Immunohistochemical Staining for Type II Collagen in Regenerated Cartilage after Microfracture Surgery / 대한정형외과연구학회지

PURPOSE: The purpose of this study is to identify nature of regenerated articular cartilage after microfracture surgery. MATERIALS AND METHODS: From Oct. 1997 to Nov. 1998, 40 knees were treated for osteoarthritis by arthroscopic microfracture technique. In the 18 knees, during the second arthroscopic procedure, biopsy specimens extending to the subchondral bone were taken and immunohistochemical staining was done to identify type of collagen. One patient was man and 17 patients were women. Average age of the patients were 58 years (range, 40-75 years). RESULTS: Type II collagen in articular cartilage appeared to be brown color with this staining. Degree of staining were +3 in 4 knees(22%), +2 in 2 knees(11%), +1 in 7 knees(39%) and trace in 5 knees(28%). CONCLUSION: Microfracture surgery restores the function of the joint by forming predominantly hyaline-like cartilage containing type II collagen. As analyzing amounts of type II collagen with an immunohistochemical staining in regenerated cartilage, we can presume the prognosis of regenerated cartilage tissue after microfracture surgery.

What is the Cause of Signal Inhomogeneity at the Carotid Bifurcation During Contrast Enhanced Carotid MRA?: In Vivo and in Vitro Studies

PURPOSE: To evaluate the hemodynamic causes of signal inhomogeneity at the carotid bulb that might be misinterpreted as pathologic signal defect in carotid contrast enhanced MRA(CEMRA). MATERIALS AND METHODS: Both carotid CEMRA and fast digital subtraction angiography(DSA) were conducted on 15 patients (28 carotid arteries) and arterial phase CEMRA images were compared with fast DSA images of the same patients. A 1.5T MR imager was used. The Turbo-FLASH sequence emplayed was TR/TE/FA= 3 .2m s / 1.3m s / 35 degree. For experimental study, we utilized handmade silicon phantoms of the tortuous carotid bifurcation; these might be expected to clearly demonstrate turbulent flow at the carotid bulb. In a closed circulatory system, both CEMRA and fast DSA involved the use of these phantoms. RESULTS: During CEMRA, inhomogeneous signals of varying degrees were found at the carotid bulb in 12/28 carotid arteries. When compared with sequential DSA images, incomplete mixing of contrast agent due to turbulent flow at the carotid bulb might be responsible for this inhomogeneity. This hypothesis was reinforced by successfully reproducing signal defects at the carotid bulb from the experimental CEMRA study using carotid phantoms that showed marked turbulent flow in the same area during DSA. CONCLUSION: Incomplete mixing of contrast agent caused by turbulent flow at the carotid bulb might be responsible for the signal inhomogeneity seen on carotid CEMRA.