Bone metastases with "false negative" findings on 18F-FDG PET/CT in patients with angiosarcoma: A case series with literature review.

RATIONALE: Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) is considered a reliable and indispensable imaging method when evaluating distant metastases and clinical staging of angiosarcomas. Here, we report 2 cases of angiosarcoma with bone metastases with "false negative" findings on 18F-FDG PET/CT. PATIENT CONCERNS: Case 1, a 39-year-old woman, who had undergone mastectomy for primary angiosarcoma 2 years prior, presented with a 5-month history of right coxalgia. Case 2 was a 37-year-old woman, who had undergone mastectomy for primary angiosarcoma 4 months prior. During postoperative follow-up, multiple bone lesions were detected on magnetic resonance imaging (MRI). DIAGNOSES: Based on the histopathological findings, both cases were diagnosed with bone metastases of angiosarcoma. Although MRI showed multiple bone metastatic lesions, 18F-FDG PET/CT showed no uptake or osteolytic destruction in both cases. INTERVENTIONS: Weekly paclitaxel was initiated as a salvage chemotherapy in both cases. OUTCOMES: No uptake or osteolytic lesions were observed on 18F-FDG PET/CT, despite multiple bone metastases detected on MRI. LESSONS: False-negative findings on 18F-FDG PET/CT should be considered when evaluating bone metastases of angiosarcoma. Even with negative findings on 18F-FDG PET/CT, open biopsy should be performed if MRI indicates bone metastases.

Hip Transposition Can Provide Early Walking Function After Periacetabular Tumor Resection: A Multicenter Study.

BACKGROUND: Reconstruction after periacetabular bone tumor resection involves important tradeoffs; large bone grafts or endoprostheses are reported to offer fair walking function in general but can be technically demanding and carry a high risk of severe complications. Conversely, hip transposition avoids implant-related risks, but stability and functional return may be less consistent. Fewer studies are available on hip transposition, which is also appealing in more resource-constrained environments, and little is known about the time course from surgery to functional return after hip transposition. QUESTIONS/PURPOSES: (1) What is the time course of recovery of walking function after hip transposition, especially in the first 6 months? (2) What factors are associated with a greater likelihood of early functional recovery? (3) Is early (2-month) functional recovery associated with a greater likelihood of walking ability and higher Musculoskeletal Tumor Society (MSTS) scores? METHODS: Between 2009 and 2019, six tertiary care centers in Japan treated 48 patients with internal hemipelvectomy for malignant tumors. During that time, the preferred reconstructive approach was hip transposition, and 92% (44 of 48) of our patients were treated with this procedure. Among them, 86% (38 of 44) had follow-up of at least 6 months, had no local recurrence during that time, and were included in our retrospective study. We chose 6 months as the minimum follow-up duration because the endpoints in this study pertained to early recovery rather than reconstructive durability. Hip transposition involved moving the proximal end of the femur (femoral head, resection end of the trochanteric area, and spacers such as prostheses) upward to the underside of the resected ilium or the lateral side of the sacrum if sacroiliac joint resection was performed. The end of the proximal femur was stabilized to the remaining ilium or sacrum using polyethylene tape, polyethylene terephthalate mesh, an iliotibial tract graft, or an external fixator, according to the surgeon's preference. The median age at surgery was 46 years (range 9 to 76 years), there were 23 women and 15 men, and the median follow-up duration was 17 months (range 6 to 110 months). The postoperative time course of functional recovery was assessed with a record review, the timing of functional milestones was identified (wheelchair, walker, bilateral crutches, single crutch or cane, and walking without an aid), and the MSTS score at the final follow-up was assessed. Additionally, demographic and surgical factors were reviewed, and their association with short-term functional recovery and the final functional outcome was analyzed. RESULTS: Patients started using a walker at median postoperative day (POD) 20 (IQR 14 to 36) and with bilateral crutches at median POD 35 (IQR 20 to 57). At POD 60, which was the approximate median date of discharge, 76% (29 of 38) of patients were able to walk using bilateral crutches (the early recovery group) and 24% (nine of 38) of patients were not able to do so (the delayed recovery group). No baseline factors were different between the two groups. The early recovery group had a higher median MSTS score than the delayed recovery group: 57% (range 17% to 90%) versus 45% (13% to 57%) (p = 0.047). Moreover, more patients acquired better function (a single crutch or cane or more) in the early recovery group, with a median of 5 months (95% CI 4 to 11) than did those in the delayed recovery group (median not reached) (p = 0.0006). The HR was 15.2 (95% CI 2.5 to 93). Forty-two percent (16 of 38) underwent additional surgery for wound management. CONCLUSION: It took patients a fair amount of time to recover walking function after hip transposition, and patients who could not walk on bilateral crutches at POD 60 seemed less likely to regain walking function and were likely to have lower MSTS scores thereafter. Wound-related complications were frequent. This method may be a realistic alternative for younger patients who have the strength for a long rehabilitation period or those who want to minimize prosthesis-related complications. Future studies with more patients are necessary to understand the risk factors associated with delayed recovery.Level of Evidence Level III, therapeutic study.

[Symptomatic Epilepsy].

The notion of symptomatic epilepsy was historically reviewed. The structural etiologies of epilepsy include cerebrovascular diseases, neurodegenerative diseases, neoplasms, and traumatic brain injuries. Infections are the most common etiology worldwide. Metabolic epilepsy directly results from a known or presumed metabolic disorder. Immune epilepsy occurs because of autoimmune-mediated central nervous system inflammation.

Clinical characteristics of sarcoma cases in which long-term disease control was achieved with trabectedin treatment: A retrospective study.

Trabectedin is a therapeutic option for patients with advanced sarcoma. While a randomized trial demonstrated its prolonged progression-free survival (PFS), the reported PFS was <6 months. Some patients can achieve long-term disease control with this treatment. However, the reference information is insufficient. Herein, we retrospectively reviewed 51 sarcoma patients who received trabectedin. We analyzed the clinicopathological features, trabectedin dose, administration schedule, and clinical outcomes, including the overall response rate (ORR) and PFS. Among them, we assessed the detailed data of patients who achieved long-term disease control (PFS >1 year). The ORR in the 49 evaluable patients was 8%, and the median PFS in 51 patients was 7.5 months. Six patients (12%) achieved PFS of >1 year. Five of the six patients had metastatic lesions at trabectedin initiation. The pathological subtypes were myxoid liposarcoma (n = 2), leiomyosarcoma (n = 2), synovial sarcoma (n = 1), and Ewing sarcoma (n = 1). The final administration dose was the minimum dose (0.8 mg/m2) in two patients who continued the treatment over 20 cycles. The best radiological response was partial response (PR) in two myxoid liposarcoma patients and stable disease in four. The durations from trabectedin initiation to the first response in the two PR cases were 163 and 176 days, respectively. Our results support the validity of continuing trabectedin at a sustainable dose and interval in patients who can tolerate it. These results may be useful when considering the clinical application of trabectedin.

Complications and Functional Outcome Differences in Carbon Ion Radiotherapy and Surgery for Malignant Bone Tumors of the Pelvis: A Multicenter, Cohort Study.

BACKGROUND: Carbon ion radiotherapy (CIRT) is an evolving treatment option for malignant pelvic tumors in patients with poor surgical indications. However, the difference in complications and functional outcomes between CIRT and surgery is poorly understood. This study compares the complications and functional outcomes of CIRT and surgery to facilitate treatment selection. METHODS: A total of 28 patients who underwent CIRT for pelvic bone tumors while theoretically meeting the surgical resection criteria were included. Sixty-nine patients who underwent surgery for pelvic bone tumors were included as controls. Major complication rates and functional outcomes (ambulatory, pain, urination, constipation) were evaluated and compared at several time points (pretreatment, discharge, and final follow-up) between the groups. RESULTS: Early (within 90 days) major complications were not observed in the CIRT group but occurred in 30% of the surgery group, which was statistically significant (P < 0.001). In contrast, late (after 90 days) major complications occurred more often in the CIRT group than in the surgery group (18% and 4%, respectively; P = 0.042). From pretreatment until discharge, all functional outcomes in the surgery group deteriorated (P < 0.001 for all) but did not change in the CIRT group (P = 0.77-1.00). At the final follow-up, all functional outcomes showed no significant intergroup difference (P = 0.28-0.92) due to the recovery trend in the surgery group and the deterioration trend in the CIRT group. CONCLUSIONS: Compared with surgery, CIRT may have favorable safety and stable functional outcomes in the short-term but more late complications. Mid-term functional outcomes were similar between the groups.

Dedifferentiation in low-grade osteosarcoma: a Japanese Musculoskeletal Oncology Group (JMOG) study.

BACKGROUND: Low-grade osteosarcomas, namely parosteal osteosarcoma (POS) and low-grade central osteosarcoma (LGCOS), occasionally dedifferentiate into high-grade malignancy, referred to as dedifferentiation in low-grade osteosarcoma (DLOS). This study aimed to elucidate the clinicopathologic features of DLOS, which are poorly described to date due to the extreme rarity of the disease. METHODS: A total of 33 patients with DLOS were included. Clinical characteristics, including the diagnostic accuracy of tumor biopsy, multimodal treatments, and clinical course, were retrospectively reviewed. Univariate analysis was performed to identify prognostic factors associated with overall survival (OS) and metastasis-free survival (MFS). RESULTS: The tumor subtypes comprised 10 cases (30.3%) of LGCOS and 23 cases (69.7%) of POS. The timing of dedifferentiation was synchronous in 25 (75.8%) and metachronous in 8 (24.2%) patients. The rates of preoperative diagnosis of DLOS were 40.0% and 65.4% for core needle biopsy and incisional biopsy, respectively. All patients underwent surgery and 25 patients received perioperative chemotherapy. Of the 13 patients who received neoadjuvant chemotherapy, 11 exhibited a poor histological response. The 5-year OS and MFS rates were 88.1% and 77.7%, respectively. Univariate analysis revealed that local recurrence was associated with poor OS (P < 0.01) and MFS (P < 0.01). Perioperative chemotherapy did not affect OS or MFS. CONCLUSIONS: The diagnostic accuracy of tumor biopsy for DLOS was lower than that for bone sarcomas, as reported previously. In contrast to conventional osteosarcomas with high chemosensitivity, both histological responses and survival analysis revealed low efficacy of chemotherapy for DLOS.

Clinical Outcome of Patients with Pelvic and Retroperitoneal Bone and Soft Tissue Sarcoma: A Retrospective Multicenter Study in Japan.

This study aimed to retrospectively analyze the clinical outcomes of patients with pelvic and retroperitoneal bone and soft tissue sarcoma (BSTS). Overall, 187 patients with BSTS in the pelvis and retroperitoneal region treated at 19 specialized sarcoma centers in Japan were included. The prognostic factors related to overall survival (OS), local control (LC), and progression-free survival (PFS) were evaluated. The 3-year OS and LC rates in the 187 patients were 71.7% and 79.1%, respectively. The 3-year PFS in 166 patients without any distant metastases at the time of primary tumor diagnosis was 48.6%. Osteosarcoma showed significantly worse OS and PFS than other sarcomas of the pelvis and retroperitoneum. In the univariate analyses, larger primary tumor size, soft tissue tumor, distant metastasis at the time of primary tumor diagnosis, P2 location, chemotherapy, and osteosarcoma were poor prognostic factors correlated with OS. Larger primary tumor size, higher age, soft tissue tumor, chemotherapy, and osteosarcoma were poor prognostic factors correlated with PFS in patients without any metastasis at the initial presentation. Larger primary tumor size was the only poor prognostic factor correlation with LC. This study has clarified the epidemiology and prognosis of patients with pelvic and retroperitoneal BSTS in Japan.

Pre-Treatment Neutrophil-to-Lymphocyte Ratio (NLR) as a Predictive Marker of Pazopanib Treatment for Soft-Tissue Sarcoma.

Pazopanib with trabectedin and eribulin is widely used to treat soft-tissue sarcoma (STS). We have shown that baseline neutrophil-to-lymphocyte ratio (NLR) may predict the efficacy and patient prognosis of eribulin. Changes in NLR, but not baseline NLR, can predict patient prognosis of trabectedin. However, prognostic factors of pazopanib for STS have not been identified. We present a retrospective analysis of 141 patients treated with pazopanib for recurrent or metastatic non-round cell STS. Univariate and multivariate analyses were performed to determine the predictive factors of durable clinical benefit (DCB), overall survival (OS), and progression-free survival. L-sarcoma histology (odds ratio [OR] = 0.31, 95% CI = 0.12-0.79; p = 0.014) and pre-treatment NLR < 3.0 (OR = 2.03, 95% CI = 1.02-6.67; p = 0.045) were independent predictive factors of DCB. Pre-treatment NLR < 3.0 (hazard ratio [HR] = 0.55, 95% CI = 0.36-0.84; p = 0.0057), liposarcoma histology (HR = 1.78, 95% CI = 1.09-2.91; p = 0.022), primary extremity site (HR = 0.48, 95% CI = 0.31-0.75; p = 0.0010), ECOG PS ≥ 1 (HR = 1.62, 95% CI = 1.08-2.42; p = 0.019), and CRP < 0.3 (HR = 0.52, 95% CI = 0.33-0.82; p = 0.0050) were independent predictive factors of OS. These findings indicate that baseline NLR predicts the efficacy and patient prognosis of pazopanib for STS.

Platelet-derived lysophosphatidic acid mediated LPAR1 activation as a therapeutic target for osteosarcoma metastasis.

Osteosarcoma is the most common primary malignant bone cancer, with high rates of pulmonary metastasis. Osteosarcoma patients with pulmonary metastasis have worse prognosis than those with localized disease, leading to dramatically reduced survival rates. Therefore, understanding the biological characteristics of metastatic osteosarcoma and the molecular mechanisms of invasion and metastasis of osteosarcoma cells will lead to the development of innovative therapeutic intervention for advanced osteosarcoma. Here, we identified that osteosarcoma cells commonly exhibit high platelet activation-inducing characteristics, and molecules released from activated platelets promote the invasiveness of osteosarcoma cells. Given that heat-denatured platelet releasate maintained the ability to promote osteosarcoma invasion, we focused on heat-tolerant molecules, such as lipid mediators in the platelet releasate. Osteosarcoma-induced platelet activation leads to abundant lysophosphatidic acid (LPA) release. Exposure to LPA or platelet releasate induced morphological changes and increased invasiveness of osteosarcoma cells. By analyzing publicly available transcriptome datasets and our in-house osteosarcoma patient-derived xenograft tumors, we found that LPA receptor 1 (LPAR1) is notably upregulated in osteosarcoma. LPAR1 gene KO in osteosarcoma cells abolished the platelet-mediated osteosarcoma invasion in vitro and the formation of early pulmonary metastatic foci in experimental pulmonary metastasis models. Of note, the pharmacological inhibition of LPAR1 by the orally available LPAR1 antagonist, ONO-7300243, prevented pulmonary metastasis of osteosarcoma in the mouse models. These results indicate that the LPA-LPAR1 axis is essential for the osteosarcoma invasion and metastasis, and targeting LPAR1 would be a promising therapeutic intervention for advanced osteosarcoma.

Surgical Treatment of Intramuscular Myxoma.

PURPOSE: Intramuscular myxoma (IM) is a rare benign myxoid tumor that may be challenging to differentiate from sarcoma in small amounts of biopsied material. Although IM appears to be well-circumscribed macroscopically, it infiltrates the adjacent edematous muscle microscopically. The recommended treatment is resection, but there is controversy with regard to the appropriate surgical margin. This study aimed to clarify which surgical procedure that should be applied when the preoperative diagnosis is IM and how to manage treatment if the postoperative diagnosis turns out to be a sarcoma. METHODS: We retrospectively examined 55 IM patients treated from January 1982 to December 2014. Patient characteristics, tumor location, tumor size, radiograph, preoperative and postoperative pathological reports, surgical techniques, treatment outcome, and complications were reviewed. The patients were followed up on for at least 5 years. All patients were confirmed not to have Mazabraud syndrome. RESULTS: In the 55 IM patients examined, the mean patient age was 48 years and most were female. The most common tumor locations were in the muscles of the thighs (47%) and buttocks (20%). The mean tumor diameter was 5 cm. Wide resection and marginal resection were performed in 24 and 31 patients, respectively. The mean follow-up duration was 19 years. No local recurrence, malignant transformation, or complications were observed. CONCLUSIONS: Marginal resection is suitable in patients whose preoperative diagnosis is IM, as it is able to prevent local recurrence and allows for the preservation of muscle and muscle fascia. If the postoperative diagnosis turns out to be myxoid sarcoma, minimum surgical contamination makes additional wide resection less invasive.

The Clinical Features of Multicentric Extra-abdominal Desmoid Tumors.

Background: Extra-abdominal desmoid tumors often occur in the necks, shoulder, chest wall, back, arm, buttock, thigh and leg. Multicentric extra-abdominal desmoids are rather rare and seem to have other clinical features. The aim of our study was to investigate clinical features, especially multicentric occurrence of extra-abdominal desmoid tumors. Patients and Methods: A total of 135 patients diagnosed with extra-abdominal desmoid were enrolled in this study from January 2005 to December 2019 at the Cancer Institute Hospital of The Japanese Foundation for Cancer Research. The operative procedure was principally wide excision. The clinicopathological factors [e.g., age, gender, pain, restriction of range of motion (ROM), tumor site, tumor size, surgical margin, multicentric occurrence, local recurrence, tumoral regression] were collected and assessed by univariate analysis. We assessed how multicentric occurrence influenced clinicopathological factors of desmoid tumors. Results: The median follow-up was 39.9 months (range=0.29-259 months). Among 135 patients, 20 had multicentric occurrence. Multicentric extra-abdominal desmoids occurred in the neck in six cases, shoulder in four, chest wall in three, back in three, thigh in two and leg in two. In the case of multicentric occurrence on thighs and legs, tumors arose not in the anterior compartment but in the posterior compartment. Univariate analysis showed association of multicentric extra-abdominal desmoids with high local recurrence (p=0.0003), restriction of ROM (p=0.0012) and tumor size larger than 5 cm (p=0.04) but surgical margins were not correlated with local recurrence (p=0.37). Conclusion: Surgery should be performed in those who have severe pain or restriction of ROM. A 'Wait and see' policy is a first-line management, especially for those with multicentric extra-abdominal desmoids.

Definitive surgery of primary lesion should be prioritized over preoperative chemotherapy to treat high-grade osteosarcoma in patients aged 41-65 years.

BACKGROUND: Recently, the number of osteosarcomas in middle-aged and older patients has demonstrated an increasing trend; moreover, their results are comparatively worse than those of young patients. In Europe and the USA, the prognosis for osteosarcoma in middle-aged and older patients has improved with adjuvant chemotherapy. In Japan, however, the prognosis has remained poor. MATERIALS AND METHODS: We retrospectively analyzed the outcomes of osteosarcoma, especially in regards to preoperative chemotherapy, from January 1980 to July 2014. A total of 29 patients with high-grade osteosarcoma between the age of 40 and 65 years were included. We included patients without distant metastasis and with primary lesions that were deemed resectable. The mean age was 52.8 years (range 41-65 years), and the mean follow-up period was 103.2 months (range 5-314 months). RESULTS: Adjuvant chemotherapy was administered to 27 of 29 patients (93%), and 8 of 15 cases (53%) were able to undergo preoperative chemotherapy as planned, including CDDP. A major complication of chemotherapy was acute kidney injury due to CDDP (26%). The 5-year OS and 5-year EFS were 64.9% and 57.1%, respectively. After 2006, a policy to prioritize the resection of the primary lesion was implemented, and if the primary lesion was deemed resectable, preoperative chemotherapy was either not administered or administered for only a short duration. The 5-year OS after 2006 improved to 78.8%. CONCLUSIONS: This study shows that administration of high-dose intensity preoperative chemotherapy was difficult in middle-aged and older patients due to their high rate of acute kidney injury by CDDP. For cases of osteosarcoma in middle-aged and older patients, if the primary lesion is resectable, preoperative chemotherapy should be minimized to prioritize the resection of the primary lesion. It was considered that, with appropriate measures to prevent complications, adjuvant chemotherapy may lead to improved prognosis. LEVEL OF EVIDENCE: V.

Simultaneous bifocal and asymptomatic intramuscular nodular fasciitis of the thigh: A case report.

Nodular fasciitis (NF) is a rapid-growth benign that is misdiagnosed as sarcoma and leads to overtreatment. The spontaneous regression of NF is a possible phenomenon. "Wait and see" ideal is one of the treatment strategies of NF.

The Role of Neoadjuvant Chemotherapy in Resectable Primary Synovial Sarcoma.

BACKGROUND: The role of neoadjuvant chemotherapy for localized synovial sarcoma is still controversial. This study aimed to explore the influence of neoadjuvant chemotherapy combined with surgery in localized synovial sarcoma through analysis of our hospital's patient records. PATIENTS AND METHODS: A total of 122 patients diagnosed with synovial sarcoma were enrolled in this study from January 1980 to December 2016 at the Cancer Institute Hospital of The Japanese Foundation for Cancer Research. The impact of neoadjuvant chemotherapy on overall survival was assessed to show how clinicopathological factors (e.g. age, tumor size, treatment, dose intensity, pathological pattern and histological grading) influenced patient prognosis. RESULTS: Among 106 patients, 76 (71.7%) received neoadjuvant chemotherapy and 30 (28.3%) did not. The median follow-up was 39.2 (range=12-286) months. The 5-year and 10-year overall survival rates were 65.4% and 58.4% respectively. The tumor size and histological grade influenced the patient's overall survival (p<0.05). Among the patients with grade 2 tumor, tumor size did not influence prognosis. Neoadjuvant chemotherapy improved the overall survival of patients who had grade 3 tumors. CONCLUSION: Treatment with neoadjuvant chemotherapy proved beneficial for high-risk patients with grade 3 synovial sarcoma but was not effective for those with low-risk and grade 2 tumor. Tumor size and histological grade were important factors in patient prognosis but had no connection with pathological patterns.

The Extracompartmental Tumoral Invasion of Extraskeletal Myxoid Chondrosarcoma Induces Distant Metastasis.

BACKGROUND: Extraskeletal myxoid chondrosarcoma (EMC) is a rare malignant soft-tissue tumor and often shows extracompartmental tumoral invasion. The aim of our study was to investigate the clinical features, especially extracompartmental tumoral invasion (ETI) of EMC. PATIENTS AND METHODS: A total of 35 operative patients diagnosed with EMC were enrolled in this study from January 1980 to March 2018 in the Cancer Institute Hospital of The Japanese Foundation for Cancer Research. The operative procedure was principally wide excision. Univariate analysis assessed how clinicopathological factors (e.g. age, gender, tumor site, tumor size, histopathological grade, surgical margin, metastasis before operation, barrier invasion, local recurrence, metastasis after operation) influenced patient prognosis. We assessed how clinicopathological factors influenced ETI of EMC. RESULTS: Among 35 patients, 10 patients showed ETI. The average follow-up was 5.57 (range=0.2-20 years). The 5- and 10-year overall survival was 91.3% and 71.2%, respectively. The 5- and 10-year overall survival of patients with M0 disease was 96.1% and 73.2%, respectively, while both were 75.0% for those with M1 disease, respectively. The patients with distant metastasis at first visit tended to have a poor prognosis (p=0.07). It is notable that all of the 10 patients with ETI had distant metastasis after surgery. CONCLUSION: Patients with distant metastasis at first visit tended to have a poor prognosis. ETI of EMC induced distant metastasis after surgery. Patients with ETI of EMC should, therefore, be carefully monitored over a prolonged period.

The long noncoding RNA Crnde regulates osteoblast proliferation through the Wnt/ß-catenin signaling pathway in mice.

In the past decade, a growing importance has been placed on understanding the significance of long noncoding RNAs (lncRNAs) in regulating development, metabolism, and homeostasis. Osteoblast proliferation and differentiation are essential elements in skeletal development, bone metabolism, and homeostasis. However, the underlying mechanisms of lncRNAs in the process of osteoblast proliferation and differentiation remain largely unknown. Through comprehensive analysis of lncRNAs during bone formation, we show that colorectal neoplasia differentially expressed (Crnde), previously viewed as a cancer-related lncRNA, is an important regulator of osteoblast proliferation and differentiation. Crnde was found to be expressed in osteoblasts, and its expression was induced by parathyroid hormone. Furthermore, Crnde knockout mice developed a low bone mass phenotype due to impaired osteoblast proliferation and differentiation. Overexpression of Crnde in osteoblasts promoted their proliferation, and conversely, reduced Crnde expression inhibited osteoblast proliferation. Although ablation of Crnde inhibited osteoblast differentiation, overexpression of Crnde restored it. Finally, we provided evidence that Crnde modulates bone formation through Wnt/ß-catenin signaling. Therefore, our data suggest that Crnde is a novel regulator of bone metabolism.

The Size of Intramedullary Fixation Affects Endochondral-Mediated Angiogenesis During Fracture Repair.

OBJECTIVES: To explore the effect of intramedullary pin size on the biology of a healing fracture, specifically endochondral angiogenesis. We hypothesized that fracture fixation with a smaller pin would permit greater interfragmentary strain resulting in increased total amount of vascular endothelial growth factor within the callus and greater angiogenesis compared to fixation with a larger pin. METHODS: Transverse mid-shaft femur fractures in 8-week-old mice were fixed with either a 23-gauge (G) or 30-G pin. Differences in interfragmentary strain at the fracture site were estimated between cohorts. A combination of histology, gene expression, serial radiography, and microcomputed tomography with and without vascular contrast agent were used to assess fracture healing and vascularity for each cohort. RESULTS: Larger soft-tissue callus formation increased vascular endothelial growth factor-A expression, and a corresponding increase in vascular volume was observed in the higher strain, 30-G cohort. Radiographic analysis demonstrated earlier hard callus formation with greater initial interfragmentary strain, similar rates of union between pin size cohorts, yet delayed callus remodeling in mice with the larger pin size. CONCLUSIONS: These findings suggest that the stability conferred by an intramedullary nail influences endochondral angiogenesis at the fracture.

Platelet-Derived TGF-ß Induces Tissue Factor Expression via the Smad3 Pathway in Osteosarcoma Cells.

Over the last three decades, the prognosis of osteosarcoma has remained unchanged; the prognosis for patients with lung metastasis is still poor, and the development of new treatments is urgently required. We previously showed that aggressive osteosarcoma cells express more tissue factor (TF) and demonstrate enhanced extrinsic pathway capacity. Furthermore, tumor growth can be suppressed with the anticoagulant low molecular weight heparin. However, the molecular mechanisms underlying TF regulation are still unclear. Here, we report that transforming growth factor-ß (TGF-ß) upregulates TF, which can occur via activated platelets. TF was found to be expressed on osteosarcoma cell surfaces, which mediated the production of Xa and thrombin. TF induction by TGF-ß was observed in several osteosarcoma cells, and especially in MG 63 cells. Both TF expression by TGF-ß and extrinsic pathway activity through TF were rapidly increased. This reaction was inhibited by a TGF-ß type I receptor inhibitor and TGF-ß neutralizing antibody. Although TGF-ß was found to phosphorylate both Smad2 and Smad3, their roles were markedly disparate. Surprisingly, Smad2 knockdown resulted in no inhibitory effect, whereas Smad3 knockdown completely suppressed TGF-ß-induced TF expression. Next, data suggested that platelets were the source of TGF-ß. We confirmed that thrombin-activated platelets and osteosarcoma cells could release TGF-ß, and that platelet-derived TGF-ß could induce TF expression. These processes were also inhibited by a TGF-ß type I receptor inhibitor and Smad3 knockdown. Moreover, CD42b, TF, TGF-ß, Smad2/3, and p-Smad2/3 were also detected in a biopsy sample from an osteosarcoma patient. Collectively, these finding suggested that the interaction between osteosarcoma cells and platelets, via thrombin and TGF-ß, results in a continuous cycle, and that anti-platelet or anti-TGF-ß therapy could be a promising tool for disease treatment. © 2018 American Society for Bone and Mineral Research.

Autologous chondrocyte grafting promotes bone formation in the posterolateral spine.

BACKGROUND CONTEXT: Pseudarthrosis following spinal fusion remains problematic despite modern surgical and grafting techniques. In surgical spinal fusion, new bone forms via intramembranous and endochondral ossification, with endochondral ossification occurring in the hypoxic zones of the fusion bed. During bone development and fracture healing, the key cellular mediator of endochondral ossification is the hypertrophic chondrocyte given its ability to function in hypoxia and induce neovascularization and ossification. We therefore hypothesize that hypertrophic chondrocytes may be an effective bone graft alternative. PURPOSE: Spinal fusion procedures have increased substantially; yet 5% to 35% of all spinal fusions may result in pseudoarthrosis. Pseudoarthrosis may occur because of implant failure, infection, or biological failure, among other reasons. Advances in surgical techniques and bone grafting have improved fusion; however pseudarthrosis rates remain unacceptably high. Thus, the goal of this study is to investigate hypertrophic chondrocytes as a potential biological graft alternative. METHODS: Using a validated murine fracture model, hypertrophic chondrocytes were harvested from fracture calluses and transplanted into the posterolateral spines of identical mice. New bone formation was assessed by X-ray, microcomputed tomography (µCT), and in vivo fluorescent imaging. Results were compared against a standard iliac crest bone graft and a sham surgery control group. Funding for this work was provided by the Department of Orthopaedics and Rehabilitation, the OREF (Grant #16-150), and The Caitlin Lovejoy Fund. RESULTS: Radiography, µCT, and in vivo fluorescent imaging demonstrated that hypertrophic chondrocytes promoted bone formation at rates equivalent to iliac crest autograft. Additionally, µCT analysis demonstrated similar fusion rates in a subset of mice from the iliac crest and hypertrophic chondrocyte groups. CONCLUSIONS: This proof-of-concept study indicates that hypertrophic chondrocytes can promote bone formation comparable to iliac crest bone graft. These findings provide the foundation for future studies to investigate the potential therapeutic use of hypertrophic chondrocytes in spinal fusion.