A new study by researchers at Hospital for Special Surgery (HSS) finds that a safe and painless ultrasound test can pinpoint the exact cause of heel pain, a common ailment that can be severely debilitating if not properly diagnosed and treated. The study, published in Journal of the American Podiatric Medical Association, finds that many times, a diagnosis based on a medical examination alone is inaccurate.
In the study, ultrasound failed to confirm an initial diagnosis of plantar fasciitis in 27 percent of the feet tested. Heel pain affects an estimated two million Americans annually. Stabbing pain in the heel can literally stop patients in their tracks. Unable to perform activities they enjoy, stand on their feet for extended periods or, at times, even walk, quality of life can suffer tremendously.
The cause is often diagnosed as plantar fasciitis based on a clinical exam. Plantar fasciitis is an inflammation of a thick band of tissue called the plantar fascia that runs across the bottom of the foot, connecting the heel bone to the toes. Although plantar fasciitis is the most common reason for heel pain, there can be other causes, and that is why ultrasound is an important diagnostic tool, according to Rock G. Positano, DPM, MSc, MPH, lead investigator and director of the Non-Surgical Foot and Ankle Service at Hospital for Special Surgery.
"Physicians often diagnose plantar fasciitis based on the clinical exam alone, without performing ultrasound to rule out other possible causes. The wrong diagnosis can not only prolong a patient's suffering, but can do more harm than good if the incorrect treatment is prescribed. It can also lead to unnecessary surgery," said Dr. Positano. Tears of the plantar fascia and plantar fibroma, a benign cyst, are commonly found in patients with heel pain, but often their diagnosis is overlooked, he noted.
"Our study demonstrates the usefulness of diagnosing heel problems using ultrasound and therefore verifying the presence or absence of plantar fasciitis, plantar fibroma or a plantar fascia tear, so the physician can develop the most effective and safe treatment plan," Dr. Positano said.
A misdiagnosis caused one of Dr. Positano's patients, a ballerina, to give up dance and suffer constant foot pain. For an entire year, Alexandra Ansanelli says she saw multiple doctors, receiving a new diagnosis every month. She had CT scans, X-rays and an M.R.I. Several physicians told her she would probably never dance again.
Dr. Positano finally was able to make the correct diagnosis. It turns out that she had almost severed the plantar fascia in her foot. She began treatment and improved enough to dance again as a principal ballerina in the New York City Ballet and subsequently the Royal Ballet of London.
Although Ms. Ansanelli's odyssey to find the correct diagnosis and treatment was years ago, Dr. Positano says people continue to suffer the consequences of misdiagnosis. What has changed, though, are advances in ultrasound imaging. "Technical advances and higher-frequency transducers have made ultrasound technology more desirable than MRI in the diagnosis of foot pain, and it's much less costly," Dr. Positano said.
For the study, investigators reviewed the medical records and diagnostic ultrasound reports of 143 patients seen at the Joe DiMaggio Sports Medicine Foot and Ankle Center at HSS over a 13-month period. Patients ranged in age from 16 to 79. All had a clinical presentation of plantar fasciitis or a previous diagnosis of plantar fasciitis. Ultrasound evaluation was then performed to confirm the diagnosis.
Thirty-two of the patients had an ultrasound evaluation of both feet due to pain, resulting in a total of 175 feet scanned for plantar fasciitis. Based on ultrasound results, plantar fasciitis was diagnosed in 73 percent of the feet scanned (128 feet). Thirty-four percent (43 feet) with plantar fasciitis also revealed concomitant plantar fascia tears on ultrasound.
Despite the initial diagnosis of plantar fasciitis, the ultrasound failed to confirm the diagnosis in 27 percent (47) of the feet tested. The ultrasound revealed the presence of at least one fibroma in 27 of those feet.
"Our findings led us to conclude that diagnostic ultrasound can effectively and safely identify the true cause of heel pain. The high prevalence of plantar fibromas and plantar fascial tears cannot be determined by clinical examination alone, and, therefore, ultrasound evaluation should be performed to confirm the diagnosis," Dr. Positano said. "The test could spare many people an incorrect diagnosis, potentially harmful treatment and needless suffering."