English

Abstract

Introduction Treatment of chronic painful midportion Achilles tendinopathy is known to be difficult. Multiple nontendon-invasive and tendon-invasive methods are used. When traditional non-invasive treatments fail, it has become increasingly popular to try injections of PRP and autologous blood, and intratendinous open surgery is indicated finally. There is little, if any, scientific evidence from human studies backing up intratendinous injection treatment, and intratendinous surgical treatment can also be questioned. The aim of this critical review is to discuss intratendinous surgery and intratendinous treatment with injection for midportion Achilles tendinopathy. Discussion Based on a recent research using immunohistochemical analyses of tissue biopsies from patients with midportion Achilles tendinopathy, new non-tendon-invasive treatment methods combined with short rehabilitation periods have been invented. These methods have shown good clinical results, few complications and decreased tendon thickness along with improved tendon structure, over time. The knowledge about innervation patterns, tendon cells and potentials in the soft tissue on the ventral (deep) side of the Achilles tendon midportion, along with good results using treatment methods focussing on the outside of the tendon, questions the use of tendon-invasive treatment methods for midportion Achilles tendinopathy. Conclusion A new science backing invasive treatment outside the tendon and newlyinvented methods such as ultrasound and Doppler-guided surgical scraping treatment have shown promising results. Introduction Although multiple treatment methods are used, treatment of midportion Achilles tendinopathy is known to be difficult1. Both conservative and surgical treatment methods are used, which can be divided into nonAchillestendon-invasive, and Achilles tendon-invasive methods. Among the non-tendon-invasive conservative methods, painful eccentric calf muscle training is considered to be the most beneficial2,3. There are also indications that shock wave treatment3 and ultrasound (US) + Doppler (DP)-guided sclerosing polidocanol injections4 are beneficial. Tendon-invasive conservative methods include injection treatments with Platelet Rich Plasma (PRP)5,6 and autologous blood (peri-or intratendineously)7,8. Stem cell injection treatment is also being used, but there are no studies on humans9. Surgical treatments include nontendon-invasive procedures such as US and DP-guided scraping10 and scraping combined with plantaris tendon removal11. Among the tendoninvasive methods, tenotomy with excision of degenerative tendon tissue is the most commonly used12–14, which is sometimes combined with a flexor hallucis longus transfer procedure15. Morphologically, in the thickened and painful tendinopathy tendon, there is an altered tendon structure, including irregular fibre bundle arrangement and local high concentrations of glucosaminoglycans (GAGs), hypercellularity and neovascularisation14. Specific studies on the cells in the hyper-cellular region have shown that some of these cells produce transmitter and pain substances, and seem to have a more stemcell-like function16–18. Using US and DP, a localised high blood flow has been found outside and inside (in close relation to regions with structural changes) the ventral side in tendinopathy tendons, but not in normal Achilles tendons19. Immunohistochemical analyses of tissue specimens, obtained with US and DP guidance, outside and inside the region with tendon changes, have shown multiple sympathetic, but also sensory, nerves outside, but very few nerves inside, the Achilles tendon20. This critical review specifically questions the use of Achilles tendon invasive treatment methods without having a scientifically verified background. Discussion The author has referenced some of his own studies in this review. These referenced studies have been conducted in accordance with the Declaration of Helsinki (1964) and the protocols of these studies have been approved by the relevant ethics committees related to the institution in which they were performed. All human subjects, in these referenced studies, gave informed consent to participate in these studies. *Corresponding author Email: hakan.alfredson@idrott.umu.se Department of Surgical and Perioperative Science, Sports Medicine Unit, Umea University, SE-90187 Umea, Sweden