Changes of the microbiological spectrum and antibiotic resistance pattern in postoperative spinal implant infections with multiple culture-positive revision surgeries.

BACKGROUND CONTEXT: In severe cases of postoperative spinal implant infections (PSII) multiple revision surgeries may be needed. Little is known if changes in the microbiological spectrum and antibiotic resistance pattern occur between revision surgeries. PURPOSE: Analysis of the microbiological spectrum and antibiotic resistance pattern in patients with multiple revision surgeries for the treatment of PSII STUDY DESIGN: Retrospective database analysis. PATIENT SAMPLE: Between 01/2011 and 12/2018, 103 patients underwent 248 revision surgeries for the treatment of PSII. Twenty patients (19.4%) who underwent multiple revision surgeries for PSII were included in this study. OUTCOME MEASURES: Microbiological spectrum, antibiotic resistance pattern. METHODS: A retrospective analysis of a prospectively maintained single center spine infection database was performed with a minimum follow-up of 3 years. Overall, 20 patients (six male/14 female) underwent 82 revisions for PSII (median 3; range 2-12). There were 55 of 82 (67.1%) procedures with a positive microbiological result. Microbiological analysis was performed on tissue and implant sonication fluid. Changes in microbial spectrum and antibiotic resistance pattern between surgeries were evaluated using Chi-Square and Fisher's exact test. RESULTS: In total, 74 microorganisms (83.3% gram-positive; 10.8% gram-negative) were identified. The most common microorganisms were Staphylococcus epidermidis (18.9%) and Cutibacterium acnes (18.9%). All S. epidermidis identified were methicillin-resistant (MRSE). Overall, there were 15 of 55 (27.3%) polymicrobial infections. The microbiological spectrum changed in 57.1% (20/35) between the revision stages over the entire PSII period. In 42.9% (15/35) the microorganism persisted between the revision surgeries stages. Overall, changes of the antibiotic resistance pattern were seen in 17.4% (8/46) of the detected microorganisms, comparing index revision and all subsequent re-revisions. Moreover, higher resistance rates were found for moxifloxacin and for ciprofloxacin at first re-revision surgery compared with index PSII revision. Resistances against vancomycin increased from 4.5% (1/23) at index PSII revision to 7.7% (2/26) at first re-revision surgery. CONCLUSIONS: Changes of the microbiological spectrum and the resistance pattern can occur in patients with severe PSII who require multiple revision surgeries. It is important to consider these findings in the antimicrobial treatment of PSII. The microbiological analysis of intraoperative tissue samples should be performed at every revision procedure for PSII.

[Interdisciplinary position paper: the value of radiofrequency denervation in the treatment of chronic pain]. / Interdisziplinäres Positionspapier: der Stellenwert der Radiofrequenzdenervierung in der Therapie chronischer Schmerzen.

Radiofrequency denervation has been established for many years as an important minimally invasive procedure for the treatment of chronic pain conditions. Positive experiences of many users for various indications are contrasted by a nonuniform evidence. With meticulous patient selection and correct assessment of the indications a longer term reduction of pain, a reduced need for analgesics and an improvement in the quality of life can be achieved. The aim of this interdisciplinary position paper is to present the value of radiofrequency denervation in the treatment of chronic pain. The summarized recommendations of the expert group are based on the available evidence and on the clinical experiences of Austrian centers that frequently implement the procedure. The position paper contains recommendations on patient selection and proven indications. We discribe safety aspects, complications, side effects and contraindications.

Predicting medical complications in spine surgery: evaluation of a novel online risk calculator.

PURPOSE: The preoperative prediction of medical complications is essential to optimize perioperative management. SpineSage™ is a free of charge online calculator to predict medical complications in spine surgery. The current study utilizes it in patients undergoing spine surgery to assess whether the predicted risks would correlate with the actual complication rate in clinical practice. METHODS: A total of 273 consecutive patients who underwent spinal surgery were assessed. The risk of medical complications was predicted for each patient, and all medical complications were recorded within 30 days of surgery. Based on their predicted risk of complication, patients were divided into three risk groups (< 15, 15-30, > 30%). RESULTS: The predicted overall risk of medical complications was 14.7% and was comparable to the observed complication rate of 16.1%. The predicted risk for major medical complications (3.8%) was also similar to the observed complication rate (3.3%). Detailed analysis of the segmented risk groups suggests a close correlation between predicted and actual complication rates. Receiver operating characteristic analysis revealed an area under the curve of 0.71 (p < 0.001) for the prediction of overall medical complications and 0.85 (p < 0.001) for major complications. CONCLUSIONS: The online risk calculator predicted both overall and major medical complications. The tool can assist in preoperative planning and counseling of patients. These slides can be retrieved under Electronic Supplementary Material.

Taurine chloramine induces apoptosis in human osteosarcoma cell lines.

Although combination of surgery with chemotherapy has noticeably improved the survival rate of osteosarcoma patients, the application of anticancer drugs is still associated with significant adverse reactions, for instance acquisition of drug-resistant phenotypes, necessitating the development of new chemotherapeutical agents. Therefore, the aim of this study was to research, if taurine chloramine (NCT) induces apoptosis in the osteosarcoma cell lines HOS, MG-63, and SAOS-2. Proliferation of osteosarcoma cells was detected with the "EZ4U Cell Proliferation and Cyotoxicity Assay" showing a time- and dose-dependent cytotoxic effect of NCT on these cell lines. After 3 h of incubation all cell lines showed significantly less cells at 5.5 mM NCT solutions, after 6 h at concentrations of 1.1 and 2.2 mM. Acridine-orange fluorescence nuclear staining showed characteristic features of apoptosis. DNA fragmentation was detected via ELISA, showing significant results for HOS and MG-63 after 6 h at an NCT concentration of 3.3 mM. Results of JC-1 mitochondrial FACS analysis presented a significant increase in apoptotic cells after 6 h at 3.3 mM for the tested cell lines. Summarized, the results of this study indicate that NCT is a promising agent in osteosarcoma therapy.

Stabilising effect of dynamic interspinous spacers in degenerative low-grade lumbar instability.

The aim of the study was to investigate the stabilising effect of dynamic interspinous spacers (IS) in combination with interlaminar decompression in degenerative low-grade lumbar instability with lumbar spinal stenosis and to compare its clinical effect to patients with lumbar spinal stenosis in stable segments treated by interlaminar decompression only. Fifty consecutive patients with a minimum age of 60 years were scheduled for interlaminar decompression for clinically and radiologically confirmed lumbar spinal stenosis. Twenty-two of these patients (group DS) with concomitant degenerative low-grade lumbar instability up to 5 mm translational slip were treated by interlaminar decompression and additional dynamic IS implantation. The control group (D) with lumbar spinal stenosis in stable segments included 28 patients and underwent only interlaminar decompression. The mean follow-up was 46 months in group D and 44 months in group DS. A visual analogue scale (VAS), Oswestry Disability Index (ODI) and walking distance were evaluated pre- and postoperatively. The segmental instability was evaluated in flexion-extension X-rays. The implantation of an IS significantly reduced the lumbar instability on flexion-extension X-rays. At the time of follow-up walking distance, VAS and ODI showed a significant improvement in both groups, but no statistical significance between groups D and DS. Four patients each in groups D and DS had revision surgery during the period of evaluation. The stabilising effect of dynamic IS in combination with interlaminar decompression offers an opportunity for an effective treatment for degenerative low-grade lumbar instability with lumbar spinal stenosis.

Bone morphogenetic proteins 2, 5, and 6 in combination stimulate osteoblasts but not osteoclasts in vitro.

Bone regeneration is required for fracture healing. Various procedures have been used to promote osteogenesis with bone morphogenetic proteins (BMPs). We assessed the effects of BMP-2, BMP-5, and BMP-6 in isolated and combined use on the generation of osteoblasts and osteoclasts by comparing the osteoclastic potency of each on osteoclasts of primary murine bone marrow cells. Subsequently, cells were stained for tartrate-resistant acid phosphatase, and real time PCR analysis of receptor activator of NKκB ligand and osteoprotegerin was conducted. The same combination of BMPs was used to assess their potential to enhance osteoblasts, employing a mineralization assay and real-time PCR analysis of collagen type-1, runx2, and osterix. While BMP-2 alone and the combination of BMP-2 and BMP-5 significantly enhanced osteoclastogenesis, BMP-2, BMP-5, and BMP-6 in combination did not have additional effects. However, the combined use of BMP-2, BMP-5, and BMP-6 had an additive effect on matrix mineralization and osterix expression in osteoblasts. Our study shows that the combination of BMP-2, BMP-5, and BMP-6 stimulates osteoblasts but not osteoclastogenesis. Thus, the synergistic use of various BMPs might improve effective bone regeneration in the clinical setting.

Altered bone matrix mineralization in a patient with Rett syndrome.

Rett syndrome (RTT) is a common X-linked neurodevelopmental disorder caused by mutations in the coding region of methyl-CpG-binding 2 (MECP2) gene. Patients with RTT have a low bone mineral density and increased risk of fracture. However, very little is known if bone matrix mineralization is altered in RTT. A 17-year-old girl with a classical form of RTT with a heterozygous nonsense mutation in exon 3 in the MECP2-gene was treated in our hospital. Her femoral neck BMD is 43.3% below the 3rd percentile when compared to age and sex-matched controls. She underwent surgery for correction of her scoliosis, which provided a unique opportunity to obtain bone tissue to study bone matrix mineralization (Bone Mineralization Density Distribution-BMDD) using quantitative backscattered electron imaging (qBEI) and histomorphometry. BMDD outcomes were compared to recently published normative reference data for young individuals. qBEI analysis showed a significant shift to lower matrix mineralization despite histomorphometric indices indicate a low bone turnover. There was a reduction in CaMean (-7.92%) and CaPeak (-3.97%), which describe the degree of mineralization. Furthermore the fraction of low mineralized matrix (CaLow: +261.84%) was dramatically increased, which was accompanied with an increase in the heterogeneity of mineralization (CaWidth: +86.34%). Our findings show a significantly altered bone matrix mineralization of a typical patient with RTT. This may partly explain the low bone density seen in these patients. These results also warrant further studies on the molecular role of MECP2 in bone matrix mineralization.

Sacral fractures after multi-segmental lumbosacral fusion: a series of four cases and systematic review of literature.

Spine surgeons are becoming increasingly aware of sacral insufficiency fractures as a complication after lumbosacral fusions. We present four patients who suffered from sacral fractures after multi-segmental posterior lumbosacral fusion together with a systematic review of the literature that yielded six papers reporting on 12 cases. Summarizing these 16 cases, the typical patient suffering from this complication is a female, elderly individual [66.4 +/- 12.3 (mean +/- SD) years of age, 95% confidence interval 57.89-71] undergoing multilevel fusion of 4.9 +/- 3.4 (95% CI 3.1-6.8) segments. Due to nonspecific clinical complaints and inconclusive imaging there has been a median delay in diagnosis of 5 (IQR 3-6, range 1-49) weeks after onset of pain. It remains unclear whether this complication is rare or rather under-diagnosed. Fortunately, these fractures are predominantly benign conditions that respond well to conservative management in the majority of cases, depending on location.

Treatment of intravertebral pseudarthroses by balloon kyphoplasty.

OBJECTIVE: This paper presents an open prospective investigation of the efficacy of balloon kyphoplasty in the treatment of intravertebral pseudarthrosis. Several described intravertebral radiolucent lines-the so-called vacuum phenomenon-originated from degenerative diseases. Pain arose from intravertebral dynamic mobility and local kyphosis. METHODS: We reduced and stabilized 24 intravertebral pseudarthroses with the balloon kyphoplasty. Pain and disability showed a rapid and distinct decrease. Radiologic features and life quality were compared with respect to the different shapes of fractures type A1, A3.1, and A3.3. The follow up was 2 years. RESULTS: The patients with fractures type A3.3 were older than those of type A1 and A3.1. In pseudarthrosis of type A3.1 fractures, the kyphotic wedge could be reduced to 13 degrees and the height could be increased to 85% with balloon kyphoplasty. In the A3.3 group, the wedge could be reduced to 8 degrees but the height could be increased only to 75%. No restoration of deformity was achieved in fractures type A1. A long-lasting effect on pain and disability was seen only after balloon kyphoplasty of fractures type A3.1. CONCLUSIONS: The treatment of intravertebral dynamic mobility with balloon kyphoplasty is useful in fractures type A3.1. In pseudarthroses type A1, the negligible reduction and only short-lasting reduction of pain stands against the costs. In pseudarthroses type A3.3, the lack of a long-lasting benefit could be the consequence of the disadvantageous shape of the vertebral body, the higher age of patients or the primary diseases.

Outcome assessment of hemiarthroplasty of the shoulder: a 5-year follow-up with 4 evaluation tools.

BACKGROUND: Outcome measurement of shoulder arthroplasty is not standardized. We compared 3 scores and 1 evaluation form. PATIENTS AND METHODS: We report on 35 hemiarthroplasties of the shoulder (32 cementless). Mean age of the patients was 62 (29-87) years. After a mean follow-up of 6 years (range 2-18 years) patients were evaluated with the Neer score, the Constant-Murley score, the score of the University of California in Los Angeles (UCLA) and the Society of Shoulder and Elbow Surgeons Basic Shoulder Evaluation Form. We also performed radiographic evaluation and sonographic evaluation of the rotator cuff. RESULTS: Although pain relief and patient satisfaction were promising, the overall results of the respective score showed low values (Neer score 56/100 points, Constant-Murley score 43/100 points, and UCLA score 19/35 points on average). INTERPRETATION: We recommend choice of a score with a high impact of pain and patient satisfaction. Furthermore, ability to cope with activities of daily living should be of more importance than strength.

Prevalence of aneurysmal and solitary bone cysts in young patients.

Aneurysmal and solitary bone cysts develop most commonly during skeletal growth. The objective of our epidemiologic study was to evaluate the prevalence, recurrence rate, and probability of recurrence-free survival for aneurysmal and solitary bone cysts in young patients. We did a population-based analysis of 141 histologically confirmed cases. Seventy-three patients with aneurysmal bone cysts and 68 patients with solitary bone cysts were registered. The annual prevalence was 0.32 per 100,000 individuals (range, 0-1.238) for aneurysmal cysts, with a 1.8:1 male to female ratio and a median age of the patients of 11.1 years (range, 1-19.7 years). For solitary bone cysts, the calculated annual prevalence was 0.30 (range, 0-0.963) with a median age of the patients of 1.1 years (range, 0.5-19.9) and a 1.96:1 male to female ratio. Recurrent lesions occurred frequently in young males. Secondary aneurysmal bone cysts were observed only in females. During skeletal growth, aneurysmal and juvenile bone cysts more often occur in males with a peak prevalence at approximately 11 years of age. A greater prevalence of aneurysmal bone cysts in young individuals is associated with skeletal growth and immaturity. Young age and male gender are associated with an increased risk of local recurrence.

Minimal invasive stabilization of osteoporotic vertebral fractures: a prospective nonrandomized comparison of vertebroplasty and balloon kyphoplasty.

OBJECTIVE: During recent years, the benefits of balloon kyphoplasty and vertebroplasty have been frequently discussed for the treatment of osteoporotic vertebral compression fractures. Because of the lack of comparative studies, we performed an investigation to describe the mechanical effects and the impact on life quality during a follow-up period of 2 years. METHODS: Patients with nonrecent fractures of vertebral bodies, ongoing bone remodeling, and major kyphotic deformity were treated with minimal invasive stabilization. The median duration of pain was 8 weeks before surgery. Because of the availability of the equipment, 28 patients were nonrandomly assigned to balloon kyphoplasty and 23 patients to vertebroplasty. The follow-up was performed 2 years after surgery. RESULTS: The kyphotic wedge of the vertebral bodies was decreased 6 degrees by balloon kyphoplasty but not by vertebroplasty. With both methods, we found a rapid decrease of pain down to one-half of the preoperative value. A long-lasting effect on pain was found only after balloon kyphoplasty. In the kyphoplasty group, a decrease of the Oswestry Disability Index (ODI) score was found during the first postoperative year. After 2 years, the ODI was not different from preoperative values in both groups. CONCLUSIONS: In nonrecent fractures, the reduction of the kyphotic wedge by balloon kyphoplasty was superior in decreasing pain persisting over a period of 2 years. The ability to improve disability after kyphoplasty was limited to 1 year. In nonrecent fractures, the consequences of age and osteoporosis seem to equalize the effects of the restored sagittal profile on disability but not on pain.

Chondrosarcoma of the hand: is a wide surgical resection necessary?

Chondrosarcomas of the hand are rare and generally treated with surgical resection. Thirteen patients with Grade 1 chondrosarcoma of the small bones of the hand were followed up for a mean of 99.8 months (range, 26-293 months). In eight patients (Group 1) curettage and reconstruction with cancellous bone was done and in five patients (Group 2) a wide resection was done. No patient experienced relapse in Group 2. In Group 1 one patient had a local relapse 18 months after intralesional resection. Using the Musculoskeletal Tumor Society score for evaluation, the clinical results showed an average of 98% and 95% of the normal function in Groups 1 and 2, respectively. None of the patients had evidence of systemic spread of the disease. With a relapse rate of 12.5% and no distant metastases after curettage, intralesional resection is the preferred method of treatment in Grade 1 chondrosarcoma of the hand, allowing the patient to avoid amputation and major loss of function.

Reconstruction of the pelvis after tumor resection in children and adolescents.

Thirty patients younger than 19 years with malignant bone tumors of the pelvis were treated by limb salvage surgery between 1970 and 1998. Functional and oncologic results were reviewed retrospectively. In 10 patients the defect was reconstructed by an endoprosthesis and in 20 patients reconstruction by autologous grafts (n = 7), allograft and prosthesis combinations (n = 2), bone cement reconstruction (n = 1), iliosacral arthrodesis (n = 1), modified Girdlestone procedure (n = 3), or resection without reconstruction (n = 6) was done. Three and one-half reoperations per patient were necessary postoperatively after allograft reconstruction, 2.5 reoperations per patient were necessary after endoprosthetic reconstruction, and 0.8 reoperations per patient were necessary after other or no reconstruction. After a mean followup of 52 months (range, 2-241 months), 17 patients were alive, 15 of whom were continuously disease-free, and 13 patients had died of their disease. Functional ratings were 81% after autograft, 73% after allograft, and 60% after endoprosthetic reconstruction. Defect reconstruction varied according to the type of resection. Type I resections were best reconstructed by biologic methods. Endoprosthetic reconstruction after periacetabular resection with the advantage of preservation of a functional hip and body integrity was associated with a high rate of complications and reoperations. Its role compared with allograft reconstruction, modified Girdlestone procedure, or no reconstruction requires additional investigation.