The giant cell tumor of bone (GCT) is a locally aggressive intraosseous neoplasm, with an uncertain biological behavior, constituted of giant multinuclear cells spread over tumoral tissue with a nucleus presenting the same features of the ovoid and fusiform cells forming its stroma. The local recurrence of GCT is often observed, mainly in the first three years after treatment, giving a rate of recurrence ranging in 20 to 50% of cases. Further aggravating the recurrence is the fact that after the relapse, the patient often also presents metastases in other organs.

The aim of this study was to identify and to characterize differentially expressed genes that can be used in the prognostic, treatment and understanding of this physiopathology. To identify novel genes differentially expressed in GCT, we have applied rapid subtractive hybridization (RaSH). Samples of GCT and normal tissues were obtained at Tumor Bank of Barretos Cancer Hospital. After RNA extraction and cDNA synthesis the samples were submitted to Rapid hybridization Subtraction (RaSH) methodology for subtractive libraries elaboration.

The RaSH subtractive libraries reveals the presence of 619 different clones including both normal and tumor tissues were identified. Of these, 450 in tumor sample and 169 in control tissue. Four biomarkers candidates were selected for validation: ZAK, KTN1, NEB, and ROCK1 genes, whose functions are, related to cell cycle checkpoint, transport of organelles, cytoskeletal matrix and cell adhesions. The validation of selected differentially expressed genes was performed using real time PCR. The putative molecular markers found in this work may help to find the basis for a molecular comprehension of GCT, thus improving diagnosis, treatment and outcome for patients with this tumor.

Aims: Numerous techniques for subtalar arthrodesis have been described, with intraarticular and extraarticular methods. The purpose of this paper is to show our results with subtalar arthrodesis with arthroscopic technique.

Methods: We reviewed 30 subtalar fusions and followed 26 patients (20 females and 6 males, average age 56,3 years) for an average of 48 months.

The preoperative diagnosis was primary arthrosis in 19 cases, arthrosis secondary to trauma in 7 cases and subtalar instability secondary to neuropathic conditions in 4 cases. Patients are placed in a prone position. All arthroscopic procedures were done with non-invasive distraction, thigh tourniquet. Two portals, one each side of Achilles tendon, 2,5-3,0 cm above the junction of posterosuperior surface of the calcaneus and the Achilles tendon. A 4,0 mm 30 degree oblique arthroscope and a rotatory 4mm burr were used. Fixation was done with dynamic cannulated screw from calcaneus into talus.

Results: Fusion occurred in all cases. Using the American Orthopaedic Foot and Ankle Society (AOFAS) scored system the patients averaged is 92,7. Twenty four patients (92,3%) were satisfied and two are not satisfied (7,7). No Complications were reported. All patients wore normal shoes.

Conclusions: Arthroscopic subtalar arthrodesis and open arthrodesis have similar results, with less morbidity in first one. It can be the chirurgical technique of choice for subtalar arthrodesis in all cases without hind-foot malalignment requiring correction.