As one of us commented more than 10 years ago, it is time to ‘change a confusing terminology’.1-3 We should also highlight what the mainstays of management, the new advances and management modalities of Achilles tendinopathy are.
A key characteristic of science is the specificity and accuracy in its descriptions. Terminology is important in terms of presentation of scientific knowledge and communication between fellow scientists. It is not just a matter of what term we use, but also of what we understand behind the term we use. Using an inappropriate term to describe a medical condition carries the risk of choosing the wrong management regime. Is posterior heel pain and swelling, coupled with decreased physical ability, ‘tendinitis’, ‘tendinosis’, ‘paratendinosis’, ‘partial tear of the tendon’, or is it ‘tendinopathy’? The authors dedicated one paragraph in their article to the ‘Terminology’ of conditions affecting the Achilles tendon. They correctly mention that “there is now a general consensus that these lesions should not be called tendonitis because of a lack of inflammatory cells at histopathology”, but then they stated that “current terminology would suggest the term tendinosis for a thickened tendon with abnormal signal / echogenicity either by ultrasound or MRI”, without citing any references for the latter.
By definition, ‘tendinitis’ implies an acute inflammatory process. The term ‘tendinosis’ was first used by Puddu et al4 in 1976, and implies tendon degeneration without clinical or histological signs of intratendinous inflammation. Puddu et al4 correctly stated that a tendon with histopathological features of ‘tendinosis’ is not necessarily symptomatic. Although areas of ‘tendinosis’ seem to be a constant feature in patients with Achilles tendon ruptures, the vast majority of them never experienced pain before the rupture. On the other hand, patients requiring surgery for pain in the Achilles tendon region also have clearly pathological areas in their tendons, although their histopathological features are not as advanced as those in patients with ruptures. Why is the tendon with histopathologically abnormal features painful in some patients, and asymptomatic in others? Why are ruptures seen in such clinically silent tendons?
There is now some evidence that pain might not (only) be structural, but also biochemical in origin.5 This may greatly influence clinical management: the aim of treatment would be to modify the biochemical milieu, rather than to focus on reducing inflammation (which is in any case not a feature) or stimulating collagen repair. Surgery may play a role through denervation. Furthermore, histological evidence has confirmed the failed healing response nature of tendinopathy, where excessive or inappropriate loading of the musculotendinous unit is believed to be central to the disease process, although the exact mechanism by which this occurs remains uncertain.3
Do we define the condition according to its clinical presentation, according to the imaging findings, or according to histopathology findings? The terms tendinitis, tendinosis, paratendinosis etc should be reserved for specific histopathological features of tendon conditions. ‘Tendinitis’ should be avoided, as inflammatory cells are not present in specimens of patients with chronic pain.6 ‘Tendinosis’ should only be used when the patient had surgery, and a sample at histology showed mucoid or lipid degeneration. Paratenonitis, similarly, is a histological diagnosis, and is characterised by acute oedema and hyperaemia of the paratenon, with infiltration of inflammatory cells, possibly with production of a fibrinous exudate that fills the tendon sheath. The term partial tear of a tendon should describe a macroscopically evident subcutaneous partial tear of a tendon. This is an uncommon acute lesion,1,2 although many radiologists report an imaging feature of dishomogeneity of a tendon as a ‘partial rupture’. In any case, the modern interpretation of the histopathological features is of a ‘failed healing response’, with hypercellularity, loss of the tightly bundled collagen appearance, an increase in proteoglycan content, and, commonly, neovascularisation.1-3 At immunohistochemistry, neoinnervation is also evident.1-3 In everyday practice, the term tendinopathy should be used as a generic descriptor of the clinical condition characterised by pain, swelling, impaired performance and pathological changes in and around tendons, occurring as a result of overuse, or, in some patients, for unknown reasons.3 What is the management of tendinopathy? The readers should not be given the impression that management is guided by the ultrasonographic or MRI findings: clinical examination still reigns. The mainstay of the management of tendinopathy remains non-operative.2,3 Several non-operative (pharmacological and non-pharmacological) modalities have been proposed. Heavy-load eccentric exercises, which have been shown in controlled trials7 to decrease the pain and possibly to lead to normalised tendon structure,8 require highly motivated individuals who are willing to perform 180 painful repetitions of the exercise 7 days a week for 12 weeks.2,3 There is accumulating evidence from randomised controlled trials regarding the efficacy of extracorporeal shock wave therapy (ESWT) as an adjunct in the management of Achilles tendinopathy.9 Several other modalities have been described and are in common use, but their level of evidence is still scanty, despite enthusiastic proponents.3 Finally, surgery can be undertaken if and when appropriate non-operative management undertaken for long enough has failed. However, surgery does not necessarily completely eliminate symptoms and the complication rate is in the range of 10%.2,3,10 The goal is to excise fibrotic adhesions and degenerated nodules and to modify vascularity and stimulate the remaining viable cells to initiate cell-matrix response and healing. This can be performed with minimally-invasive techniques, which are still evolving, and need to be evaluated by randomised controlled studies, compared to ‘traditional’ open techniques.11
The management of Achilles tendinopathy is complex, not always successful, and extremely multifaceted. It should be tailored to each individual, keeping in mind that, paradoxically, the patients who will have worse results and will be less satisfied will be the sedentary ones, not the highly competitive professional athletes.3 Appropriate terminology should be used: although the terminology of tendinopathy has been adopted by the vast majority of ‘tenologists’ (as witnessed by the increasingly widespread use of the term in scientific articles), its use has not yet filtered through the whole profession.
1. Maffulli N, Khan KM, Puddu G. Overuse tendon conditions: time to change a confusing terminology. Arthroscopy 1998;14:840-4.
2. Longo UG, Ronga M, Maffulli N. Achilles tendinopathy. Sports Med Arthrosc 2009;17:112-6.
3. Rees JD, Maffulli N, Cook J. Management of tendinopathy. Am J Sports Med 2009;37:1855-67.
4. Puddu G, Ippolito E, Postacchini F. A classification of Achilles tendon disease. Am J Sports Med 1976;4:145-150.
5. Khan KM, Cook JL, Maffulli N, Kannus P. Where is the pain coming from in tendinopathy? It may be biochemical, not only structural, in origin. Br J Sports Med 2000;34:81-3.
6. Khan KM, Cook JL, Bonar F, Harcourt P, Astrom M. Histopathology of common overuse tendon conditions: update and implications for clinical management. Sports Med 1999;27:393–408.
7. Rompe JD, Furia J, Maffulli N. Eccentric loading versus eccentric loading plus shock-wave treatment for midportion achilles tendinopathy: a randomized controlled trial. Am J Sports Med 2009;37:463-70.
8. Mafi N, Lorentzon R, Alfredson H. Superior short-term results with eccentric calf muscle training compared to concentric training in a randomized prospective multicenter study on patients with chronic Achilles tendinosis. Knee Surg Sports Traumatol Arthrosc 2001;9:42-7.
9. Öhberg L, Lorentzon R, Alfredson H. Eccentric training in patients with chronic Achilles tendinosis: normalised tendon structure and decreased thickness at follow up. Br J Sports Med 2004;38:8-11.
10. Rompe JD, Furia JP, Maffulli N. Mid-portion Achilles tendinopathy--current options for treatment. Disabil Rehabil 2008;30:1666-76.
11. Maffulli N, Longo UG, Oliva F, Ronga M, Denaro V. Minimally invasive surgery of the achilles tendon. Orthop Clin North Am 2009;40:491-8.
Maffulli N, MD, MS, PhD, FRCS(Orth), FFSEM (UK), Centre Lead and Professor of Sports and Exercise Medicine, Consultant Trauma and Orthopaedic Surgeon
Queen Mary University of London, Barts and The London School of Medicine and Dentistry, Institute of Health Sciences Education, Centre for Sports and Exercise Medicine, Mile End Hospital, London, United Kingdom
Gougoulias N, MD, PhD, Locum Consultant Orthopaedic Surgeon
Frimley Park Hospital, Frimley, Surrey, United Kingdom