BACKGROUND: A new classification system for juxta-articular osteosarcoma around the knee joint was developed to allow biological reconstructions using distraction osteogenesis or frozen autograft containing tumors treated with liquid nitrogen. Type I: Tumor has metaphyseal extension to a maximum of 2 cm from the epiphyseal cartilage plate. Type II: Tumor extends to at least half the circumference of the epiphyseal ... Read more

BACKGROUND:We tested the efficacy of 4 local agents for protection against tumor growth after tumor contamination and tumor bloc inoculation. MATERIALS AND METHODS: Tumors were prepared by injecting human HT-1080 fibrosarcoma cells into the subcutaneous tissue of 6-9 -week- old male athymic nude mice (BALB/c nu/nu). When the tumors reached the desired size, the nude mice were sacrificed, and the ... Read more

STUDY DESIGN: Morphometric changes of the spinal cord and influence on spinal cord-evoked potentials and spinal cord blood flow and postoperative function of hind limbs were studied in various degrees of acute spinal column shortening in dogs. OBJECTIVES: To study the morphometric and physiologic effects of acute spinal column shortening on the spinal cord. SUMMARY OF BACKGROUND DATA: The technique ... Read more

Although frequently encountered, no available consensus about the association between skeletal abnormalities and skin pigmentation. Several syndromes are characterized by the presence of skin pigmentation in association with skeletal disorders like neurofibroamtosis 1, McCune-Albright Syndrome, Jaffe-Campanacci Syndrome and Jaffe-Lichtenstein Syndrome. Even in the absence of these syndromes, skeletal abnormalities were detected in all radiologically examined patients having patterned skin pigmentation. ... Read more

Spondylectomy for extripation of spinal tumors would be performed through piecemeal excision or by total _en bloc_spondylectomy with cutting at the neural arch by the threadwire saw (T-saw) that is sometimes inevitably intralesional.The purposeof this study was to compare the potential for tumor growth after rubbing of the cut surface of tumors cut by either T-saw or blunt instrument againstthe ... Read more

Bony abnormalities are common findings in cases of neurofibromatosis 1. We might hypothesize that neurofibromin, the protein encoded by the neurofibromatosis 1 gene, plays important roles in bone development. Loss of function of oligodendrocyte-myelin glycoprotein gene and increased activity of ras p21 might increase the level of c-fos proto-oncogene in bones with formation of fibrous dysplasia-like tissue. Also, increased ras ... Read more

We might hypothesize that the high rate of pseudarthrosis after spinal fusion for neurofibromatous scoliosis is related to two factors: the absence of neurofibromin and melatonin deficiency. Loss of the up-regulation of neurofibromin during the healing process might abolish the bone-forming effects mediated through platelet-derived growth factor (PDGF) and transforming growth factor (TGF) beta1. The absence of neurofibromin might cause ... Read more

Fibrous dysplasia of bone might be monostotic, polystotic, or occurs as a part of McCune-Albright syndrome and Jaffe-Lichtenstein syndrome. Activating mutations of GNAS1 gene was identified in patients with fibrous dysplasia. However, fibrous dysplasia might occur in the absence of these mutations and fibrous dysplastic tissue was produced in vitro by the effects of excess exogenous cAMP on human osteogenic ... Read more

Deformity combined with shortening of 18 lower limb segments of 17 patients was treated with the Ilizarov method. Limb lengthening was done at the same treatment (monofocal treatment) or a separate osteotomy (bifocal treatment) was done after acute or gradual correction of the deformity using the Ilizarov hinge system. The external fixation time, amount of deformity correction, length gained, and ... Read more

Osteomalacia is rarely encountered in association with neurofibromatosis 1, characterized by phosphate loss in the urine and its pathogenesis is still unknown. Incidence of spinal deformities in cases of neurofibromatosis 1 associated with osteomalacia seems to be high. Spinal deformities are unlikely to be due to osteomalacia itself. Melatonin deficiency was proposed to be present in cases of neurofibromatosis 1 ... Read more