A 35-year-old woman comes to the office with a 1-month history of right foot pain. She started her job as a waitress 3 months ago. The pain is worse in the morning and toward the end of her shift. Examination of the feet while standing reveals flat arches. Upon sitting, the arches re-form. She has no bony abnormalities, swelling, or skin changes over the feet and ankles. There is sharp pain on palpation over the anteromedial region of the right heel, which is worsened when the big toes are dorsiflexed at the metatarsal phalangeal joints. Palpation of the posterior heel or tapping inferior to the medial malleolus does not reproduce the pain. Strength and sensation in the foot are normal. Which of the following is the best next step in diagnosis?

Question

A 35-year-old woman comes to the office with a 1-month history of right foot pain.  She started her job as a waitress 3 months ago.  The pain is worse in the morning and toward the end of her shift.  Examination of the feet while standing reveals flat arches.  Upon sitting, the arches re-form.  She has no bony abnormalities, swelling, or skin changes over the feet and ankles.  There is sharp pain on palpation over the anteromedial region of the right heel, which is worsened when the big toes are dorsiflexed at the metatarsal phalangeal joints.  Palpation of the posterior heel or tapping inferior to the medial malleolus does not reproduce the pain.  Strength and sensation in the foot are normal.  Which of the following is the best next step in diagnosis?

Quizplus · Accepted Answer

11ec25c8_d2c5_114d_bc81_f536723da019_MD0003_00 This patient most likely has plantar fasciitis, a chronic degenerative condition of the plantar aponeurosis at its insertion on the calcaneus. The plantar aponeurosis is a thick, fibrous band that extends from the calcaneus to the metatarsal heads and supports the arch of the foot. Overuse during high-impact activities (eg, running, prolonged standing) and conditions that place excessive stress on the arch (eg, obesity, flat feet [as seen in this patient with flat arches when standing]) are risk factors for plantar fasciitis. The pain is felt over the plantar heel/hindfoot and is often worse when first standing from rest, improves with activity, then worsens after long periods of weight bearing (eg, end of waitressing shift). Examination shows tenderness at the insertion of the plantar aponeurosis at the calcaneus (eg, anteromedial heel), especially with the toes passively dorsiflexed. The diagnosis is based on clinical findings; although MRI and ultrasound may show plantar fascial thickening, no imaging is necessary unless a secondary pathology (eg, fracture, tendon or ligamental tear in the case of trauma) is suspected or if the pain does not improve after treatment (Choices B and C). Differential diagnosis includes Achilles tendinopathy, which causes posterior heel pain at the insertion of the Achilles tendon on the calcaneus, and tarsal tunnel syndrome (ie, posterior tibial nerve compression), which presents with plantar numbness and paresthesia and a positive Tinel sign (ie, reproduction of pain by tapping over the nerve inferior to the medial malleolus). Achilles tendinopathy (Choices A and E) Imaging is not necessary to diagnose plantar fasciitis. However, when a fracture (eg, significant trauma) or anatomical bony abnormality (eg, tarsal coalition) is suspected, a CT scan or x-ray of the foot should be obtained. Although this patient's flat feet and pain raise concern for tarsal coalition (abnormal bone formation between the tarsal bones), this condition is characterized by arch rigidity, which is unlikely given the reconstitution of the pedal arches upon sitting (indicating flexibility in the arches) seen in this patient. Educational objective: Plantar fasciitis is caused by degeneration of the plantar aponeurosis at its insertion on the calcaneus due to overuse. The diagnosis is made clinically. Imaging is not required unless a secondary pathology (eg, fracture) is suspected or if the pain does not improve after treatment. References: Plantar fasciitis. (http://www.ncbi.nlm.nih.gov/pubmed/31194492)

A 35-Year-Old Woman Comes to the Office with a 1-Month