Low-intensity pulsed ultrasound |
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Low-intensity pulsed ultrasound (LIPUS) is a technology that can be used for therapeutic purposes. It exploits low intensity and pulsed mechanical waves in order to induce regenerative and anti-inflammatory effects on biological tissues, such as bone, [1] cartilage, and tendon. [2] Even if the real mechanism underlying its effectiveness has not been understood yet, it is plausible that the treatment relies on non-thermal phenomena, such as microbubbles and microjets induced by cavitation, acoustic streaming, and mechanical stimulation. [3] [2]
LIPUS uses generally 1.5 MHz frequency pulses, with a pulse width of 200 μs, repeated at 1 kHz, at a spatial average and temporal average intensity of 30 mW/cm2. [4]
Starting around the 1950s this technology was being used as a form of physical therapy for ailments such as tendinitis. [5]
As of 2009 research for the use of LIPUS to treat soft tissue injuries were in the early stages. [4] As of 2012 it was being studied for dental problems. [6]
Low intensity pulsed ultrasound has been proposed as a therapy to support bone healing after fractures, [1] osteomies, or delayed healing. A 2017 review, however, found no trustworthy evidence for the use of low intensity pulsed ultrasound for bone healing, mostly based on the large pragmatic randomized controlled trial published in 2016. [7] [8] An associated guideline issued a strong recommendation against its use in bone healing. [9] Evidence as of 2023 was insufficient to justify its use to prevent non healing of bone fractures. [10] Tentative evidence supports better healing with the use of the system in long bones that have not healed after three months. [11] Some reviews suggested inconclusive evidence of benefit. [12] [10] One industry supported meta-analysis suggested it as a potential alternative to surgery for established nonunions. [13] Most studies suggesting benefit were funded by manufacturers of ultrasound devices. [7]
In 2018, a study published in the journal Brain Stimulation , reported that experiments on mice showed that whole-brain LIPUS therapy markedly improved cognitive dysfunctions without serious side effects by enhancing specific cells related to dementia's pathology. Clinical trials are underway. [14]
In vitro experiments have confirmed the LIPUS capability to regulate cell proliferation and differentiation as well as the opening of cell membrane channels. [2]
Osteoporosis is a systemic skeletal disorder characterized by low bone mass, micro-architectural deterioration of bone tissue leading to bone sterility, and consequent increase in fracture risk. It is the most common reason for a broken bone among the elderly. Bones that commonly break include the vertebrae in the spine, the bones of the forearm, the wrist, and the hip. Until a broken bone occurs there are typically no symptoms. Bones may weaken to such a degree that a break may occur with minor stress or spontaneously. After the broken bone heals, the person may have chronic pain and a decreased ability to carry out normal activities.
Arthroscopy is a minimally invasive surgical procedure on a joint in which an examination and sometimes treatment of damage is performed using an arthroscope, an endoscope that is inserted into the joint through a small incision. Arthroscopic procedures can be performed during ACL reconstruction.
Tendinopathy is a type of tendon disorder that results in pain, swelling, and impaired function. The pain is typically worse with movement. It most commonly occurs around the shoulder, elbow, wrist, hip, knee, or ankle.
Sore throat, also known as throat pain, is pain or irritation of the throat. Usually, causes of sore throat include:
A bone fracture is a medical condition in which there is a partial or complete break in the continuity of any bone in the body. In more severe cases, the bone may be broken into several fragments, known as a comminuted fracture. A bone fracture may be the result of high force impact or stress, or a minimal trauma injury as a result of certain medical conditions that weaken the bones, such as osteoporosis, osteopenia, bone cancer, or osteogenesis imperfecta, where the fracture is then properly termed a pathologic fracture.
Electrotherapy is the use of electrical energy as a medical treatment. In medicine, the term electrotherapy can apply to a variety of treatments, including the use of electrical devices such as deep brain stimulators for neurological disease. The term has also been applied specifically to the use of electric current to speed wound healing. Additionally, the term "electrotherapy" or "electromagnetic therapy" has also been applied to a range of alternative medical devices and treatments.
Nonunion is permanent failure of healing following a broken bone unless intervention is performed. A fracture with nonunion generally forms a structural resemblance to a fibrous joint, and is therefore often called a "false joint" or pseudoarthrosis. The diagnosis is generally made when there is no healing between two sets of medical imaging, such as X-ray or CT scan. This is generally after 6–8 months.
A meniscus is a crescent-shaped fibrocartilaginous anatomical structure that, in contrast to an articular disc, only partly divides a joint cavity. In humans, they are present in the knee, wrist, acromioclavicular, sternoclavicular, and temporomandibular joints; in other animals they may be present in other joints.
Venous ulcer is defined by the American Venous Forum as "a full-thickness defect of skin, most frequently in the ankle region, that fails to heal spontaneously and is sustained by chronic venous disease, based on venous duplex ultrasound testing." Venous ulcers are wounds that are thought to occur due to improper functioning of venous valves, usually of the legs. They are an important cause of chronic wounds, affecting 1% of the population. Venous ulcers develop mostly along the medial distal leg, and can be painful with negative effects on quality of life.
High-intensity focused ultrasound (HIFU) is a non-invasive therapeutic technique that uses non-ionizing ultrasonic waves to heat or ablate tissue. HIFU can be used to increase the flow of blood or lymph or to destroy tissue, such as tumors, via thermal and mechanical mechanisms. Given the prevalence and relatively low cost of ultrasound generation mechanisms, The premise of HIFU is that it is expect a non-invasive and low-cost therapy that can at minimum outperform operating room care.
Heat therapy, also called thermotherapy, is the use of heat in therapy, such as for pain relief and health. It can take the form of a hot cloth, hot water bottle, ultrasound, heating pad, hydrocollator packs, whirlpool baths, cordless FIR heat therapy wraps, and others. It can be beneficial to those with arthritis and stiff muscles and injuries to the deep tissue of the skin. Heat may be an effective self-care treatment for conditions like rheumatoid arthritis.
Extracorporeal shockwave therapy (ESWT) is a non-invasive, out-patient alternative to surgery for those with many joint and tendon disorders. ESWT sends acoustic shock waves into bone or soft tissue, in effect reinjuring the area on a cellular level and breaking up the scarring that has penetrated tendons and ligaments. The controlled reinjuring of tissue allows the body to regenerate blood vessels and bone cells. The resulting revascularization leads to faster healing and often a return to pre-injury activity levels. ESWT is mostly used for kidney stones removal, in physical therapy and orthopedics.
An open fracture, also called a compound fracture, is a type of bone fracture that has an open wound in the skin near the fractured bone. The skin wound is usually caused by the bone breaking through the surface of the skin. Open fractures are emergencies and are often caused by high energy trauma such as road traffic accidents and are associated with a high degree of damage to the bone and nearby soft tissue. An open fracture can be life threatening or limb-threatening due to the risk of a deep infection and/or bleeding. Other complications including a risk of malunion of the bone or nonunion of the bone. The severity of open fractures can vary. For diagnosing and classifying open fractures, Gustilo-Anderson open fracture classification is the most commonly used method. It can also be used to guide treatment, and to predict clinical outcomes. Advanced trauma life support is the first line of action in dealing with open fractures and to rule out other life-threatening condition in cases of trauma. The person is also administered antibiotics for at least 24 hours to reduce the risk of an infection. Cephalosporins are generally the first line of antibiotics. Therapeutic irrigation, wound debridement, early wound closure and bone fixation are the main management of open fractures. All these actions aimed to reduce the risk of infections. The bone that is most commonly injured is the tibia and working-age young men are the group of people who are at highest risk of an open fracture. Older people with osteoporosis and soft-tissue problems are also at risk.
Therapeutic ultrasound refers generally to any type of ultrasonic procedure that uses ultrasound for therapeutic benefit. Physiotherapeutic ultrasound was introduced into clinical practice in the 1950s, with lithotripsy introduced in the 1980s. Others are at various stages in transitioning from research to clinical use: HIFU, targeted ultrasound drug delivery, trans-dermal ultrasound drug delivery, ultrasound hemostasis, cancer therapy, and ultrasound assisted thrombolysis It may use focused ultrasound (FUS) or unfocused ultrasound.
Pulsed radiofrequency is the technique whereby radio frequency (RF) oscillations are gated at a rate of pulses (cycles) per second (one cycle per second is known as a hertz (Hz)). Radio frequency energies occupy 1.0×104 Hz to 3.0×1011 Hz of the electromagnetic spectrum. Radio frequency electromagnetic energy is routinely produced by RF electrical circuits connected to a transducer, usually an antenna.
Pulsed electromagnetic field therapy, also known as low field magnetic stimulation (LFMS) is the use of electromagnetic fields in an attempt to heal non-union fractures and depression. By 2007 the FDA had cleared several such stimulation devices.
Microbubbles are bubbles smaller than one hundredth of a millimetre in diameter, but larger than one micrometre. They have widespread application in industry, medicine, life science, and food technology. The composition of the bubble shell and filling material determine important design features such as buoyancy, crush strength, thermal conductivity, and acoustic properties.
Osteoradionecrosis (ORN) is a serious complication of radiation therapy in cancer treatment where radiated bone becomes necrotic and exposed. ORN occurs most commonly in the mouth during the treatment of head and neck cancer, and can arise over 5 years after radiation. Common signs and symptoms include pain, difficulty chewing, trismus, mouth-to-skin fistulas and non-healing ulcers.
Fat removal procedures are used mostly in cosmetic surgery with the intention of removing unwanted adipose tissue. The procedure may be invasive, as with liposuction, or noninvasive using laser therapy, radiofrequency, ultrasound or cold to reduce fat, sometimes in combination with injections.
Ultrasound-triggered drug delivery using stimuli-responsive hydrogels refers to the process of using ultrasound energy for inducing drug release from hydrogels that are sensitive to acoustic stimuli. This method of approach is one of many stimuli-responsive drug delivery-based systems that has gained traction in recent years due to its demonstration of localization and specificity of disease treatment. Although recent developments in this field highlight its potential in treating certain diseases such as COVID-19, there remain many major challenges that need to be addressed and overcome before more related biomedical applications are clinically translated into standard of care.