Surgical and Oncologic Outcome following Sacrectomy for Primary Malignant Bone Tumors and Locally Recurrent Rectal Cancer.

INTRODUCTION: Bone sarcoma or direct pelvic carcinoma invasion of the sacrum represent indications for partial or total sacrectomy. The aim was to describe the oncosurgical management and complication profile and to analyze our own outcome results following sacrectomy. METHODS: In a retrospective analysis, 27 patients (n = 8/10/9 sarcoma/chordoma/locally recurrent rectal cancer (LRRC)) were included. There was total sacrectomy in 9 (incl. combined L5 en bloc spondylectomy in 2), partial in 10 and hemisacrectomy in 8 patients. In 12 patients, resection was navigation-assisted. For reconstruction, an omentoplasty, VRAM-flap or spinopelvic fixation was performed in 20, 10 and 13 patients, respectively. RESULTS: With a median follow-up (FU) of 15 months, the FU rate was 93%. R0-resection was seen in 81.5% (no significant difference using navigation), and 81.5% of patients suffered from one or more minor-to-moderate complications (especially wound-healing disorders/infection). The median overall survival was 70 months. Local recurrence occurred in 20%, while 44% developed metastases and five patients died of disease. CONCLUSIONS: Resection of sacral tumors is challenging and associated with a high complication profile. Interdisciplinary cooperation with visceral/vascular and plastic surgery is essential. In chordoma patients, systemic tumor control is favorable compared to LRRC and sarcomas. Navigation offers gain in intraoperative orientation, even if there currently seems to be no oncological benefit. Complete surgical resection offers long-term survival to patients undergoing sacrectomy for a variety of complex diseases.

Solitary, adult-onset, intraosseous myofibroma of the rib: a case report and literature review.

Myofibromas are rare benign tumors with myofibroblastic origin. They occur especially in cutis and subcutaneous tissue of the head and the neck, less frequently on the extremities. Myofibromas grow very slowly and are often painless, which is why patients often present relatively late. In the literature, there were many reports about intraosseous myofibromas of the craniofascial bones but reports of the trunk and extremities in adults are very rare. The authors present a very rare case of an intraosseous myofibroma of the ribs resulting in pathological fracture, including a research of literature from other cases of intraosseous myofibromas of the trunk or extremities.

Benign tumours of foot and ankle.

Musculoskeletal tumours of foot or ankle make up about 4-5% of all musculoskeletal tumours. Fortunately, about 80% of them are benign. However, due to the rarity and low prevalence of each single tumour entity, diagnosis is often difficult and delayed. Ultrasonography is an important diagnostic tool to safely recognize ganglion cysts as a frequently encountered 'bump' in the foot. In suspicious lesions, malignancy must be excluded histologically in a tumour center by biopsy after imaging procedures using x-ray, computed tomography (CT) and magnetic resonance imaging (MRI). Most of the benign tumours do not require any further surgical therapy. Resection should be performed in the case of locally aggressive tumour growth or local symptoms of discomfort. In contrast to malignant tumours, the primary purpose in the resection is the least possible loss of function.

Dose-Dependent Effects of a Novel Selective EP4 Prostaglandin Receptor Agonist on Treatment of Critical Size Femoral Bone Defects in a Rat Model.

Difficulties in treating pseudarthrosis and critical bone defects are still evident in physicians' clinical routines. Bone morphogenetic protein 2 (BMP-2) has shown promising osteoinductive results but also considerable side effects, not unexpected given that it is a morphogen. Thus, the bone regenerative potential of the novel selective, non-morphogenic EP4 prostaglandin receptor agonist KMN-159 was investigated in this study. Therefore, mineralized collagen type-1 matrices were loaded with different amounts of BMP-2 or KMN-159 and implanted into a 5 mm critical-sized femoral defect in rats. After 12 weeks of observation, micro-computed tomography scans were performed to analyze the newly formed bone volume (BV) and bone mineral density (BMD). Histological analysis was performed to evaluate the degree of defect healing and the number of vessels, osteoclasts, and osteoblasts. Data were evaluated using Kruskal-Wallis followed by Dunn's post hoc test. As expected, animals treated with BMP-2, the positive control for this model, showed a high amount of newly formed BV as well as bone healing. For KMN-159, a dose-dependent effect on bone regeneration could be observed up to a dose optimum, demonstrating that this non-morphogenic mechanism of action can stimulate bone formation in this model system.

Treatment of Critical-Size Femoral Bone Defects with Chitosan Scaffolds Produced by a Novel Process from Textile Engineering.

The purpose of this study was to investigate, in vitro and in vivo, the suitability of chitosan (CHS) scaffolds produced by the net-shape-nonwoven (NSN) technology, for use as bone graft substitutes in a critical-size femoral bone defect in rats. For in vitro investigations, scaffolds made of CHS, mineralized collagen (MCM), or human cancellous bone allograft (CBA) were seeded with human telomerase-immortalized mesenchymal stromal cells (hTERT-MSC), incubated for 14 days, and thereafter evaluated for proliferation and osteogenic differentiation. In vivo, CHS, MCM and CBA scaffolds were implanted into 5 mm critical-size femoral bone defects in rats. After 12 weeks, the volume of newly formed bone was determined by microcomputed tomography (µCT), while the degree of defect healing, as well as vascularization and the number of osteoblasts and osteoclasts, was evaluated histologically. In vitro, CHS scaffolds showed significantly higher osteogenic properties, whereas treatment with CHS, in vivo, led to a lower grade of bone-healing compared to CBA and MCM. While chitosan offers a completely new field of scaffold production by fibers, these scaffolds will have to be improved in the future, regarding mechanical stability and osteoconductivity.