Plantar Fasciitis

Abstract

Plantar fasciitis is one of the most common causes of heel pain in adults. Up to 15% of the population will be affected by heel pain. Although clinical history and examination can often diagnose this condition, there are several other disease processes that mimic plantar fasciitis. Nonsurgical treatment is successful in 95% of the cases. Recalcitrant pain after failure of nonsurgical management requires surgery after 6 months of consistent effort.

Keywords

Heel pain, plantar fasciitis

Synonyms
Plantar fasciosis Heel spur syndrome
ICD-10 Code
M72.2	Plantar fasciitis

Definition

Plantar fasciitis, one of the most common causes of heel pain, presents a challenge to both primary care physicians and orthopedic surgeons. Estimates of up to 15% of all adults will encounter heel pain and seek medical treatment. Plantar fasciitis is often described as an overuse injury, stemming from inflammatory changes at its origin on the medial aspect of the calcaneus. Classically, pain tends to be worse in the morning with the first steps upon waking, improving throughout the day, only to have a return in severity near the end of a long work-day. Commonly seen in ambulatory jobs including nursing and construction, it can also afflict more obese, sedentary patients, revealing that the root cause is likely multifactorial beyond a simple overuse injury. The fascia itself is a multilayered, thick aponeurosis. It originates from the medial tubercle of the calcaneus, extending into three different components (medial, central, lateral bands). These bands then divide into separate fibrous extensions to each proximal phalanx of each toe, which runs into the volar plate, periosteum, and flexor sheaths of each digit forming the windlass mechanism ( Fig. 92.1 ).

The fasciitis portion of the injury stems from repetitive microtrauma to the origin of the plantar fascia, causing increased inflammatory changes to the area. Some studies have shown that there actually may be minimal if any true inflammatory cells in the area of trauma, meaning the injury is a true degenerative process rather than inflammatory process. This has led to some experts referring to this as more of a fasciosis than fasciitis.

This process affects men and women alike. Typically, an increase in activity level has been associated with plantar fasciitis, especially in runners increasing their training. Careers that require a great amount of standing, including police officers and teachers, are also at risk for the injury. Besides career risk factors, physical risk factors such as obesity, pes planus, excessive pronation, as well as Achilles tendon contracture all play a role in the development of the ailment. Historically, plantar fasciitis was associated with heel spurs, which were considered to be bony growth resulting from the pull of the plantar fascia. However, further studies have shown that a plantar heel spur does not indicate plantar fasciitis. The size of the calcaneal heel spur has no correlation with severity of symptoms.

Symptoms

Patients describe a burning, stabbing pain in the plantar aspect of the calcaneus, usually on the medial aspect of the heel. First steps in the morning are extremely painful (postkinetic dyskinesia), and pain actually dissipates as they begin their day. This pain usually has an insidious onset, and is rarely described with trauma. Some may describe that they are “toe walkers” in the morning in order to prevent that initial pain stimulus with early morning ambulation (source 3). These symptoms will usually decrease throughout the day, but a majority will have a return of their symptoms near the end of a normal work-day. Bilateral symptoms are common, and the physician should inquire about the contralateral limb. True plantar fasciitis does not give symptoms of numbness or paresthesias. These symptoms should alert the physician to another diagnosis of heel pain.

Physical Examination

Palpation of the foot is essential to differentiate between plantar fasciitis versus other causes of heel pain. Pain overlying the medial tuberosity of the calcaneus at the plantar fascial origin is a classic finding. Dorsiflexion of the toes, specifically at the metatarsophalangeal joint, will place the fascia on tension, usually exacerbating a patient’s symptoms. Assessment of heel cord contracture is essential, as many patients will have concomitant heel cord tightness. Percussion over the tarsal tunnel may elicit the patient’s symptoms. If so, this is indicative of entrapment of the lateral plantar nerve (Baxter’s nerve) instead of true plantar fasciitis. Range of motion may be limited in dorsiflexion due to Achilles or gastrocnemius contracture, but a plantar fasciitis patient should otherwise have normal strength and sensation, as well as normal reflexes, barring any additional pathology (i.e., neuropathy).

Functional Limitations

Symptoms of plantar fasciitis usually come from two camps: the obese and sedentary versus active athletes/workers. For sedentary patients, the initial pain symptoms in the morning can be life limiting, and may alter their ability to participate in physical activity, thereby exacerbating other pathologies associated with obesity. For workers, specifically in careers in which patients are on their feet the majority of the day (nurses, physicians, laborers, etc.), plantar fasciitis can be severely limiting and lead to lost wages, time off work, or need for significant job modifications.

Diagnostic Testing

Laboratory testing and advanced imaging is usually not required for a diagnosis of plantar fasciitis due to its classic symptoms and clinical findings. However, lab work as well as other diagnostic tools may be needed to rule out other pathologies in the differential. X-ray imaging may be standard for any orthopedic complaint. For a majority of patients without trauma, these will likely be normal. Heel spurs may be seen, but are not indicative of plantar fasciitis. Only obvious calcaneal stress fractures may be visible on the lateral projection. MRI may be indicated to rule out other pathologies, including entrapment of Baxter’s nerve, infection, tumor, or stress fracture. MRI may show thickening and increased signal on T2- weighted imaging of the fascia at the calcaneal insertion; however, these findings may be non-specific ( Fig. 92.2 ). Bone scan, although better geared to diagnose an underlying calcaneal stress fracture, may show an increased uptake at the origin. Ultrasound has been used to show thickening of the origin of the plantar fascia. It may also be helpful in distinguishing a nerve entrapment by finding a nerve with increased fluid. Electromyography (EMG), while not indicated for isolated plantar fasciitis, can be useful to rule out radiculopathy or nerve entrapment, which may be difficult to distinguish on clinical exam alone.

Laboratory work is guided by the patient’s history. Systemic symptoms, including weight loss or fevers, raise significant concern for underlying malignancy or infection, and infectious lab work is indicated. If patients present with multiple complaints, including bilateral heel pain with other associated joint pain, rheumatologic workup is indicated, including RF and ANA.

Differential Diagnosis