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Vascular Medicine
http://vmj.sagepub.com/content/13/3/235
The online version of this article can be found at:
DOI: 10.1177/1358863X08091970
2008 13: 235Vasc Med
Joseph Bernstein, John L Esterhai, Mitchell Staska, Sally Reinhardt and Marc E Mitchell
of leg pain
The prevalence of occult peripheral arterial disease among patients referred for orthopedic evaluation
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The prevalence of occult peripheral arterial disease among
patients referred for orthopedic evaluation of leg pain
Joseph Bernstein
1,2
, John L Esterhai
1,2
, Mitchell Staska
2
, Sally Reinhardt
2
and Marc E Mitchell
3
Abstract: Lower extremity peripheral arterial disease (PAD) and musculoskeletal con-
ditions both produce symptoms of leg pain, and may coexist. This study assesses the
prevalence of PAD among patients referred to orthopedic surgery for evaluation of
lower extremity pain. Fifty consecutive patients aged 50 years or more who had a
chief complaint of leg pain, no history of trauma, and no previous history of PAD
were studied prospectively. The presence of known risk factors for PAD and classic
claudication symptoms was assessed by telephone interview and medical record
review. Individuals were then evaluated by measurement of the ankle–brachial index
(ABI) using Doppler and pulse volume recordings (PVR). A patient was deemed to
have PAD if the ABI was below 0.9 or if the PVR demonstrated significant abnormali-
ties. Occult PAD was detected in 10 of the 50 patients (20%) on the basis of the non-
invasive vascular studies. There were no differences between patients with PAD and
those without PAD regarding the presence of risk factors for PAD. None of the
patients without PAD had claudication, while only one of the 10 patients with PAD
had symptoms of classic claudication. In conclusion, 20% of patients referred by pri-
mary care providers to the orthopedic surgery clinic for lower extremity pain were
discovered to have occult PAD. The majority of these patients did not have claudica-
tion. Orthopedic surgeons and primary care providers must maintain an appropri-
ately high index of suspicion for PAD when evaluating patients with non-traumatic
lower extremity pain.
Key words: claudication; degenerative joint disease; peripheral artery disease
Introduction
Among older patients presenting to orthopedic sur-
gery for evaluation of lower extremity pain, muscu-
loskeletal conditions such as degenerative joint dis-
ease (DJD) and peripheral arterial disease (PAD)
may be found concurrently; both are afflictions
associated with advanced age. In some patients,
PAD not musculoskeletal disease, may be the
source of their symptoms. In those cases where a
diagnosis of DJD is suspected, it is important to
exclude the possibility of concurrent occult PAD,
especially when surgical treatment for arthritis is
contemplated. There is evidence indicating that pri-
mary care providers may be unaware of PAD in
many patients.
1
Patients presenting to orthopedics
for evaluation of atraumatic lower extremity pain
may have been inadequately assessed for the condi-
tion, and may indeed have undiagnosed PAD. The
purpose of this study is to determine the prevalence
of occult PAD in these patients.
Materials and methods
All new patients 50 years of age or older presenting
to the orthopedic surgery practice at the Philadel-
phia Veterans Affairs Medical Center (VAMC)
between July and December of 2005 were screened
consecutively for possible inclusion in the study.
This practice serves as the primary orthopedic ser-
vice for the hospital and its outpatient clinics, as well
as the tertiary referral service for other nearby
VAMCs. Only patients who have been referred by
another physician are seen; patients cannot refer
themselves to the orthopedic clinic. Patients with a
chief complaint of leg pain and no history of trauma
were contacted by the study nurse to determine
study eligibility. Inclusion criteria for the study
included: aged 50 years or more, leg pain, no history
of trauma within the last 3 years, no previous
1
Department of Orthopedic Surgery, University of
Pennsylvania, Philadelphia, PA, USA;
2
Veterans Affairs
Medical Center, Philadelphia, PA, USA;
3
Department of
Surgery, University of Mississippi, Jackson, MS, USA
Correspondence to: Marc E Mitchell, Professor and Chair,
Department of Surgery, University of Mississippi, 2500 North
State Street, Jackson, MS 39216, USA.
Email: memitchell@surgery.umsmed.edu
Vascular Medicine 2008; 13: 235–238
© 2008 SAGE Publications, Los Angeles, London, New Delhi and Singapore 10.1177/1358863X08091970
by guest on May 11, 2011vmj.sagepub.comDownloaded from
history of PAD, and referral to orthopedic surgery
by a primary care provider.
Eligible patients completed a brief telephone
interview regarding risk factors for PAD and symp-
toms of claudication (Table 1). The electronic med-
ical record was also utilized to determine the pres-
ence or absence of risk factors, history of
claudication, previous history of PAD, and presence
or absence of the diagnosis of DJD.
Patients were evaluated in the non-invasive vas-
cular laboratory with pulse volume recordings
(PVRs) and ankle–brachial indexes (ABIs). Pressure
measurements and PVRs were obtained at the level
of the proximal thigh, distal thigh, calf and ankle
using a Parks Flo-Lab system (Parks Medical Elec-
tronics, Inc., Aloha, OR, USA). For each leg, the
ABI was calculated as the ratio of the highest ankle
pressure measured (dorsalis pedis or posterior tibial)
to the highest arm pressure measured. These studies
were reviewed by a blinded, board-certified, attend-
ing vascular surgeon both for accuracy and to pro-
vide further vascular surgery consultation if needed.
The study protocol defined PAD as an ABI < 0.9.
Patients with an ABI of 0.9 or above were given the
diagnosis of PAD if PVRs demonstrated significant
arterial occlusive disease by waveform analysis.
Waveform criteria used to make the diagnosis of
PAD included loss of the dicrotic wave, decrease
in the amplitude of the waveform, decrease in the
slope of the up-stroke, decrease in the slope of the
down-stroke, and bowing of the down-stroke away
from the baseline.
Appropriate statistical testing was conducted to
determine differences in risk factors between the
group of patients identified with PAD and the
group without PAD. The protocol was approved
by the institutional IRB and informed consent was
obtained.
Results
Fifty consecutive patients were included in this study.
All were male, with an average age of 63 years (range
50–86, standard deviation 10.7). Ten patients were
determined to have occult PAD. Nine had an ABI
below 0.9 and one had an ABI of 0.93, but was given
the diagnosis of PAD based on an abnormal PVR
with significant abnormalities of the arterial wave-
forms. Only one of the 10 patients with PAD had
symptoms consistent with claudication. None of the
40 patients without PAD had claudication.
Twenty-nine of the patients in the sample (58%)
carried the diagnosis of DJD prior to referral for
orthopedic surgery evaluation. Five of the
10 patients in the group with PAD (50%), and 24
of the 40 patients with no PAD (60%) had DJD.
This difference was not statistically significant
(p= 0.83).
The distribution of risk factors is shown in
Table 2. No statistically significant differences in
risk factors were seen between the two groups. The
mean number of risk factors present per patient was
2.4 in the group with PAD versus 2.1 in the group
without PAD. This difference was not statistically
significant (p= 0.45).
Discussion
This study demonstrates that a significant number
of older patients referred to orthopedic surgery for
evaluation of lower extremity pain, have occult
Table 1 Telephone interview protocol
1 Do you consent to be interviewed?
2 Do you have leg pain?
3If yes to number 2
Do you have pain on exertion, with every bout of
activity, that increases with activity and improves
with rest?
4 Have you suffered trauma to the affected leg within
the last 3 years?
5 Have you smoked within the last 10 years?
6 Do you have now or have a history of heart attack or
heart disease, stroke, high blood pressure, diabetes,
peripheral arterial disease, hyperlipidemia?
7 Does anyone in your family have a history of heart
attack or heart disease, peripheral arterial disease,
stroke?
8 Do you agree to undergo vascular testing?
Table 2 Prevalence of risk factors for peripheral arterial disease
Risk factor Prevalence in sample
population n=50
Prevalence in subgroup
with PAD n=10
Prevalence in subgroup
without PAD n=40
Hyperlipidemia 22 (44%) 7 (70%) 15 (38%)
History of cardiac disease 7 (14%) 1 (10%) 6 (15%)
History of stroke 3 (6%) 0 3 (8%)
Smoking within the last 10 years 12 (24%) 4 (40%) 8 (20%)
Diabetes 10 (20%) 3 (30%) 7 (18%)
Hypertension 23 (46%) 5 (50%) 18 (45%)
Family history of myocardial infarction,
stroke or PAD
29 (58%) 4 (40%) 25 (63%)
236 J Bernstein et al.
Vascular Medicine 2008; 13: 235–238
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PAD. Furthermore, neither the presence of known
risk factors for PAD, nor symptoms of claudication
were useful predictors of occult PAD in these
patients. Along with prior reports,
1–5
this study
serves to remind physicians that occult PAD is an
important diagnostic entity, worthy of heightened
clinical suspicion.
It is not surprising that 20% of this group of
patients over the age of 50 were found to have
PAD by non-invasive vascular testing. There have
been many other studies demonstrating a similar
incidence of PAD.
1,3,4
The low incidence of claudi-
cation in these patients with PAD has also been
reported in previous studies.
3,4
It has been previ-
ously demonstrated that 45% of patients with
PAD have coexisting orthopedic disease.
6
It is, how-
ever, interesting that in a group of patients with a
complaint of leg pain severe enough to warrant
referral for an orthopedic surgery evaluation, 20%
were found to have undiagnosed PAD. Although
the majority of these patients did not have symp-
toms of classic claudication, this finding suggests
that despite efforts to increase awareness regarding
PAD, it continues to be underdiagnosed.
The presence of PAD may be an important con-
sideration in the management of patients with DJD.
Radiographically confirmed DJD does not neces-
sarily result in symptoms commensurate with the
severity of the abnormalities seen on imaging
studies.
7
Thus, the mere presence of radiographi-
cally severe DJD may not in and of itself provide a
complete diagnostic explanation for the patients’
symptoms. The same can be said of PAD. Clinicians
experienced in the management of PAD are aware
of how difficult it can be to differentiate claudica-
tion from other types of leg pain.
8
This study
demonstrates that coexistent DJD and PAD is not
uncommon, and that the latter is not always recog-
nized prior to orthopedic surgery evaluation. In
patients with both DJD and PAD, it is entirely pos-
sible that neither is responsible for the symptoms.
More sophisticated testing may be required to deter-
mine the cause of the symptoms.
The treating orthopedic surgeon must be attuned
to the possibility of PAD, as this condition may
influence the outcomes of surgical treatment for
arthritis, either by increasing the risk of perioperative
complications, or by constraining the benefits of
treatment. In a series of 18,443 knee replacements
performed at the Mayo Clinic,
9
24 patients (approx-
imately one out of every 750) required above the
knee amputation for complications secondary to vas-
cular disease. In a study by DeLaurentis, et al.,
10
one
out of four patients with demonstrable PAD had
complications of knee replacement attributable
to vascular insufficiency. The association between
PAD and coronary artery disease is well
known.
11–13
Patients with coexistent PAD and
DJD may be at increased risk for perioperative car-
diac complications when undergoing major orthope-
dic procedures. The overall mortality risk for knee
replacement surgery is approximately 1 in 200.
Although not specifically addressed in this study,
patients with coexisting PAD are at higher risk for
perioperative cardiac morbidity and mortality. The-
oretically, PAD may also increase the risk of wound
complications or infection among patients undergo-
ing lower extremity orthopedic surgery.
Occult PAD may also mar an otherwise successful
joint replacement procedure. As noted by Stewart
and Baird,
14
symptoms of PAD are seen only if
“exercise tolerance is not restricted …forthisreason,
patients with disabling arthritis of the knee may not
experience the early symptoms of intermittent claudi-
cation if their exercise tolerance is restricted primarily
by arthritis.”There may be a group of patients with
no claudication prior to joint replacement surgery
because they do not walk far enough, who become
severely limited by claudication once their arthritis is
successfully treated. The potential for successful
rehabilitation in these patients following surgery
could be significantly impaired by their PAD.
There are limitations associated with this study:
primarily its location and size. This investigation
was conducted within a VAMC. As such, the
patients were disproportionately male, and may rep-
resent a cohort with greater risk factors for PAD
compared with the general population. It must be
further acknowledged that the small sample size
likely limits the ability to detect differences in risk
factors between the subgroups. Lastly, the study
could have been improved if all patients were sub-
jected to an expert vascular examination, but that
was not logistically feasible.
In conclusion, this study demonstrates that occult
PAD is frequently present in patients with no his-
tory of trauma or claudication, who are referred by
primary care providers to orthopedic surgeons for
evaluation of leg pain. Moreover, the presence or
absence of risk factors for PAD is not a useful dis-
criminator between patients with and those without
PAD. Assessing patients for PAD is neither costly
nor invasive. Based on the current study, physicians
who treat patients with lower extremity pain should
have a low threshold for obtaining lower extremity
non-invasive vascular testing, even in the absence of
symptoms of claudication.
Acknowledgements
Conflicts of interest
None.
PAD prevalence among leg pain orthopedic referrals 237
Vascular Medicine 2008; 13: 235–238
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Ethical Board Review
Approved by institutional IRB.
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