ElsevierActa Medica Okayama0949-26582422019A rare manifestation of extraskeletal myxoid chondrosarcoma with a huge expanding hematoma377381ENToshinoriOmoriDepartment of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical SciencesTomohiroFujiwaraDepartment of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical SciencesToshiyukiKunisadaDepartment of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical SciencesKenTakedaDepartment of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical SciencesJoeHaseiDepartment of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical SciencesAkiYoshidaDepartment of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical SciencesHiroyukiYanaiDepartment of Diagnostic Pathology, Okayama University HospitalToshifumiOzakiDepartment of Orthopaedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical SciencesNo potential conflict of interest relevant to this article was reported. ElsevierActa Medica Okayama0949-26582422019Mini-open excision of osteoid osteoma using intraoperative O-arm/Stealth navigation337341ENTomohiroFujiwaraDepartment of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical SciencesToshiyukiKunisadaDepartment of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical SciencesKenTakedaDepartment of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical SciencesJoeHaseiDepartment of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical SciencesEijiNakataDepartment of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical SciencesYusukeMochizukiDepartment of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical SciencesMasahiroKiyonoDepartment of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical SciencesAkiYoshidaDepartment of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical SciencesToshifumiOzakiDepartment of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical SciencesBackground</br>
Although osteoid osteomas have traditionally been treated by surgical excision, radiofrequency ablation (RFA) has gained favor as a less invasive procedure. However, RFA is contraindicated for osteoid osteomas close to the skin or crucial neurovascular structures, and is not covered by national health insurance in Japan. The aim of the present study was to evaluate the efficacy of surgical excision of osteoid osteomas using intraoperative navigation.</br>
Methods</br>
We performed a retrospective review of five patients with osteoid osteoma who underwent a mini-open excision using O-arm/Stealth navigation at our institution. The osteoid osteomas were excised using a cannulated cutter or curetted out with the assistance of navigation.</br>
Results</br>
Complete excision was achieved in all patients, which was confirmed by pathological examination. The mean skin incision was 2.1 cm (range, 1.5 to 3.0 cm) and the mean duration required for setup three-dimensional image was 15 min (range, 12 to 20 min). Although the mean visual analog scale score was 7 (range, 4 to 8) before surgery, all patients experienced relief from their characteristic pain immediately after surgery, with the mean scores of 2.2 (range, 1 to 3) and 0 at 2 days and 4 weeks after surgery, respectively. There was no intra-operative complication related to the navigation and no recurrence was observed during the mean follow-up period of 25 months (range, 13 to 33 months).</br>
Conclusions</br>
Mini-open excision using intraoperative O-arm/Stealth navigation is a safe and accurate procedure for patients with osteoid osteoma, which could cover the limitation of RFA.No potential conflict of interest relevant to this article was reported.Okayama University Medical SchoolActa Medica Okayama0386-300X6632012Statistical Analysis of Prognostic Factors for Survival in Patients with Spinal Metastasis213219ENMasakiKataokaToshiyukiKunisadaMasatoTanakaKenTakedaSatoruItaniYoshihisaSugimotoHaruoMisawaMasuoSendaShinnosukeNakaharaToshifumiOzakiOriginal Article10.18926/AMO/48560There are a variety of treatment options for patients with spinal metastasis, and predicting prognosis is essential for selecting the proper treatment. The purpose of the present study was to identify the significant prognostic factors for the survival of patients with spinal metastasis. We retrospectively reviewed 143 patients with spinal metastasis. The median age was 61 years. Eleven factors reported previously were analyzed using the Cox proportional hazards model:gender, age, performance status, neurological deficits, pain, type of primary tumor, metastasis to major organs, previous chemotherapy,
disease-free interval before spinal metastasis, multiple spinal metastases, and extra-spinal bone metastasis. The average survival of study patients after the first visit to our clinic was 22 months. Multivariate survival analysis demonstrated that type of primary tumor (hazard ratio [HR]6.80, pƒ0.001), metastasis to major organs (HR2.01, p0.005), disease-free interval before spinal metastasis
(HR1.77, p0.028), and extra-spinal bone metastasis (HR1.75, p0.017) were significant prognostic factors. Type of primary tumor was the most powerful prognostic factor. Other prognostic
factors may differ among the types of primary tumor and may also be closely associated with primary
disease activity. Further analysis of factors predicting prognosis should be conducted with respect to each type of primary tumor to help accurately predict prognosis.No potential conflict of interest relevant to this article was reported.