Objective The changes of the aquaporins 1 (AQP-1) expression may be related to the chondrocyte apoptosis. To explore the correlation between the expression of AQP-1 and chondrocyte apoptosis by observing the expression of the AQP-1 and the Caspase-3, so as to provide experimental evidence for the further study in the pathogenesis of osteoarthritis (OA). Methods Seventy-two 8-week-old clean grade male Sprague Dawley rats, weighing 286-320 g (mean, 300 g), were randomly divided into the operated group (n=24), the sham-operated group (n=24), and the control group (n=24).OA models were made by amputating the anterior cruciate l igament and medial collateral l igament, and partial excision of medial meniscus in operated group; the articular cavity was exposed only in sham-operated group; and no treatment was given in control group. The general condition of the rat was observed after model was establ ished. At 1, 2, 4, and 8 weeks, the specimens of knee joints were harvested to perform the gross and histological observations; the mRNA expressions of AQP-1 and Caspase-3 were determined by real-time fluorescent quantitative PCR; and the activity of the Caspase-3 protease was detected. The correlations between the expression of AQP-1 mRNA and the expressions of Caspase-3 mRNA and protease were analyzed. Results Totally 6 rats died after operation, and the rats were suppl ied immediately; the other rats survived to the end of experiment. The appearance and structure of knee articular cartilage were normal in control group and sham-operated group. While in operated group, the cartilage had a rough surface with fissure and vegetation, and fibrosis and irregular cell arrangement were seen on the surface of cartilage. There were significant differences in the Mankin score between the operated group and sham-operated group, control group at 2, 4, and 8 weeks (P lt; 0.05). There was no significant difference in expressions of the AQP-1 mRNA and Caspase-3 mRNA, and the activity of the Caspase-3 protease among 3 groups at 1 week after operation (P gt; 0.05); while the expressions of the AQP-1 mRNA, Caspase-3 mRNA, and the activity of the Caspase-3 protease in operated group were significantly higher than those in sham-operated group and control group at 2, 4, and 8 weeks after operation (P lt; 0.05), andthere was an increased trend over time. There was significantly positive correlation (r=0.817, P=0.000) between the expressions of AQP-1 mRNA and Caspase-3 mRNA, and the regression equation was y=0.426 7x2+0.051 5x; meanwhile, there was also significantly positive correlation (r=0.945, P=0.000) between the expression of AQP-1 mRNA and the activity of Caspase-3 protease, and the regression equation was y=15.423 0x+4.392 8. Conclusion The up-regulation of AQP-1 expression in OA cartilage may be related to the chondrocyte apoptosis, and the changes of AQP-1 expression may involve in the pathogenesis of OA.
Objective To investigate the causes and preventive methods of the bone cement leakage in percutaneous kyphoplasty (PKP) for osteoporotic vertebral body compression fracture (OVCF). Methods From April 2003 to November 2007, 116 patients with OVCF were treated with PKP, including 57 males and 59 females aged 65-92 years old (average 67.7 years old). All the patients suffered from trauma and the course of disease was 1-14 days (average 5.7 days). There were 159compressed and fractured vertebral bodies, including one vertebral body in 83 cases, two vertebral bodies in 24 cases, three vertebral bodies in 8 cases, and four vertebral bodies in 1 case. The diagnosis of OVCF was confirmed by imaging examination before operation. All the patients had intact posterior vertebral walls, without symptoms of spinal and nerve root injury. During operation, 3.5-7.1 mL bone cement (average 4.8 mL) was injected into single vertebral body. Results The operation time was 30-90 minutes (average 48 minutes). Obvious pain rel ief was achieved in all the patients after operation. X-rays examination 2 days after operation revealed that the injured vertebral bodies were well replaced without further compression and deformation, and the bone cement was evenly distributed. Fourteen vertebral bodies had bone cement leakage (4 of anterior leakage, 4 of lateral leakage, 3 of posterior leakage, 2 of intervertebral leakage, 1 of spinal canal leakage). The reason for the bone cement leakage included the individual ity of patient, the standardization of manipulation and the time of injecting bone cement. During the follow-up period of 12-30 months (average 24 months), all the patients got their normal l ife back, without pain, operation-induced spinal canal stenosis, obvious height loss of injured vertebral bodies and other compl ications. Conclusion For OVCF, PKP is a mini-invasive, effective and safe procedure that provides pain rel ief and stabil ization of spinal stabil ity. The occurrence of bone cement leakages can be reduced by choosing the suitable case, improving the viscosity of bone cement, injecting the proper amount of bone cement and precise location during operation.