K. Nishitani

070 AGE-RELATED BEHAVIOR OF COLLAGEN AND PROTEOGLYCAN IN SUPERFICIAL, MIDDLE AND DEEP ZONES OF PATELLAR CARTILAGE: FOURIER TRANSFORM INFRARED SPECTROSCOPY (FTIR) ANALYSIS OF NORMAL RABBITS

Purpose: To detect the collagen content and proteoglycan content in the superficial, middle and deep zones of articular cartilage is a trend but still technical challenge. Fourier transform infrared spectroscopy (FTIR) is powerful tool to investigate the collagen and proteoglycan in cartilage matrix. The FTIR quantifies the collagen content and proteoglycan content on histologic sections of cartilage. Because the FTIR maps the distribution of collagen and proteoglycan on the sections, the collagen and proteoglycan can be analyzed in the superficial, middle and deep zones of cartilage. Age-related behavior of the collagen and proteoglycan in each zone of patellar cartilage has not been reported yet. Therefore, the objective of this pilot study is to investigate the behavior of the collagen and proteoglycan in each zone using the FTIR. Methods: Non-treated five rabbits of various ages (3-week, 8week, 6-month, 1-year, 2.5-year) were examined. Specimens of patella were removed from each rabbit and all specimens were observed macroscopically and confirmed that the cartilage surface was smooth and glossy. Specimens were then prepared and sagittal sections were cut for histology and for the FTIR. The sections stained with safranin-O/fast green were observed using a light microscopy and confirmed that no fibrillation or no degenerative change had occurred. The sections for the FTIR were not stained. The integrated area of collagen Amide I (wave, 1590-1720 cm-1) was defined as collagen content. The integrated area of proteogly-

095 THE ULTRASOUND CAN EVALUATE MACROSCOPICALLY UNDETECTABLE CARTILAGE DEGENERATION IN RABBIT OSTEOARTHRITIS MODEL

Purpose: Early diagnosis of osteoarthritis is important, although the diagnostic method is not fully established yet. In our group, ultrasound cartilage evaluation system has been developed in order to examine material properties of the articular cartilage. The ultrasound reflected wave correlates the macroscopic osteoarthritis progression (ICRS grade). In this study, we investigated whether ultrasound has the potential to detect the macroscopically undetectable cartilage degeneration with rabbit osteoarthritis model. Methods: This investigation was approved by the Animal Research Center of our university. Eighteen female Japanese white rabbits were used. Under general anesthesia, a medial parapatellar incision was made to expose the bilateral knee joint, and the patella was laterally dislocated. Then, the both anterior cruciate ligaments were exposed and the left anterior cruciate ligament transection (ACLT) was performed and instability was manually confirmed. The patella was reduced, and joint capsule and skin were closed. The rabbits were sacrificed at 1, 2, 4, 12 weeks after the operation and 4 rabbits were assigned for each group. Two untreated rabbits were used as 0 week control. The lateral femoral chondyle (LFC) was evaluated in this study. The cartilage was scored macroscopically from 0 (intact) to 4 (massive cartilage defect) by two investigator. The mechanical properties of the cartilage were measured with our ultrasound cartilage evaluating system with wavelet transform method. The maximum magnitude of the reflected wave from the surface of the articular cartilage was defined as signal intensity. The paraffin section of the LFC was stain with safranin-O/fast green, haematoxylin/eosin (HE) and evaluated. The data was statistically analyzed with Mann-Whitney U test or Student T test appropriately. P < 0.05 was set to significant difference. Results: The macroscopic score of the left LFC (ACLT) was median: 0 (minimum: 0maximum: 0) at 0, 1 and 2 weeks, 0.5 (0-1) at 4 weeks and 2.25 (1-3) at 12 weeks. The score of the right LFC (sham) was 0 (00) at 0, 1 and 2 weeks, 0 (0-0.5) at 4 weeks and 0.5 (0.0-0.5) at 12 weeks. At 12 weeks, there was significant difference between the macroscopic score of the left (ACLT) and the right (sham). The signal intensity of the left knee was decreased as the time going. At 2 weeks, the signal intensity of the left (ACLT) and right (sham) were 0.74±0.20 and 1.19±0.29, respectively (p < 0.05). There were significant differences between the signal intensity of the left (ACLT) and the right (sham) at 2, 4, and 12 weeks. In the histology of the left LFC, slight fibrillation and decrease of safranin/O staining were observed at 2 weeks. At 12 weeks, the cartilage of the left LFC resulted in osteoarthritic change with severe fibrillation, cell clustering and decrease of safranin/O staining. Conclusions: Although there was no macroscopic change at 2 weeks, the signal intensity of the anterior cruciate ligament transection knee was significantly decreased (38% decrease to sham). At 2 weeks, the cartilage degeneration was already observed in the histology. The ultrasound analysis has the possibility to detect the very early change of the osteoarthritis. 096

454 ULTRASOUND PROPERTIES OF ARTICULAR CARTILAGE IN PATELLOFEMORAL JOINT IN KNEE OSTEOARTHRITIS: DIFFERENCE BETWEEN THE INTERNATIONAL CARTILAGE REPAIR SOCIETY GRADE-0 AND GRADE-1

Greater change in the enthalpy was observed in osteoarthritic cartilage: −1414.78 J/g compared to 1357.70 J/g in avascular necrosis. Consequently these samples required larger amount of energy for decomposition. Statistical tests proved these calculations to be significant (p< 0.05). All samples showed a clear denaturation peak on the calorimetric curve. Conclusions: This study clarifies the previously reported thermoanalytical results, with acquiring normal cartilage from live surgery, thus providing similar sample environment. The use of DSC as part of thermal analysis was a reliable method for differentiating osteoarthritic hyaline cartilage from necrotic samples. All samples showed a clear denaturation peak on the calorimetric curve, therefore volume of the curve was easily calculated giving the enthalpy change of the sample. These changes correlated with the water content of the samples. The calorimeter that was available for use proved to be adequate for these measurements. The use of thermal analysis could be a simple and effective method for differentiating between pathological disease progression. The relationship between the different pathomorphologic influences, and the role extracellular matrix homeostasis will be necessary to reveal potential targets of therapy. While there is rapid progress in understanding the complexities of joint diseases a simple basic research technique like thermal analysis can be an effective method for controlling the relationship between biomarkers and disease progression.

P140 Intraoperative acoustic evaluation of living cartilage of the elbow and knee during mosaicplasty for osteochondritis dissecans of the elbow

Intraoperative acoustic evaluation of living cartilage of the elbow and knee during mosaicplasty for osteochondritis dissecans of the elbow K. Nishitani, Y. Nakagawa, T. Gotoh, K. Mori, M. Kobayashi, H. Kuroki, K. Yasura, Y. Okamoto, T. Nakamura; Orthopaedic Surgery, Graduate school for Medicine, Kyoto University, Kyoto, Japan, Department Of Orthopaedic Surgery, Faculty Of Medicine, Kyoto University, Kyoto, Japan, Department Of Orthopaedic Surgery, Otsu Red Cross Hospital, Otsu, Japan, Department Of Applied Medical Engineering Science, Graduate School of Medicine, Yamaguchi University, Ube, Yakaguchi, Japan, Orthopaedic Surgery, Kyoto University, Kyoto, Japan, Department Of Physical Therapy, School of Health Sciences, Faculty of Medicine, Kyoto University, Kyoto, Japan, Department Of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan