The effect of shock waves on mineralization and regeneration of distraction zone in osteoporotic rabbits

OBJECTIVE: Osteoporotic individuals suffer from various complications such as spontaneous bone fractures due to decreased bone strength and failure in bone healing as a result of decreased bone mineral density and deterioration of bone microstructure. In this study, the effects of Extracorporeal Shock Wave Therapy (ESWT) in a distraction osteogenesis model in osteoporotic rabbits were investigated to prevent these failures and improve bone microstructure. MATERIAL AND METHODS: A total of 28 female New Zealand rabbits underwent mandibular distraction osteogenesis and were divided into four groups: non-ovariectomized control (Cont), ovariectomized control (O-Cont), ovariectomized ESWT1 (O-ESWT1) and ovariectomized ESWT2 (O-ESWT2). ESWT was only applied to the ESWT2 group before the osteotomy, and to both the ESWT1 and ESWT2 groups after the osteotomy. Dual-energy x-ray absorptiometry was used to determine bone mineral density on both the 7th and 28th day of the consolidation. Stereological methods were used to identify new bone formation, connective tissue and neoangiogenesis volume. RESULTS: According to the dual-energy x-ray absorptiometry examination both at the 7th and 28th day of the consolidation, lower bone mineral density was seen in the ESWT groups. However, the stereological examination showed that shock wave therapy significantly increased new bone formation both ESWT1 and ESWT2 compared with O-Cont, significantly increased neoangiogenesis in O-ESWT1 compared with O-Cont. CONCLUSIONS: The application of ESWT in these parameters after osteotomy was beneficial for bone regeneration in mandibular distraction in osteoporotics. However, ESWT has been shown to be ineffective in improving bone mineral density. KEY MESSAGES: 1. The osteoporotic model can be successfully established in rabbits and the subjects can tolerate the distraction procedures. 2. Stereology is a useful analysis method that can determine the volume of the new bone formation and neoangiogenesis. 3. Extracorporeal shock wave therapy has biostimulatory effects on bone tissue.