Tendinitis, Tendinosis, Tendinopathy – Do you know the difference?

In the UK the average Anatomy & Physiology course contains little information about tendons beyond that “they attach muscle to bone”, as opposed to ligaments which “attach bone to bone”. Sound familiar? When learning how to massage the emphasis is on origin and insertion with treatment being focussed on the muscle belly. If you have trained or are training in remedial or sports massage then you will have studied some pathologies associated with tendons, but treatment protocols will largely consist of conservative management techniques for inflamed tissue. After all that’s what it says in the majority of text books; however, it would seem little has been done to stay up-to-date with current research and practices developed largely in physiotherapy. This article therefore aims to explore how to select techniques that will be effective in resolving issues with tendons based on science, research and practical experience.

Anatomy of a Tendon

Before discussing pathologies, it is important to understand the structure of a tendon. According to Kanus (2000), tendons consist of collagen (mostly type I collagen) and elastin embedded in a proteoglycan-water matrix with collagen accounting for 65-80% and elastin approximately 1-2% of the dry mass of the tendon.

Collagen

The organisation of collagen is not dissimilar to that of muscle tissue in that collagen aggregates into microfibrils and then into fibrils which form a collagen fibre, the basic unit of a tendon. Each collagen fibre is surrounded by a sheath of connective tissue called endotenon which binds fibres together. A bunch of collagen fibres forms a primary fibre bundle, and a group of primary fibre bundles forms a secondary fibre bundle. A group of secondary fibre bundles, in turn, forms a tertiary bundle, and the tertiary bundles make up the tendon. The entire tendon is surrounded by a fine connective tissue sheath called epitenon.

The function of a tendon

Kanus explains that the complex structure of the tendon is important in preventing damage. Within one collagen fibre, the fibrils lie in three directions; longitudinal, transverse and horizontal. Some of the longitudinal fibres cross each other forming spirals. Similarly, some of the fibrils form spiral-type plaits. The basic function of the tendon is to transmit the force created by the muscle to the bone, and, in this way, make joint movement possible. During various phases of movements, the tendons are exposed not only to longitudinal but also to transversal and rotational forces. In addition, they must be prepared to withstand direct contusions and pressures. The three-dimensional internal structure of the fibres thereby forms a buffer medium against forces of various directions.

So what is the difference between tendinitis, tendinosis and tendinopathy?

In a nutshell, tendinopathy is a clinical diagnosis of pain, stiffness and impaired tendon function. Perhaps the most widely understood term is tendinitis being inflammation of tendon tissue. Contrary to long-held belief it is also the least likely tendon pathology you will encounter in your clinic. Tendinosis by contrast is a degeneration of the tendon’s collagen in response to chronic overuse.

Tendinitis explained

To expand a little more on these terms, let’s look first at tendinitis. This is an acute injury caused when the tendon is overloaded with symptoms including pain and swelling from tears in the affected tendon. Treatment is as usual for an acute soft-tissue injury and will include PRICE and anti-inflammatory medication initially, followed by massage to encourage the healing process and a gradual return to activity. This would take place over approximately six weeks.

Tendinosis explained

Tendinosis on the other hand is a chronic injury and although there is pain, there is little or no inflammation present and so PRICE and anti-inflammatory medication would be ineffective and may even prevent collagen repair. This pathology is a degeneration of the tendon’s collagen in response to chronic overuse. When overuse is continued without giving the tendon time to heal and rest, such as with repetitive strain injury, tendinosis will result. Even tiny movements, such as clicking a mouse can cause tendinosis when done repeatedly. Bass (2012) states that a microscopic view of tendinosis reveals an increase of immature type III collagen fibres (mature type I fibres dominate in healthy tendon tissue); loss of collagen continuity so that collagen fibres are no longer aligned with each other and sometimes fail to link together to facilitate load-bearing; an increase in ground substance (the material between the body’s cells); and a haphazard increase of vascularization. These vascular structures “do not function as blood vessels” and “are not associated with increased healing.” The appearance of the tendon shifts from a reflective, “white, glistening and firm” surface to a “dull-appearing, slightly brown and soft” surface. These changes result in a loss of strength in the tendon and an increase in its bulk.

So, what is the difference?

The confusion about the difference between tendinitis and tendinosis is widespread. Many injuries commonly presumed to be tendinitis are actually tendinosis. For example, tennis elbow is usually described as tendinitis of extensor carpi radialis brevis; however, medical research has not been able to find evidence of any inflammation in patients with clinically diagnosed tennis elbow syndrome. This proves that tennis elbow is not tendinitis but that it is actually tendinosis. The most important reason to distinguish between tendinitis and tendinosis is the differing treatment goals and timelines. The most prominent treatment goal for tendinitis is to reduce inflammation. By contrast, some treatments to reduce inflammation are contraindicated with tendinosis. For example, Ibuprofen is associated with inhibited collagen repair.

The healing time for tendinitis is several days to 6 weeks, depending on whether treatment starts with early presentation or chronic presentation. Khan et al (2002) states that treatment for tendinosis recognised at an early stage can be as brief as 6–10 weeks; however, treatment once the tendinosis has become chronic can take 3–6 months. It is suggested by Rattray and Ludwig (2001) that effective treatment might take up to 9 months once the tendinosis is chronic. Knowing these timelines is part of creating an effective treatment plan. Khan et al (2002) support this by suggesting that tendons “require over 100 days to make new collagen.” Given this claim, treating chronic tendinosis for a matter of weeks would provide little benefit to the long-term repair of the tendon.

Massage Helps

After the acute phase and as part of a complete treatment programme, both tendinitis and tendinosis benefit from deep-friction massage. According to Bass (2012), in the case of tendinitis deep friction serves to reduce adhesions and create functional scar tissue once inflammation has subsided. In the case of tendinosis, deep-friction treatments serve to stimulate fibroblast activity and collagen production.

Treatment and self-care recommendations for tendinosis include rest, paying attention to ergonomics/biomechanics, use of appropriate support, conservative stretching and movement, application of ice, eccentric strengthening, massage and nutrition (various vitamins and minerals are important for collagen production). It is unlikely that the damage will be completely reversed; however, the strength of the tendon can be increased, pain can be decreased and normal daily activities can be resumed. Nevertheless, it is important to note that the tissue changes caused by tendinosis make the tendon vulnerable to injury, so an ongoing programme of massage, stretching and strength training can all help to prevent this occurring.

Massage Therapy Research

As demonstrated, it is vital to differentiate between these pathologies in order to select the correct treatment protocol and deliver an effective plan for recovery. As massage therapists it is important that we make use of research in order to provide evidence-based practice wherever possible.

So what are the scientists’ conclusions about massage therapy and treatment of tendon pathologies?

In February 2016, Jerrilyn Cambron, President of the Massage Therapy Foundation reviewed research conducted on people with a wide range of musculoskeletal conditions including tendinitis, tendinopathy and tendinosis. After reviewing several research studies, she concluded that “more high quality research is needed on specific conditions using consistent treatment methods.” The over-riding problem with the research was that it hadn’t been limited to conditions affecting tendons or focussed sufficiently on soft-tissue manipulation to be conclusive. This makes evidence-based practice in this case hard to justify.

So where does that leave us? In my view, it remains important to consider the history of the injury, the timeline and the physiology of tendons. We should also continue to look to science to develop our understanding of this important structure that does so much more than “attach muscle to bone”.

At Complementary Health Professionals, I offer one day workshops in advanced massage as well as a Sports Massage Diploma. If you are interested in furthering your knowledge as a massage practitioner and want to become more effective in your clinical outcomes, please visit our website and review the course listing and CPD listing pages.

Bass E. 2012 Tendinopathy: Why the Difference Between Tendinitis and Tendinosis Matters International Journal of Therapeutic Massage & Bodywork Vol 5(1):14-17

Cambron J. 2016 Is massage therapy effective for musculoskeletal disorders? http://www.massageandbodyworkdigital.com/i/640605-march-april-2016 <accessed 11/11/2016>

Kannus P. 2000 Structure of the Tendon Connective Tissue Scand J Med Sci Sports. Vol10(6):312-20. Review

Khan K.M., Cook J.L., Kannus P., Maffulli N., Boner SF. 2002 Time to abandon the “tendinitis” myth: Painful, overuse tendon conditions have a non-inflammatory pathology BMJ. Vol 324(7338): 626-627

Rattray F, Ludwig L. Clinical Massage Therapy: Understanding, Assessing and Treating Over 70 Conditions Elora, Ontario: Talus Inc; 2001

Images

Anatomy of a Tendon image courtesy of Encyclopedia Britannica

https://www.britannica.com/science/tendon <accessed 13/11/2016>

Tendontitis image courtesy of the Colorado Foot Institute at http://coloradofootinstitute.com/achilles_tendonitis.html <accessed 13/11/2106>

Tendinosis Image courtesy of http://www.stretching-exercises-guide.com/runners-stretches.html <accessed 13/11/2016>

Massage Image courtesy of http://acupunturayosteopatia.com/tendinitis-aquilea-tratamiento/ <accessed 13/11/2016>