Osteoarthritis (OA) is the most common chronic progres- sive joint disease in the elderly and has a signi cant impact on quality of life as functional status decreases as a result of the pain. Furthermore, dif culties in carrying out activities of daily living have detrimental effects on psychological well-being. In general, the goals of clinically managing knee OA are to provide pain relief and to maintain or to improve functionality. A diverse range of pharmacological, non-oper- ative and surgical options are available for treating OA, yet each therapeutic modality has its respective limitations and side effects1). Short-wave diathermy, transcutaneous electrical nerve stimulation, ultrasound (US) therapeutic acoustic radiation, and applying hot packs are all commonly utilized noninvasive modalities to control both acute and chronic OA pain2). Therapeutic acoustic radiation is transmitted into target tissues by US via high-frequency pressure waves that are
*Corresponding author. Mustafa Aziz Yıldırıım (E-mail: mustafaaziz1907@hotmail.com)
©2015 The Society of Physical Therapy Science. Published by IPEC Inc. This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives (by-nc- nd) License .
generated by piezoelectric crystals in the transducer. Heat is generated by the pressure waves, and it has been shown that low-intensity US pulses stimulate cellular metabolism that enhance tissue regenerative capacity3–6). This relatively new treatment modality has been shown to promote the repair of full-thickness tears in articular cartilage. Speci cally, it has been found that the pressure waves induce stromal cell and chondrocyte proliferation in addition to mesenchymal stem cell differentiation at the lesion site7–9). However, the therapeutic effects of US are more pronounced in the joint spaces, such as the knee joints, because synovial uid has high water content10). It is the one of several physical therapy modalities suggested for the management of pain and loss of function due to OA and can be used as part of an over all rehabilitation program11).
Several studies compare US and physical therapy versus placebo for patients with knee OA, but the clinical ef cacy of US remains controversial2, 12–21). Despite these results, US therapeutic acoustic radiation is still very popular for the treatment of musculoskeletal disorders and it has been asserted that it reduces edema, relieves pain, and increases range of motion12–14). The aim of this prospective random- ized single-blinded trial was to evaluate whether an 8-minute regimen of US therapeutic acoustic radiation is superior to a 4-minute regimen for the treatment of knee OA.