About tendon injury.
Tendinosis is tendinitis that can’t be proven to be associated with inflammation, but tendinitis is. Or maybe tendinosis might be failed repair of a previously inflamed tendon, so might be tendinitis then not tendinitis. Also, tendinosis is chronic and is not painful except when it is painful, and then maybe it’s tendinitis again. Unless its tenosynovitis, which definitely is inflammatory. Or maybe that was paratenonitis.
If you are, you are part of long list of health care providers and researchers who have struggled with tendon pathology, the terminology used to describe it, and what to do about it when it is detected.
For some time authorities have been calling for a revision in the terminology used to describe tendon disruption and to more clearly explain the apparent discrepancies in understanding of how pain and structural change interact. For example, in 1998,1 research was published calling for just this, and suggesting that in fact the clinical entity that is expressed by pain, performance interruption and swelling should perhaps better be called tendinopathy.
Enter Jill Cook and colleagues, who, across two important publications, have proposed and revised a continuum model of tendon pathology, and refuted much of the current thinking regarding the pathophysiology of tendinopathy.2,3 Their continuum model describes three phases of tendinopathy, with the reactive and degenerative phases straddling an intermediate tendon dysrepair phase.2 They point out that the tendon is a dynamic structure, primarily acting to store and release energy, that responds and adapts to loading, and that structural change and nociception after a period of abusive loading2, analogous to injury, can occur at any point in the continuum.3 They further suggest that models of tendon pathology which characterise pain by mechanisms of collagen disruption/tearing or inflammation are unlikely to be accurate.3 It is well worthwhile reading the two papers here and here.
It is also worth noting that the stages of the continuum model can be visualised with ultrasound imaging (see Figures A-D). Such imaging, incorporated into a clinical picture of tendinopathy characterised by a patient’s presentation and the specific interaction of pain, tissue change and function (more next time), is likely to help direct management of tendon pathology.
Coming in the next post:
We’ll look at ideas about how incorporating ultrasound staging of tendinopathy might help frame its management. We’ll also briefly revisit that troublesome terminology.
- Maffulli N, Khan KM, Puddu G. Overuse tendon conditions: time to change a confusing terminology. ArthroscJ Arthrosc Relat Surg Off Publ Arthrosc Assoc North Am Int Arthrosc Assoc. 1998;14(8):840–3.
- Cook JL, Purdam CR. Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendinopathy. Br J Sports Med. 2009;43:409–16.
- Cook JL, Rio E, Purdam CR, Docking SI. Revisiting the continuum model of tendon pathology: what is its merit in clinical practice and research? Br J Sports Med [Internet]. 2016;bjsports-2015-095422-. Available from: http://bjsm.bmj.com/content/early/2016/04/28/bjsports-2015-095422.short?rss=1