To the Editor:
I read with great interest the article from Dr. Pettrone and Dr.
McCall “Extracorporeal shock wave therapy without local anesthesia for
chronic lateral epicondylitis”. [1] I cannot but congratulate the authors on their fine piece of work,
the title of which contains two very important messages:
“without” local anesthesia; and for “chronic” lateral epicondylitis.
I was not surprised to read that their results demonstrated low-
energy extracorporeal shock wave therapy (ESWT) without local anesthesia
to be a safe and effective treatment for chronic lateral epicondylitis,
their results in a general population mirroring in fact those of a single-
center German trial from our group in a tennis playing general population
[2] using a treatment protocol nearly identical to that reported by Dr.
Pettrone and Dr. McCall.
Hence, in combination, both trials provide additional weight of
evidence to the conclusion, that ESWT as utilized, repetitively, low-
energy, without the use of local anesthesia, is a safe and effective
treatment of chronic lateral epicondylitis.
In their discussion, Dr. Pettrone and Dr. McCall pointed out, that,
clearly, the effectiveness of ESWT is dose-related and some consistency of
methodology must be achieved to be able to objectively evaluate differing
studies.
Under these circumstances the role of meta-analyses, as conducted
currently, becomes more and more questionable. The protocol for a Cochrane review, for instance, requires collection
of data of all randomized controlled trials available which, in this case,
identify by the keywords “ESWT” or “shock wave treatment” and “lateral
epicondylitis” or “tennis elbow”.
A primary outcome measure, considered to be the most important to the
authoring research group, is chosen for the systematic review. Measures of
variance are derived from the paper, and, where not available, from p-
values given. When data are available for a pooled estimate of the impact
of intervention it is intended that meta-analyses are conducted for direct
comparisons.
Dr. Buchbinder [3], a protagonist of meta-analysis in the field of
various symptomatic musculoskeletal disorders, emailed to me, that her
Australian research group just finished the updated review for elbow pain
and ESWT, having added in the trials of Dr. Pettrone and Dr. Rompe. Even
with those two positive trials, the results still didn´t support much of a
benefit of ESWT. At least Dr. Buchbinder conceded in her email that there could be
many reasons for that result.
This is exactly the message of this Letter to the Editor. As can be predicted, if one compares apples (a disorder of various
intensity and of various duration) to oranges (various ESWT regimens
regarding number of sessions, number of shocks applied per session,
various energy flux density per shock, various periods between
applications) to peaches (various outcome measures, various periods of
follow-up, it is it to be expected that one will find inconclusive
evidence not supporting a benefit of ESWT.
A review on lateral epicondylitis and ESWT, just published by Dr.
Stasinopulos and Dr. Johnson, [4] made the same mistake. Correctly, they stated that there is consensus among the Editorial
Board of the Cochrane “Back Pain” Review Group that, if relevant valid
data are lacking (data are too sparse or of too low quality) or if data
are statistically and clinically too heterogeneous, a meta-analysis should
be avoided and reviewers should perform a qualitative review.
However, after having conducted such a qualitative review comparing
apples to oranges to peaches, and finding an inconclusive result, isn´t it
hypocritical to conclude that further research with well designed RCTs is
required to provide meaningful evidence on the effectiveness of ESWT for
the management of tennis elbow?
In my view, it is a key point for credibility of the scientific
community, to critically analyze the method of those review processes. It
must be stated clearly, how problematic it is to combine the results of a
group of studies in a meta-analysis - for example, studies of patients
with different types of treatment, different types of comparison groups,
or different clinical characteristics of patients studied.
Together, I contradict the conclusion by Dr. Stasinopoulos and Dr.
Johnson (and of Dr. Buchbinder in her hopefully quickly published Cochrane
review).
There are well designed trials providing meaningful evidence on the
effectiveness of ESWT for the management of tennis elbow. US and German
groups [1,2] have independently shown a treatment design leading to
successful outcome in close to 70% of patients with recalcitrant lateral
elbow tendinosis.
As always it is much easier to achieve unfavorable results with
various treatment regimes than to develop a successful treatment strategy.
One recent example is the trial by Dr. Chung and Dr. Wiley [5] who adopted
the treatment parameters of the above mentioned US and German trials, but
focused on patients with acute, not previously treated patients with a
tennis elbow, instead of chronic recalcitrant cases. As could be expected
from several other randomized controlled trials evaluating conservative
treatment methods for acute tennis elbow they found it impossible to beat
the self-limiting course of acute tendinosis at 8-week follow-up.
Sincerely yours,
Jan D. Rompe, MD
References
1. Pettrone F, McCall B. Extracorporeal shock wave therapy without
local anesthesia for chronic lateral epicondylitis. Journal Bone Joint
Surg 2005; 87-A:1297-1304.
2. Rompe et al. Repetitive low-energy shock wave treatment for
chronic lateral epicondylitis in tennis players. Am J Sports Med 2004;
32:734-743.
3. Buchbinder R et al. Shock wave therapy for lateral elbow pain.
Cochrane Database Syst Rev 1:CD003524, 2001.
4. Stasinopoulos D, Johnson MI. Effectiveness of extracorporeal shock
wave therapy for tennis elbow (lateral epicondylitis). Br J Sports Med
2005; 39:132-136.
5. Chung B, Wiley JP. Effectiveness of extracorporeal shock wave
therapy in the treatment of previously untreated lateral epicondylitis: a
randomized controlled trial. Am J Sports Med 2004; 32:1660-1667.
Letters to the Editor: ![[Read Letter to the Editor]](/icons/misc/sectionDOWN.gif){kind=icon}
