OBJECTIVETo observe the effect of copper on bone fracture healing.

METHODS160 growing chickens aged 70 days were fed in 32 cages, each consisting of five. The fracture with 1 approximately 2 mm defects at the bilateral radius of wings was created by osteotomy. The chickens were divided into four groups, 40 each. Every morning, chickens of the first group, served as controls, were fed orally 0.8% Na-CMC solution (sodium carboxymethyl cellulose), those of the other three groups were fed with copper-Na-CMC suspension (copper powder suspended in 0.8% Na-CMC) with different doses of 20, 40 and 80 mg Cu/kg body weight. Each group was sacrificed 14, 21, 28 and 35 days postoperatively. Liver was taken for analysis of Cu and Zn. Both radius were removed by dissection. CT was performed quantitatively for the ment of the gray values of the callus. The biomechanical properties of the healing radius were analyzed by a three point bending test. Afterwards, the contents of calcium, magnesium, phosphorus, copper, zinc, iron and hydroxyproline in the callus were determined.

RESULTSThe gray values of the callus increased along with the increase of copper dose and the duration of observation. 21 and 35 days after operation, the gray values of the callus were significantly higher in the high-Cu group than in the controls respectively (909 +/- 220 vs. 597 +/- 155; 973 +/- 100 vs. 763 +/- 179 HU, P < 0.05). The level of calcium and magnesium in the callus 35 days after operation was much higher in the mid and high Cu groups than in the controls respectively (Ca: 177 +/- 26.7, 176 +/- 20.5 and 137 +/- 34.7 mg/g; Mg: 2.98 +/- 0.57, 3.06 +/- 0.46 and 2.43 +/- 0.53 mg/g P < 0.05). The contents of hydroxyproline in the callus 35 days after operation were significantly higher in the high-Cu group than in the controls (34.23 +/- 1.96 vs. 32.17 +/- 1.93 mg/g respectively). The biomechanical properties of the repaired radius had a better improvement tendency in the three Cu-fed groups than in the controls.

CONCLUSIONCopper is helpful in fracture healing; however, the effect of copper on fracture healing needs further study.