RESUMEN
BACKGROUND: Problem drug use is associated with excess risk of infectious and other somatic diseases resulting mainly from injecting drug use. MATERIAL AND METHODS: At the end of 2013, a complete medical history and physical examination was done in 40 problem drug users (30 males and 10 females), mean age 35.5 years (37.0 and 30.9, respectively), recruited in 4 low-threshold facilities in Prague. Of them, 37 were ex- or active injecting drug users, predominantly of methamphetamine (pervitin) and less often of buprenorphine. RESULTS: The study physician rated the health status as -good or satisfactory in 35 participants and as unsatisfactory in five participants (12.5%). The most common pathologies were dental problems (36 participants, i.e. 90.0%) and skin conditions (15.0%). The most prevalent dental pathology was caries while dermatological disorders were mostly trophic skin lesions on the lower legs, including crural ulcers, and injection site infections. Gynaecological pathology was found in 2 of 10 females. The study subjects were most commonly diagnosed with chronic hepatitis C, status post hepatitis A and B, chronic caries, missing teeth, post-thrombotic swelling and trophic skin lesions on the lower legs, purulent skin lesions, and gastroduo-denal ulcer. A vast majority of the study participants were smokers. All were referred to various specialists for further examination or treatment, mostly to stomatology, hepatology, gastroenterology, and internal/general medicine departments. However, in reality the treatment participation rate is low among problem drug users due to the drug use-specific factors and needs that limit access to treatment. CONCLUSION: The incidence of diverse somatic comorbidities requiring standard general medical care is significant among problem drug users. Infectious, dermatological, and dental pathologies are predominant. In areas with high prevalence of problem drug use, implementation of a special program should be considered to provide comprehensive medical care taking account of the special needs of this target group.
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Consumidores de Drogas , Abuso de Sustancias por Vía Intravenosa/complicaciones , Adulto , Comorbilidad , Estudios Transversales , Caries Dental/epidemiología , Femenino , Hepatitis C Crónica/epidemiología , Humanos , Masculino , Metanfetamina/efectos adversos , Enfermedades Cutáneas Infecciosas/epidemiologíaRESUMEN
PURPOSE OF THE STUDY: To compare the anchorage strength of Socon CS cannulated pedicle screws (B. Braun, Aesculap) with that of Socon screws in human cadaver vertebrae, using pull-out strength testing. MATERIAL: Twelve samples involving T12 to L3 vertebrae were prepared and a total of 20 pedicle screws, 10 Socon CS and 10 Socon screws, were inserted in them. All screws were 55 mm in length and 6 mm in diameter. After placement, Socon CS pedicle screws were augmented with bone cement (Cimplant cement application kit, B. Braun, Aesculap). METHODS: Both Socon CS and Socon screws were subjected to monotonous loading in the testing device ZWICK Z 020-TND with tensile stress applied in the screw axis. We evaluated the magnitude of strength resulting in screw loosening and the relationship between this strength and bone density of the sample. RESULTS: Bone density of measured samples corresponded either to osteopenia, i.e. T-score range of -1 to -2.5 SD (standard deviation) or osteoporosis, i.e. T-score -2.5 SD. The average bone density of all samples corresponded to a T-score of -3.1 SD. Bone-screw linkage was found to be associated with both bone-cement and screw-cement interface. Pull-out strength was significantly higher for the Socon CS than the Socon screws (t-test, p<0.0005). In the Socon screws, the linear correlation between pull-out strength and bone density was significant at a 5% level of statistical significance (p=0.008) while, in the Socon CS screws, it was not significant (p=0.065). DISCUSSION: The poor quality of osteoporotic bone is responsible for a higher frequency of implant failure due to loosening, particularly when implants developed for healthy bone are used. In this biomechanical study, we tested one of the possibilities of how to reduce the risk of implant failure by pedicle screw augmentation with bone cement. CONCLUSIONS: The results of this study confirm the hypothesis that the anchorage of Socon CS cannulated pedicle screws with bone cement augmentation is disrupted by significantly higher pull-out strength than that of Socon screws, when subjected to monotonous loading. However, more clinical studies are needed to evaluate clinical outcomes.
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Tornillos Óseos , Vértebras Lumbares/lesiones , Fracturas Osteoporóticas/cirugía , Fracturas de la Columna Vertebral/cirugía , Vértebras Torácicas/lesiones , Anciano , Anciano de 80 o más Años , Fenómenos Biomecánicos , Densidad Ósea , Cadáver , Humanos , Técnicas In Vitro , Vértebras Lumbares/fisiopatología , Vértebras Lumbares/cirugía , Fracturas Osteoporóticas/fisiopatología , Fracturas de la Columna Vertebral/fisiopatología , Vértebras Torácicas/fisiopatología , Vértebras Torácicas/cirugíaRESUMEN
An unusual case of implant failure after revision total knee arthroplasty (TKA) is presented and the case report is completed with the results of an ensuing biomechanical study made to explain possible causes leading to a fracture of the tibial stem. For this we used electron microscopic and biomechanical analyses. There was no material defect found at the site of fracture. By computerized modelling of the clinical situation, however, we found out that asymmetrical progressive osteolysis of the proximal tibia could have caused significant changes in mechanical straining associated with qualitative alterations in the process of degradation and erosion of the implant, eventually leading to a fracture of the tibial stem. In this way mechanical straining at the site of fracture could have exceeded the failure threshold of titanium alloy. Stem fracture of a current tibial component design has not yet been described in the literature. The only failure so far reported concerns the stem of a femoral component, and this has also been explained by biomechanical reasons. It follows from this study that patients with progressive osteolysis around the TKA should be followed up more frequently. The conclusions of this biomechanical analysis emphasize the importance of a thorough reconstruction of bone defects in order to improve long-term survival of the implant. Key words: revision, total knee arthroplasty, osteolysis, failure, fracture, tibial stem.
Asunto(s)
Artroplastia de Reemplazo de Rodilla , Falla de Prótesis , Fracturas de la Tibia/cirugía , Anciano , Fenómenos Biomecánicos , Humanos , Masculino , Reoperación , Fracturas de la Tibia/etiología , Fracturas de la Tibia/fisiopatologíaRESUMEN
PURPOSE OF THE STUDY To evaluate the results of primary total hip replacement with the CLS acetabular cup at a minimum of 15 years of follow- up. MATERIAL AND METHODS A total of 105 patients, with 112 hips, undergoing hip arthroplasty with the use of CLS acetabular cup between 1991 and 1993 were evaluated. The group comprised of 33 men and 72 women with an average age of 51.3 years (range, 28 to 66) at the time of surgery. All patients received the CLS expansion cup with a polyethylene Sulen-type liner. Cemented femoral stems were used in 75 hips and uncemented CLS stems were implanted in 37 hips. Ceramic heads of the femoral component were used in 86 hips and metal heads were used in 26 hips. The clinical outcome was assessed by the Merle dAubignnd Postel score and the Harris hip score, and the radiological results were evaluated on anterior posterior X-ray films of the pelvis and the affected hip. RESULTS The average follow-up was 16.2 years (range, 15 to 17). The average Merle dAubignnd Postel score increased from 8.1 (range, 5.7 to 9.8) pre-operatively to 14.6 (range, 14.1 to 16.8) post-operatively. The average Harris hip score improved from 42 to 86 points (range, 71 to 99). The complications requiring revision arthroplasty included aseptic loosening in two hips, fracture of the CLS shell in three, dislocation in three and replacement of the liner due to high wear in two hips. The cumulative proportion of clinical survivorship with revision for any reason was 92 %. Fixation by bone ingrowth, assessed by the method of Engh et al. occurred in 98 cases, fibrous tissue fixation was found in ten hips. Unstable fixation was recorded in four hips (two with aseptic loosening and two with fracture of the shell). There were no signs of rarefaction of bone along acetabular shell in 98 hips. No noticeable migration was found in the stable cups. Only in ten cups from 112, polyethylene wear exceeded 4 mm. Cumulative probability of radiological survivorship of the CLS acetabular cup with any radiological sign of loosening was 86.6 %. DISCUSSION The causes of fracture of the CLS cup can be explained by insufficient bone support or bone resorption in the proximallateral part of the acetabulum in patients with developmental hip dysplasia, by low bone quality due to severe osteoporosis or by insufficient primary stability of the cup. The advantages of the CLS cup include removal of a small amout of bone and favourable force distribution in circumferential anchorage. The cup showed good osteointegration even in a bone of lower quality and with defects of the acetabular bottom. CONCLUSIONS The CLS acetabular cup shows good results at 16-year follow-up period. No increase in fractures of the shell, migration or radiolucent lines, or in bone rarefaction or osteolysis was recorded with time. The reliability of this implant has been recently increased with the use of cross-linked polyethylene (Durasul). Key words: primary total hip replacement, uncemented cup.