Simple colorimetric methods for determination of sub-milligram amounts of ultra-high molecular weight polyethylene wear particles.

New colorimetric methods are described for determination of sub-milligram amounts of ultra-high molecular weight polyethylene (UHMWPE) wear particles. These methods are based on the irreversible binding of the fluorescein-conjugated bovine serum albumin or the hydrophobic dye Oil Red O to wear particles. UHMWPE particles bind both substances from their solutions and thus decrease the absorbance of these solutions. The decrease is linearly dependent on the amount of added wear particles in the sub-milligram range suitable for practical use. The newly developed method offers improved accuracy and precision compared to Fourier transformed infrared spectroscopy (Slouf M, et al. Quantification of UHMWPE wear in periprosthetic tissues of hip arthoplasty: description of a new method based on IR and comparison with radiographic appearance. Wear 2008;265:674-684.).

[Distribution of UHMWPE wear particles in periprosthetic tissues of total hip replacements]. / Distribuce oterových cástic UHMWPE v periprotetických tkáních u TEP kycelního kloubu.

INTRODUCTION: Information on the distribution of UHMWPE wear particles around joint replacements is essential for the understanding of aseptic loosening of implants. MATERIAL AND METHODS: Samples of soft tissue from around total hip arthroplasty (THA), which had a typical appearance of polyethylene granuloma, were collected from the places corresponding to the radiological zones of Gruen and DeLee. The samples were taken from 45 patients (group N1). Since the samples varied in macroscopic appearance and/or the technique of processing, a sub-group of 15 more uniform samples (group N2) were collected by the first author in order to ensure the maxi- mum reliability. The samples were examined for the extent of tissue damage and the amount of particles in each zone. The comprehensive orthopaedic evaluation of tissue damage was carried out as follows: the first author studied the joint replacement revision protocol and pre-operative radiograph in each patient. He evaluated the degree of damage in each zone and wrote down the results in the form of an ordered series according to increasing damage (relational statement). This ordered series was called orthopaedist's statement (OS). The amount of particles in each zone around THA was assessed by the IRc method developed in the laboratory of the second author. IRc method yielded numbers that were proportional to the volume of biologically active particles with size 0.1-10 microm in given zones. The set of numbers from IRc method for each individual case of THA was ordered in a series (relational statement). This ordered series was called a measurement statement (MS) and could be directly compared with orthopaedist's statement (OS). The OS's and MS's for each patient were statistically evaluated, independently for each group (N1=45, N2=15), and two hypotheses were tested: a) distribution of particles in various zones around THA is uniform, b) there is an agreement between OS and MS. RESULTS: The number of UHMWPE wear particles in different periprosthetic zones within each patient was significantly different in both groups (N1 and N2) at the significance level of P=0.001. The OS's and MS's were identical at the significance level P=0.05. Moreover, maximum amount of particles was found in zones III and 7 in 40 patients out of 45. DISCUSSION: Polyethylene wear debris is considered one of the major causes of THR failures. However, neither national nor international literature has provided a study that would show a statistically significant relationship between the numbers of wear particles in individual zones and the extent of tissue damage in these zones. This is most probably due to the fact that four independent methods had to be developed in order to compare OS's and MS's: 1) accurate technique of tissue sampling during THA revisions, 2) accurate method of isolating wear particles from the tissues collected, 3) efficient, reliable and reproducible quantification of UHMWPE particles and 4) correct method of statistical analysis for comparison of the orthopaedist's statements and the measurement statements for all patients involved. CONCLUSION: The distribution of wear particles in the periprosthetic tissues of THA is not uniform, i.e. the amount of wear particles of each patient varies from zone to zone. The extent of tissue damage in each zone, as assessed by the orthopaedic surgeon (OS), was in a good agreement with the volume of 0.1-10 microm particles obtained by IRc measurement (MS) of the zone. We have provided conclusive evidence that the highest number of particles is accumulated in zone III and zone 7. As the number of particles the zones varies and the greatest damage is repeatedly found in areas with the highest particle numbers, it can be concluded with certainly that wear particles are one of the main causes of aseptic joint implant failure.

Distribution of polyethylene wear particles and bone fragments in periprosthetic tissue around total hip joint replacements.

Ultra-high molecular weight polyethylene (UHMWPE) wear particles play a significant role in failures of total joint replacements (TJRs). In this work, we investigated the distribution of these wear particles in periprosthetic tissues obtained from nine revisions of hip TJR. In the first step, all periprosthetic tissues were combined and mechanically separated into granuloma tissue (containing hard granules visible to the naked eye) and surrounding tissue (without visible granules). In the second step, the tissues were hydrolyzed by protease from Streptomyces griseus and granules were separated by filtration; this divided the sample into four groups: (i) lyzate and (ii) non-degraded large granules from the granuloma tissue plus (iii) lyzate and (iv) non-degraded small granules from the surrounding tissue. In the third step, the large as well as small granules were hydrolyzed by collagenase from Clostridium histolyticum. In the last step, the UHMWPE wear particles from all four groups were purified by HNO3 digestion and weighed. The purity of the isolated particles was verified by scanning electron microscopy, infrared spectroscopy and energy-dispersive X-ray analysis. Of the total amount of polyethylene particles in the whole granuloma tissue, 72% of particles in the size range 0.1-10 microm and 68% of those larger than 10 microm were found in granules. Therefore, the formation of granules significantly lowers the effective amount of wear particles available for interaction with reactive cells and seems to be a natural defense mechanism.

[New metod for quantification of UHMWPE wear particles around joint replacements]. / Nová metoda kvantifikace oterových cástic UHMWPE v okolí kloubních náhrad.

PURPOSE OF THE STUDY: The orthopaedic community has unanimously adopted the view that ultra high molecular weight polyethylene (UHMWPE) wear particles are a very frequent cause of aseptic implant loosening. Some studies have tried to provide objective evidence for this.We have found descriptions of particle distribution or morphology, but no report that would objectively cor- relate the number of particles in zones surrounding an implant with the extent of damage to these zones. The aim of this study was to develop a method allowing us to evaluate a number of samples with polyethylene abrasive wear large enough to find association between the extent of damage around a THA and the number of biologically active UHMWPE wear particles, 0.1 to 10 microm in size. MATERIAL AND METHODS: In 28 patients undergoing revision total hip arthroplasty (THA) at the 1st Orthopaedic Clinic, 1st Faculty of Medicine, Char- les University, we took samples of typical osteoaggressive granuloma from defined zones around the implant; the zones corresponded to those described by Gruen and DeLee. The extent of tissue damage in each zone was evaluated on the basis of pre-operative radiographs and by the extent of osteolysis and damage to soft tissues actually observed during revision THA. The volume of wear particles in each zone was assessed by the IRc method developed by us; this is based on a quantitative evaluation of infrared spectra. To verify the methodology, a comparison between tissue damage and the number of particles in each zone was made in three randomly selected patients. RESULTS: We introduced a method of detailed orthopaedic evaluation which enabled us to categorize zones around a revised THA according to the extent of damaged tissue. As a result, a series of zones ranked by the extent of damaged tissue, or an "orthopaedist's statement" (OS), was obtained. At the same time we adopted a method, based on infrared spectroscopy and termed IRc, by which the number of particles in the samples of damaged tissues and osteoaggressive granulomas collected from the area around a revised THA was determined.The results of evaluation were presented as numerical data that, in a defined way, were converted into a series of zones ranked according to the number of wear particles, i.e., the "result of measurement" (RM). In this study we verified the methods described above and made a comparison of OSs and RMs for three randomly selected patients. The very good agreement found confirmed the reliability of both methods which will soon be used to evaluate a group of patients large enough to provide statistically significant results. DISCUSSION: The IRc method determines a total volume of UHMWPE wear particles, 0.1 to 10 microm in size, which are generally considered to be most biologically active. This study suggests that the distribution of particles around a THA is uneven and that relation between tissue damage and the number of wear particles in individual zones surrounding a THA does exist. The major conclusion from the orthopaedic point of view is a confirmation of the assumption that UHMWPE wear particles are one of the chief causes of THA failure. Although this fact is generally accepted, studies correlating the number of particles with tissue damage and osteolysis in individual zones are very scarce. CONCLUSIONS: The quick and simple IRc method offers a possibility to quantify polyethylene wear particles in soft tissues. The number of 0.1 to 10 microm wear polyethylene particles correlated with pre-operative radiographic findings and orthopaedic evaluation of revision THAs in three randomly selected patients. The confirmed correlation between the extent of tissue damage in individual zones surrounding a THA and the volume of wear particles detected in these zones supports the view that UHMWPE wear particles are one of the main causes of THA failure.

[Heterotopic excessive wear granuloma mistaken for an aneurysm of the external iliac artery]. / Zámena masivního heterotopického oterového granulomu s aneuryzmatem arteria iliaca externa.

Reimplantation of a total hip arthroplasty (THA) with excessive heterotopic polyethylene granuloma is reported. An 84- year-old woman, who had undergone THA reimplantation on the right side 4.5 years previously, was indicated for revision surgery due to aseptic failure of the acetabular component. Pre-operative examination revealed a pulsating mass below the right inguinal ligament that raised the suspicion of a pseudoaneurysm of the external iliac artery. Because of this suspected late complication of the first revision arthroplasty, surgical exploration was indicated by the vascular surgeon prior the second reimplantation. A CT-scan showed a large mass attached to a preserved lumen of the external iliac artery, and this was diagnosed by the vascular surgeon as a pseudoaneurysm. However, no pseudoaneurysm was found by a vascular surgery procedure, and the large mass ventrally extending the external iliac artery appeared to be a large polyethylene granuloma well enveloped in a fibrous pseudocapsula. The granuloma was removed and the wound sutured. Twelve days later, revision total hip arthroplasty and acetabular reconstruction were successfully carried out.

[The effect of preoperative diagnostic methods on the correct selection of operative procedure on the thyroid gland]. / Vplyv predoperacných diagnostických metód na správnost' vol'by operacného výkonu na stítnej zl'aze.

The study compares three diagnostic procedures, the analysis of which is aimed at a choosing the optimal extent of resection on the thyroid. Diagnostic procedures, when based on clinical examination (palpation, scintigraphy, laryngoscopy, X-ray), lead to the optimal extent of resection in 74.2% of patients. Procedures selection performed on the basis of fine-needle aspiration cytology (FNAC) results lead to the correct extent of resection in 93.1% of patients. The procedures of frozen section lead to the correct resection extent in 81.3% of patients. (Tab. 1, Fig. 1, Ref. 25.)

[Carcinoma of the breast during pregnancy and lactation]. / Karcinóm mliecnej zl'azy pocas gravidity a laktácie.

The authors describe two patients with breast cancer which was manifested during pregnancy. The authors deal with diagnostic and therapeutic possibilities, depending on the stage of disease and the stage of the pregnancy. A delay of the diagnosis and adjuvant therapy deteriorates the prognosis of this disease.

[Surgical treatment of insulinoma]. / Chirurgická liecba inzulinómu.

The paper summarizes experience with diagnosis and surgical treatment of insulinomas of the pancreas. Experience with three patients subdued to surgical treatment at the Department of Surgery of F.D. Roosevelt Hospital in Banská Bystrica confirm the rules of effective treatment of insulinomas: importance of neurological symptoms in early diagnosis, importance of angiography as the best method for localization of insulinomas in comparison with ultrasonography and CT. In addition, algorithm of the surgical treatment of insulinomas together with the specificity of the surgical technique were confirmed.

[Cystosarcoma phylloides in adolescent women]. / Cystosarcoma phylloides u adolescentných zien.

The authors describe four cases of juvenile fibroadenoma (benign form of cystosarcoma phyllodes) in pubertal girls aged 11-15 years. They reflect on the variable behaviour of this rare tumour and differentiate the relations between fibroadenoma, virginal hypertrophy of the breast, juvenile fibroadenoma, giant fibroadenoma and cystosarcoma phyllodes. A dominant position is held by surgical treatment which is strictly individualized. The authors recommend, similarly as many other authors, an extensive excision of the tumour with a safety margin and in case of repeated relapses or the very rare malignant form which frequently behaves as a benign tumour. The operation is made in the submammary groove or on the lateral margin of the breast which ensures an excellent cosmetic effect. The authors do not consider excision of superfluous skin or reconstruction of the breast necessary with regard to the elastic properties of the skin and the capacity of the mammary gland to develop.

[Malignant cystosarcoma phyllodes]. / Cystosarcoma phylloides malignum.

The authors deal with the clinical and pathological aspects and histopathological criteria of malignity of cystosarcoma which are important from the aspect of assessment of the extent and type of surgical intervention. Large malignant cystosarcomas and cystosarcomas taking up the whole breast with damage of the skin are indicated for simple mastectomy, while small malignant cystosarcomas (i. e. in relation to the size of the breast) can be treated by a wide local excision with a safety margin, as some primary as well as recurrent phylloid tumours behave in a benign way or may transform into a fibroadenoma or a dysplastic focus. Moreover contrary to carcinoma of the breast, there is no association with a multicentric character of the disease. Axillary lymph nodes are only rarely affected; therefore dissection of the nodes is not necessary.

[Immunomodulation therapy of breast carcinoma with levamisole]. / Imunomodulacná terapia karcinómu prsníka levamizolom.

The authors present results of modality and immunomodulating treatment of breast cancer. In the treatment they use levamizole (Decaris) which has useful properties, as compared with other immunomodulating drugs--accurate dosage, simple administration and good tolerance. In a group of 84 patients it was administered after operation after adjuvant chemotherapy with Cyclophosphamide in a total dose of 300 mg orally, making check-up examinations of leucocytes and thrombocytes. As to other laboratory parameters, the authors assessed transaminases, alkaline phosphate, immunoglobulin, T-lymphocytes and carcinoembryonic antigen. During the same period the survival of patients in this group was significantly higher, as compared with a group of patients formerly treated by adjuvant chemotherapy with Cyclophosphamide without levamizole. Comparison of the results with those of other authors indicates that it is correct to include immunomodulating treatment in comprehensive treatment of breast cancer.

[Cogwheel maculopathy--a new form of pattern dystrophy?]. / Zahnradmakulopathie--eine neue Form der "Pattern Dystrophy"?

On examination, the central retinal areas of both eyes of a 44-year-old woman appeared symmetrical. So far only one other case with the same findings has been described in the literature; it was termed "cogwheel macular degeneration." Distinctive fluorescein angiographic and electrophysiological features indicate that the disease is dystrophic, primarily affecting the retinal pigment epithelium. Several criteria of the findings justify including this entity in the larger group of pattern dystrophies of the retina.