Electrical stimulation of the growth plate: A potential approach to an epiphysiodesis

Abstract

Epiphysiodesis is an operative procedure that induces bony bridges to form across a growth plate of a bone to stop longitudinal growth. This is a very common orthopedic procedure to correct disproportional long-bone growth discrepancies; however, present techniques require an operation and anesthesia. Our study was designed to develop a minimally invasive method of epiphysiodesis by using electrical stimulation with DC current. In a rabbit model, a thin titanium electrode was inserted into a single location of the distal femoral growth plate in three groups: one without current (control), one group with a constant 10 microA (low current, LC), and one group with a 50 microA (high current, HC). The current was delivered for 2 weeks. The nontreated femur served as a control for each animal. Femur lengths were measured and comparisons were made between operated (left) and nonoperated (right) femurs. Digitized histomorphometric and volumetric analyses were performed on each growth plate, and detailed assessments were made of any morphological changes. Using length measurements, the difference in femur length was significantly larger in the HC group and not in the LC or control groups, showing bone growth inhibition at the higher current. In the HC group, bony bridges and disorganized growth plates were observed. This study shows that delivery of an electrical current of 50 microA for as little as 2 weeks can markedly affect bone growth as evidenced by changes in epiphyseal plate volume and architectural organization, and the study supports the use of this minimally invasive approach as a potential method of achieving an epiphysiodesis.

Vertebral Growth Modulation by Electrical Current in an Animal Model: Potential Treatment for Scoliosis

“…Interestingly, one potential mechanism for the effect of direct current on bone is the up-regulation of osteoinductive growth factors 31. In our laboratory, we demonstrated in a previous study that a current of 50 μA, but not the clinically used 20 μA or a control device without current., would cause an inhibition of growth, i.e., an epiphysiodesis of the distal femoral physis in rabbits,15 and, as shown in the present study, a hemiepiphysiodesis can be induced by applying the electrical current asymmetrically in the distal femoral physis of rabbits. To be translationally relevant as possible the rationale for using the electrode device included the fact that titanium electrodes pass higher currents than do stainless steel without causing tissue necrosis, and that this cathode material and similar device (20 μA) is currently a FDA-approved implantable device.…”

“…In this study these were chosen as control over animals with lower or no current since this had been done in a previous study showing no marked effect on growth. 15 The 4-lead device was implanted in the 6 immature animals delivering a constant of 50 μA from each electrode, and the current was delivered continuously for 6 weeks.…”

“…Repetitive freezing of the vertebral endplate physis at a lateral/peripheral area in rabbits was tested in our laboratory; however, the degree of modulation of spinal growth was inconsistent. Recently in our laboratory, a current of 50 μA was shown to produce consistently reliable growth inhibition compared with 20 μA, and at the higher current there was an induction of bone bridges in the physis of rabbit femurs 15. The technology uses a power source and one electrode or a series of electrodes for applying a current sufficient to reduce or stop the physeal growth of a bone.…”

Electrical Implications of Corrosion for Osseointegration of Titanium Implants

“…Titanium (Ti) implants can be used as cathodes for DC electrical stimulation (Dodge et al, 2007). One such device was developed to fit inside a dental implant healing abutment and supply electrical stimulation to canine mandibular bone (Song et al, 2009).…”

Thermal epiphysiodesis performed with radio frequency in a porcine model

“…Alternative techniques such as the percutaneous technique described by Bowen have largely replaced the open technique during the past 20 years (Rosenthal et al 2003, Edmonds et al 2007). Percutaneous techniques produce bony bridges and disorganize growth plate structure, which results in growth inhibition (Dodge et al 2007, Gunderson et al 2013). Percutaneous methods reduce length of hospital stay, operating time, and postoperative pain, and they result in minor surgical scars compared to open surgery.…”