Chapter 67 What Is the Best Treatment for Plantar Fasciitis?
Plantar fasciitis is a painful heel syndrome of unclear cause. Chronic or acute injury to the origin of the plantar fascia at the medial tubercle of the calcaneus is thought to produce a cycle of microtrauma and degenerative changes. Plantar fasciitis affects both active and sedentary adults with studies reporting that up to 10% of runners and a similar proportion of the general population are affected.1–4 A significant occurrence also is reported in military personnel and professional athletes.5,6 Increased body mass index, extended time standing, and limited ankle dorsiflexion are risk factors predisposing to plantar fasciitis.7 The high prevalence, substantial pain, and decreased tolerance for activity result in large numbers of patients seeking treatment. The cumulative number of office visits in the United States is estimated to be nearly 1 million visits each year.1
TREATMENT
Plantar fasciitis tends to improve in most cases regardless of the treatment selected.8–11 As a result, conservative management is effective for nearly 90% of patients.12,13 The conservative treatments used in management of plantar fasciitis vary widely and are dependent on physician specialty.1 Common treatments include nonsteroidal anti-inflammatory drugs (NSAIDs), stretching, insoles, taping, physical therapy, and night splints. If these simple and noninvasive modalities prove ineffective, additional treatment options include iontophoresis, injections, extracorporeal shock wave therapy (ESWT), and surgical treatment. This chapter reviews the various treatment methods for plantar fasciitis, and the effectiveness and safety of these treatments as supported by the best available evidence.
Stretching
Stretching protocols for the treatment of plantar fasciitis include stretching the Achilles tendon with or without stretching of the plantar fascia. Limited evidence is available from controlled trials to establish the effectiveness of stretching.14 Prospective studies comparing a plantar fascia–specific stretching protocol before the first morning steps and Achilles tendon stretching for treating chronic plantar fasciitis found a greater improvement in pain symptoms with the plantar fascia–specific stretching after 8 weeks (Level of Evidence II).15 Long-term follow-up at 2 years was incomplete but suggested no difference between Achilles tendon stretching and the plantar fascia–specific groups, although both groups showed improvement (Level of Evidence III).16
Taping
Taping techniques are intended to alter the position and alignment of the calcaneus, and to support the longitudinal arch. The effectiveness of calcaneal taping was compared with stretching, no treatment, and sham taping in one small study. Taping produced greater improvement in reported pain on a visual analog scale (VAS) than sham taping, controls with no treatment, or stretching (Level II).14 A larger study with 92 participants that examined taping with ultrasound compared with sham ultrasound reported a small improvement with taping in first step pain, one of four measured parameters (Level I).17 Sensitivity or allergy to tape may cause skin irritation.18
Nonsteroidal Anti-inflammatory Drugs
NSAIDs are used extensively in the management of acute and chronic musculoskeletal pain. The mechanisms for the anti-inflammatory and analgesic effects of these drugs are well documented in an extensive body of basic science and clinical research. Despite this, limited evidence exists to support the efficacy of NSAIDs in shortening the course or decreasing the symptoms of plantar fasciitis. One small trial found a nonstatistically significant decrease in pain and disability with NSAID treatment of plantar fasciitis (Level II).19 Other studies have quantified NSAID use as a measure of improvement with other therapies.20 The use of NSAIDs is associated with known adverse effects, which have been reported extensively in the medical literature.
Orthoses
The use of orthoses is intended to change loading characteristics of the plantar aponeurosis. Studies using cadaveric limbs suggest that support of the medial longitudinal arch can decrease strain of the plantar aponeurosis.21 Several randomized, controlled trials have examined the use of insoles in management of plantar fasciitis. A recent study comparing custom insoles, sham insoles, and prefabricated insoles found minor improvement in symptoms 3 months after treatment with prefabricated or custom insoles compared with sham (Level I).22 Prefabricated insoles have been found to be as effective as custom insoles at a reduced total cost.22–24 Insoles may be equally effective and offer improved patient compliance compared with night splints.24,25 A randomized, placebo-controlled, double-blind study conducted with 101 patients compared magnetic insoles with sham magnetic insoles and found no statistically significant improvement in pain symptoms after 8 weeks of treatment (Level II).26
Night Splints
Tension night splints stretch the plantar fascia over several hours while the patient sleeps by maintaining a constant ankle dorsiflexion. A trial comparing night splints with conservative treatment with conservative treatment alone found no significant difference in symptoms (Level I).27 Roos and coworkers28 compared insoles with night splints and found no significant difference in pain reduction and improved compliance with insoles (Level II). 28 Three studies reported that patients find night splint treatment uncomfortable and difficult to maintain, resulting in decreased compliance.24,28, 29 A systematic review found that the evidence for the effectiveness of night splints is inconclusive (Level II).3
Casting
Limited evidence has been reported for the effectiveness of casting in treatment of plantar fasciitis. One case series of 32 patients reported improvement in pain symptoms after 6 months after treatment with casting (Level IV).30 A fiberglass walking cast was used in the study.
Iontophoresis
Iontophoresis uses an electrical potential generated by bipolar electrodes to transfer charged ions and ionizable materials including some medications through the skin to provide anti-inflammatory or analgesic treatment.31 Conflicting results have been published for the effectiveness of dexamethasone iontophoresis. In a double-blind study with 39 subjects comparing iontophoresis using dexamethasone with a placebo, significant improvement on the Maryland foot score was reported at the end of the 2-week treatment period (3.80; 95% confidence interval [CI], 0.76–6.84) but not after 1 month (0.30; 95% CI, −2.16 to 6.76) (Level I).31 A second randomized, controlled trial with 31 subjects compared iontophoresis with taping and 0.4% dexamethasone, 5% acetic acid, or 0.9% NaCl placebo. The graphical data presented in the study indicate no statistically significant improvement with dexamethasone treatment in six measured outcomes at 4 weeks and less relief of pain symptoms compared with the control group at 2 weeks of treatment. In the group treated with acetic acid, there was a significant improvement in morning stiffness at 4 weeks with no reported statistically significant difference in three measures of pain at 4 weeks and no significant improvement compared with placebo in all six parameters at 2 weeks (Level I).18
Steroid Injection
Previously published reviews have found limited evidence to support the use of steroid injections in the treatment of plantar fasciitis.3,8 Steroid injection with and without nerve block was compared with placebo in a double-blind, randomized, control trial with 91 participants (Level I).32 The study found a statistically significant benefit at 1 month with steroid injection but not at 3 and 6 months. In addition, it was reported that tibial nerve block was not effective at relieving pain associated with steroid injection. A prospective study with 132 patients comparing steroid injection with ESWT or placebo found a statistically significant improvement in pain symptoms for the group receiving steroid injection over ESWT or placebo (Level II).33 The participants in this study reported VAS pain scores that were significantly lower than for the control and ESWT groups at 3 and 12 months. Potential adverse side effects of steroid injection include fat pad atrophy and plantar fascia rupture.
Botulinum Toxin Type A Injection
Botulinum toxin is used in the treatment of a variety of pain syndromes, and its use in treatment of plantar fasciitis has been reported. A single randomized, placebo-controlled, double-blind study conducted with 27 patients and 43 treated feet found statistically significant improvement in pain symptoms 3 and 8 weeks after treatment (Level I).34 Additional studies of the use of botulinum toxin in the treatment of plantar fasciitis are necessary to further define safety and efficacy.
Extracorporeal Shock Wave Therapy
ESWT utilizes application of mechanical waves similar to those used in lithotripsy but of lower energy density, usually less then 0.36 mJ/mm2 per pulse. Therapy consists of 500 to 6000 pulses delivered at 2 to 4 Hz to treat plantar foot pain. The mechanism by which ESWT provides benefit is investigational. Current theories include stimulation of healing after increased release of growth factors and neovascularization in the environment of local tissue injury35,36 or alteration in the chemical function of small axons producing analgesic effects.37,38 The possibility of a noninvasive treatment for chronic plantar fasciitis has generated significant interest, and several studies investigating the effectiveness of this technique have been published. Many of these trials are not of sufficient quality to provide a reliable assessment of the effectiveness of ESWT.3,8, 39, 40 The studies investigating ESWT have been in many cases sponsored by the equipment manufacturers, and the randomized control trials have produced conflicting results. Good quality, randomized, placebo-controlled, double-blind clinical trials have found no significant benefit to ESWT,41–43 whereas other randomized, controlled trials44–47 have found ESWT to be beneficial. The reasons for the discrepancy in reported results are unclear. A lack of uniformity of therapy exists from study to study, with differing methods for assessment of therapy, and in some studies, significant problems with study design have been reported.3,40 Differences also exist in the definition of the terms high energy and low energy, as well as in the amount of energy used in various studies. No controlled trials adequately define and identify indications for high- or low-energy protocols for ESWT. In addition, differences in criteria for patient inclusion in the studies make it difficult to compare the trials directly. Table 67-1 summarizes double-blind, randomized studies comparing ESWT with placebo. The reported adverse reactions, including skin redness, bruising, pain, numbness, tingling, and local swelling,42,44, 46 likely do not pose serious health risks. However, clear evidence supporting the use of ESWT treatment in the treatment of plantar fasciitis has not been reported.