Influence of extracorporeal shock wave therapy (ESWT) on the metaphyseal fracture healing in an osteoporotic rat model

Aims

Due to the current demographic changes and the subsequent increase of the elderly population, osteoporosis and osteoporotic fractures are becoming an increasing social, economic and financial problem. In this experimental animal study, Extracorporeal Shock Wave Therapy (ESWT) was evaluated as a potential treatment option for the improvement of osteoporotic fracture healing.

Methods

An established osteoporotic fracture model in the metaphyseal tibia of the rat was used. 132 animals were divided into 11 groups (12 animals each). One of the groups represented the SHAM-group, the other 10 groups represented the ovariectomized, osteoporotic groups. 9 of the osteoporotic groups received ESWT treatment. Different energy flux intensities (0.15 mJ/mm2, 0.35 mJ/mm2, or 0.55 mJ/mm2) as well as different numbers of ESWT applications (once, three times, or five times throughout the 35-day healing period) were used. The fracture healing properties were assessed using micro-computed tomography imaging, quantitative real-time polymerase chain reaction (qRT-PCR) for the evaluation of the expression of specific osteoblast and osteoclast transcripts, histomorphometric analyses and biomechanical analyses.

Results

In conclusion, ESWT seems to have a beneficial effect on the healing properties of osteoporotic fractures leading to an improvement in biomechanical properties, enhanced callus-quantity and -quality, and an increase in the expression of bone specific transcription factors. In addition to enhancing surgical fracture stabilization and improving as well as expediting osteoporotic fracture healing, ESWT could prove to be an effective, easy to use, and cost-efficient treatment option for osteoporotic fractures.