3D imaging and stealth navigation instead of CT guidance for radiofrequency ablation of osteoid osteomas: a series of 52 patients.

BACKGROUND: Osteoid osteomas are benign bone neoplasms that may cause severe pain and limit function. They are commonly treated by radiofrequency ablation (RFA) through a needle inserted into the nidus of the lesion under CT guidance, which is associated with exposure of young patients to relatively high dose of radiation. The objective of this study was to investigate the amount of radiation, effectiveness and safety of an alternative imaging approach, the 3D image-guided (O-arm) technology and the Stealth navigation. METHODS: We retrospectively reviewed 52 electronic medical files of patients (mean age 24.7 years, range 8-59 years) who were treated with thermal ablation of benign osteoid osteomas guided by the navigated O-arm-assisted technique in our institution between 2015 and 2017. Data were extracted on the associated complications, the reduction in pain at 3 months and one year postoperatively, and the amount of radiation administered during the procedure. RESULTS: The level of pain on a visual analogue scale decreased from the preoperative average of 7.73 to 0 at the 3-month follow-up. The mean dose-length product was 544.7 mGycm2 compared to the reported radiation exposure of 1971-7946 mGycm2 of CT-guided radio ablations. The one intra-operative complication was a superficial burn in the subcutaneous lesion in a tibia that was treated locally with no major influence on recovery. CONCLUSIONS: RFA ablation guided by 3D O-arm stealth navigation is as effective as the traditional CT-guided technique with the advantage of lower radiation exposure. TRIAL REGISTRATION: Retrospective study number 0388-17-TLV at Tel Aviv Sourasky Medical Center IRB, approved at 25.10.17.

Hip arthroscopy as a treatment for obturator neuropathy secondary to intra-pelvic ganglion: a case report.

The most common types of cystic lesions around the hip joint are synovial or ganglion cysts. In rare cases, the cysts can compress adjacent structures and cause symptoms to arise. Obturator neuropathy secondary to a hip ganglion cyst is a rare phenomenon, with scarce reports on suggested treatment options. Hip arthroscopy is a potential minimally invasive treatment that has yet to be described in such cases. We present a 52-year-old male suffering from obturator neuropathy caused by an intra-pelvic ganglion cyst arising from the hip joint. Hip arthroscopy was performed for decompression of the cyst and dilation of the stalk opening. Six-month post-operative follow-up showed resolution of symptoms and complete elimination of the cyst on magnetic resonance imaging.

Simultaneous pigmented villonodular synovitis and synovial chondromatosis of the hip: case report.

This report presents a case of a 37-year-old female with a history of hip pain. Magnetic resonance arthrography revealed loose bodies within the joint and synovial hypertrophy indicative of synovial chondromatosis (SC). Hip arthroscopy revealed free chondral bodies and focal villonodular synovial proliferation. The focal synovial proliferation was excised, a total synovectomy performed, and all cartilaginous free bodies removed. A post-operative histological examination of the removed nodular mass and synovium yielded evidence of both SC and pigmented villonodular synovitis (PVNS). A 1-year post-operative clinical examination showed marked clinical improvement and no signs of recurrence on MR images. Despite the clinical similarities, PVNS and SC are two distinct conditions that, to our knowledge, have never been reported as simultaneously occurring in a hip joint. The simultaneous presence of both pathologies may suggest a common origin of synovial metaplasia.

ß-D-xylosides stimulate GAG synthesis in chondrocyte cultures due to elevation of the extracellular GAG domains, accompanied by the depletion of the intra-pericellular GAG pools, with alterations in the GAG profiles.

The familial disease of hereditary multiple exostoses is characterized by abnormal skeletal deformities requiring extensive surgical procedures. In hereditary multiple exostoses patients there is a shortage in the pericellular glycosaminoglycan (GAG) of heparan sulfate (HS), related to defective activity of HS glycosyltransferases, mainly in the pericellular regions of chondrocytes. This study searched for a novel approach employing xylosides with different aglycone groups priming a variety of GAG chains, in attempting to alter the GAG compositional profile. Cell cultures of patients with osteochondroma responded to p-nitrophenyl ß-D-xyloside by a significant increase in total GAG synthesis, expressed mainly in the extracellular domains, limited to chondroitin sulfate). The different ß-D-xylosides, in addition to increasing the synthesis of extracellular GAGs, led to a significant depletion of the intracellular GAG domains. In mouse chondrocyte cultures, ß-D-xylosides with different aglycones created a unique distribution of the GAG pools. Of special interest was the finding that the naphthalene methanol ß-D-xyloside showed the highest absolute levels of HS-GAGs in both extracellular and intra-pericellular moieties compared with other ß-D-xylosides and with controls without xyloside. In summary, ß-D-xylosides can be utilized in chondrocyte cultures to modify the distribution of GAGs between the extracellular and intracellular compartments. In addition, xylosides may alter the profile of specific GAG chains in each moiety.

Biological reconstruction of bone defects: the role of the free fibula flap.

This review describes the kinds of skeletal bone defects in bones which develop through enchondral ossification. It focuses on the biological reconstruction of those defects according to the two main subtypes, intercalary and osteoarticular. We list the causes of bone defects and outline the different types and configurations that result from them. We then review the currently available reconstructive options according to the patient's age and describe the theoretical options as well. Finally, the history, surgical anatomy and clinical use of the free fibula flap will be reviewed. From our own clinical experience and review of the literature, we conclude that biological reconstruction is, in many ways, superior to alloplastic materials, especially in children, adolescents and young adults.

Osteogenic sarcoma in a child with familial expansile osteolysis syndrome: an accidental association?

We present the first reported case of a child with familial expansile osteolysis syndrome (FEO) who developed osteogenic sarcoma (OS) of the iliac bone. A 17-year-old adolescent presented with pain and a mass on the left pelvis. He was from a family with several members who had been diagnosed with FEO, from which he also suffered. The median life expectancy of affected members of the family was reported as 25 to 30 years, with death ensuing as a result of various respiratory and cardiac complications of severe skeletal deformations, characteristic of increased bone turnover as seen in FEO. Biopsy of the patient's mass revealed chondroblastic OS. He was treated according to the P9754 protocol for patients with newly diagnosed nonmetastatic OS. Chemotherapy consisted of HD-MTX, ifosfomide, doxorubicin, and cisplatin. Complete resection of the tumor was carried out, but the patient subsequently developed metastatic disease and died (histologic response to neoadjuvant chemotherapy-85%). The patient's alkaline phosphatase level that was highly elevated before the start of chemotherapy, dropped significantly during treatment, with repeated elevation soon after definitive surgery, while he was recuperating and not on treatment. We speculate that chemotherapy affected not only the malignant cells of OS but normal osteoblasts as well, with a decreasing level of alkaline phosphatase even in the absence of any clinical and radiographic signs of OS. We also think that increased bone turnover, characteristic of a condition such as FEO, may facilitate de novo development of OS.

The molecular and cellular basis of exostosis formation in hereditary multiple exostoses.

The different clinical entities of osteochondromas, hereditary multiple exostoses (HME) and non-familial solitary exostosis, are known to express localized exostoses in their joint metaphyseal cartilage. In the current study biopsies of osteochondromas patients were screened with respect to a number of cellular and molecular parameters. Specifically, cartilaginous biopsy samples of nine HME patients, 10 solitary exostosis patients and 10 articular cartilages of control subjects were collected and cell cultures were established. Results obtained showed that one of the two HME samples that underwent DNA sequencing analysis (HME-1) had a novel mutation for an early stop codon, which led to an aberrant protein, migrating at a lower molecular weight position. The EXT-1 mRNA and protein levels in chondrocyte cultures derived from all nine HME patients were elevated, compared with solitary exostosis patients or control subjects. Furthermore, cell cultures of HME patients had significantly decreased pericellular heparan sulphate (HS) in comparison with cultures of solitary exostosis patients or control subjects. Immunohistochemical staining of tissue sections and Western blotting of cell cultures derived from HME patients revealed higher levels of heparanase compared with solitary exostosis patients and of control subjects. Further investigations are needed to determine whether the low pericellular HS levels in HME patients stem from decreased biosynthesis of HS, increased degradation or a combination of both. In conclusion, it appears that due to a mutated glycosyltransferase, the low content of pericellular HS in HME patients leads to the anatomical deformations with exostoses formation. Hence, elevation of HS content in the pericellular regions should be a potential molecular target for correction.

Does regular follow-up influence the survival of patients with sarcoma after recurrence? The Miri Shitrit pediatric oncology department experience.

Despite comprehensive management of pediatric sarcomas, only 60% to 70% of children become long-term survivors. This study was undertaken to evaluate whether regular follow-up improves overall survival of children with recurrent sarcomas. The medical charts of 107 children diagnosed with soft tissue and bone sarcomas were reviewed, of whom 29 relapsed. They were divided into 2 groups according to the way of relapse diagnosis: due to complaints/physical examination (14) or on routine imaging studies (15). All were followed by regular physical examination and imaging studies (chest computed tomography, magnetic resonance imaging, and bone scan/positron emission tomography-computed tomography scan with fluorodeoxyglucose) at regular intervals. Analysis of the results showed that (1) regular imaging studies do not facilitate earlier recognition of relapse in children with sarcomas; (2) regular follow-up with imaging studies does not influence overall survival of children with sarcomas; (3) other diagnostic and treatment approaches are needed to improve the survival of children with recurrent sarcomas.

The short-lived exostosis induced surgically versus the lasting genetic hereditary multiple exostoses.

Hereditary osteochondromas are often caused by mutation in the EXT1 gene. The lesions are typified by formation of a "pseudo" growth plate like lesion growing at 60 degrees to the normal growth direction of the bone. Such lesions can be mimicked surgically by reverting the position--the polarity of the zone of LaCroix. The current study attempts to compare the pathology between EXT1 gene expression in humans and surgically created osteochondroma pathology in a rat model. Tissues of human bunion, human embryonal tissue, and human adult cartilage as well as normal rat epiphyses served as controls. Rats were operated on and a 60 degree span of the ring of LaCroix was inverted as described by Delgado (Delgado, E., Rodriguez, J. I., Serada, A., Tellez, M., and Pariagoa, R.. Clin. Orthop. 201, 251-258 (1985)). The surgically created osteochondromas were assessed by histology, histochemistry, and immunohistochemistry. The findings show that the surgically created lesions contain only a small amount of FGF receptor 3 (FGFR3) expressed on mesenchymal stem cells located in the perichondrium, as compared to the cell population carrying FGFR3 in the contralateral limb. Indian hedgehog and Bcl2 are downregulated, while BMP-2 is overexpressed in the operated limb, compared to the LaCroix ring of the contralaetral limb. The shortage, as well as the disturbed migration routes of the residual mesenchymal stem cells in surgically created osteochondromas leads eventually to resorption of the pathological elements. In search of additional markers characterizing such pathological structures composed of mesenchymal stem cells and cartilaginous and bony cells, EXT1 gene was found to be expressed in the surgically created osteochondromas, like in normal growth plates. Nitric oxide synthase was also expressed like in adult cartilage, though tumor necrosis factor alpha typifying Bunion formation was absent. In summary, surgically created osteochondromas lack the massive and continuous population of mesenchymal stem cells with Bcl2 expression. However, the small residual mesenchymal cell population gives rise to short-lived EXT1-expressing cells that disappear eventually due to spontaneous resorption.