How to tendinopathy: 2
Ultrasound in the clinical picture of tendinopathy: guiding management decisions
In the previous post, we left you with the idea that ultrasound imaging can visualise the stages of the tendon continuum according to Cook et al.,1,2 and that management of tendon injury across the continuum may be directed by this imaging carefully considered within the specific presentation of each patient.
Most tendon management might be broken into intervention that targets pain, intervention that targets function, and in some cases such as those characterised by early to mid-phase tendon dysrepair, interventions that target structure (see Figure 1 below).
What are we to make to the non-painful, structurally impaired tendon then, whether functioning or dysfunctional?
Cook et al.,3 note that the painful tendon seldom ruptures; pain may be protective, limiting loading in pathological tendons. Perhaps in the presence of ultrasound images indicating degenerative tendons, repeat imaging could be obtained in order to ascertain whether pathology is worsening. Identifying tendon pathology may also be useful in predicting future painful episodes of tendinopathy. In their 2018 publication, Docking et al., demonstrate findings that suggest that while not statistically significant, Achilles and patellar tendons with poorer structure may be more likely to develop symptoms later. In addition, worsening tendon pathology may predict later symptomatic development more so than does the extent of tissue damage alone2.
Figure 1: A model showing the intersection of pain, pathology and poor function within a continuum of tendinopathy. Text boxes describe potential presentation at key intersection points, as well as likely stage of the continuum. After cook et al .2
The clinical presentation including a history of inappropriate, abusive load3, along with the imaging, is helpful in diagnosis of tendinopathy. How then should rehabilitation be framed within the continuum model? We would direct you attention to the idea of tendon capacity4, link here, which suggests rehabilitation of tendinopathy should depend on where it is in terms of its position on the continuum and its functional capacity; what is its current capacity, and where do you need to rehabilitate it to? For example, in the case of the athlete with early tendinopathy, showing a reactive swollen, painful tendon, intervention may be targeted at pain, using slow heavy loading and potentially ibuprofen to settle reactive cells2. In the case of the more advanced tendinopathy with areas of reactive fibres, interventions targeting pain as well as strength and later function may be required4; potentially consider the tendon within the function of the rest of its kinetic chain.
Tendinopathy is a useful term to explain a continuum of tendon changes, and has been suggested to supersede all other terms relating to tendon pathology5. This is good news in terms of the terminology confusion that was pointed to in the last post; we can now abandon the term tendinosis altogether5, and tendinitis can probably similarly be discarded given that while there may be inflammatory markers present in tendons during tendon loading, the aetiology of tendon pathology is unlikely to be inflammatory3. Unfortunately there is another problem to tackle. Consider the anecdote that you may have heard: “a tendon does two things: it tears, and it tears”.6 Unfortunately this seems to be a little more than just anecdote, given the recent suggestion that tears should be considered the macroscopic discontinuity on load bearing, as opposed to the microscopic5. Terminology aside for the moment, this may either suggest that microscopic change is distinct from a tear, or, given both are discontinuity of structure, that there is a spectrum of tears also. We will come back to tendon tears another time.
References:
1. 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.
2. 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
3. Cook JL. Ten treatments to avoid in patients with lower limb tendon pain. Vol. 52, British journal of sports medicine. England; 2018. p. 882.
4. Cook JL, Docking SI. “Rehabilitation will increase the ‘capacity’ of your …insert musculoskeletal tissuehere….” Defining ‘tissue capacity’: a core concept for clinicians. Vol. 49, British journal of sports medicine. England; 2015. p. 1484–5.
5. Rio EK, Mc Auliffe S, Kuipers I, Girdwood M, Alfredson H, Bahr R, et al. ICON PART-T 2019-International Scientific Tendinopathy Symposium Consensus:recommended standards for reporting participant characteristics in tendinopathy research (PART-T). Br J Sports Med. 2020 Jun;54(11):627–30.
6. Unknown Provenance.