Extracorporeal Shock Wave Therapy for Treatment of Plantar Fasciitis
Plantar fasciitis is a common foot disorder, constituting
15% of all foot complaints1. Characterized by pain along the
plantar aspect of the heel, this disorder may become chronic
and functionally disabling. Although the etiology remains
unknown, various predisposing factors have been implicated,
including minor trauma, foot pronation, improper fitting
shoes, obesity and jobs that require prolonged standing2-5.
Inflammation, microtears, fibrosis, and/or degeneration may
occur at the plantar fascia origin6. Both conservative and
surgical treatment methods have been employed with variable
Extracorporeal shock wave therapy (ESWT) has evolved
as a safe treatment option for plantar fasciitis. Shock waves
are high energy sound waves propagating in three-dimensional
space which apply mechanical energy to the interface of two
substances (tissues) with differing acoustic impedance6.
Preliminary ESWT studies have reported success rates
between 48% and 82% in eliminating heel pain11-16. Both low
and high energy protocols, as well as single and multi-treatment
regimens, have been utilized6,11-16. The purpose of this
study was to review the clinical effectiveness of high energy
ESWT for the treatment of plantar fasciitis.
Materials and Methods
A total of 37 patients underwent ESWT from April 2002 to
September 2002. Inclusion criteria were: plantar medial heal
pain with activities of daily living; symptoms greater than six
months duration; failure to respond to three consecutive treatments
including NSAIDS, physical therapy, orthotics, stretching
exercises, cortisone injection and casting; and age greater
than 18 years. Exclusion criteria included: previous surgery
or shock wave therapy for plantar fasciitis; corticosteriod injection
within one month of treatment; history of documented
autoimmune or systemic inflammatory disorder; coagulation
abnormalities; bleeding disorders; peripheral vascular disease;
diabetes; neoplasm; calcaneal stress fracture; infections; pregnancy;
and peripheral neuropathy.
All patients were given a medial calcaneal nerve block
using 10ml of 1% lidocaine 10 minutes prior to the procedure.
All patients were placed in the prone position and ultrasound
visualization of the proximal plantar fascia origin was performed
[Figure 1(b)]. The treatment consisted of 3800 shocks
(3500 at 0.36mj/mm2) for a total of 1300 mj/mm2. The shock
waves were administered using the Dornier Epos Ultra (Dornier
MedTech America, Inc., Atlanta, GA) [Figure 1(a)].
The Dornier Epos Ultra is an electromagnetic system,
which uses an electromagnetic coil and an opposing metal
membrane to produce a magnetic field which compresses the
surrounding fluid medium to generate a shock wave. An isocentric
ultrasound is included in the Epos Ultra system to allow
precise shock wave delivery to the tissues.
After treatment, patients were allowed immediate weightbearing
without any restrictions to their activities. Patients
were encouraged to continue daily stretching and icing if they
were performing these activities prior to the procedure.
All patients were evaluated prior to the procedure and at
one month, three months, and six months post-treatment.
Patients were assessed by history, physical examination, and
visual analog pain scale at each visit. Patients were judged
based upon the percentage improvement in their pain from
baseline. The treatment was considered successful if the
patient experienced greater than or equal to 50% improvement
in pain compared to the pre-procedure symptoms. Additionally,
patients were grouped based on unilateral versus bilateral presenting
symptoms. The improvement values were correlated
with patient factors including age and BMI. Bivariate correlations
and unpaired t tests (statistical significance at p<0.05)
were performed using SPSS (SPSS Inc., Chicago, Illinois)
Of the 37 patients who underwent ESWT, two received
bilateral heel treatments. All patients received only one therapy
session per heel. One patient could not be reached for follow-up
until six months post-treatment and two patients did not have
three-month follow-up examinations. There were 27 women
and 10 men with an average age of 50 years (range, 24 to 76).
The average BMI was 28 (range, 21 to 38). Fifty-seven percent
of patients complained of unilateral pain. Of these patients, the
left heel was affected in 15 cases and the right heel in six. The
mean duration of symptoms was 18 months.
At one month post-procedure, 47% of patients responded
successfully (50% or greater improvement in pain). At three
and six month follow-up, 68% (mean improvement of 50%)
and 77% (mean improvement of 64%) of patients responded
successfully to ESWT, respectively. One patient achieved 100%
improvement by one month after therapy. Six patients did not
experience any relief of pain by six months post-therapy. No
patients experienced worsening of pain following ESWT.
There was no statistically significant difference in the mean
BMI of the successful and unsuccessful groups at one month
(p=0.450). Likewise, there was no difference in the mean age
of the two groups (p=0.888). Due to a decreasing sample size
of the unsuccessful group at the three and six month time
points, analysis of BMI and age were conducted using bivariate
correlation between these factors and percentage improvement.
There was no correlation between BMI and improvement at the
three and six month time points (p=0.995, p=0.729, respectively),
but there was a significant positive correlation between
age and improvement at these time points (p=0.006, p=0.004,
When the patients were grouped according to unilateral
versus bilateral presenting symptoms, there was not a statistically
significant difference (p=0.136, p=0.860, p=0.446,
respectively) in improvement at any of the post-therapy time
points. No complications or adverse reactions were noted.
When plantar fasciitis fails to respond to conservative
treatment over an extended period of time, surgical fasciotomy
is often recommended7,9,17-19. Surgery may be associated with
variable success, complications, prolonged recovery time, and
loss of time from work20-24. Many patients and physicians will
often discount the surgical option entirely because of uncertain
results, leading to acceptance of chronic pain and loss of function.
As an alternative to surgery, ESWT has several advantages.
First, it is a noninvasive technology without the obvious potential
complications associated with surgery. Second, it has a
relatively limited recovery time during which the patient may
return to employment and normal activities of daily living25.
Third, it demonstrates a success rate comparable to surgery
and even to other conventional therapies for this disorder7,20.
Finally it has the potential to be utilized earlier in the course
of this disorder, which may limit patient suffering and health
The exact mechanism of extracorporeal shock wave therapy
remains undefined. There may be an effect on local pain receptors
leading to hyperstimulation of axons and a reflex analgesic
effect26. Other investigators have shown an increased metabolic
response at the area of healing with cellular changes, including
release of nitric oxide and growth factors27. Additionally, neovascularization
has been implicated11. It is also apparent that
higher energy shock waves (0.28 mj/mm2—0.6 mj/mm2) initiate
a more effective and quicker clinical response than lower
energy waves (0.08 mj/mm2)25.
The success of high energy ESWT in this early follow-up
study is comparable to previous reports in the literature. We
experienced a 77% success rate (64% overall improvement in
pain) at six months following ESWT. Rompe et al16 report a
57% success rate (good or excellent outcome using the Roles
and Maudsley scale) at six months in patients who received
three applications of 1000 impulses of low-energy shock waves.
Similarly, Hammer et al13 reported a 71% reduction in pain with
activities of daily living at six months in patients who received
three sessions of ESWT at weekly intervals.
Interestingly, we found no correlation between success and
BMI, which has been implicated as a risk factor for plantar fasciitis.
We found no correlation between age and success at one
month, but older patients had a statistically significant greater
improvement at three and six months. This result may be
attributable to patient activity level following the therapy. It is
possible that older patients, with fewer daily demands, allowed
for greater rest and healing of the treated area.
In conclusion, extracorporeal shock wave therapy is a safe
treatment option for proximal plantar fasciitis. In this limited
follow-up study, a single therapeutic high energy session was
effective in relieving painful chronic symptoms. Further studies
are needed to elucidate the duration of relief and mechanism
Mr. Samuel Adams is a Medical Student, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA.
Dr. George Theodore is Chief of Foot and Ankle Surgery, Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, MA.
George H. Theodore, M.D.
Massachusetts General Hospital
15 Parkman Street, Suite WACC 503
Boston, MA 02114
Phone: (617) 724-9338
Fax: (617) 726-6161
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