Effect of High Intensity Laser in Treatment of Myofascial Trigger Points in Symptomatic Knee Osteoarthritis
Condition: Myofascial Trigger Point Pain; Knee Osteoarthritis
MeSH terms: Osteoarthritis; Osteoarthritis, Knee; Myofascial Pain Syndromes
Study type: Interventional

Summary: 
      This study was conducted to investigate the effect of High intensity laser therapy( HILT) on
      pressure pain threshold, serum cortisol level, passive knee range of motion, and changes of
      functional disability in patients with active myofascial trigger points(MTrPs) pain
      associated wit knee osteoarthritis(OA) .
    

Detailed description: 
      Osteoarthritis (OA) is the most common cause of musculoskeletal pain and disability. It is a
      chronic degenerative disorder of multifactorial etiology, including acute and/or chronic
      insults from normal wear and tear, age, obesity and joint injury. The true pathogenesis
      remains poorly understood. OA is characterized by a degradation of the articular cartilage,
      resulting in an alteration of its biomechanical properties, which in turn contributes to a
      focal loss of articular cartilage, loss of joint space, osteophyte formation, focal areas of
      synovitis, per articular bone remodeling and sub chondral cysts , OA presents with symptoms
      such as joint pain, stiffness, motion limitations, motor and sensory dysfunction and
      functional impairments, thus, preventing patients from participating in regular physical
      activities , The common sites of OA appear on the knees, hands, and hips, whereas knee OA is
      the most common .

      Pain is the most frequent complaint for patients with knee OA to seek medical attention. If
      left untreated, pain and stiffness can result in a loss of physical function and independence
      during daily activities. The presence of OA-related knee pain has also been associated with
      increased risks of physical disability in the community .

      Many studies have revealed a discrepancy between patients' reports of pain and their
      radiographic findings , a plausible option is that the pain originates from the myofascial
      trigger points (MTrPs) in the surrounding muscles (myofascial pain) and cannot be visualized
      by imaging.

      The term myofascial pain is defined as "the complex of sensory, motor, and autonomic symptoms
      caused by MTrPs , MTrPs, hyperirritable spots found in the skeletal muscles, are associated
      with hypersensitive palpable nodules located in a taut band. The spots are painful on
      compression and may produce characteristic referred pain, referred tenderness, motor
      dysfunction, and autonomic phenomena.

      All studies found a high prevalence of myofascial pain in knee OA patients . study of OA
      patients, MTrPs were found in all participants, especially in the medial head of the
      gastrocnemius (92%) and the vastus medialis muscle (67%).

      The treatment of MPS includes:

      In activation of trigger points, relaxation of taut bands, and breaking the
      pain-spasm-ischemia-pain cycle. The most widely used treatment methods for MPS are education,
      exercise, non steroidal anti-inflammatory drugs (NSAIDs), superficial and deep heat,
      electrotherapy, laser therapy, and local injections.

      Laser treatment :

      Is non- invasive and painless and can be easily administered in therapy units for a wide
      range of conditions .

      Recently, high-intensity laser therapy (HILT) was introduced to the field of physical
      therapy. The advantage of HILT over Low level laser therapy(LLLT) is that HILT is able to
      reach and stimulate the large and/or deep joints that are difficult to reach in LLLT .

      The use of HILT has been proven to significantly reduce pain . Previous studies describe the
      anti-inflammatory, anti-edematous, and analgesic effects of HILT, thus justifying its use in
      the therapy of pain .
    

Intervention name(s): High intensity laser treatment; sham HILT.; knee osteoarthritis conventional exercises program
Intervention type(s): Radiation; Device; Other
Intervention description(s): 20 patients received high power laser therapy . Zimmer High power laser applied by laser probe perpendicular to and in slight contact with the skin around knee joint , the total energy was delivered to the patient during one session was 1060 j in 3 phases of treatment.; 20 patients received placebo laser " sham laser . The same treatment protocol of HILT was given to the sham group, but the laser instrument was switched off during applications. All laser applications were performed by the same physiotherapist.; knee osteoarthritis conventional exercises program in form of stretching exercises for both vastus medialis and gastrocnemius muscles , ROM exercises for knee flexion and extension , and isometric strengthening exercise of previously mentioned muscles .
all interventions were done under the supervision of physiotherapist for 30 minutes once a day for 3 days per week during a period of 4 weeks.
Other intervention name(s): Zimmer High power laser (with 810 and 980 nm and maximal output power of pmax 7 w cw , made in Germany) with serial number : IEC 60825-1:2007
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Treatment