Side-effects of prosthetic materials on the human body

Wear behavior and histopathology of classic cemented metal on metal hip endoprostheses

The authors reviewed their collection of retrieved all metal hip joints (9 McKee-Farrar, 7 Müller, and 3 Huggler type prostheses) and tissues from the joint capsules and implant beds. The amount of wear was measured, and the total volume was calculated. The tissues were analyzed by atomic absorption spectral analysis or inductively coupled plasma mass spectrometry and examined by light and scanning electron microscopy. The size of particles was measured with a texture analysis system. The articulating surfaces showed many delicate scratches which represent normal wear. The calculated annual wear averaged approximately 5 mm3 per year, which is low compared with polyethylene. The cellular reaction to metal wear particles was regarded as mild. The cellular reaction to scattered and worn bone cement was always more pronounced than to metallic debris. Scanning electron microscopy confirmed the irregular shapes and mostly submicron size of the metal particles. The analytically detected metal content of the periarticular tissue was relatively low and in accordance with the wear measurements from the articulating surfaces. The excess of chromium in the tissues is discussed in the light of the elimination of cobalt as well as the relation between elements representing either corrosion products or elements still bound in wear particles.

Measurement of polyethylene thickness in total hip arthroplasty. A technique analysis

Accurate radiographic measurement techniques are necessary to evaluate wear characteristics of different metals, ceramics, and plastics. This study evaluated a standard technique for radiographic measurement of acetabular component thickness. Twenty-one acetabular components retrieved after revision surgery were studied. Radiographic measurement of polyethylene thickness was performed at two points on radiographs taken within 2 months of the revision surgery. Measurements were made at the area of greatest polyethylene wear and at the center of the component, and these measurements were compared to direct measurement of the retrieved component. The 42 data points obtained revealed an average difference between the radiographic and direct measurements of 0.18 mm. A regression model demonstrated no significant difference (P = .85) between these measurements. Additionally, when comparing the central-point measurement to the thinnest wear-point measurement, no difference was noted, indicating that wear in the sagittal plane did not affect radiographic measurement accuracy. Radiographic measurement of acetabular component thickness is accurate to within 0.18 mm. This degree of accuracy allows for radiographic wear analysis, as long as the standard measurement technique is utilized.

Polyethylene delamination in the PCA total knee. Material analysis in two failed cases

Two patients had severe polyethylene-wear synovitis after total knee arthroplasty for arthrosis. Full-leg length weight-bearing radiographs were diagnostic. The polyethylene of the tibial components showed excessive delamination. The morphology and crystallinity of the polyethylene showed that surface treatment of the material could well be held responsible for the massive wear.

Femoral lysis after cemented hip arthroplasty

The cause of femoral lysis after cemented total hip arthroplasty is unknown. Clinical aspects are poorly understood, and there have been only a few reports, with small numbers of cases, in the literature. The author analyzed common factors and clinical aspects in 51 cemented hip arthroplasties with lysis around the femoral component, in an effort to understand the cause of lysis. The process frequently starts where metal abuts against bone or where cement is deficient or fractured. Men are more commonly affected than women (4:1). Pain is the only symptom, but lysis can occur without pain. Lysis is progressive and always culminates in implant loosening. Progression is usually slow but can be alarmingly rapid. Twenty-six percent of cases in this series had associated acetabular loosening. After bilateral hip arthroplasty, lysis can be bilateral but usually is not. The major causative factor may be microfragmentation of any of the component parts of the artificial joint complex.

The role of macrophages and giant cells in loosening of joint replacement

Macrophages and foreign-body giant cells from the bone-cement interface of loosened joint replacement were assayed for direct bone resorption in an in vitro experimental model. Human osteoclasts from giant cell tumors and experimental animal osteoclasts were not capable of resorbing the bone under experimental conditions, but osteoclasts are. It is suggested that macrophages and giant cells in loosened implants may initiate bone resorption, removing the extra-cellular barrier that normally protects mineral crystals from osteoclastic recognition.

Metal ions in body fluids after arthroplasty

We measured levels of metal ions in urine and plasma of 17 patients 7-15 years after they had a Co-Cr-Mo alloy total hip replacement. They had higher levels of cobalt and chromium than controls. No case of skin sensitivity to the investigated metals was observed. The values of cobalt and chromium in plasma and urine were considerably lower than in professionally exposed groups and do not represent a toxic hazard for the patients.

A histopathologic comparison of the tissue reaction to prosthetic materials in the knee joint of rats

The five kinds of prosthetic materials: powders of cobalt alloy, stainless steel, alumina ceramic, HDP plastic and bone cement, were injected to the knee joints of 16 rats for each material. Two controls were used, one with saline solution and the other untreated. Some of the rats were sacrificed at one week, being left untreated. Some of the rats were sacrificed at one, four, 12 and 25 weeks after injection. The knee joints of these rats were taken out for a histopathologic study. The main changes were fibrosis and granulation due to foreign bodies, but no remarkable change in the degree of tissue reactions was observed within each material group, nor did the length of period have any effect thereon. Comparing the degree of the above changes caused by each material in the tissue, ceramic powder showed the most significant change, followed by bone cement, HDP, stainless steel and cobalt alloy powder, in that order. No tumorous condition was observed.

Involvement of metal particles in loosening of metal-plastic total hip prostheses

Four loosened metal-on-plastic total hip prostheses and associated tissues were examined. Each implant showed an uncommonly high formation of metal particles produced by wear or corrosion of the femoral stem. The granulation tissue between bone and cement was characterized by macrophages containing metal particles. Histological, histochemical, and ultrastructural investigations have been performed to assess cellular reactions to ingested metal particles. Pathogenesis of loosening in these cases is discussed in relation to the role of macrophages in bone resorption.

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

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.

Dermatitis from a chromium dental plate

Systemic absorption of metal or metallic salts from dental and orthopedic surgical implants can produce a cutaneous allergic dermatitis in susceptible individuals. Mercury, nickel and cobalt are the most common metals to elicit such systemic allergic reactions from chronic internal exposure. A case is presented of a generalized eczematoid dermatitis apparently caused by allergy to chromium liberated from a metal dental plate.

Metal determination in organic fluids of patients with stainless steel hip arthroplasty

In 20 stainless steel Charnley hip arthroplasties (with a follow-up of 10-13 years) nickel, chromium and manganese levels were measured in blood, plasma and urine by atomic absorption spectrophotometry. Skin patch tests for these metals, and clinical and roentgenographic results of arthroplasty were also assessed. Metal levels in organic fluids were plotted against a control population homogeneous for age, residence and anamnestic conditions with the first, but which had never undergone a prosthesis or other metallic implant surgical procedure. Nickel levels in blood, plasma and urine, manganese levels in blood and urine and chromium levels in plasma were significantly higher in the hip prostheses population. Metal ion release from stainless steel prostheses is discussed with regard to implant failure, metal sensitivity and carcinogenesis.

Postoperative results of Yoshino total knee prosthesis. A report of 264 arthroplasties performed between 1974 and 1980

A review was made of 264 Yoshino total knee arthroplasties performed on 154 patients between February 1974 and July 1980. The average duration of the follow-up was 3 years and 2 months. Eighty-six percent were rheumatoid patients. Complications occurred in seven patients. The evaluation results indicated excellent relief of pain and improvement in walking ability. However, pain of the patellofemoral joint was noted in a number of osteoarthritic patients. This implies that a patella implant is necessary in the case of osteoarthritis. In addition, a new surgical technique was performed on "stiff" knees to improve their degree of movement; the average range of movement achieved in these patients was 70 degrees.

Preliminary report on postoperative results of newly designed stable total knee prosthesis

A newly designed stable total knee prosthesis was made for the severely destructed knee. This prosthesis was named the Yoshino total knee prosthesis, and is a non-hinged type prosthesis consisting of a vitallium femoral component and a ultra-high molecular weight polyethylene tibial component. Clinical results of 127 Yoshino total knee arthroplasties showed the following characteristics: 1) good stability, and 2) good mobility. Stability was exceptionally good, and the results were the same as the hinged total knee prosthesis.