This may also suggest too that ultrasound can affect longitudinal bone growth post skeletal maturity via articular cartilage endochondral ossificaiton.
GROWTH MODULATION BY STIMULATING THE GROWTH PLATE: A PILOT STUDY
“This study investigates the ability of low-intensity pulsed ultrasound (LIPUS) or direct injection of recombinant growth hormone (rGH) to stimulate local growth of long bones. In a randomized controlled animal trial, healthy immature rabbits were allocated to 1 of the following 4 conditions: epiphyseal rGH periosteal injection, transdermal LIPUS, saline periosteal injection, or no treatment. New bone deposition was labeled with calcein at days 1 and 18, and microscopic measurements of growth were conducted by blinded observers.
Statistically significant differences in growth were observed between the LIPUS and rGH stimulated legs compared with contralateral control legs (35% p = 0.04 and 41% p = 0.04, respectively);{35% is huge!} whereas no difference was observed between the 4 control groups (p = 0.37). There was no evidence of physeal bar formation, suggesting that direct injection of rGH and application of LIPUS around the distal femoral physis in rabbits may have a positive effect on microscopic growth without short-term adverse sequelae.”
“Low-intensity pulsed ultrasound (LIPUS) has been demonstrated to improve fracture healing in multiple double-blinded controlled trials, as well as stimulate chondrocytes in culture to increase calcium and aggrecan expression”
“that ultrasound stimulation of chondrocytes in vitro can reversibly change the shape and the orientation of the primary cilium dependent on the duration and pressure-amplitude of the signal and can enhance the cyclic Adenosine Monophosphate level in culture media only in ciliated chondrocytes.”
“The primary cilium is a place of high concentration of integrins that are believed to connect the extracellular matrix and the cytoskeleton in mechanotransduction”
“The bone stimulator used was Exogen (Bioventus, Durham, NC, USA). It emits low-frequency (1.5 MHz) ultrasound with a 1-kHz repetition module creating a 200-ms signal with an intensity of 30 mW/cm2″<-theoretically this could be applied to the articular cartilage
have been approaching skeletal maturity at that time.”
“Direct macroscopic femoral length measurements and radiographic length measurements revealed no statistical difference in growth in animals between any of the treatment arms.”<-So LIPUS didn’t really increase bone length at the macroscopic level? But if you look at 3a I do see a slight difference.
However they directly say “external application of LIPUS and injection of growth hormone does affect the longitudinal growth of bone with no adverse effects such as physeal bar or angular deformity noted.”
“Selective growth stimulation of active growth plates may become a novel noninvasive method to address limb length discrepancies and spine deformities
in children.”<-and in adults via articular cartilage endochondral ossification possibly