Get the Diagnosis Right: It’s Not Tendonitis, It’s Tendinosis

Tendinosis vs Tendinopathy: What’s the Difference?

The word “tendon” comes from the Latin root “to tie”. When referring to bone or any other soft tissue, it refers to its connective tissues (the fibers that make up the muscle, ligament, nerve, etc.) and not necessarily to its structure. For example when someone says they have a sore shoulder joint, they are actually saying their tendons are tight.

When referring to bones, the term “bone” refers specifically to the skeleton itself. A bone does not include its connective tissues or blood vessels; therefore, when we say a person has osteoporosis, we mean that their bones are weak and may eventually break under stress.

In contrast, a tendon is made up of many different types of cells called fibroblasts which give rise to collagen fibers. Collagen fibers are what give our skin, hair, nails, teeth and bones their strength.

A tendon is usually composed of long strands of collagen fibers that run through it. These tendons form a network inside the body. They help support the muscles and joints in various ways such as keeping them flexible and strong during movement.

However, if these tendons become damaged or inflamed then they can cause pain and inflammation throughout your body.

The big difference between tendonitis and tendinosis is that the former is a short-term condition that refers to an acute inflammation of a tendon. On the other hand, the latter refers to a long-term degeneration of a tendon.

Tendonitis is more common in people who regularly engage in sports activity. For example, a person may place too much stress on their patellar tendon when playing basketball. The strain or pull on this tendon would be felt immediately.

It would cause immediate pain and the affected person would have to rest in order for the pain to go away. In the days following, the pain would slowly begin to subside.

In contrast, a tendon that has suffered from tendinosis has undergone degenerative changes over a period of time. This can be the result of an accident or perhaps a more common cause is due to repetitive stress being placed on that tendon. In the case of tendinosis, the pain does not come on immediately.

Get the Diagnosis Right: It's Not Tendonitis, It's Tendinosis - Image

It can happen hours or even days after the initial incident that caused the injury. The pain can be persistent and may gradually get worse over a long period of time.

Other Types of Tendon Injuries

There are three main types of tendon injuries including tendonitis, tenosynovitis and tendon rupture. Of these three, tendonitis is the most common. We have briefly described tendonitis above.

Sources & references used in this article:

Patellar tendinopathy in athletes by KHE Peers, RJJ Lysens – Sports Medicine, 2005 – Springer

Current opinions on tendinopathy by JF Kaux, B Forthomme, C Le Goff… – Journal of sports …, 2011 –

Distribution of sonographically detected tendon abnormalities in patients with a clinical diagnosis of chronic achilles tendinosis by WW Gibbon, JR Cooper… – Journal of clinical …, 2000 – Wiley Online Library

Patellar tendinopathy: diagnosis and treatment by D Figueroa, F Figueroa, R Calvo – JAAOS-Journal of the American …, 2016 –

Overuse tendinosis, not tendinitis: Part 2: Applying the new approach to patellar tendinopathy by JL Cook, KM Khan, N Maffulli… – The Physician and …, 2000 – Taylor & Francis

‘Lateral elbow tendinopathy’is the most appropriate diagnostic term for the condition commonly referred-to as lateral epicondylitis by D Stasinopoulos, MI Johnson – Medical hypotheses, 2006 – Elsevier

Long head of the biceps tendinopathy: diagnosis and management by SJ Nho, EJ Strauss, BA Lenart… – JAAOS-Journal of the …, 2010 –

Calcific tendinopathy of the rotator cuff: pathogenesis, diagnosis, and management by HK Uhthoff, JW Loehr – JAAOS-Journal of the American Academy …, 1997 –

High hamstring tendinopathy in runners: meeting the challenges of diagnosis, treatment, and rehabilitation by M Fredericson, W Moore, M Guillet… – The Physician and …, 2005 – Taylor & Francis