from native aorta and need to be optimized. The supposed benefit of a prosthesis with artificial sinuses of Valsalva could first be checked by numerical calculations. Two simplified base geometries were used for simulating the flow and pressure distributions, especially in the coronary arteries. One model approximates the ascending aorta as a tube, and the other uses a design with toroidal dilation of the aortic root to approximate the native geometry of the sinuses of Valsalva. The flow and pressure distributions in both models were compared in the ascending aorta as well as in the right and the left coronary arteries. Both the pressure and the velocity distribution in the coronary artery region were not significantly higher in the model with the sinus design compared to the tube model. The sinus design only slightly increased the mean pressures and the velocities in both the ascending aorta and in the coronary arteries. Higher pressure in the coronary arteries should improve the blood circulation and decrease the risk of a surgery-related coronary incident. The sinus design did not show the hoped-for benefits, and therefore it is only a minor factor in optimizing future aortic root prostheses.

Achieving Functional Ambulation in a Patient with Chopart Amputation

Chopart amputation provides an interesting functional dilemma for the patient, physiatrist, and prosthetist. This problem is further complicated when the patient develops an equinus contracture from an unbalanced short forefoot lever. Also, genu recurvatum occurs as a consequence of recurrent knee hyperextension from this contracture. There are few reports on the most functional prostheses for this type of patient. We present a case of a pediatric patient with a Chopart amputation who demonstrated genu recurvatum during ambulation. After experimenting with many different types of prostheses, he had persistent lower-limb pain. We prescribed a Chopart prosthesis with a flexible inner socket and a carbon fiber energy-storing keel with posterior calf struts. At his follow-up clinic visit, he no longer had pain, and he was able to play soccer. This device provides a functional alternative for those patients with Chopart amputation who are unable to participate in athletic activities.

Total hip arthroplasty in Jesenice General hospital 1985–2006 – what has been done and look forward

Background: Total arthroplasty is one of the most interesting and fast developing fields in orthopaedic surgery. Practically every joint in the human body is involved, total hip arthroplasties (THA) being most frequent and with the longest history. Information on long-term results and survival of different types of prosthesis is invaluable for both patients and surgeons. Patients and methods: Between 1985 and 2006 there were 1563 THAs performed in Jesenice General Hospital. Average age at the time of operation was 67 years, almost two thirds of patients were women. The reason for operation was in 72 % idiopathic arthrosis and in 14 % sequaele of dysplasia. Results: There were 1370 primary procedures and 193 revisions (12.6 %). Aseptic loosening of the implant was the most frequent reason for revision (74 %) and infection was observed in 1.5 %. In the first ten years of this research hybrid type of prosthesis was most frequently used, but nowadays, non-cemented prosthesis is used in majority of cases. Conclusions: Total hip arthroplasty is well established procedure at the Jesenice General Hospital. It considerably improves quality of life of the patient, for both, short- and long term, results are very good. New minimal invasive surgical techniques make postoperative rehabilitation faster and easier. The Register of prosthesis enables us to regularly analyze the results and provides treatment outcome information concerning the choice of prosthesis and the optimal surgical technique. Jesenice General Hospital is well recognized as one of the centers for arthroplasties in our country.

FEMORAL COMPONENT DESIGN AND POSITIONING DURING IMPLANTATION AFFECTS ACL TENSION - A FINITE ELEMENT STUDY

Total knee replacement (TKR) has a long clinical tradition in orthopedic arthroplasty and is a procedure to reduce pain and to restore function in patients with arthritis. Different types of prostheses are available according to the patient’s anatomical and biomechanical requirements. Most differences in prosthesis design refer to the issues of integrity and balance of the cruciate ligaments. One potential risk is an increased tension in the anterior cruciate ligament (ACL) due to impingement of the ligament against an ACL sparing femoral component. This risk is pronounced in extension of the knee joint. In this study it was analyzed how the design and the position of the femoral intercondylar notch affects the tension of the ACL in extension.

Early results of Bentall-type operations during the last 10 years: comparison of mechanical valves and stentless bioprostheses

OBJECTIVE. Various types of prostheses have been used for combined diseases of the aortic root and ascending aorta. All Bentall-type operations (n=64) between 1996 and 2005 were retrospectively studied, comparing different types of prosthesis in the aortic position. The patients were 29-87 years old (mean 59.5 +/- 14.0 years) and included 47 men and 17 women. Mechanical valves, stentless bioprostheses (Freestyle), stented bioprostheses, and a homograft were used in 31, 29, 3, and I patients, respectively. Early results, especially hemodynamics, were analyzed among two groups: mechanical valve group (M-group) and Freestyle group (F-group). The average age was significantly higher in the F-group (62.8 +/- 12.7 years) than in the M-group (54.9 +/- 14.0 years) (P = 0.025). The implanted valve was significantly larger in the F-group (26.0 +/- 2.3 mm) than in the M-group (23.5 +/- 2.1mm) (P = 0.000). The estimated effective orifice area of the prosthesis was significantly larger in the F-group (2.23 +/- 0.38 cm2) than in the M-group (1.84 +/- 0.49 cm2) (P = 0.001). The pressure gradient across the prosthesis was significantly lower in the F-group (18.6 +/- 5.5 mmHg) than in the M-group (25.4 +/- 7.6 mmHg) (P = 0.001). The Bentall-type procedure using the Freestyle valve has an advantage regarding hemodynamics compared to the procedure employing mechanical prostheses.