CORR Insights®: Platelet-rich Plasma or Autologous Blood Do Not Reduce Pain or Improve Function in Patients with Lateral Epicondylitis: A Randomized Controlled Trial.

Although lateral epicondylitis was described more than 100 years ago and affects 1% to 3% of the population, its causes and the best treatment approaches remain obscure [4]. Earlier, the prevailing thought was that its etiology was inflammatory (thus the “itis” at the end of the condition’s name), but more recently, it has been seen as a complex process of degeneration, decreased healing potential, and hypovascularity [4, 8]. Lateral epicondylitis is not a tendinopathy but rather an enthesopathy, associated with myxoid degeneration involving the origin of the extensor carpi radialis brevis muscle. A study comparing cadaveric and surgical specimens found that that the condition evolves through several stages, beginning with degenerative angiogenesis and ending with fibrosis and calcification [1]. Most patients with this diagnosis can be treated effectively without surgery, because in most patients the condition is self-limited and resolves over the course of 12 to 18 months. However, some patients remain symptomatic for years [8]. Nonsurgical treatments range from wait-and-see to a variety of injections, occupational or physical therapy, iontophoresis or phonophoresis, shock wave therapy or laser therapy, and splinting [8]. Corticosteroids are the most-commonly used product in injections for lateral epicondylitis and are usually mixedwith a local anesthetic [1, 4, 5, 10]. Retrospective studies showed that corticosteroid injections have shortterm effectiveness, but randomized controlled studies suggested that they are not superior to placebo in the longterm [3, 10]. Edwards and Calandruccio [3] described an injection of autologous blood for refractory lateral epicondylitis, with 50% improvement with one injection and 79% with two injections. They suggested that autologous blood may induce angiogenesis and healing in the area of the lateral epicondyle. Plateletrich plasma (PRP) was also introduced as an injection agent; an increased concentration of platelets may increase the release of growth factors and cytokines from platelets, thus enhancing the healing process [7]. A study showed that botulinum toxin A injections had a beneficial effect, but these injections likely weaken the extensor muscles [8] and there were no long-lasting benefits. Recent studies add to the confusion. Some studies found a benefit from using corticosteroids [1], autologous blood, or PRP [2, 5], while other studies found no benefit to the use of these approaches when compared with placebo [5, 8, 9]. One systematic review of overlapping meta-analyses found some evidence suggesting that corticosteroid injections provide short-term pain relief and improvement in function [5]. However, in the long-term, therewas no evidence that one method was superior to the other or to the wait-and-see approach. Looking at the available This CORR Insights is a commentary on the article “Platelet-rich Plasma or Autologous Blood Do Not Reduce Pain or Improve Function in Patients with Lateral Epicondylitis: A Randomized Controlled Trial” by Linnanmäki and colleagues available at: DOI: 10.1097/CORR. 0000000000001185. The author certifies that neither he, nor any members of his immediate family, have any commercial associations (such as consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article. The opinions expressed are those of the writer, and do not reflect the opinion or policy of CORR or The Association of Bone and Joint Surgeons. N. H. Naam (✉), Southern Illinois University, Southern Illinois Hand Center, 901 Medical Park Drive, Effingham, Illinois 62401 USA, Email: drnaam@handdocs.com