Objective To study the effects of a self-controlled and totally-enclosed type perfusion skin and tissue expansion in which pressure was continuous and constant. Methods Totally-enclosed type perfusion system included single-used infusion apparatus, triplet, soft water storage bag, catheter, and common expander. Continuous pressure-constant system included inflatable infusion apparatus and common spring sphygmomanometer. Expander was filled from soft water storage bag which was put in inflatable infusion apparatus by crushed ball. The pressure of expander was controlled by patients according to pain threshold. 26 expanders were used in 20 patients in clinical practice. The volume of expander was about 100 ~ 400 ml. After 3~5 days from operation, water began to fill in the expander and stopped when the expansion area reached. Results The volume of expander was 120~640 ml and the duration of expansion was 10~16 days, average (13.6? 2.1) days, without any complication. Conclusions The tissue expansion with continuous and constant pressure and totally-enclosed perfusion is worth popularizing because of its easy preparation, simply operation, rapid expansion, safety and comfort.

Objective To evaluate the value of DTI in mild articular cartilage injury in patellofemoral joint.Methods The DTI and arthroscopy data of 82 patients wih routine MRI diagnosed as mild articular cartilage injury were analyzed retrospectively.According to the results of arthroscopy,40 cases of mild articular cartilage injury with Outerbridge classification Ⅰ or Ⅱ were divided into experimental group,and 33 cases with normal patellofemoral articular cartilage were divided into control group.There were 8 articular cartilage injury patients with Outerbridge classification Ⅲ or Ⅳ in patello-femoral join were excluded.The DTI data were analyzed compared with arthroscopy.Results Arthroscopy detected 62 lesions of cartilage injury in experimental group.Totally 49 lesions (49/62,79.03 ％) were detected by ADC pseudocolor image and 51 lesions (51/62,82.25 ％) were detected by FA pseudocolor image.The DTI pseudocolor images of articular cartilage injury showed uneven levels.The red or pink levels can been observed.Compared with the control group,ADC value increased and FA value decreased significantly in experimental group (both P＜0.05).Conclusion DTI can clearly display and detect mild articular cartilage injury in patellofemoral joint,which provide valuable information for early cartilaginous injury.