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-