Introduction
Plantar fasciitis is the result of degenerative irritation of the plantar fascia origin at the medial calcaneal tuberosity of the heel as well as the surrounding perifascial structures. The plantar fascia plays an important role in the normal biomechanics of the foot and is composed of three segments, all of which arise from the calcaneus. The fascia itself is important in providing support for the arch and providing shock absorption. Despite the diagnosis containing the segment "itis," this condition is notably characterized by an absence of inflammatory cells.
Plantar fasciitis is very common in the US with millions experiencing heel pain every year. The cause of plantar fasciitis is multifactorial but most cases result from overuse stress. The classic presentation is of sharp localized pain at the heel. In some cases, a heel spur may be found. Plantar fasciitis is not easy to treat and patient dis-satisfaction is common with most treatments. The majority of cases are managed non-surgically but recurrence of pain is frustrating.
Etiology
This is often an overuse injury that is primarily due to a repetitive strain causing micro-tears of the plantar fascia but can occur as a result of trauma or other multifactorial causes. Some predisposing factors are pes planus, pes cavus, limited ankle dorsiflexion, and excessive pronation or supination. Pes planus can cause increased strain at the origin of the plantar fascia. Pes cavus can cause excessive strain on the heel because the foot does not effectively evert or absorb shock. Tight gastrocnemius, soleus, and/or other posterior leg muscles have also been commonly found in patients with this condition. It is thought that these tight muscles can alter the normal biomechanics of ambulation. Approximately 50% of patients with this condition will also have heel spurs, but the spurs themselves are not the cause. It is often associated with runners and older adults, but other risk factors include obesity, heel pad atrophy, aging, occupations requiring prolonged standing, and weight-bearing. Plantar fasciitis has been found to be associated with various seronegative spondyloarthropathies, but in approximately 85% of cases, there are no known systemic factors.
Epidemiology
Plantar fasciitis is the most common cause of heel pain presenting in the outpatient setting. The exact incidence and prevalence of plantar fasciitis by age are unknown, but estimates do show that approximately one million patient visits per year are due to plantar fasciitis. This condition accounts for about 10% of runner-related injuries and 11% to 15% of all foot symptoms requiring professional medical care. It is thought to occur in about 10% of the general population as well, with 83% of these patients being active working adults between the ages of 25 and 65 years old. It may present bilaterally in a third of the cases. Some literature shows prevalence rates among a population of runners to be as high as 22%.
Pathophysiology
This condition is primarily a degenerative process. Aside from degenerative changes, histological findings include granulation tissue, micro-tears, collagen disarray, and notably a lack of traditional inflammation. Ultrasound evaluation often reveals calcifications, intrasubstance tears, and thickening and heterogeneity of the plantar fascia. These changes, often seen on ultrasound, suggest a non-inflammatory condition and dysfunctional vasculature.
It is believed that the condition starts with microtears due to the repetitive stress associated with standing upright and weight bearing. The constant stretching of the plantar fascia results in chronic degeneration of the fasica, eventually leading to pain during sleep or at rest.
History and Physical
Patients will often present with a history of progressive pain at the inferior and medial heel, but can, however, radiate proximally in more severe cases. They will often describe the pain as sharp and worst with the first few steps out of bed in the morning. Long periods of standing, or in severe cases, sitting for prolonged periods, will also exacerbate symptoms. Pain often decreases with ambulation or beginning an athletic activity, but then increases throughout the day as activity increases. Pain can usually be reproduced by palpating the plantar medial calcaneal tubercle at the site of the plantar fascial insertion on the heel bone. Pain can also be reproduced with passive dorsiflexion of the foot and toes. Specifically, passive dorsiflexion of the first metatarsophalangeal joint is known as the windlass (or Jack's) test and considered a positive test if pain is reproduced. Secondary findings may include a tight Achilles heel cord, pes planus, or pes cavus. It may also be beneficial to assess a patient's gait to assess for biomechanical factors or predisposing factors mentioned previously. When considering the diagnosis of plantar fasciitis, one should consider fat pad contusion or atrophy, stress fractures, and nerve entrapments such as tarsal tunnel syndrome in the differential.
Evaluation
Plantar fasciitis is a clinical diagnosis and imaging is not necessary. A provider may consider obtaining x-rays or ultrasound evaluation if history or physical exam indicate other injuries or conditions or the patient fails to improve after a reasonable amount of time. X-rays and/or ultrasound evaluation may show calcifications in the soft tissues or heel spurs on the inferior aspect of the heel. Additionally, ultrasound may show thickening and swelling of the plantar fascia which is a typical feature. If the patient is not responding to conservative therapy after longer periods of time, then the provider may consider ordering an MRI to evaluate for tears, stress fractures, or osteochondral defects.
Treatment / Management
Relative rest from offending activity as guided by the level of pain should be prescribed. Ice after activity as well as oral or topical NSAIDs can be used to help alleviate pain. Deep friction massage of the arch and insertion has been shown to help. Shoe inserts or orthotics and night splints can be prescribed in conjunction with the previously mentioned therapies. Providers should educate patients on proper stretching and rehab of the plantar fascia, Achilles' tendon, gastrocnemius, and soleus.
If the pain does not respond to conservative measures, then consider more advanced or invasive techniques such as extracorporeal shock-wave therapy, botulinum toxin A, or various injections that could include autologous platelet-rich plasma, dex prolotherapy, or steroids. The more advanced and invasive techniques should be combined with conservative therapies. Surgery should be the last option if this process has become chronic and other less invasive therapies have failed.
No matter what treatment is selected, it needs to be carried out for at least 6 weeks. At the same time, stretching, icing, and strapping of the heel are recommended. The patient should be urged to modify work-related activities. A night splint may help patients with recalcitrant pain.
Surgery is the last resort and may include fasciotomy via an open or endoscopic approach. However, the surgical release does not guarantee a successful outcome. Complications of surgery include nerve injury, plantar fascia rupture and flattening of the longitudinal arch.
Differential Diagnosis
Calcaneus injury
Infection
Sickle cell bony pain
Bone contusion
Neuropathic pain
Tendinitis
Osteoporosis
Malignancy
Prognosis
About 75% of cases resolve spontaneously within 12 months. About 5% need surgery but the results are not consistently good. Even with treatment, the resolution of symptoms can take weeks or months. The morbidity from plantar fasciitis is enormous leading to time off work and sports. Some individuals require an ambulatory device to avoid weight-bearing.
Complications
Complications of plantar fasciitis include the following:
Rupture of tendon, especially if corticosteroid injections are done
Fat pad necrosis
Flattening of the arch, which increases strain
Pearls and Other Issues
After diagnosis, thorough patient education, and a prescription for conservative treatment, patients can typically follow-up as needed.
It is usually a self-limited condition, and with conservative therapy, symptoms are usually resolved within 12 months of initial presentation and often sooner.
Sometimes more chronic cases of this condition will need additional follow-up to consider more advanced therapies and evaluation of gait and biomechanical factors that can potentially be corrected through gait retraining.
Corticosteroid injections have been shown to be beneficial in the short-term (less than four weeks) but ineffective in the long term.
Evidence of the efficacy of platelet-rich plasma, dex prolotherapy, and extra-corporeal shockwave therapy is conflicting.
Enhancing Healthcare Team Outcomes
an interprofessional approach to plantar fasciitis is necessary as no single treatment works in everyone. Even when a treatment works, symptoms often take weeks/months to subside.
Plantar fasciitis affects many people, usually young people and athletes. The condition can be disabling if not appropriately managed. The key is the education of the patient. The nurse, pharmacists, physical therapist and rehabilitation specialist play a vital role in the recurrence of symptoms. Patients need to be told that the symptoms may take weeks or months to improve. In addition, the patient may have to enroll in a physical therapy program and even wear a night splint. Patients have to be taught how to stretch the plantar fascia with basic home exercises. In addition, a podiatry consult may be required to get the appropriate shoes with adequate arch support. Patients should be educated on avoiding long periods of standing. Further, losing weight and stretching before starting an exercise program is important. Those with acute symptoms should be told to avoid walking barefoot and limit repetitive exercises that traumatize the heel. If all these maneuvers fail, the last resort is a referral to an orthopedic surgeon. (Level V)