New Treatment Options for Osteosarcoma - Inactivation of Osteosarcoma Cells by Cold Atmospheric Plasma.

BACKGROUND/AIM: Cold atmospheric plasma has been shown to inhibit tumor cell growth and induce tumor cell death. The aim of the study was to investigate the effects of cold atmospheric plasma treatment on proliferation of human osteosarcoma cells and to characterize the underlying cellular mechanisms. MATERIALS AND METHODS: Human osteosarcoma cells (U2-OS and MNNG/HOS) were treated with cold atmospheric plasma and seeded in culture plates. Cell proliferation, p53 and phospho-p53 protein expression and nuclear morphology were assessed. RESULTS: The treated human osteosarcoma cell lines exhibited attenuated proliferation rates by up to 66%. The cells revealed an induction of p53, as well as phospho-p53 expression, by 2.3-fold and 4.5-fold, respectively, compared to controls. 4',6-diamidino-2-phenylindole staining demonstrated apoptotic nuclear condensation following cold atmospheric plasma treatment. CONCLUSION: Cold atmospheric plasma treatment significantly attenuated cell proliferation in a preclinical in vitro osteosarcoma model. The resulting increase in p53 expression and phospho-activation in combination with characteristic nuclear changes indicate this was through induction of apoptosis.

Fracture care using percutaneously applied titanium mesh cages (OsseoFix®) for unstable osteoporotic thoracolumbar burst fractures is able to reduce cement-associated complications--results after 12 months.

BACKGROUND: Despite the known demographic shift with expected doubled rate of vertebral body fractures by the year 2050, a standardized treatment concept for traumatic and osteoporotic incomplete burst fracture of the truncal spine does not exist. This study aims to determine whether minimally invasive fracture care for incomplete osteoporotic thoracolumbar burst fractures using intravertebral expandable titanium mesh cages is a suitable procedure and may provide improved safety in terms of cement-associated complications in comparison to kyphoplasty procedure. METHODS: In 2011/2012, 15 patients (10 women, 5 men; mean age 77) with 15 incomplete osteoporotic thoracolumbar burst fractures (T10 to L4) were stabilized using intravertebral expandable titanium mesh cages (OsseoFix®) as part of a prospective study. X-ray, MRI and bone density measurements (DXA) were performed preinterventionally. The clinical and radiological results were evaluated preoperatively, postoperatively and after 12 months according to the visual analogue scale (VAS), the Oswestry Disability Index (ODI), X-ray (Beck Index, Cobb angle) and CT analyses. Wilcoxon rank sum test, sign test and Fischer's exact test were used for statistical evaluation. RESULTS: A significant reduction in pain intensity (VAS) from preoperative 8.0 to 1.6 after 12 months and significant improvement in activity level (ODI) from preoperative 79.0 to 30.5 % after 12 months were revealed. Radiologically, the mean kyphotic angle according to Cobb showed significant improvements from preoperative 9.1° to 8.0° after 12 months. A vertebral body subsidence was revealed in only one case (6.7 %). No changes in the position of the posterior wall were revealed. No cement leakage or perioperative complications were seen. CONCLUSION: As a safe and effective procedure, the use of intravertebral expandable titanium mesh cages presents a valuable alternative to usual intravertebral stabilization procedures for incomplete osteoporotic burst fractures and bears the potential to reduce cement-associated complications. TRIAL REGISTRATION: German Clinical Trials Register (DKRS) DRKS00008833 .

Bony healing of unstable thoracolumbar burst fractures in the elderly using percutaneously applied titanium mesh cages and a transpedicular fixation system with expandable screws.

INTRODUCTION: There is a high incidence of vertebral burst fractures following low velocity trauma in the elderly. Treatment of unstable vertebral burst fractures using the same principles like in stable vertebral burst fractures may show less favourable results in terms of fracture reduction, maintenance of reduction and cement leakage. In order to address these shortcomings this study introduces cementless fixation of unstable vertebral burst fractures using internal fixators and expandable intravertebral titanium mesh cages in a one-stage procedure via minimum-invasive techniques. MATERIAL AND METHODS: A total of 16 consecutive patients (median age 76 years, range 58-94) with unstable thoracolumbar burst fractures and concomitant osteoporosis were treated by an internal fixator inserted via minimum invasive technique one level above and below the fractured vertebra. Fracture reduction was achieved and maintained by transpedicular placement of two titanium mesh cages into the fractured vertebral body during the same procedure. Intra- and postoperative safety of the procedure as well as analysis of reduction quality was analysed by 3D C-arm imaging or CT, respectively. Clinical and radiographic follow-up averaged 10.4 months (range 4.5-24.5). RESULTS: Stabilization of the collapsed vertebral body was achieved in all 16 cases without any intraoperative complication. Surgical time averaged 102 ± 6.6 minutes (71-194). The postoperative kyphotic angle (KA) and Cobb angle revealed significant improvements (KA 13.7° to 7.4°, p < 0.001; Cobb 9.6° to 6.0°, p < 0.002) with partial loss of reduction at final follow-up (KA 8.3°, Cobb 8.7°). VAS (Visual Analogue Scale) improved from 7.6 to 2.6 (p < 0.001). Adjacent fractures were not observed. One minor (malposition of pedicle screw) complication was encountered. CONCLUSION: Cementless fixation of osteoporotic burst fractures revealed substantial pain relief, adequate maintenance of reduction and a low complication rate. Bony healing after unstable osteoporotic burst fractures is possible. TRIAL REGISTRATION: www.germanctr.de DRKS00005657.

Cementless fixation of osteoporotic VCFs using titanium mesh implants (OsseoFix): preliminary results.

INTRODUCTION: Vertebral compression fractures (VCFs) affect 20% of people over the age of 70 with increasing incidence. Kypho-/vertebroplasty as standard operative procedures are associated with limitations like cement leakage, limited reduction capabilities, and risk for adjacent fractures. To address these shortcomings, we introduce a new minimal invasive cementless VCF fixation technique. METHODS: Four patients (72.3 years, range 70-76) with VCFs type AO/Müller A1.3 and concomitant osteoporosis were treated by minimal invasive transpedicular placement of two intervertebral mesh cages for fracture reduction and maintenance. Follow-up included functional/radiological assessment and clinical scores and averaged 27.7 months (24-28). RESULTS: Endplate reduction was achieved in all cases (mean surgery time: 28.5 minutes). Kyphotic (KA) and Cobb angle revealed considerable improvements postoperatively (KA 14.5° to 10.7°/Cobb 10.1° to 8.3°). Slight loss of vertebral reduction (KA: 12.6°) and segment rekyphosis (Cobb: 10.7°) were observed for final follow-up. Pain improved from 8.8 to 2.8 (visual analogue scale). All cases showed signs of bony healing. No perioperative complications and no adjacent fractures occurred. CONCLUSION: Preliminary results in a small, selected patient collective indicate the ability of bony healing for osteoporotic VCFs. Cementless fixation using intravertebral titanium mesh cages revealed substantial pain relief, adequate reduction, and reduction maintenance without complications. Trial registration number is DRKS00005657, German Clinical Trials Register (DKRS).

Expression and function of the ACE2/angiotensin(1-7)/Mas axis in osteosarcoma cell lines U-2 OS and MNNG-HOS.

The renin-angiotensin-system (RAS), via its classical angiotensin-converting enzyme (ACE)/angiotensin II/angiotensin II type 1 receptor (AT1R)-axis, is associated with proliferation and metastasis of numerous types of solid tumor. AT1R blockers reduce tumor volume and decrease liver and lung metastasis in murine models of osteosarcoma. Expression and function of the alternative ACE2/Ang(1-7)/Mas axis in osteosarcoma is yet to be studied. In the present study, the basic and interleukin (IL)-1ß-stimulated expression of components of this alternative RAS axis were analyzed and the impact of Mas on proliferation and/or migration of U-2 OS and MNNG-HOS osteosarcoma cells was studied. Quantitative polymerase chain reaction revealed that the two cell lines expressed the Ang(1­7)-generating peptidases ACE2, neutral endopeptidase 24.11 and prolyl-endopeptidase together with the putative receptor for Ang(1-7), Mas. IL-1ß provoked an induction of Mas mRNA and protein expression which was associated with a reduction of proliferation and migration. By contrast, small interfering RNA-mediated knockdown of Mas expression led to increased cell proliferation. In conclusion, osteosarcoma cells express a functional active alternative ACE2/Ang(1-7)/Mas axis. The induction and reinforcement of this axis may be beneficial for the treatment of osteosarcoma by reducing growth and preventing cancer metastasis. These effects may be achieved directly by the administration of Mas agonists or, indirectly, via blocking the classical AngII RAS axis via ACE inhibitors or AT1R antagonists.

Proton-density fat fraction and simultaneous R2* estimation as an MRI tool for assessment of osteoporosis.

OBJECTIVE: To investigate multi-echo chemical shift-encoded MRI-based mapping of proton density fat fraction (PDFF) and fat-corrected R2* in bone marrow as biomarkers for osteoporosis assessment. METHODS: Fifty-one patients (28 female; mean age 69.7 ± 9.0 years) underwent dual energy X-ray absorptiometry (DXA). On the basis of the t score, 173 valid vertebrae bodies were divided into three groups (healthy, osteopenic and osteoporotic). Three echo chemical shift-encoded MRI sequences were acquired at 3 T. PDFF and R2* with correction for multiple-peak fat (R2*MP) were measured for each vertebral body. Kruskal-Wallis test and post hoc analysis were performed to evaluate differences between groups. Further, the area under the curve (AUC) for each technique was calculated using logistic regression analysis. RESULTS: On the basis of DXA, 92 samples were normal (53 %), 47 osteopenic (27 %) and 34 osteoporotic (20 %). PDFF was increased in osteoporosis compared with healthy (P = 0.007). R2*MP showed significant differences between normal and osteopenia (P = 0.004), and between normal and osteoporosis (P < 0.001). AUC to differentiate between normal and osteoporosis was 0.698 for R2*MP, 0.656 for PDFF and 0.74 for both combined. CONCLUSION: PDFF and R2*MP are moderate biomarkers for osteoporosis. PDFF and R2*MP combination might improve the prediction in differentiating healthy subjects from those with osteoporosis.

Percutaneous Stabilization System Osseofix® for Treatment of Osteoporotic Vertebral Compression Fractures - Clinical and Radiological Results after 12 Months.

STUDY DESIGN: A prospective consecutive cohort study (follow-up study). OBJECTIVE: Our study investigated whether implantation of an expandable titanium mesh cage (Osseofix®) is a successful and safe minimally invasive therapy for osteoporotic vertebral compression fractures (VCF). Our experiences, clinical and radiological findings after 12 months follow-up are presented. Kypho- and vertebroplasty are well-established minimally invasive procedures for the treatment of osteoporotic VCF. The main complications associated with both procedures are uncontrolled bone cement leakage. Therefore a suitable alternative has been investigated. METHODS: During June 2010 to May 2011 24 patients were included with 32 osteoporotic VCF (T6 to L4). All of them were stabilized with the Osseofix® system. Preinterventionally we performed X-ray, MRI, and bone density measurements (DXA). Clinical and radiological results were evaluated preop., postop. and after 12 months postop. based on the Oswestry Disability Index (ODI) and the Visual Analogue Scale (VAS), X-ray (Beck Index, Cobb-angle) and CT. RESULTS: There was a significant improvement in the mean ODI (70,6% to 30,1%) as well as a significant reduction in pain intensity (VAS) (7,7 to 1,4) after 12 month. The mean kyphotic angle according to Cobb showed significant improvements (11,7° to 10,4°) after 12 months. Postinterventional imaging showed only one case of loss of height in a stabilized vertebral body (3.1%). We saw no changes in posterior vertebral wall or adjacent fractures. Except for one pronounced postoperative hematoma we saw no surgical complications including no cement leakage. CONCLUSIONS: Stabilization of symptomatic osteoporotic VCF with Osseofix® system is a safe and effective procedure, even in fractures with posterior wall involvement. The clinical mid-term results are good at a very low complication rate. The Osseofix® system is an interesting alternative to the established procedures of cement augmentation.

Combined administration of EGCG and IL-1 receptor antagonist efficiently downregulates IL-1-induced tumorigenic factors in U-2 OS human osteosarcoma cells.

Chronic inflammation represents one of the hallmarks of cancer. Of special relevance to the malignant process is the pro-inflammatory cytokine IL-1 playing a crucial role in cancer-related inflammation. Recent observations indicate increased IL-1 levels in an animal model of human osteosarcoma, the most frequent primary malignant bone tumor in man. In patients with bone sarcomas, increased serum levels of tumor-promoting cytokines, including IL-6, IL-8 and VEGF can be found, correlating with poor overall survival. The link between cancer and inflammation makes it clear that there is a need to reduce the external factors inducing inflammation as a preventive or therapeutical measure. Therefore, in the present study the effects of anti-inflammatory IL-1 receptor antagonist (IL-1Ra) was tested alone and in combination with (-)-epigallocatechin-3-gallate (EGCG), an anti-inflammatory chemopreventive agent from green tea, on the production of IL-1-induced tumorigenic factors in U-2 OS human osteosarcoma cells. We found that IL-1Ra and EGCG downregulated IL-1-induced IL-6 and IL-8 release from U-2 OS cells by 65-85%. IL-1Ra and EGCG also reduced secretion of invasiveness-promoting MMP-2 and pro-angiogenic VEGF to 62-75% without affecting the metabolic response and caspase-3 activity. In conclusion, downregulation of IL-1-induced tumorigenic factors (IL-6, IL-8, VEGF, MMP-2) in U-2 OS by IL-1Ra and EGCG may positively affect tumor-associated inflammation and, as a consequence, lead to reduction in angiogenesis and invasiveness. This renders a combined administration of EGCG and IL-1Ra a promising approach as an adjuvant therapy in patients with osteosarcoma.

Small ubiquitin-like modifier 1 [corrected] mediates the resistance of prosthesis-loosening fibroblast-like synoviocytes against Fas-induced apoptosis.

OBJECTIVE: To study the expression of small ubiquitin-like modifier 1 (SUMO-1) in aseptic loosening of prosthesis implants and to investigate its role in regulating the susceptibility of prosthesis-loosening fibroblast-like synoviocytes (FLS) to Fas-induced apoptosis. METHODS: Specimens of aseptically loosened tissue were obtained at revision surgery, and the expression of SUMO-1 was analyzed by in situ hybridization. SUMO-1 levels in FLS were determined by quantitative polymerase chain reaction and Western blot analysis. Immunohistochemistry and confocal microscopy were used to study the subcellular localization of SUMO-1. The functional role of SUMO-1 in Fas-induced apoptosis of prosthesis-loosening FLS was investigated by small interfering RNA-mediated knockdown of SUMO-1 and by gene transfer of the nuclear SUMO-specific protease SENP1. RESULTS: SUMO-1 was expressed strongly in aseptically loosened tissue and was found prominently at sites adjacent to bone. Prosthesis-loosening FLS expressed levels of SUMO-1 similar to the levels expressed by rheumatoid arthritis (RA) FLS, with SUMO-1 being found mainly in promyelocytic leukemia protein nuclear bodies. Knockdown of SUMO-1 had no effect on spontaneous apoptosis but significantly increased the susceptibility of prosthesis-loosening FLS to Fas-induced apoptosis. Gene transfer of the nuclear SUMO-specific protease SENP1 reverted the apoptosis-inhibiting effects of SUMO-1. CONCLUSION: These data suggest that SUMO-1 is involved in the activation of both RA FLS and prosthesis-loosening FLS by preventing these cells from undergoing apoptosis. Modification of nuclear proteins by SUMO-1 contributes to the antiapoptotic effects of SUMO-1 in prosthesis-loosening FLS, providing evidence for the specific activation of sumoylation during their differentiation. Therefore, SUMO-1 may be an interesting target for novel strategies to prevent aseptic prosthesis loosening.

Long-term results after arthroscopic treatment of synovial chondromatosis of the shoulder.

PURPOSE: The purpose of this study was to document the results of arthroscopic treatment for synovial chondromatosis of the shoulder with loose body removal and partial synovectomy. METHODS: Five cases of shoulder arthroscopy performed for synovial chondromatosis were reviewed. Removal of loose bodies and partial synovectomy was performed in all cases. Follow-up of 4 to 9 years was obtained on these 5 patients. RESULTS: The clinical result was very good for all patients. Radiologic signs of chondroma were observed in two patients. Revision surgery was not necessary in either case. CONCLUSIONS: The clinical results referring to the Constant and Murley score and subjective assessment were very good at 4 to 9 years following surgery. However, in two out of five subjects, radiographs revealed evidence of persisting or recurrent synovial chondroma at follow-up. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Cementless CUT femoral neck prosthesis: increased rate of aseptic loosening after 5 years.

BACKGROUND: Bone-saving hip arthroplasty techniques, which facilitate revision, are gaining importance as the number of hip replacements in younger patients increases. PATIENTS AND METHODS: 123 CUT femoral neck prostheses (ESKA Implants, Lübeck, Germany) were implanted in 113 patients (average age 53 years) between 1999 and 2002. After a mean follow-up of 5 (3-7) years, we determined the state of 120 prostheses; 3 patients could not be located. 97 patients with 107 prostheses, none of which had been revised, were evaluated clinically and radiographically. RESULTS: The median Harris hip score improved from 51 points to 92 points in the unrevised hips. 13 CUT prostheses (11%) had been revised, 7 because of aseptic loosening, 3 because of persisting thigh pain, 1 because of immediate vertical migration, and 2 because of septic loosening. The 5-year survival rate of the CUT prosthesis was 89%. INTERPRETATION: The medium-term survival with this type of femoral component is unsatisfactory, with a high rate of aseptic loosening. The surviving prostheses had a good clinical outcome.

Arthroscopic labrum reconstruction with capsular shift in anterior shoulder instability: improved midterm results by using a standardized suprabicipital camera position.

PURPOSE: To investigate the midterm results of a standardized arthroscopic technique for labrum reconstruction by using a third suprabicipital portal for better visualization of the anterior glenoid rim. METHODS: Thirty-three of 36 patients treated for recurrent anterior shoulder dislocation were followed up by telephone and/or in clinical examinations. The average age of the patients (12 women and 21 men) at the time of surgery was 25.2 years, with a mean follow-up of 35 months. On average, 7.8 dislocations occurred between the first dislocation and the stabilization procedure (mean, 45.4 months). RESULTS: Two patients suffered again from redislocations (recurrence rate 6.1%), and 3 patients had 1 or 2 subluxations (9.1%) at the time of follow-up. In the Rowe score, the patients reached 77.5 points on average; 81.8% of the patients returned to sports and leisure activities as in the time before the first dislocation, and 18.2% (6 patients) did not. Limitations for external rotation were 7.8 degrees on average postoperatively. No statistical correlation between the number of preoperative dislocations and the level of the postoperative Rowe score was found. CONCLUSIONS: The arthroscopic labrum reconstruction with capsular shift using the 3-portal technique combined with a standardized suprabicipital camera position revealed a recurrence rate and midterm results that were close to results achieved after open procedures. The failure rate, according to the number of dislocations, was 6.1% based on the patient's satisfaction of 12.1%. LEVEL OF EVIDENCE: Level IV, therapeutic case series.