A fracture is a structural break, whether it is a bone, an epiphyseal plate or the articular cartilage surface. The normal healing of a fracture is an extremely interesting biological process, especially if you consider that a broken bone, contrary to any other torn or cross tissue, is able to heal without scar, regenerating a normal bone.
It is difficult to establish the time at which a fracture should be repaired. However, despite optimal treatment, some fractures heal slowly or, simply, they do not repair.
The mechanism by which we can get the osseous consolidation begins from the time the fracture is made.
Repair process: the fibrocartilage callus in fractures
The repair process depends on most of the peripheral vessels until the consolidation of the callus. This process is regulated by electrical charges. Osteoblastic activity is carried out in an electrically positive environment.
In addition, the mild and controlled movement of the fractured member associated with the functional support of the body weight causes an immediate response of the callus, which is very favorable.
Evidences emphasizes the fact that the functional movement is more compatible with effective consolidation to forced immobilization. On the other hand, a study in Tokyo showed that with a direct current stimulation periosteal cells were activated and transformed from progenitor cells to osteoblasts and osteoid tissue. And, finally, they transformed into osteocytes, but when direct current stimulation was discontinued, after 24 hours, the osteoprogenitors cells activity was modified, differing in fibrocytes and connective tissue.
Stimulation through currents
Though the electric current stimulation shows mitosis and recruitment of osteogenic cells, the mechanism by which the direct current work as a stimulation results in the consumption of dissolved oxygen, and the pH increases.
In certain studies, it is proposed that osteogenesis is stimulated by the decrease in the tension of oxygen and by the increase in pH in the vicinity of the cathode, as a result of a electrochemical oxygen reduction. The bone growth is stimulated by an alkaline medium with low oxygen tension. With electricity in areas of natural healing of the bone, the chondroblasts, osteoblasts and chondrocytes are stimulated. It is also known that cyclic AMP significantly increases, as well as the calcium ion around the middle of it. Electrical stimulation is also used as a therapeutic method in diseases such as osteoporosis, osteoarthritis and osteonecrosis.
Studies showed that applying stimulation by direct current that vary between 5 and 100 microamps of different polarity, negative direct current of 20 microamps is optimal to cause osteogenesis. Minor currents produce minimal stimulation, but without growth, bone and currents greater than 390 microamps cause demineralization of the bone and even necrosis (tissue death), as well as the positive current.
What are the types of electrical electrostimulation for the callus?
There are different methods of electrical stimulation: invasive, semi-invasive, non-invasive.
The non-invasive method operates as a superficial electrical electrostimulation through electrodes on the skin generating a pulse signal of variable frequencies, adaptable to the requirements of the treatment. Within this method you can use the i-motion biojacket, since the electrodes can be adapted throughout the surface of the equipment and perform the treatment in a more comfortable way for the patient while performing active or passive exercises in another area of the body (non-fractured).
In addition, thanks to its high-range software, you can have full control of the recommended parameters according to the literature: application voltage: 4-8.5 v, 20 mA application current, pulsed signal frequency 8-800 Hz, pulse train frequency 80Hz – 8kHz. A positive electrode and a negative electrode should be differentiated, the first near the largest adjacent muscle mass, and the negative a little distal from the first, each of them next to the focus of the fracture.
It should be noted that any treatment that seeks a decrease in fixation time and that promotes faster recovery is deserved to be evaluated as an adjuvant therapy.
G.D. Krischak, A. Krasteva, F. Schneider, D. Gulkin, F. Gebhard, M. Kramer. Physiotherapy after volar plating of wrist fractures is effective using a home exercise program. Arch Phys Med Rehabil, 90 (2009 Apr), pp. 537-544
H.H. Handoll, R. Madhok. Conservative interventions for treating distal radial fractures in adults (Cochrane Review). Cochrane Database Syst Rev, 2 (2003).