The Effect Of Early Weight Bearing With Pre-emptive Analgesia Intervention On The Expression Of VEGF And BMP-2 In Callus And Skeletal Muscle Of Rats With Femoral Fracture

Objective: To observe the effect of early weight bearing plus pre-emptive analgesia on the expression of VEGF and BMP-2 in callus and skeletal muscle of rats with femoral fracture.Methods: A total of 60 SD male rats were randomly divided into 4 s:A(pre-emptive analgesia and early weight bearing),B(pre-emptive analgesia and delayed weight bearing),C(only pre-emptive analgesia)and D(only early weight bearing).All rats were treated with internal fixation for right femoral shaft fracture.In A,B and C,tramadol was intraperitoneally injected 15 min before operation,and D received injection of equivalent saline.In A and D,weight training was performed on the 1 day post,and B began to exercise on the 14 day post.Rats in each were subjected to oblique plate test t day before operation and 4,9,14,19,24,29 and 34 days post respectively.Rats were sacrificed at 7,14,21,28 and 35 days post respectively.The gene expression of BMP-2 and VEGF in callus and skeletal muscle were detected using Q-PCT technique and the expression of BMP-2 and VEGF in skeletal muscle were detected using Western-blot technique.Results: Oblique plate test,no difference between s before operation,A exceeds B,C and D 4 day post,A exceeds B and C 9,14 and 19 days post,A exceeds C 24,29 and 34 days post,B exceeds C 19,24,29 and 34 days post.For Western-blot detection of skeletal muscle VEGF,A exceeds B,C and D 7,14,21 and 35 days post,A exceeds C and D 28 day post,B exceeds C 28 and 35 days post.For Western-blot detection of skeletal muscle BMP-2,A exceeds B and C 7,14,28 and 35 days post,A exceeds C21 day post,B exceeds C 28,35 days post.For Q-PCR detection of skeletal muscleVEGF,A exceeds B and C 7 and 14 days post,A exceeds B and D 21 day post,A exceeds B,C and D 28 and 35 days post,B exceeds C 28 and 35 days post.For Q-PCR detection of skeletal muscle BMP-2,A exceeds B and C 7,21 and 28 days post,A exceeds C and D 35 day post,A exceeds B,C and D 14 day post,B exceeds C21,28 and 35 days post.For Q-PCR detection of callus VEGF,A exceeds B,C and D7,21 and 28 days post,A exceeds B and C 14,35 days post,B exceeds C 21,28,35 days post.For Q-PCR detection of callus BMP-2,A exceeds B,C and D in each time point,B exceeds C 21,28,35 days post.Conclusion: Pre-emptive analgesia and early weight bearing can both induce the expression of VEGF and BMP-2 in callus and skeletal muscle of rats with femoral fracture and promote their recovery of the locomotor function,joint use leads to better results.Delayed weight bearing promotes fracture healing better than no loading.