The effect of pulsed ultrasound on serum Alkaline Phosphatase during bone healing of tibia in New Zealand rabbit

Serum Alkaline Phosphatase (ALP) is a glycoprotein that is secreted from osteoblasts. In fractures, the rate of ALP will be changed. Low intensity pulsed ultrasound accelerates the growth and remodeling of fractures. However the relation between pulsed ultrasound and changing the rate of serum ALP in New Zeland rabbit is not studied yet. The aim of this study is to investigate the effect of pulsed ultrasound on serum ALP during bone healing of tibia in New Zealand rabbit. This is an experimental study. 54 male and mature New Zealand rabbits were randomly divided into six groups (3 experimentals and 3 controls). All of them were operated for inducing a model of experimental fracture. After repair of wounds, the right leg of experimental groups was exposed to pulsed ultrasound for 2, 4 and 6 weeks. The control groups were kept without any intervention during the same time. After experiment, the rabbits were anesthesied and blood samples were taken from their hearts for ALP serology, and then the rabbits were killed. Blood was centrifuged and serum ALP was read by spectrophotometer. Data was analyzed by Mann-Whitney U and Kruskal-Wallis tests. Results showed that the mean serum ALP level in experimental group after 4 weeks exposing to pulsed ultrasound was significantly higher as compared to control group (p= 0.03). There was no significant difference between the other groups. The results of this study demonstrate that pulsed ultrasound wave increases serum ALP and accelerates the bone healing.