The effects of therapeutic vs. high‐intensity ultrasound on the rabbit growth plate

Abstract

Six of 6-week-old NZ rabbits underwent ultrasound treatment using a therapeutic dose (0.5 W/cmZ) and other six were treated with a higher dose (2.2 W/cm2) to the lateral aspect of the left knee joint for 20 min per day and a total of six weeks. The right knee joint served as a control. The goal of this study is to see if the therapeutic dose and high dose (approximately 45-fold therapeutic dose) will have toxic effects on the physis. Histological review appeared normal growth plate in the therapeutic group. In the high dosage group three of six cases displayed flattening of the distal femoral epiphysis and wedging of the proximal tibial plateau and indistinct growth plate lines. It is of interest to note that there are opening radiolucent area in the lateral aspect on the femoral metaphysis in five of six cases, where bone resorption has taken place. Histological results showed that there are disordered arrays of the cartilaginous cells in the proliferative zone. The height of the lateral physis in the high dose group is not only greater than that in the therapeutic dose (1083.8 vs. 500.3 pm), but also greater than that in their contralateral control (530.7 pm) ( P < 0.05). This shortterm study demonstrates that high dose ultrasound has profound pathologic effects in growing bone. Therapeutic doses of ultrasound do not have an adverse effect on bone growth in the short-term follow-up.

Effects of Low-Intensity Pulsed Ultrasound on the Expression and Activity of Hyaluronan Synthase and Hyaluronidase in IL-1β-Stimulated Synovial Cells

“…4 Different intensities of pulsed US have distinct biological effects on in vitro mineralization processes and in vivo experiments. 25,33 LIPUS is used clinically as an accelerator of fracture healing. 15 Furthermore, various cell types have been reported to be sensitive to US Single US exposure to the HIG-82 cells stimulated with IL-1b significantly (p < 0.01 or p < 0.05) upregulated HA production as compared with untreated control, US-exposed, and IL-1b-stimulated cells.…”

Radiofrequency Application to the Growth Plate in the Rabbit: A New Potential Approach to Epiphysiodesis

“…42 Growth plates have also been shown to be affected by less invasive physical agents such as high-intensity ultrasound. 43 With the emergence of these new techniques meant to reduce operative time, postoperative pain, and length of hospital stay, this study was conducted to assess the effects of radiofrequency energy on the growth plate, with the stipulation that it could produce epiphysiodesis. The radiographic part of this study clearly shows that radiofrequency energy applied to the growth plate achieves efficient and rapid growth arrest and this seems to be temperature dependent.…”

Efeitos do ultra-som terapêutico sobre o crescimento longitudinal do fêmur e da tíbia em ratos

“…[18][19][20] Since many of the histological descriptions considered pathological by literature were found in our study, both on the right side and on the left side (untreated) and also in the control group not submitted to ultrasound, we suggest that some histological findings of studies from literature, besides being pathological alterations, are products of the techniques used to obtain segments and to prepare slides and/or represent different aspects of normality. Based on the statistical analysis it is concluded that ultrasound did not produce an effect of inhibition or stimulus on bone growth of the femur or tibia, in comparison with the control group.…”

“…The results of the studies, although with some differences, 11 show vascular alterations, 12 stimulus to the healing of skin ulcers, 13 of tendons, 14 in the formation of fracture callus, 15,16 but not in bone neoformation, 17 with few more recent studies on its effects on longitudinal bone growth and on the epiphyseal plate. [18][19][20] This diversity makes it hard to compare the data and to have a clear understanding of the biological effects of ultrasound, so much so that Wells 3 considered the scientific knowledge about the biological bases of its use "disappointing" and Haar 4 and Leighton 6 considered the need for more investigations in this respect. We decided to prepare this study, aiming to investigate the effects of different powers of therapeutic ultrasound on longitudinal bone growth of the femur and tibia, under conditions similar to those employed in clinical therapeutics, using common use …”