Definition & Overview
Electrical stimulation is a medical procedure used in the treatment of bone injuries such as fractures. It is known for its unique ability to speed up bone healing. Doctors nowadays use it to help patients resume their normal activities as quickly as possible after a bone injury. The procedure works by using electric current to stimulate bone cells and cause changes in the bones’ growth factors. As a result, the bones heal faster.
Who Should Undergo and Expected Results
Electrical stimulation is beneficial for all patients who suffer from bone injuries, such as fractures. It is also helpful as a method for spinal fusions and osteotomies. Although broken bones can heal by themselves due to their ability to regenerate, this process may take a long time. The longer it takes for bones to heal, the higher are the chances that the patient will develop complications such as nonunion, delayed union/delayed healing, and malunion.
Due to the risk of complications, several techniques to speed up bone healing have been developed. These include biomechanical and biological techniques. Aside from electrical stimulation, doctors also use low-intensity pulsed ultrasound and extracorporeal shockwaves. All three techniques work by stimulating faster bone regeneration and union.
Aside from its ability to speed up bone healing, electrical stimulation also offers several other potential benefits for the patients. It is minimally invasive and safer than an autograft procedure. It also boasts lower complication rates so the patient is expected to recover and experience an improved mental and emotional well-being faster.
How is the Procedure Performed?
A variety of electrical devices for bone healing have now been developed. These include:
Invasive DC (direct-current) stimulators – These stimulators deliver electrical energy through electrodes that are implanted in the patient’s body. Two electrodes are used: the cathode (which is placed in the bone) and the anode (which is placed in the surrounding bone tissues). These electrodes are connected to a power source or generating unit, which can either be external or also implanted in the body.
Non-invasive CC (capacitive coupling) stimulators – The CC technique, unlike the DC technique, is applied externally. This means no devices are implanted. Special CC devices are instead used to deliver the electric current. These devices, which are made up of two cutaneous electrodes, are simply placed on top of the skin on opposite sides of the fracture. The electric current is then released by a power source that is connected to the electrodes and the patient’s cast. This creates an electrical field around the fracture site.
Non-invasive IC (inductive coupling) stimulators - Like the CC technique, this is also a purely external method. In this technique, the electrical stimulation to aid bone healing is carried out using an external field generator. However, it uses pulsed electromagnetic field or PEMF to create the stimulation. The electromagnetic field radiates within the fracture site.
These techniques may differ in the specific manner through which they work. But the principle behind them is the same. They are designed to stimulate the synthesis of the structural extracellular matrix or ECM proteins, which are the bones’ growth factor. By doing so, it initiates a cascade of events that lead to cellular repair.
Of all three techniques, DC stimulators are considered to be the most effective. This is because they provide constant stimulation of the bone at the actual fracture site. Also, since the device is already implanted, there is less risk of patient non-compliance.
Patients who wish to undergo electrical stimulation to aid bone healing will be given a treatment regime that is unique to their needs. The treatment regime will include treatment goals and a schedule of follow-up visits.
Possible Risks and Complications
Electrical stimulation to aid bone healing is a generally safe way to speed up bone healing. It is highly beneficial in cases where nonunion or delayed union is either suspected or likely to take place. The associated risks can be controlled by making sure that the procedure is carried out properly. This includes delivering the right doses of electrical current to the affected site.
Both CC and IC techniques are non-invasive, as they only use external devices. This means that the devices can be used at home, provided that the patient is devoted to comply with the treatment regime.
While the DC technique is most effective, it places the patient at an added risk of infection, pain, and discomfort, as well as stress due to the surgery needed to implant the device into the patient’s body.
Griffin M, Bayat A. “Electrical stimulation in bone healing: critical analysis by evaluating levels of evidence.” Eplasty. 2011; 11: e34. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3145421/
Kuzyk P, Schemitsch EH. “The science of electrical stimulation therapy for fracture healing.” Indian J Orthop. 2009 Apr-Jun; 43(2): 127-131. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2762253/