Tendinopathy involves cellular apoptosis, matrix disorganization and neovascularization.Classic characteristics of "tendinosis" include degenerative changes in the collagenous matrix, hypercellularity, hypervascularity, and a lack of inflammatory cells which has challenged the original misnomer "tendinitis".Histological findings include granulation tissue, microrupture, degenerative changes, and there is no traditional inflammation. As a consequence, "lateral elbow tendinopathy or tendinosis" is used instead of "lateral epicondylitis".Examination of tennis elbow tissue reveals noninflammatory tissue, so the term "angiofibroblastic tendinosis" is used.Cultures from tendinopathic tendons contain an increased production of type III collagen.Longitudinal sonogram of the lateral elbow displays thickening and heterogeneity of the common extensor tendon that is consistent with tendinosis, as the ultrasound reveals calcifications, intrasubstance tears, and marked irregularity of the lateral epicondyle. Although the term "epicondylitis" is frequently used to describe this disorder, most histopathologic findings of studies have displayed no evidence of an acute, or a chronic inflammatory process. Histologic studies have demonstrated that this condition is the result of tendon degeneration, which causes normal tissue to be replaced by a disorganized arrangement of collagen. Therefore, the disorder is more appropriately referred to as "tendinosis" or "tendinopathy" rather than "tendinitis".Colour Doppler ultrasound reveals structural tendon changes, with vascularity and hypo-echoic areas that correspond to the areas of pain in the extensor origin.Load-induced non-rupture tendinopathy in humans is associated with an increase in the ratio of collagen III:I proteins, a shift from large to small diameter collagen fibrils, buckling of the collagen fascicles in the tendon extracellular matrix, and buckling of the tenocyte cells and their nuclei.
Treatment of tendinitis helps reduce some of the risks of developing tendinosis, which takes longer to heal.There is tentative evidence that low-level laser therapy may also be beneficial in treating tendinopathy. The effects of deep transverse friction massage for treating tennis elbow and lateral knee tendinitis is unclear. NSAIDs
NSAIDs may be used to help with pain. They however do not alter long term outcomes. Other types of pain medication, like paracetamol, may be just as useful. Steroids
Steroid injections have not been shown to have long term benefits but have been shown to be more effective than NSAIDs in the short term. They appear to have little benefit in tendinitis of the rotator cuff. There are some concerns that they may have negative effects. Other injections
There is insufficient evidence on the routine use of injection therapies (autologous blood, platelet-rich plasma, deproteinised haemodialysate, aprotinin, polysulphated glycosaminoglycan, skin derived fibroblasts etc.) for treating Achilles tendinopathy. As of 2014 there was insufficient evidence to support the use of platelet-rich therapies for treating musculoskeletal soft tissue injuries such as ligament, muscle and tendon tears and tendinopathies. Prognosis
Initial recovery is usually within 2 to 3 months, and full recovery usually within 3 to 6 months. About 80% of people will fully recover within 12 months. Epidemiology
Tendon injury and resulting tendinopathy are responsible for up to 30% of consultations to sports doctors and other musculoskeletal health providers. Tendinopathy is most often seen in tendons of athletes either before or after an injury but is becoming more common in non-athletes and sedentary populations.