We cover the latest research into the chronic tendon injuries commonly called tendinopathy, tendinosis, and repetitive strain injury.
Chronic tendon injuries occur over time as the collagen that forms the tendons becomes increasingly abnormal. Researchers are trying to find ways to improve healing in these chronic injuries.
About 16.5 million tendon and ligament injuries have been reported per year in the USA, and a great many of these injuries are chronic. If you have a chronic tendon injury, this site can help you.
If you are new to tendon pain:
The BasicsInside StoryFailed HealingFor news from the research front:
Research NewsWe cover the latest research into the chronic tendon injuries commonly called tendinopathy, tendinosis, and repetitive strain injury.
Chronic tendon injuries occur over time as the collagen that forms the tendons becomes increasingly abnormal. Researchers are trying to find ways to improve healing in these chronic injuries.
About 16.5 million tendon and ligament injuries have been reported per year in the USA, and a great many of these injuries are chronic. If you have a chronic tendon injury, this site can help you.
If you are new to tendon pain:
The BasicsInside StoryFailed HealingFor news from the research front:
Research NewsDo you have pain in a tendon that started from some specific activity and gradually became so much worse that the pain now accompanies all kinds of activities? The pain might burn, sting, or ache. Sometimes the pain can start without knowing the cause, but usually you'll know it started from a repetitive motion activity such as typing, tennis, playing the drums, or running. You can often tell that the pain is located specifically in a tendon, and you can point to the spot.
Chronic tendon injuries like those described above are called tendinosis or tendinopathy. These words refer to an accumulation over time of small-scale tendon injuries that don't heal properly, resulting in a chronic injury of failed healing. Although you can't see the tendinosis/tendinopathy injury on the outside of your body, researchers can see the injury on the cellular scale by viewing slides of tendons under the microscope. Tendinopathy can occur in many different areas, such as the wrist, forearm, elbow, shoulder, knee, and heel.
Tendons are rope-like structures that attach muscles to bones. Ligaments are similar structures that attach bones to other bones. When muscles and bones move, they exert stresses on the tendons and ligaments that are attached to them.
When your muscles move in new ways or do more work than they can handle, your muscles and tendons can sustain some damage on a cellular scale. If the increase in demand is made gradually, muscle and tendon tissues will usually heal, build in strength, and adapt to new loads. Athletes use these principles to build muscle and tendon strength with good training programs.
You can, however, do some activity that injures a tendon on a microscopic scale and then do more injury before the tendon heals. If you continue the injurious activity, you will gradually accumulate these micro-injuries. When enough injury accumulates, you'll feel pain. This kind of injury that comes on slowly with time and persists is a chronic injury. (Acute tendon injuries, on the other hand, are sudden tears that cause immediate pain and swelling.) Tendon injuries often require patience and careful rehabilitation with physical therapy because tendons heal more slowly than muscles.
Tendinitis: The suffix "itis" means inflammation; the term tendinitis should be reserved for acute tendon injuries accompanied by inflammation.
Tendinosis: The suffix "osis" implies a pathology of chronic degeneration without inflammation. Tendinosis is an accumulation over time of microscopic tendon injuries that don't heal properly. Although inflammation can be involved in the initial stages of the injury, it is the inability of the tendon to heal that perpetuates the pain and disability.
Tendinopathy: Tendinopathy is a term that has no implication about the pathology of the injury, so it is more general and is being used more frequently today. The role of inflammation on the cellular level in tendinopathy is currently under study and debate, but some inflammatory processes have been shown to exist.
Paratenonitis: Paratenonitis is inflammation of a thin sheath of tissue called the paratenon that surrounds some tendons, such as the Achilles.
Tenosynovitis: Tenosynovitis is inflammation of the synovial sheath that surrounds some tendons, such as the flexor tendons in the hands.
Chronic injuries occur slowly over time and persist, as opposed to acute injuries like tendon ruptures (partial or complete), that occur suddenly.
Tendinopathy can result from long hours of activities such as playing sports, using computers, playing musical instruments, or doing manual labor. It can result from activities performed as part of your profession or recreation. Some occupations that have increased risk for chronic tendon injuries include assembly line workers, computer programmers, writers, court recorders, data entry processors, sign language interpreters, cashiers, professional athletes, and musicians. The amount of overuse (per day, month, year) and lack of recovery time affects the severity of the injury.
Some health and medical conditions can predispose you to tendinopathy. If you are overweight and/or have diabetes, you have increased risk. Losing weight, improving your diet, and controlling your blood sugar can improve your tendons. Women are more prone to tendinopathy after menopause, and older people (over 60) in general are more prone than younger people. Certain collagen diseases can also predispose you (see Genetics, below). Maintaining fitness with proper training techniques can help to reduce risk. Using ergonomic tools in your daily activities also reduces risk.
Genetics play a factor in tendinopathy, but much more research is needed in this area. Collagen defects like Ehlers-Danlos Syndrome seem to be associated with higher risk for acute and chronic tendon injuries, and other specific genetic variants are being discovered. Here is a sampling of some research into genetic variants that seem to be associated with increased risk for tendinopathy.
Four classes of prescription drugs have been associated with chronic tendon injuries: quinolones, long-term glucocorticoids, statins, and aromatase inhibitors. Antibiotics in the fluoroquinolone family (such as Cipro, Levaquin, and Avelox) have been associated with serious tendon injuries in some people. Many patients are not informed of this risk and are not given the chance to decide whether to take an alternative antibiotic. The FDA issued a warning about quinolones in May 2016, saying that their risks outweigh their benefits for sinusitis, bronchitis, and UTI whenever other treatment options can be used instead. A case study about fluoroquinolone-induced tendinopathy can be found here. Some studies have raised questions about the effects of statins on tendons, such as one study that found differences in collagen construction during healing of tendon injuries with and without statins, and one study that found changes in tendons after chronic exposure to statins, and one study that found statins have negative effects on mesenchymal stem cells; however, a systematic review of literature did not find a cause and effect relationship between statins and tendinopathy, so the jury is still out on statins.
Tendinopathy usually sneaks up on you. At first, the pain only comes after a long or hard session of the activity that aggravates it. Later, the pain comes at lower levels of the activity and lasts longer. Finally, the pain becomes a part of your daily life and even normal activities can make it worse. Try to catch the injury as early as you can. Whatever your activity, you can help minimize your risk by following these tips:
You should see a specialist for diagnosis and treatment. Sports medicine doctors and physiatrists are often excellent choices for chronic tendon injuries, and they will likely refer you to a physical therapist. Sometimes a rheumatologist can also be helpful. You can use sites like this one to learn more about your injury and treatments for it, but you'll need a doctor to help design a program tailored to your specific case and needs..
Diagnosis of tendinopathy is usually made through evaluation of medical history and symptoms, physical exam, and imaging with MRI or ultrasound. Some statistics comparing the accuracy of ultrasound vs MRI in diagnosis of tendinopathy can be found in a summary of the 2012 second International Scientific Tendinopathy Symposium (ISTS) in Vancouver (this article also summarizes current treatments).
