Purpose:
Distal radius fractures are the most prevalent adult fracture, accounting for 17.5% of
all fractures. Complex regional pain syndrome (CRPS) is a common complication that can
occur in this population, with a reported incidence of up to 32%. CRPS can lead to
permanent disability and is costly to the patient and to the healthcare system, with an
estimated cumulative outpatient and pain prescription cost of $42,026 over 8 years after
diagnosis. In addition, amidst the opioid epidemic, the risk of increased opioid use in
patients with CRPS prompts the need to find viable treatment strategies.
While there have been various proposed treatment modalities, evidence from randomized
studies is lacking. Several small studies (retrospective and prospective case series)
have shown potential efficacy of glucocorticoids for the treatment of CRPS. To our
knowledge, there are no randomized controlled trials that evaluate treatment of CRPS in
distal radius fractures with glucocorticoids.
The purpose of this pilot study is to evaluate a short course of oral prednisone as
potential treatment for patients identified as developing early signs of CRPS after
sustaining a distal radius fracture that was treated operatively. We will examine
feasibility metrics including patient recruitment rate, adherence to allocation and
protocol, withdrawal from study, and follow-through, in order to inform design of a
definitive clinical trial. We will also assess the resolution of CRPS, post-operative
opioid use, and any adverse events in patients who sustain a distal radius fracture after
receiving prednisone vs placebo for 2 weeks post-operatively, with 6 months follow up
post injury.
Hypothesis:
We hypothesize that the proposed pilot trial will demonstrate feasibility of a future
definitive trial.
In addition, we hypothesize that there will be higher rates of CRPS resolution, lower
amounts of opioid consumption, and no increased adverse effects, and better clinical
outcomes in patients who receive prednisone treatment compared to those who received
placebo. However, formal hypothesis testing will not be performed for this pilot trial.
Justification:
Developing CRPS after sustaining a distal radius fracture can lead to devastating
outcomes, including permanent disability, opioid dependency, and the inability to return
to work. In addition, diagnosing CRPS can be a prolonged process due to the range of
vague symptoms on presentation, which can lead to delay in treatment and worsening of
outcomes. Patients with CRPS may require more follow-up and referrals, which further
burdens the healthcare system.
The pathogenesis of CRPS is complex and not fully known; evidence suggests nervous system
sensitisation, autonomic dysfunction, and inflammatory changes. There are numerous
treatment options for CRPS, though little high-quality evidence supports their efficacy.
These include but are not limited to oral anti-depressants, parenteral lidocaine and
corticosteroids, surgical treatment with compressed nerve release, counselling, and
occupational and physical therapy. Vitamin C has been proposed as effective prophylaxis
for CRPS in distal radius fractures but data have been conflicting, with the most recent
randomized controlled trial (RCT) in 2014 by Ekrol et al. showing no difference in
functional outcomes or rate of CRPS in patients with distal radius fractures given
Vitamin C versus placebo.
Given the prevalence of distal radius fractures in adults, a relatively high CRPS
incidence in this population, and no established efficacious treatment options, more
research is needed to determine evidence-based and effective treatment options for this
destructive condition. Studies have identified that using glucocorticoids can potentially
be effective and safe for treating patients with CRPS, possibly due to the
anti-inflammatory properties of glucocorticoids. One retrospective study of patients
undergoing surgery for terrible triad elbow (complex elbow fracture dislocation) injuries
demonstrated improved elbow range of motion for patients receiving intraoperative
dexamethasone and 6-day oral course of methylprednisolone compared to patients who did
not, with no increased postoperative infection. Furthermore, the anti-inflammatory nature
of glucocorticoids deserves investigation for its potential to decrease opioid
consumption after distal radius surgery.
A variety of doses and duration of glucocorticoids have been used in studies to manage
CRPS, with a recent review article by Kwak et al showing starting doses between 30 mg to
100 mg of prednisolone. Although glucocorticoids are known to be associated with adverse
effects, most are only seen with long term therapy. In addition, studies have shown that
a short-course of glucocorticoids (less than 3 to 4 weeks), irrespective of dose, do not
require a tapering regimen and is not associated with increased risk of adrenal
insufficiency. While osteoporosis and fracture non-union are known adverse events of
long-term glucocorticoid use, this has not been demonstrated in literature for short-term
use. Moreover, given the risk of non-union in distal radius fractures is exceedingly rare
(0.2%), this calls for less concern for using glucocorticoids in this population.
Therefore, evaluating prednisone, a relatively cheap, accessible, and safe oral
medication when used for a short duration, as an anti-inflammatory and potential early
treatment agent for CRPS in distal radius fractures in this pilot study may have
implications for the complication profile and functional outcome for this common
fracture.
Research Design:
This will be a pilot double-blind randomized control trial in patients who sustain a
distal radius fracture treated operatively with a volar locked plate and identified as at
risk of developing CRPS. Follow up will be 6 months, involving 4 study visits that
correspond to standard post-operative clinic visits.
Statistical Analysis:
A power analysis assuming incidence of 20% CRPS and absolute risk reduction (ARR) of 10%
with prophylaxis yielded a sample size of 199 patients per arm, with 80% power and
significance level (α) of 0.05 (performed using online sample size calculator at
clincalc.com/stats/samplesize.aspx). Incidence and ARR were estimated based on previous
RCTs assessing Vitamin C as prophylaxis for CRPS in distal radius fractures. We aim to
recruit 10% for this pilot study, with 20 per arm (placebo vs prednisone), for a total of
40 patients.
The CONSORT guidelines for reporting of randomized pilot and feasibility trial will be
followed for the analysis and reporting of results. An intention-to-treat analysis will
be utilized.
Primary Outcomes: Descriptive statistics, reported as count and percentage, will be used
to summarize the feasibility outcomes (95% CI). Table 2 presents the traffic lights
criteria for each outcome of the pilot study. Green indicates feasible, red indicates not
feasible, and yellow indicates likely feasible but will require adjustments to the
protocol. (please see attached protocol)
Secondary and Tertiary Outcomes: Chi-square (or Fisher's Exact) test will be used to
compare the proportion of CRPS between groups. Either Mann-Whitney U test or two-sample t
test will be used for the other quantitative outcomes depending on the variable
distribution. Multivariable regression analysis will be conducted to test for
associations between the intervention and each outcome, controlling for differences in
patient characteristics. All P values will be 2-sided and statistical significance will
be set at P < 0.05. For this pilot trial, formal hypothesis testing will not be performed
as it is underpowered.