Effects of nerve growth factor on early-stage fracture healing of the tibia combined with peripheral nerve injury

Guichun ZHANG; Yongxian ZHANG

ABSTRACT

BACKGROUND:

It is exhibit that nerve growth factor(NGF)and its receptor expresses in normal bone tissue and callus,the local administration of exogenous NGF can promote the healing of fractures.When fracture following peripheral nerve injury happened,the quality of callus significantly affected.

OBJECTIVE:

To verify the effect of NGF on tibia with peripheral nerve injury in early-stage fracture healing.DESIGN,TIME AND

SETTING:

A randomized grouping design,animal controlled experiment was performed at the Experimental Animal Center,General Hospital of Jinan Military Area Command of Chinese PLA between May and November 2007.MATERIALSForty-eight male Wistar rats,weighting(220?20)g;NGF injection was produced by Xiamen Road of Beijing University Bio-Engineering Co.,Ltd.(Batch number20070502).

METHODS:

Forty-eight male Wistar rats were randomly divided into 4 groups,with 24 limbs in each group.Rats in the sodium chloride group were injected sodium chloride after tibia fracture.Rats in the nerve injury with sodium chloride group were injected sodium chloride after tibia fracture combined with nerve injury.In the NGF group,rats were injected NGF after tibia fracture.Rats in the nerve injury with NGF group were nerve injury plus tibia fracture plus NGF.First,the mid-point department circumference of tibia was measured,and then a wedge-shaped groove on the upper tibia anterior was got,and then femoral nerve about 10 mm at the level of the inguinal ligament was cut.Tibia slotted for the opposite,exposed,but not to remove nerve.Turn to prone position,executed the sciatic nerve with a length of about 10 mm on the side of femoral nerve resection at the same time.Contralateral incision exposed.After the surgery,sodium chloride group and nerve injury with sodium chloride group were injected with physiological saline,0.1 mL/limb per day.The rats in the NGF group and nerve injury with NGF group were injected 0.1 mL(0.2 U)NGF per day.MAIN OUTCOME

MEASURES:

The circumference of crus,X-ray film,wet weight of specimen,and callus metrology observation was measured at weeks 2 and 4 after operation.

RESULTS:

①The crus shrunk more obvious after never injury,however,NGF promoted the muscle restoration.②The wet weight of specimen and callus at the nerve injury side was more than contralateral side.③There were more callus at the never injury side of nerve injury with sodium chloride group and nerve injury with NGF group than contralateral side at the 2 and 4 weeks,but there were more osteoid,which lacking of normal bone trabecula structure.The callus quantity of NGF group and nerve injury with NGF group had small amount of high density callus with orderly arrayed bone trabecula.

CONCLUSION:

During fracture,whether nerve injury or not,local injection of NGF can have a passive effect.