Experimental Evaluation Of The Fracture Healing Of Rats Following Selective Radicotomy

Objective To observe and analyze the effect of selective radicotomy on the fracture healing by selective nerve root rhizotomy and to study the peripheral nervous system on fracture healing further more.Method Mature female Wistar rats which had undergone random unilateral selective radicotomy from L4 to L6 were divided into six groups,incluing the sham operate group(SO),the anterior rhizotomy group(ART),the posterior rhizotomy group-before spinal nerve ganglion(PRYB),the posterior rhizotomy group-after spinal nerve ganglion(PRTA),the radicotomy group(RT1 'ART+PRTB'),the radicotomy group(RT2 'ART+PRTA').All the rats were inflicted with transverse fracture at random side of tibia and selective root nerve radicotomy,using the bone nail to make the fixation for the transverse-fracture-tibia. All animals were executed after 4 weeks.The BMD was measured in proximal end of every tibia and the size of bony callus was evaluated by wet weight and radiograph.The biomechanical elongation-test were recorded to evaluate the mechanical properties of bony callus on the modified Instron5050 electrical univerials tester.The callus property was monitored by histological assessment.To use the all data of transverse-fracture-tibia deviding the data of homologous uninjured-side tibia got the relative number for every pair tibia.Analyzed the data through using absolute number and relative number.Result(1)There were no statistical significance between the SO group and the other groups of the tibia BMD data.(2)The wet weight and radiograph showed an increased callus formation, but elongation-test indicated mechanical properties of bony callus were weaker for all denerved groups.(3)The experimental groups that were inflicted with posterior rhizotomy,including the group PRTB,PRTA,RT1,RT2,which the data of mechanical properties of bony callus had statistical significance making comparion with other groups.(4)The data of bony callus properties indicated there were statistical significance between the group s of posterior rhizotomy group-before spinal nerve ganglion(PRTB)and posterior rhizotomy group-after spinal nerve ganglion(PRTA).conclusion(1)The sensory fibers could be more important than the motor fibers during the bone fracture healing.(2)The spinal nerve ganglions are important for bone fracture healing.(3)Intact innervation is essential for normal fracture healing because nerve injury fracture can form the callus that is large,but mechanically insufficient.