The relationship between different tourniquet pressures in total knee arthroplasty and the pain and swelling of the affected limb after surgery / 医学研究生学报

ABSTRACT

Objective The use of tourniquets in total knee arthroplasty has been controversial. Many studies have focused only on the different time courses and neglected the effects of pressures. Currently,there is no study explaining the mechanism of tourniquet-induced injury. The aim of this study was to explore the effects of different tourniquet pressures on pain and swelling after total knee arthroplasty and to explore the mechanism of injury. Methods Ninety-six patients who underwent total knee arthroplasty at Nanjing General Hospital from June 2017 to December 2017 were randomly as-signed to 240 mmHg group (low pressure),270 mmHg group (medi- um pressure),and 300 mmHg group (high pressure). The patient's pain and thigh circumference were measured before and 1-2 days after surgery. Blood samples were taken before and 3,8,and 24 hours after surgery. Superoxide dismutase 1 (SOD1),prostaglandin E2 (PGE2) and myoglobin were detected,analysed and compared. Results In the perspective of the pain and swelling of affected limb after surgery,the 300 mmHg group (73.24±10.51) was significantly different from the 240 mmHg group (58.18±9.66) and the 270mmHg group (63.06±10.06). In the perspective of the SOD1 level in serum,the 300mmHg group (97.77±13.82) was significant-ly different from the 240mmHg group (63.72±15.02) and the 270 mmHg group (70.58±5.85) at 3h after surgery,and then the diver-gence was gradually decreased. In the perspective of the PGE2 level in serum,the 300 mmHg group (478.05±35.80) was significantly different from the 240mmHg group (334.42±33.12) and the 270mmHg group (391.85±19.41) at 3h after surgery,and the divergence was started to decrease after 8 h. In the perspective of the myoglobin level in serum,the 300 mmHg group (30.43±9.79) was also sig-nificantly different from the 240 mmHg group (17.58±1.93) and the 270 mmHg group (22.28±4.21) at 8 h after operation,the diver-gence was started to decrease after 24 h. which began to decrease after 24 h. Correlation analysis showed that there was a significant cor-relation between pain (correlation coefficient 0.518,P<0.001),swelling (correlation coefficient 0.345,P<0.05) and stress after sur-gery. Conclusion The pain and swelling of the affected limb is positively correlated with the pressure of the tourniquet during the operation. Muscle necrosis is the main mechanism of the injury. Oxidative stress occurs in the ischemic phase and inflammation occurs in the reperfusion phase.