Effects of essential amino acids and lactose on bony fractures and defectsin rabbits: a preliminary histomorphometric study

An experimental study was performed in order to test the possibility of imp roving bone repair with the administration of a drug (Calciofix, Farmaceuti ci Damor SpA, Naples, Italy) containing essential amino acids and lactose. Fifty rabbits were submitted to an open transversal fracture of the left fi bula and to a right femoral condyle defect. They were left untreated or tre ated daily with the drug orally and were divided into subgroups depending o n the experimental time: 15, 30, 40, 50, 60 days. Histomorphometric data sh owed a significantly faster healing rate in treated animals compared with u ntreated ones. Firstly, on day 30 there was a significantly larger amount o f cartilage in the control bone callus (P < 0.01). On day 50 a significant difference existed between trabecular and lacunar percentages in the two su bgroups (P < 0.0005). At 60 days no significant differences were observed, but bony trabeculae had become more oriented parallel to the long axis of t he bone in treated animals. Secondly, after 15 days the defect area was sig nificantly smaller in treated animals than in the untreated ones (P < 0.01) . At 30 and 40 days, respectively, significant differences existed between the two subgroups in connective tissue and mature bone percentages (P < 0.0 1 and P < 0.001). Our results seem to demonstrate that the drug significant ly accelerates the rate of bone formation in fractures and bone defects in rabbits.