Seudoartrosis atrófica. Efecto de la aplicación de ondas de choque extracorpóreas en un modelo experimental en tibia de conejos. [Atrophic pseudoarthrosis. Effect of extracorporeal shock waves aplication in an experimental model in tibia of rabbits].

The effects of extracorporeal shock wave therapy (ESWT) have been investigated in: human osteoblasts, fracture foci, non union and periosteum cells. The best results of non union treatment with ESWT have been documented for hypertrophic type. The objective of this study is to investigate the effects of ESWT in an atrophic non union focus generated in a rabbit tibia model. Methods Three groups were included:  a) Group A: fractures receiving extracorporeal shock wave therapy (ESWT); b) Group B: (“control”): fractures not receiving ESWT; c) Group C: no fractures (right leg). Staining with hematoxylin-eosin was performed. ESWT included one session of 2000 extracorporeal shock wave impacts at 10 kV. A biomechanical analysis with a 3-point loading system was performed. Eighteen samples were included in the biomechanical study, 7 in Group A, 3 in Group B and 8 in group C. The samples were placed between two 19 mm cylindrical supports which were 75 mm apart, oriented concentrically to the compression punch. Results The histological test evidenced signs of union - periosteal and endosteal fracture callus - which were considerably larger in the tibias in Group A (treated with extracorporeal shock wave therapy) as compared to the control group (Group B). The maximum load for the healthy tibia Group (Group C) was higher as compared to Groups A (p<0.001; t:7.988) and B (p<0.001; t:6.599). Conclusion This report shows a significant radiographic and histological changes after focus intervention with application of ESWT.