Tendinitis and Other Tendon Injuries

Por Linda Rath | 10 de julio de 2024

Tendons are thick bands of tissue that attach muscles to bone. Their job is to move bones when a muscle tightens or relaxes. Tendons are made mostly of collagen that's arranged in bundles. Some tendons in the hands and feet are covered with a sheath of tissue (the synovial membrane) that produces a fluid that helps the tendon glide smoothly within the sheath.   

There are thousands of tendons in the body; the size and shape depend on their location and function. Short, thick tendons are associated with powerful muscles, like the four quadriceps muscles in the front of the thighs. Strengthening these muscles can help prevent and treat knee pain, especially from osteoarthritis (OA). Tendons in the fingers are longer, thinner and can perform finer movements. 

While tendon injuries can happen to anyone, they’re more common in athletes, people who exercise vigorously, those whose jobs require repetitive movements and in adults over 40, when tendons start to lose their strength and flexibility.  

Types of Tendon Injuries

The three main types of tendon injuries have similar symptoms but different treatments, outcomes and spellings. Here's a closer look.

What it is: Inflammation and swelling in a tendon near where it attaches to a bone. It usually causes a dull achy pain. Tendinitis can occur in any tendon but is especially common around the shoulders, knees, elbows and heels. 

Causas 

A sudden injury like a fall or blow to the body can sometimes cause tendinitis, but it’s more likely to result from: 

• Repetitive movements. This is by far the most common cause of tendinitis. Anything you do over and over, whether it’s playing sports (running, throwing, hitting), working at a physically or ergonomically demanding job, gardening or even cleaning, can inflame a tendon.
• Certain medications. Corticosteroids, statins and aromatase inhibitors (a breast cancer treatment) can also damage tendons. Certain antibiotics called “fluoroquinolones,” such as ciprofloxacin (Cipro) have carried a boxed warning for tendinitis and tendon rupture since 2008. The Food and Drug Administration (FDA) has since strengthened this warning, advising doctors to reserve these for patients who have no other treatment options to avoid severe and irreversible side effects, including tendon rupture. They can also interact with methotrexate, but that’s less likely with lower doses for arthritis than the high doses used to treat cancer.
• Spondyloarthritis (SpA). A family of rheumatic diseases that can cause pain and swelling at the point where tendons and ligaments attach to bone, called entheses. An example is the Achilles tendon, which connects the calf muscle to the heel bone. In one study, SpA patients who had Achilles tendinitis had worse outcomes at two years than those who didn’t have tendinitis.

Tratamiento

Tendinitis almost always gets better on its own or with fairly simple measures, including: 

• Rest. Taking a break from the activity that caused tendinitis is key. Be sure to allow enough time for the tendon to heal fully – usually four to six weeks, depending on how serious the injury is. You should still continue to exercise to maintain muscle strength and overall fitness. If you have a shoulder or biceps injury, consider jogging or other lower body exercises. For Achilles tendonitis, you might start with swimming and other low-impact exercises, then slowly work up to more weight-bearing activities.
• Over-the-counter pain relievers such as naproxen sodium (Aleve) or ibuprofen (Advil, Motrin). Although doctors often recommend them, some experts believe these drugs delay healing. Icing the tendon the day of injury and topical pain relievers may work as well as pills for some people.
• Platelet-rich plasma (PRP). This involves taking a sample of your blood and spinning it down to concentrate platelets, which contain growth factors, anti-inflammatory proteins and signaling molecules that promote healing. Although PRP injections have proved effective for tendon injuries, many insurers don’t cover them. 
• Fisioterapia. When tendinitis is severe or slow to heal, physical therapy is essential to restore lost strength and range of motion. Physical therapists mainly focus on eccentric exercise, a type of resistance training that emphasizes the lowering phase of an exercise. One example: the phase of a biceps curl when you bring the weight down from the curl.  Eccentric exercise is better at building muscle, and it’s also thought to help build more collagen in tendons.

What It Is

Degeneration of the collagen in a tendon, leading to pain, stiffness and limited range of motion. Unlike tendinitis, tendinosis doesn't ultimately involve inflammation, though it usually starts that way. For reasons that aren't fully understood, the initial inflammation doesn't fully go away. In time, collagen fibers start to deteriorate, becoming harder, thicker and more disorganized. Some experts suspect that treating inflammation with nonsteroidal anti-inflammatories (NSAIDs) or corticosteroids may interfere with healing.

Tendinosis affects the same joints as tendinitis. Doctors used to think tendinitis was more common, but it now seems likely that tendinosis simply isn't recognized and diagnosed as often. A simple, in-office ultrasound can help providers tell the difference.

Despite efforts to standardize the terminology, some doctors refer to tendinosis as tendinopathy, while others consider tendinopathy a blanket term for all tendon problems. Be sure you understand what your doctor means when they diagnose a tendon injury.

Causas 

Tendons can deteriorate over time, even in people who aren't active. But for the most part, the same overuse, overloading and medications that lead to tendinitis also can cause tendinosis.

• High-intensity sports or overuse – about half of all sports-related injuries involve a tendon
• Repetitive movements, including using a keyboard or mouse for hours without a break
• Older age 
• Diabetes, which makes tendons thicker and more likely to tear. The troublemakers here are advanced glycation end products (AGEs), which form when proteins or fats mix with sugar in your bloodstream. AGEs bond to the collagen in tendons, changing its structure and making it less able to withstand normal stress. Diabetes also makes it harder for a damaged tendon to heal properly.
• Statins, corticosteroids and fluroquinolone antibiotics, especially ciprofloxacin (Cipro). Taking both Cipro and steroids raises the risk of tendon rupture nearly 50-fold.  

Tratamiento

Like tendinitis, treatment for tendinosis focuses on taking a break from any activity that contributed to it, icing the tendon and eccentric exercise training with a physical therapist. Over-the-counter NSAIDs and steroids aren't recommended. While they may provide short-term relief, they can damage tendons over time. Tendinosis takes longer to heal than tendonitis - about three to six months. If you're not any better after three months, other options include:

• Platelet rich plasma
• Percutaneous ultrasonic tenotomy (PUT). In this brief, minimally invasive procedure, a small ultrasonic needle device is inserted through the skin to remove damaged tendon tissue and stimulate healing. PUT received FDA approval 14 years ago and is often used to successfully treat tendon injuries.  
• Stem cell therapy. Recent studies suggest that stem cells can be an effective treatment for injured tendons. Stem cells divide to make exact copies of themselves but can also turn into different types of specialized cells, including tendon cells.
   

What It Is

Tenosynovitis is inflammation of the protective sheath around tendons, mainly in the hands, wrists and feet. These parts of the body are particularly vulnerable because tendons are small and intricately arranged to enable fine movements.

Tenosynovitis can cause pain and swelling and interfere with normal movement of a joint. Two of the most common types of tenosynovitis are deQuervain tenosynovitis, which affects tendons at the base of the thumb, and trigger finger, in which finger tendons freeze in a curled position, unable to straighten or fully bend.
 

Causas

Tenosynovitis can result from the same overuse and repetitive motion injuries as tendinitis and tendinosis, but it doesn't affect the Achilles tendon, which doesn't have a sheath. Tenosynovitis is also closely associated with diabetes, occurring in about 10% to 20% of people with the disease, and with autoimmune and inflammatory forms of arthritis.

• Rheumatoid arthritis (RA). Estimates vary, but recent research suggests about 87% of people who have RA develop tenosynovitis. Recent research also suggests it may be the earliest warning sign of the disease, visible at first only on imaging tests. 
• Gout. Estimates of the number of gout patients who have tenosynovitis also vary widely. One small older study found that 16% of people who have gout have tendon sheath inflammation.  
• Infecciones. Many infections can spread to the tendon’s synovial membrane, leading to infectious tenosynovitis. Depending on the germs involved, this can be very serious, causing severe damage to the tendon and surrounding tissues.

Tratamiento

Treatment depends on the cause, though splints and braces are often recommended for many people with hand and wrist tenosynovitis. Other treatments include:

• Taking a break from the activity that caused the inflammation
• Icing the affected area
• Working with a physical therapist  
• Controlling diabetes and arthritis  
• Treating infectious tenosynovitis, usually with antibiotics 

It's not always possible to prevent tendon injuries, especially if you play sports, train hard or have a repetitive job or hobby. Still, some things can reduce your risk:

• Ease into new exercises
• Give your body time to recover after vigorous activity or sports
• Take breaks about every 30 minutes from a job or activity that requires repetitive movements
• Try to avoid medications known to damage tendons, including steroids and ciprofloxacin
• Stay active to keep muscles and tendons strong and flexible