Showing papers on "Prosthesis published in 1983"

Retrieval analysis of total knee prostheses: A method and its application to 48 total condylar prostheses

Abstract: A technique for the classification and quantification of damage in retrieved total knee prostheses is presented and applied to the examination of 48 removed total condylar-type knee replacements. The technique involves inspection of all metallic and polyethylene components for evidence of gross deformation, fracture, and damage to articulating surfaces. A grading system was developed to quantitate surface damage on polyethylene components. Results of the examinations are combined with patient variables (weight, activity level, radiographic findings, time of implantation, and results of histology performed on surrounding tissue) to determine correlations between clinical variables and the mechanical damage experienced by the prostheses. For the 48 total condylar-type prostheses, significant positive correlations were found for the surface damage correlated with the patient's weight and the time the prosthesis was implanted.

Hip arthroplasty with a Moore prosthesis with porous coating. A five-year study.

Abstract: The five-year clinical experience with Moore hip prostheses with a porous coating has been encouraging. The results have been equivalent to those of a simultaneous experience using cemented prostheses. The patient population chosen for hip arthroplasty using prostheses with a porous coating was a group at high risk for failure with cemented prostheses. The mean Harris hip ratings for the 26 patients have improved rather than deteriorated with time. Based on current knowledge, it is the author's opinion that the implants in these 26 patients were firmly fixed by a combination of fibrous and bony tissue ingrowth. The presence of radiopaque lines in one-third of the patients at a two-year follow-up examination indicates that micromotion often was present. Close inspection of the three- and four-year follow-up roentgenograms reveals that the tissue ingrowth seems to have provided implant fixation sufficiently uniform to prevent the roentgenographic signs of localized high-stress concentration so frequently seen with smooth-stem Moore prostheses of the same design. The tissue ingrowth also has produced stress transfers sufficiently uniform to provide roentgenographic signs of healthy bone modeling. With four-year follow-up roentgenograms now available in ten patients, there has been no roentgenographic evidence of bone resorption due to femoral stress shielding by the relatively high-modulus implant with a porous surface.

Moore prosthesis in the treatment of fresh femoral neck fractures: A critical review with special attention to secondary acetabular degeneration

Abstract: A consecutive series of 106 patients with displaced femoral neck fractures was treated initially with Moore prostheses. The patients' mean age was 82.5 years (range, 67–91). At follow-up after two years, 71 patients attended. Thirty-seven per cent of these were in need of a conversion of their one-piece device to a total hip replacement on account of hip pain. When only active patients living in their own homes were considered, 55 per cent were found to need total hip replacements. The main reason for the development of hip pain was acetabular derangement. It was concluded that active patients, disregarding their age, should not be treated with one piece prostheses if their fractures could be satisfactorily reduced and pinned. If this cannot be accomplished, a primary total hip replacement may be considered.

A long-term review of children with congenital and acquired upper limb deficiency

Abstract: A long-term review of 131 children fitted with upper limb prostheses at the Ontario Crippled Children's Centre between 1965 and 1975 is reported. There were 116 children with congenital deficiencies and 15 who had had amputations. Follow-up ranged from 7 to 17 years. A total of 42 children had abandoned their prostheses, 37 of whom had congenital deformities and five were amputees. The level of deficiency was of fundamental importance in determining whether the prosthesis would be accepted; in the forearm, the longer the stump, the more likely it was that the child would discard the prosthesis. Overall, 50 per cent of children fitted over the age of two years abandoned their prostheses compared with only 22 per cent of patients who had been fitted before the age of two years. The highest drop-out rate was at the age of 13 years when the children became more conscious of their cosmetic appearance. Suggestions for reducing the high drop-out rate in the early teens are put forward.

A comparison of the SACH and single axis foot in the gait of unilateral below-knee amputees:

Abstract: The gait patterns of unilateral below-knee amputees wearing prostheses with either a SACH foot or a single axis foot were compared. A temporary below-knee prosthesis was fabricated for each subject using plaster of Paris and Plastazote for the socket, a pylon and an artificial foot. Eight subjects were filmed at two separate sessions, one in which the SACH foot was worn on their prosthesis and one with the single axis foot on their prosthesis.Measurements of the normal leg with a SACH foot on the prosthetic limb were compared to measurements of the normal leg with a single axis foot on the prosthesis. Measurements of the prosthetic leg with both devices were also compared. A one tailed t test (p<.05) was used to determine statistical significance of the results obtained in six measurements of lower limb joint angles and on the percentage of the time of gait cycle for stance and swing phase of the prosthetic leg.Discussion centres on the interpretation of the results from both statistical and clinical poin...

Preliminary experience with a noncemented nonconstrained total joint arthroplasty for the metacarpophalangeal joints

Abstract: A nonconstrained, nonarticulated ball-and-socket-type stemmed resurfacing implant for the metacarpophalangeal joints of the fingers has been developed. The prosthesis is inserted with a press fit, and is made of a carbon material that allows appositional bone growth and biologic fixation. Preliminary experience in 15 patients (43 joints) with up to two years followup has demonstrated satisfactory clinical results and biologic acceptance of the device. A few complications have occurred, including recurrent deformity and subluxation of the prostheses. The device is indicated in patients with traumatic arthritis, and in younger patients with rheumatoid arthritis who have minimal soft-tissue disease and deformity.

Failure of dacron arterial prostheses caused by structural defects.

Abstract: We have observed unusual aneurysmal complications associated with structural defects of Dacron fabrics in three patients. The first patient had beadshape aneurysms along the course of the bilateral axillo-femoral prosthetic bypasses 4 or 5 years after surgery. Round defects or longitudinal rents in the lower third of the prostheses (Vascular-D knitted Dacron graft of high porosity, USCI) were the source of the aneurysmal complications. In the second patient, the transverse diameter of the aorto-femoral Dacron graft (Vascular-D, USCI) was increased to twice that of the original graft with formation of an anastomotic false aneurysm in the groin 3 1/2 years after surgery. The defective prostheses in these two cases were successfully replaced by Cooley double velour knitted Dacron grafts. The third patient developed an arterio-ureteral fistula originating from a round defect of the aorto-femoral prosthesis (Tetoron that is woven Dacron graft with a low porosity, Nakao-Filter, Japan) 8 years postoperatively and died from massive hematuria and subsequent disseminated intravascular coagulopathy. Microscopic examination of the removed prostheses revealed a complete loss of the conformation of the weave with fragmentation and disruption of the graft fibers. Therefore, patients with Dacron arterial prostheses should be followed up regularly and with great care.

Gastroschisis--primary fascial closure. The goal for optimal management.

Abstract: Since Raffensperger and Jona reported an 80% success rate with primary skin closure including a 16% rate of complete fascial closure in 24 patients with gastroschisis in 1974, primary fascial closure has been the author's preferred method. It has been possible to achieve complete fascial and skin closure in 17 of the last 21 patients (81%). Four infants in this series, one of whom was initially managed by another surgeon, were treated with brief application of a silon prosthesis with subsequent reduction and closure. The two keys to success of this method are thorough wash out of the meconium from the entire intestine and vigorous stretching of the abdominal wall. Assisted ventilation may be needed for 24 to 48 hours after operation and has been well tolerated. Transposition of an umbilical artery for cannulation and blood gas monitoring has been an important adjunct. The one death (5% mortality) resulted from prolonged bowel dysfunction and liver failure three months after operation. Other complications have been few and mild. Since some recent reports have indicated that primary closure is not being widely used in the treatment of gastroschisis, this series is presented to emphasize that this method can be used in most infants and with a very low complication rate.

Complications of oriental augmentation rhinoplasty.

Abstract: Augmentation rhinoplasty has become a popular plastic operation in Asia. In Korea most surgeons prefer using silicone rubber prosthesis instead of autogenous material. The authors have used the standard shaped silicone prosthesis, boat-shaped and also L-shaped prostheses. The standard shape prosthesis has less extrusion and fixation problems. In over 1,500 cases, there were 357 complications (20.8%). All the complications were due to the silicone prosthesis acting as a foreign body or failure in design of implant or unskillful operative technique. In order to minimise complications, care should be taken to use the proper size of prosthesis, the correct shape of implant and to ensure that there is adequate undermining and meticulous closure technique. To minimise the overlying skin tension at the tip and on the dorsum of the nose, the cutting of the depressor septi nasi muscle and transverse part of the nasalis muscle are recommended. In this review, we report the types and incidence of complications by analysing the cases seen during the past 10 years in our Unit and offer a few solutions to overcome these complications.

Comparison of Charnley and T-28 total hip arthroplasty.

Abstract: A retrospective review of a matched series of 40 Charnley and 40 T-28 total hip arthroplasties was performed. The mean follow-up period after surgery was 5 1/2 years. The clinical status and detailed radiographic appearance were carefully evaluated prior to operation, two months after operation, and at the final follow-up examination. The clinical results were similar. The Charnley femoral components tended to be positioned in a more valgus orientation than the T-28 prostheses by 2.2 degrees (p less than 0.02). After operation, the patients with T-28 prostheses had larger leg-length discrepancies than the patients with Charnley prostheses (p less than 0.01). Calcar resorption was not significantly different between the two groups, nor were subsidence of the femoral components and migration of the acetabular components. A collared T-28 femoral component has little clinical advantage over a noncollared prosthesis with respect to calcar resorption and femoral component subsidence.

Evaluation of the patency rate of fibrous microvascular polyurethane prostheses after implantation in the rat aorta.

Abstract: Two types of fibrous polyurethane prostheses with different compliances were implanted into the rat aorta with interrupted sutures and a running suture line Excluding two technical failures, one unexplained death, and three infected prostheses, both groups (n = 21) showed a patency rate of 100%, up to 6 months after implantation Rapid reendothelialisation occurred, and a stable neo-intima was formed Compliance of the prostheses, as well as the suture technique used, has proven to be an unimportant factor in the rat aorta model, probably due to the low magnitude of the pulsations of the rat aorta The experience of the surgeon with microsurgical techniques seems to be an underestimated factor in determining patency rates of microvascular prostheses

The bi-articular hip prosthesis for fractures of the femoral neck—a preliminary report

Abstract: The bi-articular hip prosthesis (BHP), based on an original design by Bateman, is a bi-polar hemi-arthroplasty which seeks to reduce acetabular wear. We have used this prosthesis to treat 101 elderly patients with displaced intra-capsular fractures of the neck of the femur. The results of the first two years experience with this prosthesis are encouraging. Post-operative hip pain was not significant and did not interfere with mobility. The use of the antero-lateral approach to the hip joint prevented dislocation of the prosthesis, in contra-distinction to reports of series in which the Southern approach was used.

Five years' experience with the Silicone-Silver Penile Prosthesis: Improvements and new developments

Abstract: Five years' experience using the Standard Version (SV) of the Silicone-Silver Penile Prosthesis is reported, based on evaluation of 1890 implantations done by 309 physicians. In 72.4% the indication was diabetes mellitus, vascular disease or postpelvic surgery; 81.2% of the patients were between 40 and 69 years of age. Early complications occurred in 5.1%, late complications in 2.8%. Of 1834 implantations, 19 (=1.04%) of the devices had to be removed. The overall success rate was 92.1%. To improve availability and lower costs, the Variable Version (VV) was designed, a device which can be trimmed down to appropriate size during surgery. Preparation of the prosthesis is described. The most recent modification is the Trimming-Tip Version (TTV). As the proximal end of this device can be shortened up to 3 cm, two pairs of prostheses per diameter (total: 4 pairs) are sufficient to fulfill all length requirements from 16 to 25 cm. Two further features of the TTV are: a conic distal end and a bulk diameter of 11 or 13 mm, both of which improve placement within the corpus and the cosmetic results.

[Evaluation of Neer's hemi-arthroplasty in the treatment of humeral fractures].

Abstract: Eighteen patients with fractures of the proximal humerus with at least four fragments, with or without dislocation (group IV, V and VI of Neer's classification), were treated by hemiprosthetic replacement. The average age was 59 years. The follow-up was from 1 to 7 years. Patients were assessed on two occasions by two evaluators using Neer's protocol. The glenohumeral and the scapulothoracic movements, using the other shoulder as control, were measured radiologically at 0 degrees, 45 degrees and maximal abduction. Pain, function and range of motion were recorded. No complication was encountered. By radiologic assessment, it was possible to classify results in three groups. In all of the unsatisfactory results, the centre of motion of the prosthesis was displaced proximally. Satisfactory and excellent results were obtained in 66%. The best results are obtained if patients are operated on early; repair of the rotator cuff is important. The centre of rotation of the prosthesis must be in precise biomechanical relation to the glenoid fossa; such a relation is of prognostic value.

Inflatable Penile Prosthesis: Experience with 100 Patients

Abstract: The experience with 100 consecutive patients in whom an inflatable penile prosthesis was implanted for the treatment of chronic erectile impotence over a two-year period is reported. Each patient was thoroughly evaluated by history, physical examination psychologic investigation, and appropriate laboratory testing. Of these patients, the most common indication for prosthesis implantation was diabetes mellitus of adult onset, followed by vascular disease and radical pelvic surgery. Restoration of erectile function was accomplished in 99 patients. Mechanical complications and malfunction occurred in 12 patients; all such complications were surgically corrected in subsequent operative procedures. One diabetic patient experienced infection of the prosthesis, requiring its removal. The implantation of an inflatable penile prosthesis in properly selected patients, with careful surgical technique by a skilled and experienced surgeon, can produce excellent functional results and return of normal sexual activity.

The hip cast-brace for hip prosthesis instability.

Abstract: The use of a hip cast-brace in the treatment of unstable hips following prosthetic replacement is described A retrospective study of 21 patients with 22 hip prostheses treated with the cast-brace is reported Seventeen Charnley low friction arthroplasties (LFA) were treated--four cast-braces were used for prophylaxis, five for single dislocations and eight for recurrent dislocations To date, only four hips have required an operation to achieve stability Five patients with Thompson hemi-arthroplasties were treated following dislocation with only one requiring surgery to achieve stability A hip cast-brace is recommended as a useful alternative to surgical management of prosthetic instability

Hinge prosthesis of the knee. Apropos of 185 cases

Abstract: On hundred and ninety-five hinge prostheses have been inserted between 1970 and 1981, most of them of the G.U.E.P.A.R. type. One hundred and forty-three were followed up. The etiology of five per-operative deaths is discussed. It is concluded that this dramatic event was related to gas embolism. Precautions necessary to avoid such accidents are described particularly at the time of release of the tourniquet. There were 11 cases of sepsis, eight loosenings and four post-operative fractures of the femur or tibia. The functional results were found to be satisfactory but better with the G.U.E.P.A.R. type than with the Shiers prosthesis. Most of the post-operative pain originated from the patella; this aspect of the pain should be able to be avoided by systematic use of patellar resurfacing. The authors conclude that a hinge prosthesis should be used only in cases of severe deformity, of severe instability or in cases of failure of resurfacing procedures.

Complications of a total hip prosthesis revealing a renal cell carcinoma.

Abstract: Case report of pelvic dislocation of a total hip prosthesis cup on an acetabular signal metastasis, occured 22 months after surgery.

Long-term results from metacarpophalangeal arthroplasty.

Abstract: The authors have been using Swanson's prostheses for MP joint replacement in rheumatoid arthritis since 1968. After thirteen years of experience, they present an analysis of these prostheses from a clinical and radiological point of view. 88 joints replacements in 20 patients are reviewed. These operations were performed between 1968 and 1976. The average follow-up is nine years. The authors compare their results with those obtained in a previous study made in 1975. They show that a replacement arthroplasty with a Swanson type prosthesis, imparts considerable benefits to the patient in the form of complete disappearance of pain, improvement in function, and a more normal looking hand, in spite of radiologic deterioration.

The Radiology of Prosthetic Cardiac Valves

Abstract: Since Harken et al. in 1959 and Starr and Edwards in 1960 successfully implanted the first caged-ball valve prostheses in the aortic valve, continuous and dramatic improvement in operative mortality, the quality of the prosthetic devices, and the rate of postoperative complications has been achieved. At the present time, late deaths related to prosthetic valve implantation occur in approximately 10% of patients. Death is due in large part to intrinsic cardiac problems, such as myocardial infarction and arrhythmias, and also to complications directly related to the prosthesis itself. Life-threatening complications associated with cardiac valve implantation include thromboembolism, hemolysis, paravalvular or valvular insufficiency, infection, and those of anticoagulation (1).