Table 2.

In vivo studies.

Author	Year	Models	Treatment	Main findings
Brighton et al.[58]	1983	New Zealand white rabbits	Stimulation with capacitively coupled electrical field at wave signals of 60 kHz frequency and various voltages (2.5,5, 10, and 20 V peak-to-peak) at the proximal tibial growth plate for 48 h.	Rabbit growth plate consistently stimulated to statistically significant accelerated growth in a capacitively coupled electrical field. A dose-response effect was noted, with 5 V peak-to-peak exhibiting maximum growth acceleration.
Brighton et al.[56]	1985	New Zealand white rabbits	Right fibula stimulated with capacitively coupled electrical field (60 kHz) continuously for 14 days	Exist a dose- response curve for capacitive coupling and fracture healing. 220 mV, 250 mA, 60 kHz applied electrical signal is the most effective for fracture stimulation in the model studied.
Brighton et al.[59]	1989	Male Sprague Dawley rats	Stimulated with various capacitively coupled electrical fields for six and eight weeks at two and 4.5 months after castration	60 kHz 100 mA signal significantly reversed the castration-induced osteoporosis in the lumbar vertebrae and restored bone mass per unit of volume in rats that had been stimulated for 8 weeks after castration
Carter et al.[60]	1989	Sprague Dawley rats	Stimulated with capacitively coupled electrical field (60 kHz)	Two pair of transversely placed electrodes spaced by at least three vertebral bodies produced the most uniform field distributions. At a current density of 3.0–5.0 mA/cm2 where evidence of a reversal bone loss in castration osteoporosis
Carter et al.[65]	1990	Sprague Dawley rats	Stimulated with capacitively coupled electrical field (60 kHz)	Continuous strip is the best choice of electrodes. The current density generated in cardiac tissue during electrical stimulation at 60 kHz is insufficient to cause cardiac fibrillation. Patients with large amounts of subcutaneous fat require lower input current to maintain the same level of current density in their vertebral bodies as patients with little fat but with the same overall dimensions.
Chan et al.[62]	2019	Sprague Dawley rats	Induced disc generation with percutaneous stab. Rats divided into three groups: sham control, needle stab, needle stab +PEMF. Treated rats exposed to PEMF immediately following surgery and for either 4 or 7 days for 4 h a day.	In untreated animals that at day 7 after injury, inflammatory cytokines and catabolic factors significantly increased at both gene and protein levels. At day 7, PEMF treatment significantly inhibited inflammatory cytokine gene and protein expression induced by needle stab injury. At day 4, PEMF down- regulated FGF-1 and upregulated MMP-2 compared to the stab-only group
Ducheyne et al.[66]	1992	Sprague Dawley rats	Rat tibia stimulated with capacitively coupled electrical field using a porous intramedullary implant	While the current density in the pores are reduced in comparison to the region just outside the pore, a significant current density still exists in the pore region. The presence of the implant increases the current densities in trabecular bone while decreases in cortical bone.
Gilotra et al.[67]	2012	New Zealand white rabbits	Rabbits subjected to a spine infection model with a single dose of intravenously administered systemic ceftriaxone prophylaxis. Rabbits were randomly treated with a capacitive coupling or control device. Instrumentation and soft tissue bacterial growth were assessed after 7 days.	Sites treated with capacitive coupling showed a decrease in the incidence of positive culture: 36% versus 81% in the control group. Overall bacterial load was not decreased with capacitive coupling.
McLeod et al.[61]	1992	Male Turkeys	Left ulnae of turkeys functionally isolated by creation of distal and proximal epiphyseal osteotomies and then exposed to an electrical field for one hour each day for 56 days.	Disuse resulted in a 13% mean loss of osseous tissue. Exposure to the pulsed electrical fields prevents this osteopenia and stimulated a 10 per cent mean increase in the bone area. Osteogenic influence was dependent on the frequency (150, 75 and 15 hertz sinusoidal fields respectively generated a −3%, +5% and +20% mean change in the bone area).
Muttini et al.[37]	2014	Appenninica Breed Sheep	Electricity directly connected with the central pins of an external fixator, stimulated with capacitively coupled electrical field for 12 h daily for 60 days.	Biophysical treatment with alternating electricity in combination with external fixator enhances new-bone formation
Ochi et al.[63]	2003	Japanese White Rabbits	After a dental implant was inserted into each femur of Japanese white rabbits, Solcoseryl (2 ml/kg) was administered intravenously in the ear vein and a capacitively coupled electric field was applied for 4 h per day for 14 days	The degree of bone formation on microscopic observation, bone contact ratio, bone surface area ratio, and the level of removal torque of the implant in the Solcoseryl + CCEF treated group were significantly higher than the control group.
Pepper et al.[64]	1996	Male Beagles	Beagles underwent a right tibia mid-diaphyseal corticotomy, followed by a 5- day delay, and then 21 days of lengthening (1 mm/day). At the start of the post-distraction period (day 27), stimulation (60 kHz) was applied for 28 days.	37% lower maximum torque capacity and a 40% decrease in strain energy to failure in the stimulated group compared with the nonstimulated group. When this dose of capacitive coupled electrical stimulation is applied to the regenerating bone created during distraction osteogenesis, it delays the recovery of bone strength compared with an untreated control.
Yoshida et al.[68]	2009	Male Japanese White Rabbits	Rabbits received external fixation at the right tibia and were assigned to a control group and a fractured group. The bone electrical impedance (Z values) was misured non-invasively by using external fixation pins as electrodes.	Z values in fractured group increased through 5 weeks after surgery while remained constant in control group at 3 weeks. The resistivity and fracture cross.sectional area (FrA) in fractured group decreased through 5 weeks while maximum bending stress (Bmax) increased, reaching a plateau at 5 weeks