Effect of posterior root amputation on rabbit knee joint cartilage and proprioception

Objective:To Observe the characteristics of changes in the cartilage of the rabbit's knee joint after spinal nerve transection,as well as the influence of proprioceptors and proprioceptive pathways,and explore the relationship between proprioception disorder and knee osteoarthritis.Methods:According to the principle of random allocation,20 New Zealand white rabbits were divided into groups,9 in the control group and 11 in the model group.In the model group,the posterior roots of the L5-L6 spinal nerve were cut off using the posterior root cutting method,while the control group only cut the skin and paraspinal muscles.8 weeks after the operation,the modified Tarlov scoring standard was used to evaluate the behavioral differences between the two groups of rabbits,and electrophysiology-SEPs(Somatosensory Evoked Potentials)and EMG(Surface Electromyography)were used to evaluate proprioception and muscle contraction.After the test was completed,it was unified They were sacrificed and performed HE staining.Mankin's score was used to evaluate the pathological conditions of the knee articular cartilage in the two groups.The anterior cruciate ligament(ACL)of the right knee was taken and the Bielschowsky nerve staining method was used to observe the number of proprioceptors in the two groups.Results:8 weeks after the operation,the hind limbs of the model group showed a light stroke posture,and the motor function basically returned to normal.Compared with the control group,there was no significant difference in behavioral changes(P>0.05);the model group rabbits SEPs and EMG were compared with the control group Compared with the prolonged incubation period,the amplitude decreased,and the difference was statistically significant(P<0.05).The rabbit articular cartilage surface of the model group was rough or even disappeared,and the cell arrangement was disordered.The Mankin's score was significantly higher than that of the control group(P<0.01),and cartilage damage was more severe.Compared with the control group,the number of proprioceptors in the model group was significantly reduced,the morphology changed,and the ligament tissue was loose and constricted.The difference was statistically significant(P<0.01);the rabbit chondrocytes in the model group were over-apopted and the rate of apoptosis It was significantly higher than the control group(P<0.01).Conclusion:The transection of the spinal nerve can lead to loss of proprioception,excessive apoptosis of chondrocytes,degeneration of articular cartilage,and promotion of the occurrence and development of knee osteoarthritis.