Analysis of Survival and Prognostic Factors in Patients of Pulmonary Metastasis from Osteosarcoma / 대한정형외과학회잡지

PURPOSE: We analyzed survival rates and the prognostic factors of pulmonary metastases from osteosarcoma. MATERIALS AND METHODS: Between 1989 and 2001, of 312 patients who were diagnosed and treated for osteosarcoma in our institute, 35 patients with pulmonary metastases were included in the present study. We examined the overall survival rates and analyzed prognostic factors, such as age, gender, chemotherapeutic response, number of the pulmonary lesions, and disease-free interval. RESULTS: Overall 3-year and 5-year survival rates were 62.3% and 39.3%. Patients treated with thoracotomy and chemotherapy seemed to survive longer than patients without thoracic surgery. In the thoracostomy group, the degree of tumor necrosis after neoadjuvant chemotherapy, the number of metastatic nodules, and the tumor free interval were meaningful factors of survival. CONCLUSIONS: In osteosarcoma with pulmonary metastasis, complete metastatectomy and intensive postoperative chemotherapy can improve survival in selected patients.

Significance of the Methylation of Cyclin-Dependent Kinase Inhibitor 2A gene in the Prognosis of Osteosarcoma / 대한정형외과학회잡지

PURPOSE: The methylation status of the CpG promoter regions of the p16INK4A and p14ARF genes, mutations of 4 exons of the CDKN2A gene, and the expression of the corresponding proteins were examined. Prognostic implications were assessed in osteosarcoma. MATERIALS AND METHODS: Methylation-specific PCR, sequence analysis, and immunohistochemical staining were performed upon 32 frozen osteosarcoma tissues. RESULTS: Methylation of p16INK4A was found in 16%, and methylation of p14ARF in 47%. Metastasis and poor survival was statistically related to the methylation of p14ARF. The methylation of p14ARF correlated with the repression of the corresponding protein, and repression of p14ARF with the repression of p21 and of wild type of p53. No sequence alterations were found in the four exons of the CDKN2A gene. Methylation of p14 showed highest hazard ratio by multivariate survival analysis. CONCLUSION: Our data suggest that methylation of the CDKN2A gene seems to be the main mechanism of protein repression. For p14ARF, the methylation of its promoter region was related to the repression of p21 and wild type p53, distant metastasis and a poor prognosis. Further study regarding cell cycle regulatory factors should shed light on oncogenesis and the possibility of a new treatment strategy for osteosarcoma.

The Changes in the Removal Torque of Screws after Local Heating / 대한정형외과연구학회지

PURPOSE: The extraction of well-fixed metallic implants can be extremely demanding and time consuming, resulting in damage surrounding bone. Therefore, a less traumatic method of removing a well-fixed implant from bone is necessary. Our hypothesis was that a well-fixed implant can be extracted more easily if it is heated to a high temperature. The present study was conducted to evaluate the effect of local heating on the removal torque of well-fixed titanium screws. MATERIALS AND METHODS: A titanium screw (2.7 mm diameter, 12 mm length) was bilaterally inserted into the distal femur of 14 New Zealand White rabbits at identical locations. Five rabbits were sacrificed at 8 weeks, and 9 rabbits were sacrificed at 20 weeks after screw insertion. Both femurs were harvested, and screw removal torques were measured using a torque gauge. Before removal, the screws in right femurs were heated with an electric soldering iron and then cooled with dry ice, whereas screws in the left femur were removed without heating. After removing the screws, Hematoxylin & Eosin staining was performed to allow the histological assessment of bone tissues around the implants, and picrosirius red F3BA staining was performed to assess the extent of bone damage. Statistical differences between the heat treated and untreated groups were determined using the Wilcoxon Signed Ranks test and differences with respect to the duration of implantation were evaluated by the Mann-Whitney test. A p value of & .05 was considered to be significant. RESULTS: The removal torques for the heated screws were significantly lower than those for the non-heated screws for both 8 and 20 weeks groups. For non-heated screws, removal torques for the screws implanted 20 weeks was significantly higher than those of the screws implanted for 8 weeks (p & .05). H & E staining showed that the screw-bone interface was denatured in heat treated group. Polarized microscopy after picrosirius red F3BA staining showed that the collagen in the thermally damaged region had denatured, resulting in a loss of its natural birefringence. The maximal depth of the thermally damaged region from the screw/bone interface was less than 400 micrometer. CONCLUSION: Controlled local heating may be a less traumatic method of removing a well-fixed implant from bone.

Reconstruction of Proximal Femoral Bone Loss using Autogenous Unicortical Iliac Bone Plate in Revision Hip Arthroplasty / 대한정형외과학회잡지

PURPOSE: Since 1995, we have reconstructed defects of the proximal femoral bone with the autogenous unicortical iliac bone by revision hip arthroplasty. We report the preliminary results of this method. MATERIALS AND METHODS: Among cases of revision hip arthroplasty reconstructed with autogenous unicortical iliac bone graft between March 1995 and December 1997, we studied 45 cases, which had been followed for more than 2 years. The loss of femoral bone was classified using AAOS classification. Twenty four cases belonged to level 1, segmental type and 21 cases belonged to level 1, segmental with level 2 cavitary type. We documented the healing process of grafted bone by simple radiography every 6 months and evaluated clinical results by Harris scoring. RESULTS: The average Harris score improved from 67.2 to 79.5. Radiological union was found at an average 4.5 months, and complete union at an average 19 months. There were 2 cases of loosening, 4 prolonged pain on the bone-harvested site, 3 trochanteric nonunion, one sciatic nerve palsy and one pulmonary embolism. CONCLUSION: Small sized defects of the proximal femur are reconstructed satisfactorily by using autogenous unicortical iliac bone graft in revision hip arthroplasty.

Clinical Application of Unilateral-Ring Hybrid Fixation Using DynaExtor(R) / 대한정형외과학회잡지

PURPOSE: We have used a hybrid fixation, in which DynaExtor(R) and Ilizarov rings are connected each other with special connectors. Here, we report upon the technical tips learned and the clinical outcomes of the first twenty five consecutive cases treated using this method. MATERIALS AND METHODS: Between May 1997 and December 1999, 25 patients were treated using hybrid fixation aimed at simple lengthening (8 patients), concomitant deformity correction and lengthening (12), deformity correction alone (3), and fracture fixation (2). RESULTS: In the group requiring simple lengthening, the healing index (H.I.) was 38.3 day/cm (23.6-66.8 day/cm). For concomitant deformity correction and lengthening, the mean amount of angular correction was 33.8degrees (15-75degrees) and the length gain, 4.7 cm (2.2-8.9 cm). For deformity correction alone, the amount of angular correction was 50.1degrees (15-120degrees). For fracture fixation, the mean external fixation time was 59.5 days (26-93 days). Complications included mild pin-tract infection in 8 patients, a temporary stiff joint in 5, and equinus of the foot and delayed union in one patient each. CONCLUSION: The DynaExtor(R) hybrid-fixation system is an effective and convenient method that can be selectively applied to cases that need deformity correction, lengthening, or fixation of the long bone.

Clinical Features of Metastatic Spine Tumor and Needs for Surgical Treatment / 대한척추외과학회지

STUDY DESIGN: A retrospective study. OBJECTIVES: To analyze the clinical features of spinal metastasis, and to evaluate what is the most appropriate treatment. SUMMARY OF LITERATURE REVIEW: Severe pain and neurological compromise induced by metastatic spine tumors deteriorates the quality of life. Surgical treatment may improve the quality of life effectively. MATERIALS AND METHODS: Between January 1995 and May 1999, we studied 61 patients diagnosed for spinal metastasis, and followed for more than 1 year or to their death. They were divided into three groups, such as surgery group, radiotherapy group, and other conservative therapy group. The results were evaluated with Turgut classification for functional status, WHO analgesics cascade for pain grading, and Frankel classification for neurological symptoms. RESULTS: Forty nine patients were followed to death. The average of survival time was 15 months, and it depends on the histology of primary tumor. In the review of treatment methods, non-operative treatment was preferred by medical oncologist in majority of cases. Eleven patients were treated surgically, and their pains and neurological symptoms were improved in varing degrees. But in case of posterior decompression alone, pain was not relieved. Surgical decompression with stabilization was effective for pain and neurological symptoms. In 50 patients, radiotherapy or other conservative therapy was applied, but results were not satisfactory. CONCLUSION: In view of the quality of life, surgical treatment should be considered in more cases of patients suffering from severe pain and neurological symptoms caused by metastatic spine tumor.

Tracing Study on Neuroaxis of Medial Rectus Muscle in the Brain Stem of the White Rat

To clarify neuronal connection of the medial rectus muscle at brain stem, Bartha strain of the psecudorabies virus(PRV-Ba) and cholera toxin-horeserdish peroxidase(CT-HRP) was injected into medial rectus muscle of the rat. About 84 hours after PRV or CT-HRP injection, the brain was removed and processed immunohistochemical stain for PRV-Ba and neurohistochemical stain for CT-HRP using tetramethyl benzidine. The CT-HRP positive reaction was only present in ipsilateral oculomotor nucleus, contralateral abducence nucleus and bilaterally in rostral interstitial nucleus of medial longitudinal fasciculus, olivary pretectal nucleus, medial and superior vestibular nucleus, nucleus prepositus hypoglossi, prerubral field, nucleus Darkschewitsch, lateral substantia nigra, terminal nucleus of accessory nucleus, dorsal raphenucleus, locus ceruleus and pontime reticular formation. This study confirmed that both oculomotor nucleus and abducence nucleus were connected with each other through the medial longitudinal fasciculus, and neuronal connection of the medial rectus muscle in the rat brain stem.