Extract
We read the letter of our colleague, Dr. Frölke, with great interest.
First, on the basis of our study, we believe that vitamin C does prevent
complex regional pain syndrome. Unfortunately, most of Dr. Frölke's
comments do not apply to our study.The number of enrolled patients in our study in relation to the number of
eligible patients was mentioned in the Discussion of our article. The quality
of reduction was studied in this paper and in our paper in
Lancet1
as well. In both studies, there was no relationship between the occurrence of
complex regional pain syndrome and the need to undergo fracture reduction.
Moreover, the quality of reduction did not influence the chance of complex
regional pain syndrome developing. We performed the current study because, to
our knowledge, there have been no published studies since
19991 that either
confirm or refute our original findings.
We read the letter of our colleague, Dr. Frölke, with great interest.
First, on the basis of our study, we believe that vitamin C does prevent
complex regional pain syndrome. Unfortunately, most of Dr. Frölke's
comments do not apply to our study.
The number of enrolled patients in our study in relation to the number of
eligible patients was mentioned in the Discussion of our article. The quality
of reduction was studied in this paper and in our paper in
Lancet1
as well. In both studies, there was no relationship between the occurrence of
complex regional pain syndrome and the need to undergo fracture reduction.
Moreover, the quality of reduction did not influence the chance of complex
regional pain syndrome developing. We performed the current study because, to
our knowledge, there have been no published studies since
19991 that either
confirm or refute our original findings.
To our knowledge, no prospective study has ever demonstrated an association
between the prevalence of complex regional pain syndrome and the quality of
reduction. Retrospective studies do not have the level of evidence that is
needed. Dr. Frölke makes a misjudgment by citing the article by Arora et
al.2. Arora et al.
found that, of 114 patients followed for one year, five had type-I complex
regional pain syndrome and three had type-II complex regional pain syndrome.
Thus, the prevalence of type-I complex regional pain syndrome in their study
is 4.39% (not 3.5% as stated in Dr. Frölke's letter) and is higher than
our overall prevalence of 4.2%; it stands in contrast with the 2.4% for all of
our patients treated with vitamin C. The difference is even more striking when
the 4.39% rate is compared with the prevalence of only 1.8% in our group
receiving 500 mg of vitamin C and 1.7% in the group receiving 1500 mg.
Why the articles by
Rowbotham3,
Oerlemans et al.4,
and Sherry et al.5
are cited is unclear to us. Our study is about the possible prevention of
complex regional pain syndrome after a wrist fracture in adults treated with a
prophylactic dose of vitamin C and not about the therapy for complex regional
pain syndrome itself. The end point of our study was defined as the presence
of complex regional pain syndrome at any time within one year after the
fracture (see the Study Design section). The article by
Rowbotham3 deals
with pharmacotherapy in patients with complex regional pain syndrome.
The article by Oerlemans et
al.4 is a very
well-respected trial comparing adjuvant physical therapy with occupational
therapy for patients with complex regional pain syndrome. Here lies the
difference with our fracture patients. If we had treated our patients with
physical therapy as well, we would have created our own confounding factor.
Skeptics would have challenged our conclusions and pointed to the positive
effect of the physical therapy rather than to the effect of vitamin C, as Dr.
Frölke does now.
When complex regional pain syndrome develops in patients who have sustained
a wrist fracture, it is of course treated with physical therapy and
medication, if
necessary6. The
article by Sherry et
al.5 deals with the
outcome in children with complex regional pain syndrome after exercise
therapy. However, we believe that complex regional pain syndrome in children
is a completely different entity than complex regional pain syndrome in
adults, and so is the approach to its treatment. This was confirmed by Wilder
et al.7, who
reminded us that, in children, complex regional pain syndrome most often
involves the lower extremity (87% [sixty-one] of seventy cases), which is in
contrast to the situation in adults, who have more upper-extremity complex
regional pain syndromes. The therapie used by Sherry et
al.5 consisted of
aerobic functionally directed exercises, hydrotherapy, and desensitization.
Which therapy achieved the desired outcome? Can it get more confounding than
this?
Zollinger PE, Tuinebreijer WE, Kreis RW,
Breederveld RS. Effect of vitamin C on frequency of reflex sympathetic
dystrophy in wrist fractures: a randomized trial. Lancet.
1999;354:
2025-8.3542025
1999
[PubMed][CrossRef]
Arora R, Lutz M, Hennerbichler A,
Krappinger D, Espen D, Gabl M. Complications following internal fixation of
unstable distal radius fracture with a palmar locking-plate. J Orthop
Trauma. 2007;21:
316-22.21316
2007
[CrossRef]
Rowbotham MC. Pharmacologic management
of complex regional pain syndrome. Clin J Pain.
2006;22:
425-9.22425
2006
[PubMed][CrossRef]
Oerlemans HM, Oostendorp RA, de Boo T,
Goris RJ. Pain and reduced mobility in complex regional pain syndrome I:
outcome of a prospective randomised controlled clinical trial of adjuvant
physical therapy versus occupational therapy. Pain.
1999;83:
77-83.8377
1999
[PubMed][CrossRef]
Sherry DD, Wallace CA, Kelley C, Kidder
M, Sapp L. Short- and long-term outcomes of children with complex regional
pain syndrome type I treated with exercise therapy. Clin J
Pain. 1999;15:
218-23.15218
1999
[CrossRef]
Wilder RT, Berde CB, Wolohan M, Vieyra
MA, Masek BJ, Micheli LJ. Reflex sympathetic dystrophy in children. Clinical
characteristics and follow-up of seventy patients. J Bone Joint Surg
Am. 1992;74:
910-9.74910
1992