ESSENTIALS OF DIAGNOSIS
Heel pain worse in the morning with initial weight bearing or after a period of rest.
Heel pain precipitated by a recent increase in activity.
Localized tenderness at the medial calcaneal tubercle.
Pain with passive dorsiflexion of the great toe.
Plantar fasciitis is the most prevalent condition treated by podiatrists and is the most common cause of heel pain. Each year, an estimated 2 million Americans are affected, resulting in more than 1 million clinician visits. The estimated annual cost of treatment for plantar fasciitis is between $192 and $376 million.
The plantar fascia is a thick and fibrous aponeurosis that helps support the medial longitudinal arch of the foot through the windlass effect. It originates at the medial calcaneal tubercle and forms three bands: a thick central band and thinner medial and lateral bands. The plantar fascia divides distally into digital bands that insert onto the base of the proximal phalanx of each digit and metatarsal heads. Fibers from the plantar fascia also blend into the deep transverse metatarsal ligament and the flexor sheath.
Plantar fasciitis is believed to be caused by repetitive microtrauma and biomechanical overuse. Risks factors include pes planus as well as pes cavus foot types, obesity, limb length discrepancy, Achilles tendon tightness, and occupations that require prolonged standing or walking.
The chief complaint is typically sharp and stabbing heel pain that is most severe in the morning or standing after rest. The pain usually improves with ambulation but may worsen after activity or at the end of the day. On physical examination, there is localized tenderness upon palpation of the medial calcaneal tubercle. Passive dorsiflexion of the hallux may cause pain or discomfort in the plantar fascia. Evaluation of the ankle joint may reveal decreased dorsiflexion, indicating a tight Achilles tendon.
Imaging is rarely needed, since the diagnosis of plantar fasciitis is usually clinical. Imaging should be obtained if the diagnosis is uncertain or the patient has not responded to treatment. Weight-bearing anteroposterior, medial oblique, and lateral views of the foot can determine biomechanical etiologies of plantar fasciitis. An infracalcaneal heel spur seen on the radiograph may be associated with symptoms of plantar fasciitis and can indicate that the condition has occurred chronically. However, a heel spur does not necessarily correlate with symptoms and is found in asymptomatic individuals (15–25% of the general population); many patients with plantar fasciitis do not have heel spurs.
Changes in the consistency and thickness of the plantar fascia have been noted both on MRI and ultrasonography in patients with plantar fasciitis; however, these diagnostic tests should be reserved for confirmation of plantar fascia rupture.