Prospective Comparison of a Metal-Free Ceramic Total Knee Arthroplasty with an Identical Metal System.

AIMS: The aim of this open-label, prospective, short-term study was to carry out an initial comparison of a completely metal-free ceramic with a geometrically identical metallic arthroplasty over a 1-year follow-up period. METHODS: This study investigates a completely metal-free system using a composite matrix material containing aluminum oxide (Al2O3, BPK-S Integration, Peter Brehm GmbH, Weisendorf, Germany) or zirconium oxide (ZrO2, BPK-S Integration Ceramic, Biolox Delta-CeramTec GmbH, Plochingen, Germany). Eighty patients (40 in each group) received either a completely metal-free ceramic system (matrix of aluminum and zirconium oxide) or an anatomically identical metallic knee system made of a cobalt-chromium alloy. Clinical assessment was performed preoperatively, and during follow-up at 3 and 12 months, using the Knee Society Score, Oxford Knee Score, and EQ-5D-VAS. For radiological evaluation, standard preoperative and postoperative standardized radiographs were taken at the given follow-up visits. RESULTS: The postoperative clinical scores improved significantly at the 3- and 12-month follow-ups, but did not differ statistically between the two groups. The radiologically evaluated mean postoperative mechanical and anatomical axes showed proper alignment within both groups at all times. No revision surgery had to be performed, and no complications or loosening were recorded whatsoever. CONCLUSIONS: To our knowledge, this is the first study comparing a total ceramic metal-free knee system with a geometrically identical metallic TKA (total knee arthroplasty). Longer follow-ups will be required to demonstrate the overall efficiency of this TKR and perhaps to expand its medical indication.

Antibacterial Effect of a 4x Cu-TiO2 Coating Simulating Acute Periprosthetic Infection-An Animal Model.

The purpose of our study was to investigate the antibacterial effect of a spacer (Ti6Al4V) coated with 4x Cu-TiO2 in an animal model simulating an acute periprosthetic infection by Staphylococcus aureus. Ti6Al4 bolts contaminated with Staphylococcus aureus were implanted into the femoral condyle of rabbits (n = 36) divided into 3 groups. After one week in group 1 (control) the bolts were removed without any replacement. In group2 Ti6Al4V bolts with a 4x Cu-TiO2 coating and in group 3 beads of a gentamicin-PMMA chain were imbedded into the borehole. Microbiological investigation was performed at the primary surgery, at the revision surgery and after scarification of the rabbits 3 weeks after the first surgery. Blood tests were conducted weekly. The initial overall infection rate was 88.9%. In group 2 and 3 a significant decrease of the infection rate was shown in contrast to the control group. The C-reactive protein (CRP) levels declined one week after the first surgery except in the control group where the CRP level even increased. This is the first in vivo study that demonstrated the antibacterial effects of a fourfold Cu-TiO2 coating. For the future, the coating investigated could be a promising option in the treatment of implant-associated infections.

Elastic Stable Chest Repair as a Means of Stabilizing the Anterior Chest Wall in Recurrent Pectus Excavatum with Sternocostal Pseudarthrosis: An Innovative Fixation Device.

INTRODUCTION: Open surgical procedures in the treatment of pectus excavatum (PE) involve predetermined incisions in the parasternal cartilage and the bony ribs. For some procedures, the ribs are even dissected from the sternum for better sternal mobilization and thus better elevation of the funnel. Secure restoration of the sternocostal junction is then required, with the consequence that healing may be quite impaired. Patients may also subsequently suffer from sternocostal nonunion, for example, pseudarthrosis, and dislocated ribs, as well as pain and a recurrence of PE. MATERIALS AND METHODS: Patients underwent another open surgery with revision of the pseudarthrotic sternocostal junctions and sufficient mobilization of the anterior chest wall, followed by an open reduction and internal fixation using Matrix Rib titanium plates (Synthes, Oberdorf, Switzerland). This procedure consisted of elevating the anterior chest wall and fixing the ribs to the sternum. In 2011 and 2012, we studied this procedure, known as elastic stable chest repair (ESCR), in a series of 20 patients. The patients underwent clinical and ultrasound examinations and X-ray radiographs after the operation, after 6 weeks, and at 3- and 12-month intervals. RESULTS: Follow-up showed high patient tolerance, although a loose plate was observed in one patient and a broken plate in three patients. A stable union was achieved for all sternocostal pseudarthroses. PE improved highly significantly (p < 0.001), as the Haller index decreased from 3.6 (range: 2.7-6.6, standard deviation [SD]: 0.92) to 2.7 (range: 2.0-3.7, SD: 0.42). Pain in the anterior chest wall was significantly reduced after the operation in the majority of cases. All but one patient was mobilized already the day after the operation. CONCLUSIONS: ESCR in recurrent PE achieved functional stabilization of the anterior chest wall combined with satisfactory results.

Surgical fixation of sternal fractures: locked plate fixation by low-profile titanium plates--surgical safety through depth limited drilling.

PURPOSE: Operative treatment of sternal fractures has become a matter of increasing interest. Anterior plating seems to be the most appropriate method for fixing sternal fractures. However, there are several concerns in relation to the operative procedure such as severe injuries to mediastinal organs, patient comfort and proper stabilisation, for example. This paper describes a safe method of anterior sternal plating using locked plate fixation with limited depth drilling. METHODS: Ten patients with sternal fractures were included in this cohort study and were treated by anterior plating using one or two plates in parallel through a median approach to the sternum. Follow up was performed after six weeks, 12 weeks and six months. RESULTS: Follow up revealed no serious complications. One patient suffered from postoperative wound seroma. No problems were caused by the plates. CONCLUSIONS: Sternal plating using low profile locked titanium plates seems to be a safe and stable method with a high level of patient comfort.

Release of Cu2+ from a copper-filled TiO2 coating in a rabbit model for total knee arthroplasty.

The aim of this study was the investigation of a copper-filled TiO2 coating, that in vitro showed good antibacterial properties combined with good tissue tolerance in an animal model. To better understand the antibacterial mechanism of the bioactive coating the release of copper (Cu) ions over time was monitored to be able to detect possible threats as well as possible fields of application. 30 New Zealand White rabbits were divided into two groups with 15 animals per group. In group 1 (control group) Ti6Al4 V bolts were implanted into the distal femur, in group 2 the Ti6Al4 V bolts were coated with four TiO2-coatings with integrated Cu(2+)-ions (4 × Cu-TiO2). Blood tests were performed weekly until the animals were sacrificed 4 weeks postoperative. The maximum peak of Cu and ceruloplasmin concentration could be seen in both groups one week postoperative, whereas the Cu values in group II were significantly higher. The Cu concentration in both groups approximated the initial basic values 4 weeks postoperative. The 4 × Cu-TiO2 coating tested in our rabbit model for total knee arthroplasty is an active coating that releases potentially antibacterial Cu(2+) for 4 weeks with a peak 1 week postoperative. The bioactive coating could be a promising approach for a use in the field of implant related infection, orthopaedic revision and tumor surgery in the future.

Low incidence of oncogenic EGFR, HRAS, and KRAS mutations in seborrheic keratosis.

Seborrheic keratosis (SK) represents a frequent epidermal skin tumor. Although lacking a malignant potential, these tumors reveal multiple oncogenic mutations. A previous study identified activating mutations in 89% of SK, particularly in FGFR3 and PIK3CA genes. The aim of this study was to identify further oncogenic mutations in human SK. Therefore, we screened for mutations in EGFR, FGFR2, PIK3R1, HRAS, KRAS, and NRAS genes using both Sanger sequencing of selected exons and a multiplex SNaPshot assay in 58 SK of 14 patients. We identified a somatic EGFR p.L858R mutation in 1 SK. Furthermore, the HRAS mutations p.G13R (2/58 SK) and p.Q61L (2/58 SK) were found. These mutations have not been described in human SK yet. In addition, 1 SK revealed the KRAS p.G12V mutation, which has already been reported in SK. No mutations were detected in FGFR2, PIK3R1, and NRAS genes. The results of this study suggest that activating mutations of EGFR, HRAS, and KRAS contribute to the pathogenesis of human SK, although at a lower frequency than FGFR3 and PIK3CA mutations. FGFR2, PIK3R1, and NRAS mutations obviously do not have a significant role in the development of SK.

Keratinocytic epidermal nevi are associated with mosaic RAS mutations.

BACKGROUND: Activating RAS mutations in the germline cause rare developmental disorders such as Costello syndrome. Somatic RAS mutations are found in approximately 30% of human cancers. Keratinocytic epidermal nevi (KEN) represent benign congenital skin lesions arranged along Blaschko's lines. A subgroup of KEN is caused by hotspot oncogenic FGFR3 and PIK3CA mutations in mosaicism, but the majority lack these mutations. METHODS: This study screened 72 KEN for activating mutations in RAS genes and other oncogenes. RESULTS: Activating RAS mutations were identified in 28/72 (39%) of KEN. HRAS was the most commonly affected oncogene (86%), with the HRAS p.G13R substitution representing a new hotspot mutation. CONCLUSION: These results indicate that activating RAS somatic mutations leading to mosaicism result in benign KEN of the skin. Given the prevalence of KEN, mosaic HRAS mutations appear to be more common in patients than germline ones. These findings identify KEN as a mosaic RASopathy and lend further support to the notion that genetic mosaicism is an important contributor to disease.

Morphological and biochemical T2 evaluation of cartilage repair tissue based on a hybrid double echo at steady state (DESS-T2d) approach.

PURPOSE: To use a new approach which provides, based on the widely used three-dimensional double-echo steady-state (DESS) sequence, in addition to the morphological information, the generation of biochemical T2 maps in one hybrid sequence. MATERIALS AND METHODS: In 50 consecutive MRIs at 3.0 Tesla (T) after matrix-associated autologous chondrocyte transplantation (MACT) of the knee, by the use this new DESS-T2d approach, the morphological Magnetic resonance Observation of CArtilage Repair Tissue (MOCART) score, as well as biochemical T2d values were assessed. Furthermore, these results were correlated to standard morphological sequences as well as to standard multi-echo spin-echo T2 mapping. RESULTS: The MOCART score correlated (Pearson:0.945; P < 0.001) significantly as assessed with standard morphological sequences (68.8 ± 13.2) and the morphological images of the DESS T2d sequence (68.7 ± 12.6). T2 and T2d relaxation times (ms) were comparable in between the control cartilage (T2: 52.5 ± 11.4; T2d: 46.6 ± 10.3) and the repair tissue (T2: 54.4 ± 11.4; T2d: 47.5 ± 13.0) (T2: P = 0.157; T2d: P = 0.589). As expected, T2d values were lower than the standard-T2 values, however, both functional relaxation times correlated significantly (Pearson:0.429; P < 0.001). CONCLUSION: The presented hybrid approach provides the possibility to combine morphological and biochemical MRI in one fast 3D sequence, and thus, may attract for the clinical use of biochemical MRI.

Low incidence of EGFR and HRAS mutations in cutaneous squamous cell carcinomas of a German cohort.

Epidermal growth factor receptor (EGFR) is highly expressed in squamous cell carcinoma (SCC). The response of patients with lung cancer to EGFR inhibitors is significantly associated with the presence of EGFR mutations. Although these drugs have already been used for the treatment of advanced cutaneous SCC, the knowledge about EGFR mutations in this cancer is limited to one previous study in the US population. We analysed the presence of EGFR and concomitant HRAS mutations in a German cohort of 31 patients with cutaneous SCC by direct sequencing of EGFR and SNaPshot analysis of concomitant RAS mutations. We found a low prevalence of EGFR mutations (1/31; 3%) and HRAS mutations (1/31; 3%). The detected P741L EGFR mutation was proven to be somatic. Our results indicate that both EGFR and HRAS mutations are rare events in the carcinogenesis of cutaneous SCC, and therefore, only a small subgroup of patients will benefit from the screening for EGFR mutations in the run-up to targeted therapies with EGFR inhibitors.

Identification of new genes associated with melanoma.

PURPOSE: Repeated failures in melanoma therapy made clear that the molecular mechanisms leading to melanoma are still poorly understood. In this study, we aim to provide a more comprehensive understanding of the transcriptional profiles and signalling pathways associated with melanoma. METHODS: Gene expression was analysed using the Affymetrix Human Genome U133A 2.0 GeneChip arrays. To avoid culture artifacts, we used microdissected fresh frozen material of 18 melanocytic nevi (MN), 20 primary melanomas (PM) and 20 metastatic melanomas (MM). Statistical analysis was performed with Genomatix Chipinspector, Ingenuity™ Software, SPSS Software and Partek Genomic Suite 6.4. Expression levels of selected transcripts were verified by quantitative real-time RT-PCR and immunostaining of a tissue microarray sampling more than 280 cases of MN, PM and MM with known clinical outcome. RESULTS: A total of 284 differentially expressed genes was detected in PM compared with MN and 189 genes in MM compared with PM affecting common cancer pathways such as MAPK-, Wnt- and Notch-signalling. Using principal component analysis, the samples could be grouped according to their histological entity. We identified a panel of novel melanoma-associated markers: frizzled-related protein, an antagonist of Wnt; tranducin-like enhancer of split 1, a transcription factor partner of TCF/LEF-1; CNTN1, an activator of Notch signalling; two Serpin peptidase inhibitors, Serpin B3/B4 and the TGF-ß family member GDF15, the latter with association to MAPK-signalling.

Generalized solar lentigines in a patient with a history of radon exposure.

A woman with generalized lentigines without associated non-cutaneous abnormalities is described. The patient showed brownish-pigmented flat or slightly elevated spots with a diameter of 1­5 mm. The histopathology of the lesions was compatible with a diagnosis of solar lentigines (SLs) or flat seborrhoeic keratosis. Unlike SLs, which develop typically on sun-damaged skin of the face, the dorsum of the hands and forearms, this patient showed the lentigines most prominently on the thighs and lower legs. Besides increased recreational UV exposure, the patient had a history of occupational radon exposure in a spa with radon-containing water. Genetic analysis identified a p.S249C FGFR3 hotspot mutation in 1 lesion, supporting the diagnosis of SLs. It remains elusive whether the occupational exposure to radon-containing water in addition to the recreational UV light exposure caused the unusual distribution of the SLs in this patient.