The effect of zoledronic acid on growth plates and high turnover bones

Bisphosphonates have preventive effect on bone resorption caused by osteoclasts.We aimed to investigate the histopathological effects of zoledronic acid (ZA) on the jaw and long bones and growth plates of rats.

Thirty-six 12 week-old female Sprague-Dawley rats were divided into the control (C, n=18) and ZA groups (Z, n=18). Z group animals were administered 0.1 mg/kg saline-diluted ZA intraperitoneally three times per week for 8 weeks. C group animals were administered the same amount of saline simultaneously. At the end of 11th week, half the subjects from either the control group (C1) and ZA group (Z1) were sacrificed. At the end of 14th week, the remaining half from both groups were also sacrificed (C2 and Z2). In all animals, no dental procedures were performed; the posterior and anterior mandible and the knee joint including distal femur and proximal tibia were histopathologically investigated.

Histological examination revealed that inflammation and necrosis were limited to the posterior mandible of the Z1 and Z2 groups, while the anterior mandible and knee joint including distal femur and proximal tibia remained unaffected however the development of the growth plate of the proximal tibia was found to be arrested in animals of the Z1 and Z2groups.

Due to it is inhibitory effect over growth plate and inflammatory and necrotic effect over high turnover bones, zoledronic acid should be administered cautiously, especially in pediatric patients who are still in their growth and development stages (Fig. 6, Ref. 34).