Recent research implies that
using surgery to treat carpal tunnel syndrome (CTS) may
be like using a machine gun to kill a mosquito. The Spanish
study poses the logical, and possibly overdue, question:
why use a knife when a needle will do the trick? This
research suggests that if carpal tunnel patients want
their symptoms resolved fast, they would be better off
with a steroid injection rather than the current gold-standard
treatment — decompression surgery.
The study, published in the February
issue of the journal Arthritis & Rheumatism,
indicates that CTS patients are typically either over-or
undertreated. Currently, those with severe CTS with
partial paralysis or loss of sensation undergo surgery,
while milder cases often go completely untreated.
NOT
CUTTING IT
At present, a proportion of patients are started on
a conservative regime of splinting and anti-inflammatories,
but the success rate of this strategy is comparatively
low. It's often the patients who fail to respond to
this approach who end up receiving steroid injections,
say the authors. But they believe that steroid injections
could help a wider range of CTS patients as a first-line
treatment, and set out to test this theory.
The researchers, led by Dr Domingo
Ly-Pen of the Gandhi Primary Care Unit in Madrid, randomized
163 patients with diagnoses of CTS into two groups.
Eighty patients received standard decompression surgery,
while the remaining 83 were given local steroid injections.
While the trial was originally intended to test the
efficacy of a single injection, patients were permitted
a second shot if they asked for it — which most
did.
The primary endpoint of the study
was the percentage of patients' wrists whose visual
analogue scale score for nocturnal paresthesias (nighttime
tingling and numbness) had improved by 20% in the course
of the three months following treatment. At three months,
94% of the injected patients had seen such an improvement
— significantly more than the 75% figure achieved
in the surgery group.
At six months, the surgery patients
had overtaken the steroid group, with 85.5% seeing a
20% improvement compared to 76.3% among the injected
patients. This was, however, a statistically insignificant
difference. The picture remained the same at 12 months,
with no significant difference between the two groups.
Seventy-five percent of the surgery patients still maintained
a 20% improvement, compared to 69.9% of the injected
patients.
MAKING
THE CASE
Over the short term, conclude the authors, "local steroid
injection is better than surgical decompression for
the symptomatic relief of CTS. At one year, local steroid
injection is as effective as surgical decompression
for the symptomatic relief of CTS." They argue that
the explanation for the early advantage of steroid injection
may be that "in the short term, local steroid injections
produce dramatic relief of symptoms, but the surgical
incision may still be painful because of scarring and
local inflammation."
The authors acknowledge that their
trial has weaknesses. In particular, the randomization
was done strictly by wrist diagnosis and ignored the
overall patient characteristics. Moreover, the study
was not double-blinded.
Finally, since the study halted
followup at one year, the question remains as to whether
these injected patients will eventually have to return
for surgery or further injections — if further
steroid injections will indeed prolong the benefit.
Arthritis Rheum Feb, 2005;52(2):612-9
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