Diagnostic Ultrasound: Can It Have An Impact For Plantar Fasciitis?
The use of ultrasound can reportedly lead to a more pinpoint diagnosis of plantar heel pain and aid in facilitating more direct treatment of the causal pathology. Accordingly, this author examines the research on the subject, discusses how he has modified his approach with ultrasound-guided injections and offers a compelling case study on how the use of ultrasound helped put an end to 12 years of bilateral heel pain.
There is no question that many of the strides in medical diagnostic capabilities have come from incredible advances in imaging techniques. This generation of physicians enjoys the advantage of being able to look into the human body to find the culprits of pathology and tailor the treatment protocol accordingly.
One such breakthrough in diagnostic imaging came in the form of soundwaves. Ultrasound as a medical diagnostic tool has been around for a long time since its initial utilization in 1942. Advances in ultrasound technology led to the first report of musculoskeletal sonography in 1958 by Dussik and colleagues.1 Ultrasound’s widespread acceptance as a diagnostic tool dates back to 1972 when McDonald and Leopold published their findings in the British Journal of Radiology.2
From a clinical standpoint, imaging techniques are not only useful to establish a diagnosis but can facilitate treatment in many conditions. When the physician can pinpoint an area of pathology, then one can target treatment to the most precise area, which helps facilitate better outcomes. The use of fluoroscopy has long since facilitated intra-articular injections and many of our podiatric colleagues have performed this type of procedure with improved results for many years.
One of the most common pathologies we see is heel pain. Researchers have reported that plantar fasciitis occurs in 2 million Americans a year and 10 percent of the population over a lifetime.3
The differential diagnosis of heel pain is quite extensive and we must be careful not to assume that all heel pain patients are presenting with heel spur or plantar fasciitis syndromes. The differential diagnosis may also include Achilles tendinitis, arthritic enthesitis, ankylosing spondylitis, autoimmune inflammatory syndromes, stress fractures, nerve entrapment, apophysitis, arterial insufficiency, tarsal tunnel syndrome, infection, bursitis, trauma, overuse syndrome, Reiter’s syndrome, intrinsic myositis, reflex sympathetic dystrophy and many others.
When it comes to the use of ultrasound in the diagnosis of plantar fasciitis, it provides the podiatrist with an easy to perform, in-office, immediate clinical corroboration of the suspected diagnosis.
Ultrasound has afforded me the ability to diagnose fasciitis, fasciosis, plantar fascial tears, inferior calcaneal bursitis, cortical stress fractures and abscesses (with a vertical toothpick embedded in the calcaneus). At times, ultrasound has also helped me rule out these most common findings. Ruling out typical pathologies has enabled me to look further for a credible diagnosis and allowed me to uncover cases of rheumatoid arthritis, atypical gout, ankylosing spondylitis, nerve entrapment and other less common diagnoses consistent with heel pain.
Since there is currently no objective reliable diagnostic test for plantar fasciitis, one cannot make a diagnosis solely on the basis of finding a heel spur on radiographs.
What The Research Reveals
In 1993, Wall and colleagues conducted a single-blind observational study using ultrasonography to measure plantar fascia thickness in patients with clinically suspected plantar fasciitis and control patients.4 The authors concluded that the mean plantar fascia thickness is greater for people with plantar fasciitis than for people without heel pain and that the difference is clinically significant. The ultrasonic appearance of the plantar fascia in plantar fasciitis indicated inflammatory changes. They reported an average mean thickness of the plantar fascia, measured by ultrasonography, of 5.7 ± 0.3 mm in symptomatic heels in comparison with 3.8 ± 0.2 mm in asymptomatic heels.