PURPOSE: To describe the HRCT and pathologic findings of squalene-induced lipoid pneumonia in rabbits. MATERIALS AND METHODS: Three ml of squalene was instilled into the trachea between the second and the third tracheal ring in 16 rabbits. Serial HRCT scans were obtained on day 4 (n=8), at 1 week (n=7), 2 weeks (n=1), 4 weeks(n=1), 6 weeks (n=2) and 20 weeks (n=1) after squalene instillation. With sacrifice of the rabbits pathology was reviewed at 1 week (n=3), 4 weeks (n=3), and 6 weeks (n=4) after CT scans. RESULTS: Lipoid pneumonia was induced in 8 rabbits; lesions were distributed mainly in the dependent posterior lung. On serial HRCT scans, airspace consolidation, as seen on an air-bronchogrm, and nodular opacities were early findings; these gradually diminshed and with time were replaced by nodular & linear opacities. Histologically, pulmonary fibrosis appeared one week after squalene instillation and progressed over time. Alveolar septal thickening and cuboidal change of the alveolar lining epithelium were more prominent at week 6. CONCLUSION: The early change of squalene-induced lipoidpneumonia in rabbits is the proliferation of intraalveolar macrophage, which is responsible for air-space consolidation with air-bronchograms on HRCT. Nodular and linear opacities on HRCT are due to the appearance of pulmonary fibrosis one week after squalene instillation, and its subsequent progression.
Animals ; Epithelium ; Lung ; Macrophages ; Pathology ; Pneumonia* ; Pulmonary Fibrosis ; Rabbits* ; Squalene ; Tomography, X-Ray Computed ; Trachea

PURPOSE: To evaluate the efficacy of arthroscopic synovectomy through the direct posterior-posterior approach in pigmented villonodular synovitis (PVNS) of the knee. MATERIALS AND METHODS: Between January 1997 and May 2004, twenty-one patients underwent an arthroscopic synovectomy for PVNS of knee. The mean follow-up period was 35 months. The arthroscopic and MRI findings revealed the localized form of PVNS in six patients and the diffuse form in fifteen patients. All patients underwent an arthroscopic examination and synovectomy through the direct posterior-posterior approach. The clinical results were evaluated by the range of motion, Lysholm knee score, and the knee pain score using the visual analogue scale (minimum 0-maximum 10). RESULTS: Among the fifteen cases with the diffuse form, three cases (14%) recurred and had secondary arthroscopic total synovectomy. One cases recurred again. Therefore, radiation therapy was performed. The Lysholm knee score improved from 62.5 to 87.3, and the VAS score improved from 5.9 to 1.8. Three patients had a mild limitation in knee motion. However, the others had full range of motion of the knee at the last follow-up. CONCLUSION: Arthroscopic synovectomy through the direct posterior-posterior approach could be a useful method for the treatment of PVNS of the knee, and can be used as an effective therapeutic tool particularly in posteromedial or posterolateral lesions.
Follow-Up Studies ; Humans ; Knee* ; Magnetic Resonance Imaging ; Range of Motion, Articular ; Synovitis, Pigmented Villonodular*