Non-compressive model study of experimental lumbar nucleus pulposus prolapse and histologic changes of rat cauda equina nerve roots

Objectives To design a new non-compressive animal model of lumbar nucleus pulposus prolapse and histologic changes of rat cauda equina nerve roots were observed.Methods 16 SD(Sprague-dawley)rats were chosed. The rats were divided into control group and experimental group . The suspension of muscle or nucleus pulposus of coccygeal vertebral was injected into the epidurale cavum of rat, making the non-compressive model of experimental lumbar nucleus pulposus prolapse. The histologic changes of rat cauda equina nerve roots and the mechanical withdraw threshold were observed.Results Without mechanical compression, rats autologous nucleus pulposus displayed significant hyperalgesia and histologic changes of rat cauda equina nerve roots was pronounced. Conclusions The non-compressive animal model offered to study the mechanism of disc herniation and nerve root pain is effective , reliable and cheap.