PLANTAR FASCIITIS

PLANTAR FASCITIS

Plantar fasciitis is a common foot disorder encountered in the outpatient clinic.

The typical presentation is sharp pain localized along the middle to posterior aspect of the sole of the foot.

Plantar fasciitis is often, but not always, associated with a heel spur (exostosis). Most patients with this condition have satisfactory outcomes with nonsurgical treatment.

PATHOPHYSIOLOGY

Excessive stretch of plantar fascia can result in microtrauma (microtears) of the plantar fascia at its insertion on the medial calcaneal tuberosity or along the course of the fascia.

This microtrauma, if repetitive, can result in chronic inflammation and degeneration of the plantar fascia fibers. Repetitive microtrauma at the plantar fascia may cause significant plantar pain, particularly with the first few steps after sleep or other periods of inactivity.

FREQUENCY

Plantar fasciitis is a common problem; however, the exact incidence and prevalence have not been determined.

MORTALITY/MORBIDITY

No mortality is associated with this condition, but patients may experience progressive plantar pain, leading to limping (antalgic gait) and restriction of activities, such as walking and running.

SEX

Women are affected by plantar fasciitis twice as often as men.

AGE

The exact incidence and prevalence by age of plantar fasciitis is unknown, but the condition is seen in adults essentially of all ages.

An increased incidence exists in patients with certain spondyloarthropathies (eg, ankylosing spondylitis), which often present in patients aged 20-40 years.

CLINICAL

HISTORY

• The chief complaint is plantar pain, generally localized to an area 1-2 cm distal to the medial calcaneal tuberosity.

• Inquire about the onset of the symptoms, as well as about any precipitating factors.

  • Ask the patient what makes the pain worse and what makes it better.

  • Most patients report that the pain usually is most severe during the first few steps after prolonged inactivity, such as sleeping or sitting.

• Patients may report that symptoms typically are relieved by unloading the affected foot (via sitting, elevation, or other means).

• Patients who are generally on their feet all day report that the symptoms may actually worsen by the end of the day.

• Important elements in the history of this condition include various activities, such as recreational running, as well as changes in footwear and previous trauma to the foot (eg, falls, motor vehicle accidents, work-related injuries).

• If this condition occurred in the course of the patient's employment, then it may be considered a worker's compensation issue. The physician should obtain a thorough history of the onset of the pain, any previous diagnostic assessment and/or treatments, and current functional capacities. This history is important for potential medicolegal purposes, such as impairment ratings.

PHYSICAL

• Inspection of the foot is the first step in the physical examination. Note any obvious deformities, skin changes, or congenital conditions (eg, pes planus [flatfoot]). Patients with plantar fasciitis often present with tightness of the Achilles tendon.

• The most important physical finding is reproduction of pain by palpating the plantar surface over the medial calcaneal tuberosity and along the course of the plantar fascia. Passive dorsiflexion of the toes usually does not aggravate the symptoms of plantar fasciitis, but it may do so in severe cases.

• To ensure that the patient is not presenting with retrocalcaneal bursitis or Achilles tendonitis, the clinician also should palpate the posterior aspect of the heel and ankle to look for tenderness.

• To rule out an S1 radiculopathy, perform the straight leg raise test, Achilles tendon reflex, and calf strength assessment with toe walking or 1-legged heel raises. All test results are within the reference range in the patient with plantar fasciitis.

• Tarsal tunnel syndrome can be ruled out by percussing over the tarsal tunnel behind the medial malleolus. This test produces no pain in the patient with plantar fasciitis.

• Reproduction of pain in the forefoot by compressing together the metatarsal heads of the second and third or the third and fourth toes suggests the presence of a Morton neuroma and is not a typical finding in plantar fasciitis. Morton neuroma is due to the entrapment of the common digital nerve between the metatarsal heads.

DIAGNOSIS

LABORATORY STUDIES

• No specific laboratory studies are needed to confirm the diagnosis of plantar fasciitis unless there is a bilateral presentation that appears in association with some seronegative spondyloarthropathies. Then the standard hematologic and chemistry studies may include, but are not limited to, a complete blood cell count, an erythrocyte sedimentation rate, complete metabolic panel, rapid plasma reagin, and rheumatoid factor study.

IMAGING STUDIES

• Radiographic imaging of the foot generally confirms the clinical examination and may reveal a heel spur that is the result of this condition and not a cause. The heel spur is best seen on the lateral view, located at the antero-inferior aspect of the calcaneus. Radiographic films of the foot should be obtained prior to corticosteroid injection or for any patient who continues to have symptoms despite 1-2 months of conservative, nonsurgical treatment. Standing lateral radiographs may help in the assessment for stress fractures of the calcaneus (a rare condition) in patients with pain at rest.

• Three-phase bone scanning is helpful for patients in whom there is a suggestion of a stress fracture of the calcaneus in spite of negative findings with plain radiography. In plantar fasciitis, a bone scan often shows increased uptake over the medial calcaneal tuberosity due to the local inflammation. This should not be confused with a stress fracture that shows increased uptake elsewhere in the calcaneus.

• If stress fracture remains a significant consideration despite negative radiographic findings, further imaging studies could include a computed tomography (CT) scan.

• Plantar fasciitis can be identified using ultrasonography by visualizing a thickened heel aponeurosis.

TREATMENT

PHYSICAL THERAPY

The mainstay physical therapy treatment for plantar fasciitis is stretching.

There are a number of ways to stretch the plantar fascia and the Achilles tendon.

• For patients who report that the most severe symptoms occur with the first steps after awakening, stretches should be performed before the patient even gets out of bed. This can be accomplished by keeping a long towel at the bedside. When the patient wakes up, he/she can stretch the plantar fascia by using the towel to cause passive dorsiflexion of the ankle, with each hand pulling one end of the towel, using the midportion of the towel to pull on the plantar aspect of the forefoot region.

• Other techniques for stretching the Achilles tendon include passive stretch while standing and nighttime ankle foot orthoses to keep the feet in neutral at night (thus stretching the Achilles tendon).

• The plantar fascia also can be stretched by having the patient, while seated; roll a soda can between the sole and the floor. Using a cold can of soda may give further symptomatic relief through local cooling.

• Passive stretching of the plantar fascia also can be achieved by using one hand at the plantar aspect of the forefoot region, then dorsiflexing the foot.

• A study found non – weight-bearing stretching exercises specific to the plantar fascia to be superior to the standard program of weight-bearing, Achilles tendon – stretching exercises in patients with chronic plantar fasciitis.

Massage of the plantar fascia, accomplished by running the thumb or fingers lengthwise along the fascia, can be beneficial for patients with plantar fasciitis.

The physical therapist may complete this technique within therapy sessions and may instruct the patient or family members on how to continue the massage independently at home.

Application of ice is an important part of the treatment process to reduce pain and inflammation. Ice should be applied after exercise and may be performed either as an ice massage for 5 minutes or by applying an ice pack for 15-20 minutes.

The physical therapist also may recommend other modalities, such as ultrasonography, phonophoresis, or iontophoresis, to assist further with pain relief and reduction of inflammation.

Sometimes, taping of the plantar fascia by an athletic trainer or physical therapist can help to decrease stress on the fascia, enabling the patient to better tolerate activity.

Taping techniques are used to distribute force away from the stressed and irritated fascia and to provide some relief from discomfort caused by weight-bearing activities.

If the patient needs to decrease his/her activity level due to this condition, remember to suggest alternative means of maintaining strength and cardiovascular fitness (eg, swimming, water aerobics, and other aquatic exercises).

SURGICAL INTERVENTION

• Surgical intervention, which rarely is required, involves a resection to release the plantar fascia from its bony attachment at the calcaneus.

• A study by Bazaz and Ferkel found that endoscopic plantar fascia release provided significantly improved outcomes for patients, specifically those with less severe symptoms.

OTHER TREATMENT

• Shoe inserts and heel pads - A heel pad typically is considered part of the initial treatment. These prefabricated orthotic devices, which are available at most pharmacies and surgical supply stores, are relatively inexpensive. The heel insert can be made of silicone, rubber, gel, or felt.

• Orthotic arch supports - These have also been advocated to improve symptoms. The orthotic device can support the bony arch and decrease the stress on the plantar fascia.

• Corticosteroid injection - This can be considered for plantar fasciitis in the relatively small percentage of patients who do not respond to an appropriate plantar stretching program and/or appropriate shoe inserts or orthoses.

  • A randomized, controlled study demonstrated that intralesional corticosteroid injection is more efficacious and more cost-effective than low-energy extracorporeal shockwave therapy in the treatment of plantar fasciitis that has persisted for more than 6 weeks.

  • Corticosteroid injection can be performed for plantar fasciitis, typically using a 22-gauge, 1.5-in (3.8-cm) needle to inject a mixture of 4 mL of local anesthetic (eg, lidocaine) and 1 mL (40 mg) of corticosteroid (eg, methylprednisolone [Depo-Medrol]).

  • Palpate the most anterior aspect of the medial plantar calcaneal tubercle and insert the needle at this site. Advance the needle until it reaches the most anterior (distal) aspect of the plantar medial calcaneal tuberosity. When the proximal (anterior) edge of the heel spur has been identified, advance the needle immediately anterior to this spot. Avoid injecting within the superficial layers of the subcutaneous tissue, because corticosteroid injection into the superficial fat pad can cause fat necrosis and atrophy, resulting in a loss in the shock absorption of the plantar heel.

  • In a preliminary report, a posterior tibial nerve block prior to steroid injection was shown to decrease the pain from injection and to improve compliance with treatment, without any complications.

  • Bleeding or bruising generally is expected only in patients who have bleeding disorders or are taking anticoagulants.

  • Infection at the injection site is rare, but possible. In addition to the sterile technique for the procedure itself, patients need to maintain good foot hygiene after the injection.

  • In diabetic patients, transient elevation of blood glucose levels may occur after corticosteroid injection.

  • Allergic reactions to the injected medications are rare, but possible.

  • Intravascular injection could potentially cause cardiac dysfunction, due to the inherent toxicity of local anesthetic agents.

  • Peripheral nerve dysfunction is possible if the local anesthetic is injected either close to or within the medial plantar nerve or the calcaneal branch of the tibial nerve.

  • Trials of ultrasonographically-guided steroid injection have shown its potential efficacy. It has been shown to produce a good clinical response when palpation-guided injection is unsuccessful. Accurate injection under ultrasonographic guidance may also minimize adverse effects from the injection.

  • A study of 25 patients who received corticosteroid injection for plantar fasciitis showed that patients received symptomatic relief as measured by tenderness threshold and a visual analog scale (VAS) (P <0.001). The study showed that this symptomatic benefit was obtained whether the injection was performed with image guidance (ultrasonography) or with palpation alone. However, patients injected using image guidance showed a lower rate of recurrence of heel pain. Thus, although injection with or without image guidance is helpful, image guidance does appear to provide additional benefit.

• Shockwave therapy - A meta-analysis seemed to show that shockwave therapy could be a safe and effective nonsurgical treatment for plantar fasciitis. 

• Botulinum toxin type A injection - Botulinum toxin type A injection seems to produce significant improvements in pain relief and overall foot function according to a short-term, randomized, controlled, double-blinded study.

• Cryosurgery - A prospective study suggests that cryosurgery is an effective treatment for plantar fasciitis after failed conservative management, without resorting to open, invasive surgery.

MEDICATION

Medications are used primarily to decrease pain and inflammation. The most commonly used medications are oral nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroid injections employed in conjunction with physical therapy.

NONSTEROIDAL ANTI-INFLAMMATORY DRUGS

These agents can help to decrease pain and inflammation. Various oral NSAIDs can be used, as there are no particular drugs of choice.

Choice of NSAID is largely a matter of convenience (how frequently doses must be taken to achieve adequate analgesic and anti-inflammatory effects) and cost. 

IBUPROFEN (Motrin, Advil, Nuprin, Rufen)

DOC for mild to moderate pain. Inhibits inflammatory reactions and pain by decreasing prostaglandin synthesis. Many doses are available without a prescription.

Adult: 200-800 mg PO tid/qid

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Caution in congestive heart failure, hypertension, and decreased renal and hepatic function; caution in anticoagulation abnormalities or during anticoagulant therapy 

KETOPROFEN (Oruvail, Orudis, Actron)

For relief of mild to moderate pain and inflammation.

Small dosages are indicated initially in patients with small body size, elderly patients, and those with renal or liver disease.

Doses >75 mg do not increase therapeutic effects. Administer high doses with caution and closely observe patient for response.

Adult: 25-50 mg PO q6-8h prn; not to exceed 300 mg/d

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Caution in congestive heart failure, hypertension, and decreased renal and hepatic function; caution in anticoagulation abnormalities or during anticoagulant therapy 

FLURBIPROFEN (Ansaid)

May inhibit cyclo-oxygenase enzyme, which in turn inhibits prostaglandin biosynthesis. These effects may result in analgesic, antipyretic, and anti-inflammatory activities.

Adult: 200-300 mg/d PO divided bid/qid

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

D - Fetal risk shown in humans; use only if benefits outweigh risk to fetus

Precautions

Acute renal insufficiency, interstitial nephritis, hyperkalemia, hyponatremia, and renal papillary necrosis may occur; patients with pre-existing renal disease or compromised renal perfusion risk acute renal failure; leukopenia occurs rarely, is transient, and usually returns to normal during therapy; persistent leukopenia, granulocytopenia, or thrombocytopenia warrant further evaluation and may require discontinuation of drug

CORTICOSTEROIDS

In contrast to the widespread systemic distribution of an oral anti-inflammatory drug, a local corticosteroid injection can achieve focal placement of a potent anti-inflammatory agent at the site of maximal tenderness or inflammation.

When corticosteroid injections are used, there are a variety of corticosteroid preparations to choose from. Commonly, the corticosteroid is mixed with a local anesthetic agent prior to injection. Again, there are various local anesthetic agents from which to choose. 

METHYLPREDNISOLONE (Depo-Medrol)

Corticosteroids such as methylprednisolone commonly are used for local injections of bursae or joints, to provide a local anti-inflammatory effect while minimizing some of the GI and other risks of systemic medications.

Adult: 40 mg (1 mL) intralesionally is common for injection at many sites, often mixed with a few mL of a local anesthetic, such as 1% lidocaine.