Won Jong Bahk

A case of pulmonary metastasis of giant cell tumor of bone presenting as pulmonary arteriovenous malformation.

Although giant-cell tumor (GCT) of the bone was originally classified as a benign tumor, metastasis has been reported. The radiographic features usually comprise parenchymal solitary or multiple nodules that are round-to-oval nodular opacities of homogeneous density in patients with GCT. However, the patient described in this case presented with a hypervascular mass with feeding vessels and hemothorax, which are common features of pulmonary arteriovenous malformation. To the best of our knowledge, cases of pulmonary metastases presenting as a pulmonary arteriovenous malformation have not been reported. Here, we report a case of giant-cell tumor of the bone that exhibited histologically benign pulmonary metastases and mimicked an arteriovenous malformation.

Preventive and Mitigative Effects of Alendronate on Osteolysis induced by Particulate Debris: Quantitative and Comparative Analysis Using Mouse Calvarial Model

Purpose: Wear particle induced osteolysis is a serious complication in total joint arthroplasty. The purpose of this study was to compare the preventive and mitigative effects of alendronate on particle induced osteolysis among particles using mouse calvarial model. Materials and Methods: Seventy-two mice were randomized into sham group, Ti6Al4V group, CoCr-Mo group and Ultra High Molecular Weight Polyethylene (UHMWPE) group according to the particles treated to the calvarial tissues. Each group was divided into control subgroup which received no alendronate, preventive subgroup which received alendronate for 4 weeks after particle distribution and therapeutic subgroup which received alendronate for 3 weeks after 1 week delay from particle distribution. We evaluated the effects quantitatively using histomorphometry. Number of osteoclast, fibrous thickness, eroded bone surface area, bone thickness and bone volume were measured and compared. Results: Alendronate showed significant preventive and mitigative effects on osteolysis induced by Ti6Al4V particles and showed significant preventive and somewhat less mitigative effect on osteolysis by CoCrMo particles. On UHMWPE particles, alendronate showed no preventive and mitigative effects. Conclusion: Alendronate may be useful in preventing osteolysis induced by metal particles but had no effect on ostelysis induced by UHMWPE particles.

Bone Formation of Cultured Osteoblasts in Bone Defect of Radial Shaft of Rabbit

Purpose: To evaluate the osteogenic potential of an autologous cultured osteoblast transplant to the bone defects. Materials and Methods: Radial bone defects over 15 mm were made in 20 New Zealand white rabbits using the anterior approach. There were 10 rabbits in the control group, which underwent an iliac bone graft to the preformed bone defect 3 weeks from the initial operation. There were 10 rabbits in the experimental group that underwent an autologous cultured osteoblasts injection. After 9 weeks, both groups were compared radiologically and histologically. Results: The osteogenesis in both groups were progressed similarly and there was no difference in terms of the amount of bone formation and the duration of the bone union. Conclusion: An autologous cultured osteoblast transplant to the bone defect produces bone efficiently. In addition, it can be applied to a wide field, which requires a bone grafting operation.

Anterior Cruciate Ligament Reconstruction Using a Contralateral Hamstring Tendon Graft in Combined Anterior Cruciate and Medial Collateral Ligament Injury

Purpose : We reviewed the results of a series of patients with combined anterior cruciate ligament and medial collateral ligament injury who received nonoperative management of medial collateral ligament with anterior cruciate ligament reconstruction using a contralateral hamstring tendon graft. Materials and Methods : From May 2000 to June 2001, 12 cases (20-46 years; mean, 35 years) were available for follow-up (12-23 months; mean, 16.7 months) with combined anterior cruciate ligament and medial collateral ligament injury that underwent anterior cruciate ligament reconstruction alone using a contralateral hamstring tendon graft. Follow-up evaluation involved; KT-2000 arthrometer testing, valgus stress testing and the International Knee Documentation Committee (IKDC) evaluation form. Results : Mean side to side difference of manual maximum anterior displacement using the KT-2000 arthrometer was 1.75 mm. All cases showed a firm end point by the valgus stress test. At the final IKDC evaluation, 2 cases were graded as normal, 8 nearly normal, 1 abnormal and 1 severely abnormal. The donor site result of the IKDC evaluation form showed normal in 8, nearly normal in 3 and abnormal in 1. Conclusion : These results demonstrate the effectiveness of ACL reconstruction alone using the contralateral hamstring tendon graft as an autograft in combined ACL and MCL injury, which was found to restore satisfactory stability with minimal complications at both injured and donor sites.