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Purpose Besides other diagnostic test methods, established serum inflammatory markers such as serum C-reactive protein or leukocyte count are widely used preoperatively to aid in diagnosing periprosthetic joint infections (PJI). Although low accuracies were reported, these parameters are easily accessible and routinely available. Novel biomarkers with promising results in diagnosing PJI (platelet count to mean platelet volume ratio) or other infectious conditions (percentage of neutrophils, neutrophils to lymphocytes ratio) were described. The purpose of this study was to investigate the diagnostic value of established and novel serum inflammatory biomarkers for the diagnosis of PJI so as to compare the results to find the serum inflammatory marker with the best performance. Methods In 177 patients with a previous total hip (n = 91) or knee (n = 86) arthroplasty and indicated revision surgery, the diagnostic value of the routinely available serum inflammatory markers C-reactive protein (CRP), white blood cell count (WBC), percentage of neutrophils (%N), neutrophils to lymphocytes ratio (NLR), fibrinogen and platelet count to mean platelet volume ratio (PC/mPV) were examined retrospectively via receiver operating characteristic curve analysis (AUC). The curves were compared using the z-test. Results Sensitivities of serum CRP, WBC, %N, NLR, fibrinogen and PC/mPV were calculated with 68%, 36%, 66%, 63%, 69% and 43%, respectively. Specificities were 87%, 89%, 67%, 73%, 89% and 81%, respectively. Serum CRP (0.78) and fibrinogen (0.79) showed significantly better AUCs compared with serum WBC (0.63), %N (0.67), NLR (0.68) and PC/mPV (0.62) (p < 0.0001). Patients with PJI caused by a low-virulent microorganism (median CRP: 17.6 mg/L) obtained lower CRP levels compared with infections caused by high-virulent microorganisms (median CRP: 49.2 mg/L; p = 0.044). The combination of CRP and fibrinogen showed a better sensitivity (77%) with similar specificity (83%) than one method alone but not at a significant level (CRP (p = 0.200); fibrinogen (p = 0.437)). Conclusion Serum CRP and fibrinogen showed the best accuracies among these widely available serum inflammatory parameters. However, due to the insufficient performance, these biomarkers can only be recommended as suggestive criteria in diagnosing PJI. The preoperative workup should always be complemented by more specific tests such as synovial fluid analysis.

Osteosarcoma is the most common primary malignant bone tumour. Currently osteosarcoma classification is based on histological appearance. It was the aim of this study to use a more systematic approach to osteosarcoma classification based on gene expression analysis and to identify subtype specific differentially expressed genes. We analysed the global gene expression profiles of ten osteosarcoma samples using Affymetrix U133A arrays (five osteoblastic and five non-osteoblastic osteosarcoma patients). Differential gene expression analysis yielded 75 genes up-regulated and 97 genes down-regulated in osteoblastic versus non-osteoblastic osteosarcoma samples, respectively. These included genes involved in cell growth, chemotherapy resistance, angiogenesis, steroid-and neuropeptide hormone receptor activity, acute-phase response and serotonin receptor activity and members of the Wnt/ß-catenin pathway and many others. Furthermore, we validated the highly differential expression of six genes including angiopoietin 1, IGFBP3, ferredoxin 1, BMP, decorin, and fibulin 1 in osteoblastic osteosarcoma relative to non-osteoblastic osteosarcoma. Our results show the utility of gene expression analysis to study osteosarcoma subtypes, and we identified several genes that may play a role as potential therapeutic targets in the future.

Results of our study confirm that sonicate culture of the retrieved liners and heads, which revealed the highest bacterial loads, are reliable and sufficient for pathogen detection in the clinical diagnostic routine.

Diagnosis of adverse reactions to metal debris in metal-on-metal hip arthroplasty is a multifactorial process. Systemic ion levels are just one factor in the evaluation and should not be relied upon solely to determine the need for revision surgery. Furthermore, the correlation between cobalt or chromium serum, urine, or synovial fluid levels and adverse local tissue reactions is still incompletely understood. The hypothesis was that elevated serum and urine metal-ion concentrations are associated with elevated local metal-ion concentrations in primary total hip arthroplasties (THA) and with failure of metal-on-metal articulations in the longterm. In our present study, we evaluated these concentrations in 105 cementless THA with metal-on-metal articulating surfaces with small head diameter at a minimum of 18 years postoperatively. Spearman correlation showed a high correlation between the joint fluid aspirate concentration of cobalt and chromium with the serum cobalt (r ¼ 0.81) and chromium level (r ¼ 0.77) in patients with the THA as the only source of metal-ions. In these patients serum metal-ion analysis is a valuable method for screening. In patients with more than one source of metal or renal insufficiency additional investigations, like joint aspirations are an important tool for evaluation of wear and adverse tissue reactions in metal-on-metal THA. The indication for total hip arthroplasty (THA) has increased over the past 20 years. Accelerated risk of polyethylene wear and subsequent prosthetic loosening due to osteolysis, has led to a renaissance of metal-on-metal bearings. These hard bearing surfaces seem advantageous, especially for young and active patients, 1,2 but concerns remain regarding the effects of prolonged exposure to increased level of metal ions, such as hypersensitivity, 3,4 carcinogenicity, 5,6 and fetal exposure to ions in pregnant women. 7,8 In a previous study, we evaluated the clinical and radiographic long-term results as well as the serum metal concentrations of 105 cementless primary THA with 28-mm high-carbide-concentration metal-on-metal articulating surfaces (Metasul 1 , Zimmer GmbH, Winterthur, Switzerland), a tapered rectangular stem made of titanium-aluminium-niobium alloy (Zweymü ller 1 Alloclassic 1 , Zimmer GmbH) and a conical screw cup made of pure titanium (CSF 1 , Zimmer GmbH) in 98 patients (54 female and 44 male) with an average age of 56 years, performed between November 1992 and May 1994. 9 The cumulative rate of survival of the prostheses with aseptic failure as the end point was 93.0% at 18.8 years. The median serum cobalt concentrations of the patients, with their hip replacement as the only source of cobalt was 0.7 mg/L (range 0.4-5.1 mg/L), showing no significant difference to a previous report by Grü bl et al. 10 performed after a minimum of 10 years follow-up. We investigated the systemic dissemination, which in turn, did not show severe effects, such as carcinogenicity or renal failure.There are many complex issues associated with the analysis of...

Background In the current study, we investigated midterm results of a new rotating hinge total knee arthroplasty (EnduRo prosthesis), which uses a new bearing material (CFR PEEK). Methods We prospectively analysed data of 50 patients with a minimum follow-up of 5 years. In 24 (48%) patients, a primary implantation was performed and 26 (52%) were revision cases. Clinical and radiographic examinations were performed preoperatively as well as postoperatively after 3 and 12 months and annually thereafter. The Knee Society Score (KSS), WOMAC, Oxford Knee Score (OKS), and range of motion (ROM) were used for clinical assessment. Results KSS, WOMAC, OKS, and ROM significantly improved between the preoperative and the follow-up investigations. The overall survival rate with revision for any reason as an endpoint was 77.9% after five years. The number of complications was significantly higher in the revision group (p = 0.003). Conclusion The EnduRo prosthesis provides highly satisfying clinical and functional results in severe primary as well as in revision cases. Implant-associated complications were rare. However, in cases of revision surgery, the risk for complications was considerably high, mostly related to previous joint infections and poor soft tissue quality.

Background. Indication for rotating hinge (RH) total knee arthroplasty (TKA) includes primary and revision cases, with contradictory results. The aim of this study was to report prospective early results of a new modular rotating hinge TKA (EnduRo). For this implant several new design features and a new bearing material (carbon-fiber reinforced poly-ether-ether-ketone) have been developed. Furthermore, we tried to establish a new classification of failure modes for revision TKA. Methods. 152 EnduRo rotating-hinge prostheses were implanted in two centers. In 90 patients a primary implantation has been performed and 62 patients were revision cases. Knee Society Score (KSS), Western Ontario and McMaster Osteoarthritis Index (WOMAC), Oxford Knee Score (OKS), and Range of motion (ROM) were assessed before surgery, 3 months postoperatively, 12 months postoperatively, and annually thereafter. We defined 3 types of complications: Type 1, infection; type 2, periprosthetic complications; type 3, implant failures. Results. KSS, WOMAC, OKS, and ROM revealed significant improvements between the preoperative and the follow-up investigations. There were 14 complications (9.2%) leading to revision surgery, predominantly type 2. Conclusion. Our study shows excellent clinical results of the EnduRo TKA. Furthermore, no premature material failure or unusual biological response to the new bearing material could be detected.

The aim of this study was to prospectively evaluate our single-centre one- and five-year results of anatomically correct cementless total hip arthroplasty in unilateral and bilateral Crowe type IV high hip dislocations in ten hips following iliofemoral monotube soft tissue distraction. Six consecutive patients (five females and one male) with unilateral and two female patients with bilateral high hip dislocation with an average age of 46 years and height of dislocation up to 110 mm were treated in our institution. Limb lengthening was achieved up to 100 mm. The mean leg-length-discrepancy was -4 mm postoperatively. Harris hip score increased significantly at one year (p < 0.001) and significantly further (p < 0.05) at five years postoperative. WOMAC, VAS pain scale as well as gait and pain-free walking distance also improved significantly at follow-up. Two pin infections and one temporary peroneal nerve palsy occurred during monotube extension. Three cup protrusions that required revision surgery were observed in two patients. This study shows that iliofemoral distraction prior to total hip replacement achieves leg length equality and improved gluteal function and therefore gait in patients with Crowe type IV hip dislocation.