Kansas State University (Lafene Health Center, Department of Family & Community Medicine, and Athletics Department), Wichita kvg3355@ksu.edu
The author reported no potential conflict of interest relevant to this article.
Tendinopathy, tendinitis, tendinosis, paratenonitis—they are not synonymous. Here you’ll find a review of their pathophysiology and best approaches to treatment.
The vast majority of patients with tendon problems are successfully treated nonoperatively. But which treatments should you try (and when), and which are not quite ready for prime time? This review presents the evidence for the treatment options available to you. But first, it’s important to get our terminology right.
Tendinitis vs tendinosis vs paratenonitis: Words matter
The term “tendinopathy” encompasses many issues related to tendon pathology including tendinitis, tendinosis, and paratenonitis.1,2 The clinical syndrome consists of pain, swelling, and functional impairment associated with activities of daily living or athletic performance.3 Tendinopathy may be acute or chronic, but most cases result from overuse.1
In healthy tendons, the collagen fibers are packed tightly and organized in a linear pattern (FIGURE 1A). However, tendons that are chronically overused develop cumulative microtrauma that leads to a degenerative process within the tendon that is slow (typically measured in months) to heal. This is due to the relative lack of vasculature and the slow rate of tissue turnover in tendons.2,4,5
Sports and manual labor are the most common causes of tendinopathy, but medical conditions including obesity, high blood pressure, diabetes, and high cholesterol are associated risk factors. Medications, particularly fluoroquinolones and statins, can cause tendon problems, and steroids, particularly those injected intratendinously, have been implicated in tendon rupture.4,6
The term “tendinitis” has long been used for all tendon disorders although it is best reserved for acute inflammatory conditions. For most tendon conditions resulting from overuse, the term “tendinosis” is now more widely recognized and preferred.7,8 Family physicians (FPs) should recognize that tendinitis and tendinosis differ greatly in pathophysiology and treatment.3
Tendinitis: Not as common as you think
Tendinitis is an acute inflammatory condition that accounts for only about 3% of all tendon disorders.3 Patients presenting with tendinitis usually have acute onset of pain and swelling typically either from a new activity or one to which they are unaccustomed (eg, lateral elbow pain after painting a house) or from an acute injury. Partial tearing of the affected tendon is likely, especially following injury.2,3
Tendinosis: A degenerative condition
In contrast to the acute inflammation of tendinitis, tendinosis is a degenerative condition induced by chronic overuse. It is typically encountered in athletes and laborers.2,5,8,9 Tendinotic tissue is generally regarded as noninflammatory, but recent research supports inflammation playing at least a small role, especially in closely associated tissues such as bursae and the paratenon tissue.10