Extra-corporeal Shock Wave Therapy (ESWT) is a non-surgical alternative for the treatment of foot pain associated with plantar fasciitis. Shock wave therapy has been used since the early 1980's for the treatment/break-up of kidney stones. The application of shock wave therapy to soft tissue body parts was pioneered in Europe in the 1990's and has recently begun receiving FDA approval in the USA.

In shock wave therapy, a shock wave device generates a single pulse acoustic (shock) wave. Current techniques for generating shock waves include electromagnetic, electrohydraulic, and piezoelectric. The shock wave propagates rapidly in a 3-D space through a fluid medium. Ultrasound coupling gel is used to facilitate transmission to the tissue. The generation of the shock wave causes a sudden rise in pressure at the wave front. The energy within the shock wave is dissipated at the interface of substances with differing acoustic impedance. In ESWT, shock waves are rapidly generated and focused using a lens. Cavitation, the formation and movement of small bubbles in a fluid, is the result of the shock wave. ESWT causes mechanical tissue disruption and is theorized to result in neovascularization in the treatment area.

The frequency of plantar fasciitis is equal between males and females. Approximately 70-90% of heel pain can be managed with non-operative measures. Current conservative treatments for plantar fasciitis include:

• Rest
• Physical Therapy
• Heel Cushions
• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Corticosteroid injections
• Taping
• Orthotics
• Shoe Modifications
• Nightsplinting
• Casting

ESWT is an alternative to surgery. It is recommended that individuals meet the following criteria:

• Greater that 18 years old
.
• Visual Analog Scale (VAS) score greater than five (5) for pain during the first few minutes of walking in the morning.
• Six months of unsuccessful conservative therapy to include any NSAIDs and three other conservative therapies.
• Single site tenderness with local pressure over the medial calcaneal tuberosity on passive dorsiflexion of the foot.

There are no known complications reported with the application of ESWT to plantar fasciitis. Adverse effects typically associated with treatment include:

• Pain or swelling for a brief period following treatment
• Localized numbness, tingling or decreased sensation in the foot at the site of shock wave delivery
• Local subcutaneous hematoma, minor bruising, or petechial bleeding in the foot or at treatment site

ESWT is NOT RECOMMENDED for individuals with documented:

• Systematic inflammatory disease such as rheumatoid arthritis, ankylosing spondylitis, Reiter's syndrome, etc.
• Bleeding disorder, platelet disorder or hemophilia
• Pregnancy

The Dornier Epos Ultra is an electromagnetic shock wave devise. Its total energy flux density can be varied to deliver from 0.03 - 0.98 mJ/mm² per shock. The frequency of the shock waves can be varied from 60-240 shocks/minute. Configured for ESWT of the plantar fasciitis, the focal point is cylindrical in shape and is approximately 3mm in diameter x 27mm in length.

Using the Dornier Epos Ultra, shock waves are applied to the medial aspect of the foot. The treatment protocol calls for local ankle block anesthesia. Treatment takes place in a single session. Approximately 1300mJ/mm² of energy is given over 3800 shocks. Of the 3800 shocks given, 3500 are given at "Level 7", which corresponds to a positive energy flux density of 0.36 mJ/mm² per shock. An initial 300 shocks are given at lower energy levels to adjust the patient to the treatment. Shock wave frequency is increased from 60 to 240 shocks/minute during treatment. Total treatment time is approximately 20 minutes.

Common causes of pain associated with ESWT treatment include:

• Shock waves being applied too close to the calcaneous
• Shock waves terminating on the skin of lateral aspect of the foot

After receiving ESWT, patients can resume "near" normal activity. The foot should be iced regularly and if orthotics (or other heel cushions/shoe modifications) are currently used, continue their use as prescribed. Heavy exercise or high impact activities should be avoided for 2-3 weeks. In the clinical study submitted by Dornier for the FDA approval of the Epos Ultra for the treatment of plantar fasciitis, 61.6 percent of the patients receiving treatment showed good to excellent results (using the Roles & Maudsley pain score) after 3 months. In that same study, the VAS (Visual Analog Scale) pain score decreased from 7.7 to 3.4 (10-point scale). In a separate study by Weil et. al., 82% of the patients receiving treatment were satisfied or very satisfied with the ESWT treatment after an average 8.4 months.