Showing papers on "Prosthesis published in 1978"

Total hip replacement.

Abstract: Summary Total joint replacement is a valuable new procedure in orthopedic surgery. The low friction arthroplasty of Charnley and the Charnley- Muller prosthesis are discussed. Sixty-six operations performed at the University of Illinois Hospital between June 1968 and January 1970 are evaluated. Satisfactory results in relief of pain and ability to walk were obtained in over 90 per cent of the patients. Wound infection was a major disaster, an incidence of 6.6 per cent. Ten patients required reoperations, three for replacement of a loose prosthesis, two for rewiring of the trochanter, three for removal of trochanteric wires, and two for removal of the prostheses after wound infection. The indications and contraindications are discussed as well as the relative merits of both techniques. Proper attention to the indication guidelines and to technical details are essential to insure good results.

An evaluation of facial prostheses

Abstract: A survey was conducted to evaluate patient reactions to facial prostheses that were provided to 143 patients in the past 7 years at Roswell Park Memorial Institute. Of the 76 patients who responded, 38 patients were wearing their prostheses and 38 patients were not wearing their prostheses. Reasons cited by the patients for not using their prosthesis included lack of retention, additional surgery, discomfort, and irritation. Most of the prostheses were prepared in silicone rubber with color characterization accomplished by the tattooing method. More than 69% of the prostheses were remade within a year because of rapid changes in the defect, prosthesis material, or prosthesis color. The study revealed the need for improvement in materials, adhesive techniques, and the psychological orientation of the patient. This project was conducted at a teaching and research institute. No fees for the patients were required. Therefore our data might differ from that collected from a private practice or clinic.

Influence of some operative and postoperative factors on capsular contracture around breast prostheses.

Abstract: In a follow-up of 490 patients with breast implants, neither the size of the prosthesis nor the nature of the surgical procedure (simple augmentation mammaplasty or after subcutaneous mastectomy) increased the incidence of capsular contracture. Hematoma or infection were followed by a higher incidence of capsular contracture. Drainage with suction and the instillation of steroid around the prostheses seemed to be effective in reducing the incidence of capsular contracture. In the steroid-treated group, the need for open surgical treatment was reduced. The recurrence rate after closed capsulotomy, or open capsulotomy, was not significantly different from that following the more extensive procedure of capsulectomy.

Survival and limb salvage in patients with infected arterial prostheses

Abstract: A series of 590 cases with a 2.5 per cent rate of infection of arterial prostheses is presented. When one of the anastomoses was in the inguinal area, the incidence of prosthetic infection was higher. Two infections not involving the anastomotic site healed with conservative management. The three patients with aortoduodenal fistulas died. The long-term survival was 62 per cent, and the amputation rate was 31 per cent. During the last two years, a more aggressive surgical approach of total removal of the infected prosthesis and its replacement with an extraanatomic bypass has been instituted. With this approach, only one death and one amputation has occurred in six patients.

Mechanical tests on the tibial components of non-hinged knee prostheses

Abstract: Cadaveric knees replaced with the Geomedic, ICLH, Marmor and Total Condylar prostheses were tested in axial compression, in rotation and in hyperextension in order to observe the strength of fixation of the tibial components. In axial compression the strengths at failure varied widely, both with any one prosthesis and between prostheses. This is attributed largely to the strength of the cancellous bone of the tibia, which was measured in each case and also varied widely. Three natural knees failed at loads of 7300, 7600 and 8300 newtons respectively, whereas the strengths of replaced knees ranged from 3000 to 15750 newtons. At least one example of each design failed at less than 7300 newtons, suggesting little or no reserve of strength. The strength of fixation was greater when the tibial prosthesis was large enough to rest on the whole cross-section of the tibia. In rotation the three prostheses embodying rollers in troughs were stiffer than the Marmor which had a nearly flat tibial-bearing surface. The presence or absence of the cruciate ligaments had a negligible effect on torsional stiffness. In hyperextension, knees replaced with the ICLH, Marmor and Total Condylar prostheses failed by rupture of the posterior capsule at moments of about 60 newton-metres, compared with about 100 for natural knees. With the Marmor prosthesis the anterior cruciate ligament was avulsed at about 20 newton-metres compared with about 75 in natural knees, suggesting that in this respect the retention of the cruciate ligaments contributes little. None of the four knees tested after inserting a Geomedic prosthesis showed strengths as high as those replaced with the other three designs.

The Attenborough total knee replacement

Abstract: The stabilised gliding knee prosthesis is a compromise between hinged joints and condylar prostheses. It is a two-piece implant designed to allow normal gliding movements of flexion and extension and which, stabilised by a connecting rod between the femoral and tibial components, allows a designed laxity of rotation and lateral movements. A modification of the original femoral component is described. Two hundred and forty-five knee replacement operations have been done between January 1973 and September 1977 and the results are reported. The results using this prosthesis are at least equal to those using hinged or condylar prostheses. So far there has been no case of spontaneous loosening of the components and the implant can be used in patients who, because of severe deformities and instability, are unsuitable for condylar prostheses.

Patency of Biologic and Prosthetic Inferior Vena Cava Grafts With Distal Limb Fistula

Abstract: • A 5-cm segment of the infrarenal inferior vena cava (IVC) in 27 dogs was excised and replaced with a prosthesis of bovine heterograft, venous allograft, or polytetrafluoroethylene (e-PTFE). On completion of the IVC graft, a side-to-side femoral arteriovenous fistula was constructed in the thigh. At six weeks, an IVC venogram was obtained to assess patency and the femoral arteriovenous fistula closed. After three months, the dogs were reexplored, the grafts were removed, and patency was determined. Patency of the venous allograft and bovine heterografts were maintained with the arteriovenous fistula in only two dogs and further deteriorated after closure of the fistula so that only one dog in each group had a patent IVC graft at the end of three months. Eight of the 13 e-PTFE prostheses were patent at six weeks and remained patent for three months after fistula closure. Light and electron microscopy of the patent e-PTFE specimens excised at three months showed regenerative endothelium. Expanded e-PTFE was the most suitable prostheses for replacement of the IVC, resulting in 61% patency three months after closure of a distal arteriovenous femoral fistula. (Arch Surg113:1174-1179, 1978)

Hemodynamic evaluation of the Hancock-modified orifice bioprosthesis in the aortic position.

Abstract: Porcine xenografts have had marginal hemodynamic function in the aortic position, particularly in the smaller sized valves. A new modified orifice heterograft prosthesis (MO) has been designed with the muscular leaflet of the porcine valve excised and replaced with the nonmuscular leaflet of a second valve, thus allowing 25 to 35% improvement in effective internal orifice area. In vitro studies on MO show clear hydraulic improvement over standard porcine prostheses and function comparable to that of low-profile metal prostheses. The MO has been implanted in 26 patients followed from 1 to 10 months with no prosthetic dysfunction or thromboemboli. There has been one perioperative and no late deaths. Intraoperative peak systolic gradients averaged 6.6 mm (0 to 18 mm) for 21 mm prostheses and 1.8 mm (0 to 10 mm) for 23 mm prostheses. These compare favorably with average gradients of 14.0 mm (5 to 27 mm) for standard 23 mm prostheses, 10.1 mm (0 to 30 mm) for 25 mm, and 4.0 mm (0 to 14 mm) for 27 mm prostheses. The MO valve combines the advantages of a bioprosthesis with the excellent hemodynamic performance necessary for the patient with a small aortic anulus.

Dislocation and Component Separation of the Bateman Hip Endoprosthesis

Abstract: THE BATEMAN hip prosthesis has been used at Northwestern University Medical Center since its introduction three years ago. As indicated by Bateman, the primary indications for this prosthesis are fractures of the femoral head and neck, nonunion of the femoral neck, selected instances of avascular necrosis of the femoral head, and revision of conventional femoral-head prostheses. This prosthesis can also be employed electively in certain cases of posttraumatic arthritis and osteoarthritis and rheumatoid arthritis that preponderantly involve the femoral head. 1 This bipolar-type prosthesis has certain advantages over the Austin-Moore-type prosthesis and the Charnley- or Mueller-type total hip prosthesis. Motion within the double-head assembly of the Bateman permits less motion in the acetabulum, thus providing better acetabular wear and less chance of dislocation. 1 Unusual postoperative complications of the Bateman prosthesis were found in two patients. Both patients required reoperation, thus subjecting them to the further risks of infection and

Late complications of prosthetic heart valves.

Abstract: Iatrogenic lesions induced during prosthesis insertion are likely to be encountered by a pathologist examining a patient who died of late complications of heart-valve prosthesis. The lesions are classified as those that may occur in any patient who has had a heart-valve prosthesis inserted, including the iatrogenic type and those that are uniquely associated with a particular prosthesis because of its structure or design.

Hemipelvectomy: Postoperative Rehabilitation Assessed on the Basis of 41 Cases

Abstract: Rehabilitation was evaluated on the basis of 41 consecutive hemipelvectomies for malignant tumours Owing to early metastasization and death, 11 patients were not supplied with prostheses while prosthetic fitting was attempted in the remaining 30 Of this number, 27 completed prosthetic training, with the result that 15 used their prosthesis, while 12 discarded it after some time, six because of poor general health owing to recurrence of the tumours and six because they felt that the prosthesis was too heavy and difficult to wear Twenty-three returned to work After elimination of the most severely tumour-affected patients, there were 19 one-year survivors without recurrence Thirteen of them were using their prosthesis every day, and thirteen had gone back to work Serious mental sequelae were found in five patients, including four with long-lasting exogenous depressions and one with anxiety neurosis

Five-year experience with Lillehei-Kaster prostheses in the aortic position.

Abstract: From 1972 through 1976, 140 patients underwent aortic valve replacement (AVR) with the Lillehei-Kaster (LK) prosthesis and 18 additional patients had AVR plus coronary bypass procedures. Follow- up information was obtained in 98% of the patients. The operative mortality rate was 7.5% and the actuarial 5- year survival rate was, 79%. Two episodes of thromboembolism occurred in 3,645 patient-months. Prosthesis malfunction or significant hemolysis has not occurred. Postoperative catheterization studies revealed a functional valve area of 0.81 cm2 with the 14A prosthesis; all other valve areas were greater than 1.1 cm2. Continued use of the LK aortic valve prosthesis with warfarin anticoagulation is recommended in sizes greater than 14A.

Total joint replacement in bunion surgery

Abstract: A preliminary report is given for total joint replacement arthroplasty utilizing a silicone-polyester prosthesis, in selected cases of destroyed metatarsophalangeal joints of the great toe. Fifty-three prostheses were implanted over a period from March 1971 to March 1977, with a minimum follow-up of one year. Overall results were good from the standpoint of pain relief and cosmetic correction, in severely destroyed and deformed joints. The essential aspects for successful prosthetic arthroplasty include proper seating of the prosthesis and complete realignment of the first ray, paralleling the adjacent metatarsals. On the basis of these preliminary results, it is concluded that there is a place for total joint prosthetic replacement in the surgical reconstruction of the painful, destroyed metatarsophalangeal joint of the great toe.

[On the usefulness of bone scintigraphy for detecting loosening of articular prostheses (author's transl)].

Abstract: The most important complication of articular substitution is the loosening of the prostheses as a result of permanent overstraining, trauma, chemical or infectious noxae. The value of bone scintigraphy in the diagnosis of loosening of the endoprothesis was examined in 53 articular prostheses (49 hip joints and 4 knee joints). A pathological scan was evident in all cases where the prosthesis had become loose (18 cases), whereas a normal scan was found in 34 firmly positioned prostheses. A false positive scan occurred in one case of periarthritis. Bone scintigraphy can be employed as a means of diagnosing loosening of prostheses after a period of nine months following the operation; up to that time, enhancement can be due to the operation. A positive scan in case of loosening of the prosthesis is manifested earlier than radiological signs. For this reason, scintigraphy can be recommended as a routine examination method in pain after articular substitution surgery.

Experience with the melbourne knee prosthesis, based on the first 35 operations over a three‐year period

Abstract: The Melbourne knee prosthesis is an improved hinge prosthesis. Its component parts are constructed of a chrome cobalt alloy and ultrahigh molecular weight polyethylene. The hinge has a range of flexion of 120 degrees, and while flexed, can rotate 15 degrees in either direction. Over the past three years a total of 45 prostheses have been inserted in patients with chronic degenerative arthritis of the knee joints. This survey covers the first 35 operations. The most gratifying result has been a dramatic relief of pain in 87.5% of patients. There have been few complications, and no prosthesis has had to be removed. There have been no mechanical failures of the prosthesis itself.

Diagnosis and Treatment of Dental Prosthesis Esophageal Foreign Body

Abstract: Based upon clinical experience with 20 cases with dental prosthesis esophageal foreign body, the following findings were reported.1) In our 20 cases, 2 children and 1 teenager were included. Care must be taken about the lowering in age range, which is possibly due to recent development in clinical dentistry.2) The incidence of dental prosthesis in the cases of esophageal foreign body is estimated as approximately 7% in Japan.3) Sketching of the prosthesis by the patient himself should not be taken seriously, because it may contain an important mistake.4) Stereorentogenography and rentogenological examination with barium, or other contrast medium, will be of great importance in estimating the shape and direction of the clasp and plate of the prosthesis.