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At least 1,099 records · Page 61Linked to original sources
PubMed2005

First report on a human percutaneous transluminal implantation of a self-expanding valve prosthesis for interventional treatment of aortic valve stenosis.

BACKGROUND: Percutaneous aortic valve replacement is a new technology for the treatment of patients with significant aortic valve stenosis. We present the first report on a human implantation of a self-expanding aortic valve prosthesis, which is composed of three bovine pericardial leaflets inserted within a self-expanding nitinol stent. The 73-year-old woman presented with severe symptomatic aortic valve stenosis (mean transvalvular gradient of 45 mmHg; valve area of 0.7 cm2). Surgical valve replacement had been declined for the patient because of comorbidities, including previous bypass surgery. METHOD AND RESULTS: A retrograde approach via the common iliac artery was used for valve deployment. The contralateral femoral vessels were used for a temporary extracorporal circulation, unloading the left ventricle during the actual stent expansion. Clinical, hemodynamic, and echocardiographic outcomes were assessed serially during the procedure. Clinical and echocardiographic follow-up at day 1, 2, and 14 post procedure was performed to evaluate the short-term outcome. The prosthesis was successfully deployed within the native aortic valve, with accurate and stable positioning and with no impairment of the coronary artery or vein graft blood flow. 2D and doppler echo immediately after device deployment showed a significant reduction in transaortic mean pressure gradient (from 45 to 8 mmHg) without evidence of aortic or mitral valve insufficiency. The clinical status has then significantly improved. These results remained unchanged up to the day 14 follow-up. CONCLUSION: This case report demonstrates a successful percutaneous implantation of a self-expanding aortic valve prosthesis with remarkable functional and clinical improvements in the acute and short-term outcome.

Aged↗
PubMed1987

[Total prosthesis of the hip: procedure using cement--indications, technic and results].

The prosthesis must be adapted to the bone without motoric adaptation. For biomechanical reasons it is necessary to have as large a zone of contact as possible. It is impossible to introduce an "exact size prosthesis". Exact size can be achieved only with cement. The disadvantage of too much elasticity by a thicker cement layer must be compensated by the voluminous metallic implant wedged in the bone marrow. The combination of the osteosynthesis plate, shaft and cement yields a kind of "individual prosthesis". In the long-run the cement is biocompatible. The correct technique of the application of the cement is of utmost importance. 95% success-rate in 373 replacement operations between 1977 and 1985 using the same implant material proves the validity of biomechanical considerations. Allergy as the factor influencing the loosening of the implant can be practically disregarded. Bony defects should be filled out with bone and not with cement.

Biomechanical Phenomena↗
PubMed1992

[Cemented bipolar prosthesis in multimorbidity patients with coxarthrosis. Short- and intermediate-term results].

The treatment of coxarthrosis with the cemented Duopleet prosthesis represents an efficient alternative to total hip prosthesis in elderly and polymorbid patients. The early results show a tolerable rate of complications. The patients can be mobilized early. The mortality seems to be low. Medium-term results are satisfactory. The rate of protrusions is lower than in patients with common femoral head prosthesis. Paraarticular ossifications are seen frequently. In numerous patients we found pain with projection to the operated hip.

Aged↗
PubMed2003

[Tribologic investigation of a metacarpophalangeal prosthesis].

It is the goal of this paper to introduce modern tribological investigations into the development of a new finger prosthesis, with the particular aim of optimising the material component.A new, unconstrained metacarpophalangeal prosthesis restoring the anatomy of the joint has been developed in two versions (UHMWPE-metal and PEEK-metal). In order to determine the version having better wear behaviour, these two versions were tested on a Joyce finger simulator. As the UHMWPE-metal version showed a lower amount of wear in vitro, this version was chosen to conduct a clinical study. This investigation showed the importance of conducting an in vitro wear test before any clinical studies. Such tests allow the optimisation of the wear behaviour of the tested metacarpophalangeal prosthesis and therefore permit a minimisation of the possible risks to the patients.

Equipment Failure Analysis↗
PubMed2004

Total hip arthroplasty in young patients using the thrust plate prosthesis: clinical and radiological results.

INTRODUCTION: The standard treatment for patients who require total hip replacement is the implantation of an intramedullary diaphyseal anchored hip prosthesis. A bone-sparing thrust plate hip prosthesis (TPP) can be used as an alternative device for young patients. The TPP relies on proximal femoral metaphyseal fixation. The theoretical advantage of leaving diaphyseal bone intact is easier conversion to a stemmed prosthesis. This retrospective study evaluated the medium- and short-term results after total joint replacement using the third generation TPP. MATERIALS AND METHODS: Between 1997 and 2001, 58 TPPs were used for 52 patients. Clinical and demographic data were obtained from the patients' charts and our electronic database. Their average age at time of surgery was 40.9+/-11.4 years. At follow-up, the Harris hip score, residual pain, required pain medication, and the ability to lie on the operated side were documented. Radiographic evaluation included standardized radiographs of the hip joint and the pelvis. RESULTS: Four patients required revision surgery (6.9%). For 51 of the remaining 54 TPPs, a postoperative functional and radiological status was obtained. The average follow-up was 26+/-11.0 months. 88% of the patients experienced some or complete relief of pain. The median Harris hip score at follow-up was 73+/-20.5 points. A postoperative hip dislocation occurred in 5 patients (8.6%). CONCLUSION: Since many patients experienced some or complete relief of pain, the TPP can be recommended as a feasible implant for the treatment of hip disorders requiring total hip arthroplasty in young patients. Revision surgeries are facilitated by the good bone stock remaining in the proximal femur.

Adult↗
PubMed1985

Experience with outlet strut fracture of the Björk-Shiley convexoconcave mitral valve prosthesis.

Within a period of 15 months, we encountered five patients with outlet strut fracture of the Björk-Shiley convexoconcave mitral valve prosthesis. All of the patients had acute failure of the left side of the heart and pulmonary edema. The diagnosis was made by review of the chest roentgenogram which showed features of pulmonary edema; both the outlet strut and the tilting disc were missing from the mitral prosthesis. The "missing" components might be found in the left side of the heart or in the course of the thoracic aorta. Emergency reoperation was carried out on three patients, and there were two survivors. It is essential to recognize this potentially fatal complication and undertake immediate surgical intervention. We performed the original valvular replacement operations in four of the five patients. The probability of outlet strut fracture occurring in our series of 237 patients with a Björk-Shiley convexoconcave mitral valve prosthesis is 1.69%, or 0.076 per 100 patient months.

Adolescent↗
PubMed1991

Transesophageal color Doppler echocardiography of the normal St. Jude Medical mitral valve prosthesis.

Transesophageal color flow Doppler findings are reported in 36 patients with a St. Jude Medical mechanical mitral valve prosthesis who had no auscultatory evidence for prosthetic valve dysfunction. Multiple jets consistent with mitral regurgitation originating from the central and lateral portion of the prosthesis were found in all patients. Maximum jet length ranged from 11 to 51 mm (mean 21 +/- 9 mm). Maximum jet area ranged from 0.2 to 4.1 cm3 (mean 1.2 +/- 0.9 cm2). The color M-mode Doppler interrogation showed two distinct components of the regurgitant jet: brief early systolic flow consistent with valve closure followed by holosystolic regurgitant flow consistent with transvalvular leakage. Four patients (11%) had a maximum regurgitant jet length exceeding 30 mm and absence of early systolic closure regurgitant flow by M-mode color imaging, suggesting clinically silent paravalvular leakage. Two pin-sized paravalvular suture line defects were confirmed in one patient at cardiac transplantation. We conclude that transesophageal echocardiography is a highly sensitive method for detection of mitral regurgitation in the St. Jude Medical mitral prosthesis. Clinically silent paravalvular leakage should be suspected if the maximum jet length exceeds 30 mm and color M-mode interrogation fails to demonstrate an early systolic closure regurgitant flow component.

Echocardiography, Doppler↗
PubMed2006

Electra trapezio metacarpal prosthesis: results of the first 100 cases.

The Elektra trapeziometacarpal prosthesis is a cementless, unconstrained prosthesis made by Fixano with titanium and chrome-cobalt steel. This paper examines the results of the first 100 prostheses used by the author for one indication only, viz. painful trapeziometacarpal osteoarthritis. The average follow-up period was 54 (range 36-78) months. Studies of pain, mobility and grip and pinch strength were carried out, the results of which were good in 83 cases. Seven dislocations occurred. Five of these were following severe trauma. The commonest complication was a lack of osteointegration of the trapezial part of the prosthesis, which occurred in 15 cases. Sinking into the metacarpal of the distal stem occurred early in the series in two cases. Some others complications were observed: allergy to the metal (one case), fracture after direct trauma of the thumb (one case) and very painful osteoarthritis of the scaphotrapeziotrapezoid joint (one case).

Adult↗
PubMed2001

A novel low wearing differential hardness, ceramic-on-metal hip joint prosthesis.

Osteolysis and loosening of artificial joints caused by polyethylene wear debris has prompted renewed interest in alternative bearing materials for hip prosthesis designs. Lower wearing metal-on-metal (MOM) and ceramic-on-ceramic prostheses are being used more extensively, and there is considerable interest in further improving on their performance. This study investigated the wear properties and debris morphology of a novel differential hardness ceramic-on-metal (COM) prosthesis, in comparison with MOM articulations in a physiological anatomical hip joint simulator. The COM pairings were found to have wear rates approximately 100-fold lower than the MOM pairings. The MOM pairings showed a higher "bedding in" wear rate (3.09+/-0.46mm(3)/10(6) cycles) in the first million cycles, which then reduced to a steady state wear rate of 1.23+/-0.5mm(3)/10(6) cycles. The wear rate of the COM pairings over the duration of the test was approximately 0.01mm(3)/10(6) cycles with very little wear detected on the surface of the prosthesis components. The wear particles from both articulations were oval to round in shape and in the nanometer size range. After one million cycles the mean maximum diameter of the MOM and COM wear particles were 30+/-2.25 and 17.57+/-1.37nm, respectively. After five million cycles the wear particles were statistically significantly smaller than at one million cycles, 13.9+/-0.72nm for the MOM pairings and 6.11+/-0.40nm for the COM pairings. The wear rates of the MOM prostheses were representative of clinical values. The use of differential hardness COM pairings dramatically reduced the wear rate compared to MOM hip prostheses. The wear particles from the MOM articulation were similar to particles found in retrieved tissues from around MOM prostheses. The extremely low wearing differential hardness COM bearings presented in this study produced far smaller volumetric particle loads compared to MOM prostheses currently used clinically.

Biocompatible Materials↗
PubMed1995

Insall-Burstein posterior-stabilized knee prosthesis in rheumatoid arthritis.

The authors reviewed 65 Insall-Burstein (Zimmer, Warsaw, IN) total condylar posterior-stabilized knee prostheses in 50 patients with rheumatoid arthritis with a follow-up period of at least 5 years (range, 5-13 years). Forty-two knees in 31 patients were evaluated using the Knee Society knee and functional rating scores. Radiographic assessment was performed using standing long radiographs (hip to ankle). Radiolucent lines were studied using fluoroscopic-centered views. Excellent or good clinical results were obtained in 95% of the cases, and the average knee score improved from 22.5 to 90 points. No cases of radiologic loosening were observed. Incomplete radiolucent lines around the tibial component were detected in only 17% and were nonprogressive. Two patients developed hematogenous late deep infection, which required removal of the prosthesis in both, followed, at a second stage, by arthrodesis in one and prosthesis reimplantation in the other. Three knees (7%) had a painful impingement of the patella. Two of these were successfully reoperated with arthroscopic debridement of the peripatellar synovial tissues. Survivorship analysis, based on endpoints such as prosthesis removal for any cause or radiologic loosening (complete radiolucent line thicker than 1 mm, tilt, or subsidence of the component), showed a cumulative success rate of 96.2% at 13 years.

Arthritis, Rheumatoid↗
PubMed1997

Revision total knee arthroplasty with a cemented posterior-stabilized or constrained condylar prosthesis: a minimum 3-year and average 5-year follow-up study.

The results of 57 revision total knee arthroplasties performed for aseptic failure between 1984 and 1992 with a cemented posterior-stabilized or constrained condylar prosthesis were reviewed at follow-up examinations at a minimum of 36 and an average of 62 months (range, 36-120 months). The reason for revision was aseptic loosening of 1 or both components in 32 knees (56%), instability in 16 knees (28%), polyethylene wear and osteolysis in 4 knees (7%), supracondylar femur fracture in 2 knees (4%), and a failed allograft, pain, and arthrofibrosis in 1 knee each (5% total). The average age of the patients at the time of the revision was 74 years (range, 38-90), and the original diagnosis for the majority of patients was osteoarthritis (74%). All of the revision prostheses were cemented posterior stabilized or constrained condylar-type implants. Bone deficiencies were grafted with cancellous allograft in contained defects and cortical allograft in noncontained defects. Five knees were reconstructed with allograft-prosthesis composites. The average modified Hospital for Special Surgery knee score improved from 49 to 82 (100 points possible) at final follow-up evaluation (P < 0.001). Seventy-nine percent of knees were graded as good or excellent. Kaplan-Meier survivorship analysis predicted 94%+/-6.2% survival at 40 months and 75%+/-25% at 99 months. There were 4 clinical failures, 3 of which were related to residual instability in patients with a posterior-stabilized prosthesis. Complications (3 knees) were exclusively related to the extensor mechanism. Radiographically, overall knee alignment improved from 0.3 degrees varus to 3.0 degrees valgus. Fifty-six percent of tibial components were placed in slight varus alignment. Radiolucent lines occurred in 33% of knees, but there were no complete or progressive radiolucencies. Radiolucent lines were more prevalent adjacent to press-fit intramedullary femoral stems compared with cemented stems (P < .02), but the difference did not correlate with clinical or radiographic failure. The median bone defect score, as proposed by the Knee Society Committee on Bone Defects, was significantly greater in knees that were revisions of a failed cemented total knee arthroplasty compared with revision of a failed cementless total knee arthroplasty (P = .02) but was not correlated with clinical or radiographic outcome (P > .05).

Adult↗
PubMed1998

Problems with the Rotaflex: a 10 year review of a rotating hinge prosthesis.

The results of the first 10-year review of the Rotaflex total knee prosthesis are presented. Loosening, fracture, implant failure, and damage to the extensor mechanism have been frequent findings. Of 25 implants reviewed, an arthrodesis has been performed in 4 patients and an amputation in 2. Surgery has been declined in a further 4 patients. A brace is required by 7 of 19 patients in whom the prosthesis has not been removed, and the results of surgery are considered poor in 13 of these 19 patients. With an overall complication rate of almost 80%, there would appear to be no place for this prosthesis despite its continued availability.

Activities of Daily Living↗
PubMed1997

Psoriasis is a risk factor for hip-prosthesis infection.

Risk factors for hip and knee prosthesis infection have been described, but not psoriasis. Eighty five infected patients from different centers and 202 non infected patients were included in a case-control study. Fifteen of 85 infected patients (17.6%), and 2 of 202 (1%) non infected patients had psoriasis. Odds ratio for infection in patients with psoriasis is 21.4 (4.7-195.5), and 39.7 (5.3-1718.8) in patients with hip prosthesis and psoriasis. No significant difference was found in patients with knee prosthesis. These data indicate that psoriasis is a risk factor for hip prostheses infection.

Case-Control Studies↗
PubMed2000

Loosening of a fenestrated femoral prosthesis: a case report with histomorphologic analysis.

The explanted loose stem of a trabecular cementless femoral prosthesis (Holz-Copf) was histologically analyzed revealing soft tissue 3 mm thick between the metal of the prosthesis and the cancellous bone. Direct contact between the implant and bone could not be found. Removal of the prosthesis was impossible by simple extraction so that a transfemoral approach was required. Prostheses with large fenestrations may be loose but at the same time ingrown with sufficient bone to require invasive procedures for their removal.

Arthritis↗
PubMed2001

[Long-term outcome of Swanson prosthesis management of the rheumatic wrist joint].

Silicone-wrist arthroplasty has dominated reconstructive surgery of the rheumatoid wrist for a long time. Silicone interposition wrist arthroplasty yielded good clinical results in short and midterm studies. The durability and longevity of the prosthesis however is limited and progressive X-ray deterioration and silicone synovialitis are the main shortcomings. We present the ten-year follow-up results of 102 rheumatoid wrists operated between 1984 and 1992. 72 patients with 82 wrist arthroplasties were clinically and radiologically examined. The mean age at operation was 56.9 years. The average onset of R.A. was 16.1 years. Each wrist was rated on a 100-point scale, with points based on wrist balance, range of motion, pain relief and extensor strength. The postoperative Clayton score averaged 69.4 points. Including revision cases, 51% of the Swanson implants were rated good or excellent, 16% fair, and 33% were judged poor because of pain or prosthesis breakage. Patient satisfaction and pain relief were achieved in 68.2%. Active motion with unrevised implants was 21 degrees extension and 31 degrees flexion. We noticed a moderate increase (7 degrees) for ulnar-radial deviation. There was a progressive deterioration in the radiographic appearance. Implant fracture occurred in 31% of the patients. Subsidence of the implant and significant reduction of carpal height was noticed in 82.5% of the prosthesis. Revision procedures were performed in eleven cases. We conclude that the clinical and radiological results of Swanson silicone interposition arthroplasty will deteriorate with the passage of time. Beyond the potential deleterious effects of silicone, long-term radiological complications such as implant fracture, subsidence and carpal collapse are the main disadvantages of Swanson arthroplasty of the wrist. We therefore currently recommend the MPH-total wrist design in patients with rheumatoid arthritis.

Activities of Daily Living↗
PubMed1992

[Histological studies of the behavior of the dentin ossicular prosthesis in the human middle ear].

The Dentine Ossicular Prosthesis (DOP)--introduced in the ENT-Department, University of Hamburg in 1986--has proved its worth clinically in more than 300 cases. In the meantime six of the prostheses had to be removed for various reasons. They had remained in the middle ear over a period between 2-5 and 47 months. The prostheses were investigated undecalcified by the Donath sawing and grinding technique. Prostheses in a nearly bland surrounding show a partial invagination in fibrous connective tissue without severe reaction of the prosthesis itself, whereas in prostheses removed from the neighbourhood of inflammatory processes or recurrent cholesteatoma a partial resorption of dentine with subsequent new bone formation could be observed. Due to the trouble-free clinical and histological performance in the human middle ear, the Dentine Ossicular Prosthesis can be well recommended as an alternative material in ossiculoplasty.

Adolescent↗
PubMedDate not supplied

[Treatment of necrosis of the femur condyle with a medial gliding knee prosthesis].

Spontaneous osteonecrosis of the femoral condyles occurs rather seldom particularly in elderly patients. Whereas some authors recommend valgusosteotomy and bone drilling, implantation of a unilateral knee prosthesis should be performed in the presence of large defects. It is reported a series of 11 patients suffering from osteonecrosis of the femoral condyle. All patients were treated by a unilateral knee prosthesis with good results except one case. The filling of the defect with cancellous bone prior to the implantation of the condylar part of the prosthesis is mandatory.

Aged↗
PubMedDate not supplied

[Prosthesis for tumor of the hip joint (indications and results)].

Between 1972 and 1982 34 tumour prostheses (23 total replacements, 11 semitotal replacements) of various designs were implanted at the State Orthopedic Clinic in Munich-Harlaching and at the University Orthopedic Clinic in Grosshadern. The indications were primary and secondary malignant tumours, potentially malignant tumours, peritrochanteric pseudarthroses, and loosening of prostheses where bone conditions were poor. Since 1977 only the "Harlaching" femoral tumour prosthesis, a locally developed model, has been used. Its distinguishing feature is the modular or kit principle, which renders it possible to adapt the prosthesis and define its length accurately during surgery. On the basis of 13 long-term observations, in some cases extending over 8 years, it was established that this tumour prosthesis need not be regarded as merely a palliative intervention (this applies also to younger patients with a longer life expectancy); the slight and transitory complications and the relatively good long-term functional results are encouraging.

Bone Neoplasms↗