What Is the Difference Between Tendonitis, Tendinosis, and Tendinopathy?

A tendon is a fibrous band of tissue that connects a muscle to a bone. Doctors have many names for describing when tendon tissue is inflamed, injured or damaged, including tendonitis, tendinosis, and tendinopathy as well as paratenonitis, tenosynovitis, and tendon tear (rupture).

Knowing these names and understanding the conditions they refer to can help patients understand their treatment plan and take steps to prevent future tendon problems.

Below are descriptions of the terms used to describe common tendon conditions.

Tendonitis

Once used to describe almost any tendon pain, medical professionals now only use the term tendonitis to describe acute inflammation of the tendon due to small (micro) tears (the suffix “itis” indicates inflammation).¹Bass E. Tendinopathy: why the difference between tendinitis and tendinosis matters. Int J Ther Massage Bodywork. 2012;5(1):14-7. Common symptoms include localized pain, swelling, and warmth.²Cooper, C. (2014). Elbow, Wrist, and Hand Tendinopathies. In Fundamentals of Hand Therapy (pp. 383–393). Elsevier. https://doi.org/10.1016/b978-0-323-09104-6.00028-6

Read about Achilles Tendonitis and Tendon Injuries

Tendonitis may develop as a result of a sudden, acute injury or repeated micro-traumas to a tendon or group of tendons. Recommended treatments to reduce inflammation may include resting the affected joint and taking over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (e.g. Motrin, Advil), or naproxen (e.g. Aleve, Naprosyn). Patients with tendonitis typically recover within several weeks.

Research suggests tendon inflammation is uncommon,¹Bass E. Tendinopathy: why the difference between tendinitis and tendinosis matters. Int J Ther Massage Bodywork. 2012;5(1):14-7. and what is often diagnosed as tendonitis, may actually be tendinosis¹Bass E. Tendinopathy: why the difference between tendinitis and tendinosis matters. Int J Ther Massage Bodywork. 2012;5(1):14-7.^,2Cooper, C. (2014). Elbow, Wrist, and Hand Tendinopathies. In Fundamentals of Hand Therapy (pp. 383–393). Elsevier. https://doi.org/10.1016/b978-0-323-09104-6.00028-6^,3Ahmad Z, Siddiqui N, Malik SS, Abdus-samee M, Tytherleigh-strong G, Rushton N. Lateral epicondylitis: a review of pathology and management. Bone Joint J. 2013;95-B(9):1158-64.^,4Bishai SK, Plancher KD. !e basic science of lateral epicondylosis: Update for the future. Tech Orthop 2006;21:250–255.^,5Abate M, Silbernagel KG, Siljeholm C, et al. Pathogenesis of tendinopathies: inflammation or degeneration?. Arthritis Res Ther. 2009;11(3):235.^,6Mcauliffe JA. Tendon disorders of the hand and wrist. J Hand Surg Am. 2010;35(5):846-53. (defined below). Chronic tendonitis may lead to tendinosis.¹Bass E. Tendinopathy: why the difference between tendinitis and tendinosis matters. Int J Ther Massage Bodywork. 2012;5(1):14-7.

Tendinosis

Tendinosis is the non-inflammatory degeneration of a tendon. This degeneration can include changes to the structure or composition of the tendon. These changes often result from repetitive strain-injuries to a tendon without adequate time to heal.¹Bass E. Tendinopathy: why the difference between tendinitis and tendinosis matters. Int J Ther Massage Bodywork. 2012;5(1):14-7.^,2Cooper, C. (2014). Elbow, Wrist, and Hand Tendinopathies. In Fundamentals of Hand Therapy (pp. 383–393). Elsevier. https://doi.org/10.1016/b978-0-323-09104-6.00028-6

Key differences between tendonitis and tendinosis:

• Unlike tendonitis, tendinosis may take several months to treat.
• Treatment methods for tendinosis and tendonitis may vary. For example, some experts argue that tendinosis should not be treated with NSAIDs or corticosteroids. They believe these drugs inhibit the normal reconstruction of the tendon and weaken its structure, causing long-term healing problems.⁷Rees JD, Stride M, Scott A Tendons – time to revisit inflammation Br J Sports Med 2014;48:1553-1557.^,8Oliva F, Via AG, Maffulli N. Physiopathology of intratendinous calcific deposition. BMC Med. 2012;10 95-7015-10-95.

Tendinosis usually affects people who engage in high intensity activities or sports requiring repeated tendon movement.

Tendinopathy

Tendinopathy is typically used to describe any problem involving a tendon. The suffix “pathy” is derived from Greek and indicates a disease or disorder. Therefore, tendinopathy literally means a disease or disorder of a tendon.

While most experts define tendinopathy as an umbrella term to describe all tendon conditions, others may use it to describe a chronic tendon condition that fails to heal.⁹Sharma P, Maffulli N. Biology of tendon injury: healing, modeling and remodeling. J Musculoskelet Neuronal Interact. 2006;6(2):181-90. For example, a runner who has suffered a repetitive hamstring tendon strain that does not heal properly may be diagnosed with tendinopathy.

See Chronic High (Proximal) Hamstring Tendinopathy

To avoid confusion, patients who are diagnosed with tendinopathy should ask their doctors to specify the details of their tendon injuries.

Paratenonitis

Certain tendons in the body, like the Achilles tendon, have a surrounding thin sheath of tissue, called the paratenon. Other tendons such as those in the wrists and hand are surrounded by a different type of tissue, called a synovial sheath.

• When the paratenon becomes inflamed it is called paratenonitis
• When the synovial sheath surrounding the tendon becomes inflamed, it is called tenosynovitis

Read about De Quervain’s Tenosynovitis

While tenosynovitis may be diagnosed with diagnostic tests, paratenonitis cannot be definitively diagnosed without a biopsy. Treatment for both paratenonitis and tenosynovitis involve reducing inflammation and restricting movement of the affected tendon.

Read about Nonsurgical Treatment for De Quervain’s Tenosynovitis

Complete and Partial Tendon Ruptures

When a tendon tears, it is also called a rupture. If a tendon is torn in two pieces it is called a complete rupture, and if some of the tendon still remains intact it is called a partial rupture.

Some physicians make a distinction between acute and chronic tendon ruptures.

• An acute tendon rupture is a one-time event that can result in immediate pain and decreased function of the affected joint and may be followed by swelling or bruising. An acute rupture is typically recognized and typically treated within two weeks of injury.
• Chronic tendon ruptures may result from:
  • A partial rupture that slowly worsens over a prolonged period, or
  • An acute rupture that goes untreated for several weeks (many experts believe this time varies between 4 to 6 weeks, depending on the tendon).¹⁰Flint JH, Wade AM, Giuliani J, Rue JP. Defining the terms acute and chronic in orthopaedic sports injuries: a systematic review. Am J Sports Med. 2014 Jan;42(1):235-41. doi: 10.1177/0363546513490656. Epub 2013 Jun 7. Review. PubMed PMID: 23749341.

Depending on the patient, the affected joint, the severity of the tear, and the duration of symptoms, a doctor may recommend either surgery, immobilization using a splint; or a period of rest to treat the tendon rupture.