Dear all,

Loads of studies and reviews on tendinopathy injections this month – an area full of debate and opinion – here are some highlights and my opinion to add to the pile.

Footnote: injection studies far outnumber clinical tendon loading studies – strange when we consider that loading/load management is the primary management for tendinopathy

Sadoghi reviewed PRP efficacy in Achilles ruptures (9 studies) and tendinopathy (5 studies) and found evidence for benefit in rupture only. The rupture studies were mainly animal studies showing beneficial biomechanical and histological effects.

Mautner retrospectively surveyed patients who had had PRP for tendinopathy at one of four centres. 82% of patients reported moderate improvement in symptoms (at least 50%) at 15 months. Sounds good, BUT huge and obvious limitations include 1) responders (55%) may be different to the entire cohort; 2) there is no way of knowing other factors that influenced outcomes – eg people in pain generally do as much as they can to reduce that pain, and 15 months is a long time!

Engrebretsen & Schamasch 2012 IOC position statement on PRP (update from the 2010 BJSM paper) highlights the lack of evidence and calls for caution in using blood-based products – sounds sensible to me! Here is a quote: ‘With respect to PRP, its increasing popularity appears to have outreached in some respects—the principle of medical ethics and the usual conservatism that new treatments are taken up by the clinicians.

Lui have published a systematic review of cell therapy implantation/injection for tendinopathy. Of 11 included studies, 9 were not on patients and even then showed equivocal efficacy for most outcomes (eg imaging, tissue functional characteristics). Two clinical studies included (Clarke et al. 2010-Achilles; Obaid et al 2012-patellar) show greater improvement in VISA scores than comparator groups (ie other injection). Issues /questions remain; was blinding adequate? what are the mechanisms – will trying to heal tissue help pain/function? can others replicate the findings, which are all by the same group? (or is this similar to the ‘Alfredson eccentric training effect’?)

Hutchison assessed diagnostic value of clinical tests in Achilles tendinopathy. As expected, site of pain and palpation are sensitive and crepitus, thickening and load tests (eg pain with hopping & calf raising) are specific – ie not all Achilles patients display the latter tests. Gold standard was pathology on ultrasound imaging, which explains some of the false negatives and positives given the poor relationship between pathology and pain.

Spang demonstrate morphological and biochemical features of tendinopathy in the plantaris tendons of 17 patients with long standing Achilles tendon pain. This comes from Alfredson’s group and they have previously reported a thick plantaris tendon that ‘invaginates’ the medial Achilles midportion may explain some recalcitrant cases. I like this as reminds us of potential complexity in differential diagnosis of Achilles region pain. So how do we identify plantaris involvement clinically and modify our management?

Here is a link to the abstracts: Tendon research blog feb

 

References

Clarke AW, Alyas F, Morris T, Robertson CJ, Bell J, Connell DA. Skin-derived tenocyte-like cells for the treatment of patellar tendinopathy. Am J Sports Med 2011;39(3):614–23.

Obaid H, Clarke A, Rosenfeld P, Leach C, Connell D. Skin-derived fibroblasts for the treatment of refractory Achilles tendinosis: preliminary short-term results. J Bone Joint Surg Am 2012;94(3):193–200.