Me: This type of invention seems to show that if you can get the electric signal sent to be of a certain type in shape, you can signal whether to cause osteogenesis or chondrogenesis. Somehow from the regulation of the release of NO gas using NO donors and NO synthase inhibitors as well as BMP-2 and BMP-7  you can literally control the differentiation of the progenitor cells to differentiate into chondrocytes and control the rate of the growth of the chondrocytes.  Again, this invention works on the same theory as the PEMF technology. you attach the electrodes which are connected to a signal generator to the cartilage on the body and the specific signals that is sent will control the way chondroblast behave. 

The source link for the patent was found from Google Patents HERE.

Methods for modulating chondrocyte proliferation using pulsing electric fields

James W. Kronberg et al

Compositions and methods are provided for modulating the growth, development and repair of cartilage, bone or other connective tissue. Devices and stimulus waveforms are provided to differentially modulate the behavior of chondrocytes, osteoblasts and other connective tissue cells to promote proliferation, differentiation, matrix formation or mineralization for in vitro or in vivo applications. Continuous-mode and pulse-burst-mode stimulation of cells with charge-balanced signals may be used. Cartilage, bone and other connective tissue growth is stimulated in part by nitric oxide release through electrical stimulation and may be modulated through co-administration of NO donors and NO synthase inhibitors. The methods and devices described are useful in promoting repair of bone fractures, cartilage and connective tissue repair as well as for engineering tissue for transplantation.