Pathogenesis of prosthesis-related infection.
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In spite of its incidence decreasing to 1% nowadays, prosthesis-related infection remains a research, diagnostic, therapeutic and cost-related problem. It can be defined as a presence of bacteria in the artificial joint space, which is significantly associated with evident laboratory and/or tissue markers, and clinical signs of running infection. We believe that the more precise understanding of pathogenesis, the more effective preventative and therapeutic measures, and the lower infection rate. The implants are colonized by airborne, skin-, and/ or surgeon-related bacteria during surgery despite being operated in closely respected operating regime. Some prosthetic characteristics are advantageous and may play important roles in the process of bacterial adherence. After successful attachment on the biomaterial surface bacteria multiply and physiologically transform into a "biofilm" community, making them much more resistant to antibiotic therapy and host immunity. Bacterial resistance is a complex phenomenon influenced by intrinsic and extrinsic factors, including the cell configuration in the biofilm community. So the cure of periprosthetic sepsis without removing of all foreign bodies and necrotic bone fragments is often ineffective. Acute hematogenous sepsis is suggestive of a distortion of a previously aseptic joint space by invasion of bacteria through the vessels. (+info)
Dislocations with intervertebral disc prosthesis: two case reports.
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To date, only three cases of artificial disc prosthesis dislocation have been reported in the literature. We present in detail two additional cases of prosthesis dislocation and discuss the surgical interventions undertaken that resulted in a good clinical outcome in both patients. (+info)
Grammont inverted total shoulder arthroplasty in the treatment of glenohumeral osteoarthritis with massive rupture of the cuff. Results of a multicentre study of 80 shoulders.
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We reviewed 80 shoulders (77 patients) at a mean follow-up of 44 months after insertion of a Grammont inverted shoulder prosthesis. Three implants had failed and had been revised. The mean Constant score had increased from 22.6 points pre-operatively to 65.6 points at review. In 96% of these shoulders there was no or only minimal pain. The mean active forward elevation increased from 73 degrees to 138 degrees. The integrity of teres minor is essential for the recovery of external rotation and significantly influenced the Constant score. Five cases of aseptic loosening of the glenoid and seven of dissociation of the glenoid component were noted. This study confirms the promising early results obtained with the inverted prosthesis in the treatment of a cuff-tear arthropathy. It should be considered in the treatment of osteoarthritis with a massive tear of the cuff but should be reserved for elderly patients. (+info)
Total ankle replacement in rheumatoid arthritis.
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We reviewed 21 patients with rheumatoid arthritis who had a total ankle replacement between 1984 and 2000. The average follow-up was 72 (15-169) months. Clinical results were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) score. At the latest review, three ankles had been revised. Two ankles were excellent, seven good, three fair, and 12 poor. Eleven patients with 13 ankles had residual pain, with radiographs showing a high incidence of radiolucent lines. Migration of the tibial component was seen in 13 ankles and collapse of talus in nine. Although clinical results were poor, patient satisfaction was not. (+info)
Influence of previous open synovectomy on the outcome of Souter-Strathclyde total elbow prosthesis.
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OBJECTIVES: Open synovectomy of the elbow joint is often performed in early stages of rheumatoid arthritis. Because of poor long-term results after synovectomy, insertion of a total elbow prosthesis is commonly used as a secondary procedure. The aim of this study is to evaluate the influence of previous synovectomy on the outcome after placement of a total elbow prosthesis. METHODS: We inserted 204 primary Souter-Strathclyde total elbow prostheses for rheumatoid arthritis. Two groups could be distinguished: group A with previous synovectomy 3.9 yr (mean) before the elbow replacement (n = 33) and group B without previous synovectomy (n = 171). The mean follow-up was 5.8 yr for group A and 6.3 yr for group B. All patients were assessed clinically and radiologically before the operation, 1 and 2 years later and then at regular intervals. The effect of previous synovectomy was analysed via a Cox model and a generalized linear mixed model for binomial data with multivariate normal random effects. RESULTS: No statistically significant effect of previous synovectomy on pain, function or complaints of the ulnar nerve could be found post-operatively. The post-operative flexion was significantly higher in group B than in group A. The complication-rates were similar for both groups. The overall survival rate for respectively group A and B with revision as endpoint was 66.9% (s.e. 13.4) versus 79.6 (s.e. 4.3) after 10 yr. CONCLUSIONS: Previous synovectomy does not diminish the outcome after total elbow prosthesis in this series and could therefore be considered in early, painful stages of rheumatoid destruction of the elbow joint. (+info)
Modular total shoulder system with short stem. A prospective clinical and radiological analysis.
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Between 1994 and 2001, a short-stemmed modular shoulder prosthesis was inserted in 62 shoulders in patients with rheumatoid arthritis (RA) or osteoarthrosis (OA). We reviewed 53 patients with 60 shoulders (45 RA/15 OA) with at least 24 months follow-up. In 22 shoulders, we used a total shoulder prosthesis including a glenoid polyethylene component, whereas 38 shoulders only had a humeral component. In six shoulders, the humeral component was cemented. The average follow-up was 47 (24-99) months. There were no intraoperative complications but one wound infection and one patient with proximal migration of the humeral component. Hospital for Special Surgery Score increased from 44(19-72) to 63 (21-93) points and Shoulder Function Assessment score (SFA) from 24 (12-46) to 42 (11-66)points. The VAS score for pain at rest improved from 4.3 to 1.9. Nonprogressive radiolucent lines were seen adjacent to nine glenoid and one humeral components. Fifty-six patients were satisfied with the result. (+info)
Stability of cemented all-polyethylene keeled glenoid components. A radiostereometric study with a two-year follow-up.
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We studied the stability of cemented all-polyethylene keeled glenoid components by radiostereometric analysis (RSA) in 16 shoulders which had received a total shoulder replacement. There were 14 women (one bilateral) and one man with a mean age of 64 years. The diagnosis was osteoarthritis in eight and rheumatoid arthritis in seven. Two of the shoulders were excluded from the RSA study because of loosening of the tantalum markers. Three tantalum markers were inserted in the glenoid socket, two in the coracoid process and two in the acromion. The polyethylene keeled glenoid component was marked with three to five tantalum markers. Conventional radiological and RSA examinations were carried out at five to seven days, at four months and at one and two years after operation. Radiolucent lines were found in all except three shoulders. Migration was most pronounced in the distal direction and exceeded 1 mm in four shoulders. In ten shoulders rotation exceeded 2 degrees in one or more axes with retroversion/anteversion being most common. No correlation was found between migration and the presence of radiolucencies on conventional radiographs. (+info)
Increased colonization of indwelling medical devices by quorum-sensing mutants of Staphylococcus epidermidis in vivo.
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Infections with the leading nosocomial pathogen Staphylococcus epidermidis are characterized by biofilm development on indwelling medical devices. We demonstrate that the quorum-sensing regulator agr affects the biofilm development of S. epidermidis in an unexpected fashion and is likely involved in promoting biofilm detachment. An isogenic agr mutant showed increased biofilm development and colonization in a rabbit model. In addition, nonfunctional agr occurred more frequently among strains isolated from infections of joint prostheses. Lack of functionality was based on mutations, including insertion of an IS256 element. Relative to other bacterial pathogens, quorum sensing in S. epidermidis thus has a different role during biofilm development and biofilm-associated infection. Our results indicate that disabling agr likely enhances the success of S. epidermidis during infection of indwelling medical devices. The permanent elimination of quorum-sensing regulation used by S. epidermidis represents a surprising and unusual means to adapt to a certain environment and type of infection. (+info)