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.
This makes diagnosis rather easy as ultrasound machines provide easy marking and measuring of the fascia. In reality, I have found some measurements far beyond the average and sometimes multiple focal points of inflammation exist on the same ligament.
For some reason, there seems to be great disparity among those in the profession as to whether ultrasound guided injections for plantar fasciitis are medically necessary. The argument is that once you palpate the area for maximum tenderness, you just inject your anti-inflammatory solution in that area and you are done. There are good reasons why I believe this is not the case after having utilized ultrasound guided injections for over 10 years.
Any podiatrist who has treated his or her share of plantar fasciitis cases will admit that such patients can, at times, present great challenges and that clinical outcomes are unpredicatble. Many patients who have had physical therapy, orthotics, injection therapy, stretching, night splints and other interventions, fail to respond and experience long-term, chronic disability.5 Therefore, it behooves us as clinicians to work at maximizing the efficacy of our conservative protocols. Personally, I have found that ultrasound guided injections have enabled me to resolve a greater number of cases in a shorter period of time.
Sconfienza and co-workers conducted one such study that supports my assertion and duplicates my experience.6 “Combining an ultrasound-guided technique with steroid injection is 95 percent effective at relieving plantar fasciitis within three weeks,” according to the study presented at the annual meeting of the Radiological Society of North America.
Another study compared ultrasound guided injections with palpation guided injections.7 The authors found the recurrence rate of plantar fasciitis in patients of the palpation guided group (six of 13) was significantly higher than that of the sonographically guided group (one of 12).
Facilitating More Precise Injections And Reducing Potential Side Effects
Once you become comfortable with the modality, you will soon realize that the placement of your injections without ultrasound guidance can be “misguided.” In my own experience, I realized I was not placing my injections deep enough into the tissue and often injected at a site that did not house the inflammatory changes. When you depend on patients’ subjective experience as to where the maximum pathology exists via palpation, you soon find that they often will report pain in an area adjacent to and at other times distant from the actual site of pathology. Needless to say, missing the target will not net optimal results.
Additionally, if you are injecting steroid into an area of “non-pathology,” you run the risks of the effects of local fibrolysis of the fascia and/or the subcutaneous tissue (fat pad atrophy).
Secondly, as we know, utilization of steroid injections into and around connective tissue is not hazard free. With the use of ultrasound guidance, you not only have identified the exact area requiring the medication but you can also minimize the dose of steroids in your injection because you are treating a targeted area and not hoping for the “diffusion” effect. Lower doses of steroids will obviously minimize the risk of fibrolysis, tissue atrophy and post-steroid flares while hitting the “bull’s eye” improves patient outcomes.
Finally, in the more than 10 years that I have been performing ultrasound guided injections, I have come upon quite a few cases with partial tears of the plantar fascia. Obviously, performing steroid injections in this situation can be a recipe for disaster.
In my experience, I have found that many of my patients who have been struggling with chronic plantar fasciitis failed conservative therapy because the condition was one of tearing and not just inflammation. In situations like this, I will utilize either prolotherapy or platelet rich plasma injections to facilitate repair of the ligament. Again, ultrasound guidance provides a target for your solution and will vastly improve treatment outcomes.
Case Study: How An Ultrasound Diagnosis Helped Relieve Longstanding Heel Pain
A 43-year-old female and former marathon runner presented to my office with a 12-year history of bilateral heel pain. Her original doctor used an X-ray to diagnose her and told her she had heel spurs. She notes the previous doctor did not use diagnostic ultrasound or magnetic resonance imaging (MRI).
This patient had received three cortisone injections in each heel and experienced no relief. She then underwent eight weeks of physical therapy, which relieved the symptoms by approximately 50 percent. The first podiatrist gave her orthotics and discharged her from his care.
After approximately two months, the pain was back and was just as severe. At this time, she sought care from another podiatrist. He concluded that she got the wrong type of orthotic and made her a new one. This device, which was made of a non-yielding composite, made her symptoms worse.
The patient then did nothing for about three years and languished in daily pain, taking occasional pain relievers and nonsteroidal antiinflammatory drugs (NSAIDs) when the pain became unbearable. At this time, she went to an orthopedic surgeon. He told her that her pain would never go away unless she had the spurs removed and had her plantar fascia severed.
This frightened her so she went to another podiatrist for a fourth opinion. He told her that by now the inflammation was so chronic that she needed to go on NSAIDs for a few months to heal the condition. She received a prescription for naproxen (Naprosyn) 500 mg BID. After being on the drug for three weeks, the patient did notice marked relief of the pain in her feet but she was suffering from gastrointestinal pains and stopped taking the medication herself. The pain then returned.
Now seven years into her heel pain symptoms, she went back to the orthopedist she had seen and had bilateral endoscopic plantar fasciotomies with spur resections. According to the patient, the pain grew significantly worse bilaterally and persisted. She did not seek any medical care for five years after the surgeries.
When she came to my office and shared the history with me, she told me that the orthopedist also used X-rays for the diagnosis and did not do any soft tissue imaging. When I asked her where her pain was, she told me it was in the plantar aspect of both heels, midway between the medial calcaneal tubercle and the posterior/plantar aspect of the calcaneus, where she had always experienced pain. In addition, the patient had pain in both proximal plantar fascias since undergoing surgery.
On this first visit, I performed a diagnostic ultrasound exam, which revealed bilateral inferior calcaneal bursas. In addition, when I assessed the patient while she was weightbearing, I noticed that her calcaneal inclination angle was quite depressed, obviously due to the fasciotomies. I performed two sets of injections, one week apart, under ultrasound guidance. At the third week, she was asymptomatic.
I then cast her for foot centering devices and vaulted the calcaneus with a higher inclination angle and a first ray cutout for forefoot instability. She began wearing the devices until she was able to wear them all day, every day. The pain never returned.
I will never know whether bursal sacs were present at the beginning of her treatment 12 years ago. Based on her history of marathon running and her subjective pain location, I believe bursal sacs were the more likely diagnosis, which an ultrasound would have revealed then and certainly did reveal under my care.
I use this as a case in point for a number of reasons. First of all, the bursal sacs were rather proximal in the plantar aspect of each heel. She could not specifically recall but she thought the injections she received were in the arch area (more likely near the medial calcaneal tubercle). If she had undergone an ultrasound back then, injection placement would have been more precise with a more accurate diagnosis. This may have spared her all the years of suffering and certainly could have avoided the unnecessary surgery that made her condition worse.
Ultrasound is easy to perform and quite easy to read after you have conquered the learning curve. In this case, as with many patient cases, we employed ultrasound not only to make a diagnosis but to guide the injection to the targeted area for the best results.
Dr. Kornfeld is the Director of Holistic and Complementary Podiatric Medicine in New York City and Manhasset, N.Y. He is board certified in Integrative Medicine by the American Association of Integrative Medicine (AAIM) and is a Diplomate of the College of Physicians of the AAIM.
For further reading, see “How To Detect Chronic Heel Pain With Musculoskeletal Ultrasound” in the November 2006 issue of Podiatry Today.
1. Dussik KT, Fritch DJ, Kyriazidou M, Sear RS. Measurements of articular tissues with ultrasound. Am J Phys Med 1958; 37(3):160-165.
2. McDonald DG, Leopold GR. Ultrasound-B scanning in the differentiation of Baker’s cyst and thrombophlebitis. Br J Radiol 1972; 45(538):729-32.
3. Riddle DL, Pulisic M, Pidcoe P, Johnson RE. Risk factors for plantar fasciitis: a matched case-control study. J Bone Joint Surg Am 2003; 85-A(5):872-877.
4. Wall JR, Harkness MA, Crawford A. Ultrasound diagnosis of plantar fasciitis. Foot Ankle 1993 Oct; 14(8):465-70.
5. Lynch D, Goforth W, Martin J, Odom R, Preece C, Kottor M. Conservative treatment of plantar fasciitis. A prospective study. JAPMA 1998; 88(8):375–380.
6. Sconfienza LM, Lacelli F, Serafini G, et al. What’s new in the treatment of plantar fasciitis: a percutaneous ultrasound (us)-guided approach. Presented at the Annual meeting of the Radiological Society of North America, November 30, 2008-December 5, 2008, Chicago. Presentation No. SSA13-07.
7. Tsai WC, Hsu CC, Chen CP, Chen MJ, Yu TY, Chen YJ. Plantar fasciitis treated with local steroid injection: comparison between sonographic and palpation guidance. J Clin Ultrasound 2006; 34(1):12-16.