Revista de Medicina Desportiva (English) May 2018 - Page 17

taxing, and there are studies that indi- cate effects between 1 to 24 weeks. Several studies have been carried out in recent years with the objective of comparing the intraarticular CS with hyaluronic acid injection, suggesting an almost immediate benefit with steroids, with an average duration of approximately one week, while the acid hyaluronic can promote relief from the pain framework, but usually only after four weeks of intervention. 9 Cochrane’s latest systematic review, dated 2015, included 27 clinical trials investigating the ben- efits and adverse side effects of CS intraarticular injections vs placebo or absence of treatment in patients with OA of the knee, to study the results on pain, function, quality of life and safety of the procedure. The analysis of the data suggested benefit on pain and in function optimization one week after the injection, however the CS did not prove to be beneficial in these outcomes after two to three weeks in relation to the placebo. At the same time, there was no evidence of significant adverse side effects or a decrease on the joint space. 10 However, the adverse effects of CS intraarticular injections do exist, and they are important. In 1958, Chandler and Wright were the first to describe radiographic evidence of joint destruction and cartilage lesion after several intraarticular injections of hydrocortisone in the absence of infection. 7 Saxne, Heinegard and Wollheim observed a decrease of proteoglycans at the level of synovial fluid in patients who performed sev- eral intraarticular injections of CS. However, they concluded that the decrease on the production of IL-1, TNF-A and proteases is more ben- eficial, because this effect decreases the accelerated rate of articular cartilage degradation. 11,12 Authors suggested different intervals of time between interventions, usually considering safe the intervals of 6 to 12 weeks between injections, being relatively consensual in the opinion that these procedures should not be carried out more that 2 to 3 times a year in load joints. 8 2. Hyaluronic acid The hyaluronic acid (HA) is a high molecular weight glycosaminogly- can consisting of repeated units of N-acetylglucosamine and glucuronic acid. 13 It is usually present in the most superficial layer of human cartilage and constitutes the main component of synovial fluid. 13 The average HA molecular weight of the synovial fluid of a normal individual varies between 5 and 7 × 10 6 Da. In the knee with osteoar- thritis, the molecular weight of the HA in the synovial fluid is decreased in the order of 33-50%. 14 The theo- retical assumption of the articular injection of HA or viscosupplemen- tation argues that this interven- tion improves the elasticity of the cartilage, optimizes the viscosity of the synovial fluid and consequently gains in terms of lubrication and capacity of shock/load absorption. 8 However, so far there is no clear and conclusive data of its mechanism of action, so we can say that until this moment this mechanism of action is still not very well understood. The Food and Drug Administration (FDA) approved the viscosupple- mentation for the treatment of the knee OA in 1997, “for the treatment of pain in the knee osteoarthritis in patients who did not adequately respond to conservative non-phar- macological therapy and simple analgesics, as the acetaminophen.” From a more specific point of view, the American College of Rheumatol- ogy (ACR) developed in 2012 one set of guidelines for the approach of the knee, hand and hip with OA, includ- ing viscosupplementation in the list of evaluated therapies, under the assumption of “conditioned recom- mendation” in patients without adequate response to non-phar- macological therapeutic modalities and acetaminophen in maximum analgesic dose. The document con- cluded that intraarticular injections of HA had several advantages over other therapeutic options, since it is a local intervention its systemic effects are minimized and may even delay the need for arthroplasty. 15,16 From the point of view of scien- tific evidence for its use, several studies have been carried out in this context, with no homogene- ous results. In 2015, Bannuru et al. conducted a meta-analysis that reviewed 137 studies, with a total of 33.343 patients with OA of the knee, and in these studies two or more therapeutic options in the approach of the knee OA (paraceta- mol, diclofenac, naproxen, celecoxib, CS articular, HA articular, oral placebo and placebo articular) were compared to evaluate the effects on pain, function and joint rigidity, with a follow-up of three months. They concluded that with regard to the analgesic effect, HA articular was the most beneficial treatment obtained. As far as the function is concerned, all interventions, except intraarticu- lar CS, have shown benefit compared to the placebo, and in relation to the decrease of joint rigidity no inter- vention showed benefit from one another. The main conclusion of the revision was that the intraarticular treatments were beneficial in rela- tion to the oral ones, and HA pre- sented better results than the CS. 17 3. Platelet-rich plasma One of the main limitations com- monly referred to in previous treat- ments is that they are only symp- tomatic, of “damage control”, with control of pain and inflammation within a specified period of time, with no modulation on the course of the disease, nor with the potential to condition and reverse the patho- physiological process that is under- lying. On the basis of this premise, new interventions have been devel- oped in recent years with the aim of addressing the knee OA under a regenerative perspective more than just symptomatic control. The platelet-