A 42-year-old woman comes to the office because of worsening heel pain that began two months ago. She describes a sharp, stabbing sensation on the bottom of her right foot that is most severe when she takes her first few steps out of bed in the morning. The pain improves after she walks around for a bit but returns after she has been standing for a long time at her job as a retail manager. Past medical history is negative. On physical examination, there is maximal tenderness to palpation at the anteromedial aspect of the calcaneus. Pain is elicited by passive dorsiflexion of the toes. There is no swelling, warmth, or redness.
Which of the following is the most likely diagnosis?
The correct answer is:
D) Plantar fasciitis
This patient has the classic presentation of plantar fasciitis, the most common cause of heel pain in adults. It is an overuse injury caused by repetitive microtrauma to the plantar fascia, a thick band of connective tissue that supports the arch of the foot. The pathognomonic feature is first-step pain, which is severe pain in the morning or after prolonged rest that improves with activity but worsens with long periods of weight-bearing. On examination, tenderness is specifically localized to the medial tubercle of the calcaneus where the fascia inserts. Passive dorsiflexion of the toes stretches the fascia and typically reproduces the pain.
Answer choice A: Achilles tendinitis, is incorrect. This causes pain at the posterior heel, specifically at the insertion of the Achilles tendon on the calcaneus or slightly proximal to it. It does not typically cause tenderness on the plantar surface of the foot.
Answer choice B: Calcaneal stress fracture, is incorrect. While this also causes heel pain, the pain is usually more constant and does not improve with the first few steps. Tenderness is typically found along the lateral and medial sides of the calcaneus rather than the plantar surface.
Answer choice C: Morton neuroma, is incorrect. This involves a compressive neuropathy of the interdigital nerve, usually between the third and fourth metatarsal heads. It causes burning pain and a sensation of walking on a marble in the forefoot, not the heel.
Answer choice E: Tarsal tunnel syndrome, is incorrect. This is caused by compression of the posterior tibial nerve. It presents with aching, burning, or numbness that radiates from the medial malleolus down to the sole of the foot. It is often associated with a positive Tinel sign (tingling upon percussion of the nerve behind the medial malleolus).
Key Learning Point
Plantar fasciitis is characterized by sharp heel pain that is worst with the first steps in the morning or after rest. Tenderness is localized to the plantar-medial calcaneal insertion. Management is primarily conservative, including stretching exercises (specifically for the calf and plantar fascia), arch supports, and activity modification.
