Objective: To establish reference values for the femoral condylar cartilage thickness and to observe the cartilage clarity and sharpness between different age groups of healthy Koreans employing a ultrasonographic scanner. Method: 105 healthy volunteers from the ages of twenties to the fifties, without clinical signs of osteoarthritis were recruited for the study. Cartilage thickness at both intercondylar notch, medial condylar and lateral condylar area were obtained with 12 MHz linear transducer, in supine position under maximum flexion of the knee joints. Cartilage sharpness and clarity were also recorded in grade between 0 to 3. Results: The thickness of cartilage significantly decreased with the increment of age (p＜0.05) and the cartilage of the man was much thicker than woman (p=0.000). Grade of the sharpness and clarity was not different between age groups and the checked grade was mostly grade 1 and there was no grade 3. Conclusion: This study defines standard reference values of femoral condylar cartilage for musculoskeletal ultrasonography to prevent misinterpretation of thinning of cartilage thickness in difference age groups and sex. With these findings, we can specify the range of normal degenerative change of femoral condylar cartilage. (J Korean Acad Rehab Med 2008; 32: 703-710)

Objective
Although the clinical effects of prolotherapy on osteoarthritis has been reported, there have been few previous studies showing the effects as a proliferant on articular cartilage. Also the autologous blood has been reported to used as a growth factor stimulant recently, we were trying to use dextrose and autologous serum for tissue regeneration respectively and evaluated the proliferative effect of autologous serum comparing with that of dextrose. Method: Twenty four rabbits were used for this study. The rabbits were divided into three groups. Group A did not get any special treatment. Group B was treated with 10% dextrose and group C with autologous serum. Six weeks la-ter, gross appearance and histologic findings were evaluated. Results: After sacrifice, the gross inspection of the knee joints revealed that group B and C were filled with the translucent tissue in defective cartilage. Group A still had defective cartilage. Histologic evaluation revealed increase of cellularity in the defect of the injected specimens when compared with the control. There was no morphological difference between group B and C. Conclusion: The repair process of the articular cartilage defects using dextrose and autologous serum were shown to be more effective than that of control group. (J Korean Acad Rehab Med 2006; 30: 173-178)

Objective
To evaluate the effects of proliferant by injecting blood into the articular cartilage defect. Method: The patella of rabbits were dislocated laterally and 2 mm circular and 2 mm depth full-thickness defect was made in the articular cartilage. We injected 0.2 cc autologous blood to the right defect and normal saline to the left one at 1 week after operation for six times with a 1 week interval. After injection for six weeks, the articular cartilage defect were obtained and stained with H-E and S-100. Results: The surface of the saline-injected group was easily distinguishable from the surrounding articular cartilage. But the blood-injected group had similar appearance to the surrounding cartilage, with the margin of the defect barely discerptible. Strong S-100 stained immune cartilage cells were observed in the blood-injected group. Conclusion: The repairing process of the injured articular cartilage using autologous blood was shown to be much better than that of saline-injected group although the observation period was short and the number of animal was small. So we found that autologous blood effectively repaired osteochondral defects. (J Korean Acad Rehab Med 2005; 29: 406-412)