What are the differential diagnoses for a 46-year-old female (F) with central heel pain, excluding plantar fasciitis?

Differential Diagnoses for Central Heel Pain in a 46-Year-Old Female

The most important differential diagnoses to consider for central heel pain beyond plantar fasciitis are calcaneal stress fracture, heel pad syndrome, nerve entrapment, and less commonly, calcaneal tumors or infections. 1, 2, 3

Primary Mechanical Causes

Calcaneal Stress Fracture

• Presents with progressively worsening pain following increased walking activity or change to a harder walking surface 1, 2, 3
• Pain on compression of the calcaneus from medial to lateral (calcaneal squeeze test) is highly suspicious for this diagnosis 1, 2
• Tenderness localizes to the lateral calcaneal wall, slightly posterior to the subtalar joint facet 2
• Critical pitfall: Symptoms often occur before the fracture appears on radiographs 1, 2
• If initial radiographs are negative but clinical suspicion remains high, technetium bone scanning or MRI without contrast should be obtained 1, 2
• Swelling and warmth may be present at the lateral calcaneal wall 1

Heel Pad Syndrome

• Produces deep, bruise-like pain in the middle of the heel 3, 4
• Results from atrophy or inflammation of the fat pad that cushions the calcaneus 3, 4
• Pain is typically worse with direct pressure and prolonged standing 4

Neurologic Causes

Nerve Entrapment

• Pain accompanied by burning, tingling, or numbness distinguishes this from mechanical causes 1, 2, 3
• Can involve the medial calcaneal branch of the posterior tibial nerve or first branch of the lateral plantar nerve (Baxter's nerve) 3
• If neurologic heel pain is suspected, subspecialist referral for evaluation and diagnostic testing should be considered 1, 2
• Diagnostic studies include electromyography, nerve conduction velocity studies, and MRI 1, 2
• More proximal nerve impingement syndromes (lumbar origin) can also cause heel pain or absence of sensation 1

Traumatic Causes

Acute Calcaneal Fracture

• Most common osseous cause of heel pain from acute trauma 1
• Almost always results from a fall onto the heel from height 1
• Diffuse pain in the rearfoot (poorly localized) occurs with intra-articular fractures involving the subtalar joint 1, 2
• Diagnosis requires history of trauma, focal pain on palpation, and radiographic confirmation 1, 2

Acute Plantar Fascia Rupture

• Can cause central heel pain with soft tissue trauma 1
• Radiographs and bone scans may be negative 1
• Often occurs in patients with pre-existing plantar fasciitis 5

Rare but Serious Causes

Tumors (Malignant and Benign)

• Rarely cause heel pain but require proper diagnostic testing and appropriate referral when suspected 1, 2
• Should be considered if pain is constant at rest or progressively worsening without mechanical explanation 1

Infections

• Soft tissue infections or bone osteomyelitis rarely cause heel pain 1, 2
• Require proper diagnostic testing, consultation, and appropriate referral when suspected 1, 2
• Consider if there is increasing swelling, redness, warmth, or systemic symptoms 2

Vascular Compromise

• Can result in heel pain and necessitates proper diagnostic evaluation 1, 2
• Consider in patients with risk factors for peripheral vascular disease 1

Inflammatory Causes

Arthritides

• Can cause heel pain, particularly in patients with bilateral symptoms, pain in other joints, or known inflammatory arthritis conditions 1, 2
• Consider seronegative spondyloarthropathies (ankylosing spondylitis, reactive arthritis, psoriatic arthritis) 1

Key Examination Maneuvers

• Palpate for point tenderness at the medial plantar calcaneus (plantar fasciitis), lateral calcaneal wall (stress fracture), and central heel pad (heel pad syndrome) 2, 3
• Perform calcaneal compression test by squeezing the calcaneus from medial to lateral to assess for stress fracture 1, 2
• Assess for burning, tingling, or numbness to identify neurologic causes 1, 2
• Evaluate for swelling and warmth at the lateral calcaneal wall suggesting stress fracture 1

Diagnostic Imaging Approach

• Initial weight-bearing radiographs should be obtained for persistent heel pain 2
• If radiographs are negative but pain persists beyond 1 week, MRI without contrast or CT without contrast are equivalent alternatives 2
• Technetium bone scanning is recommended for suspected stress fracture with negative initial radiographs 1, 2
• Advanced imaging (MRI, ultrasound) helps confirm diagnosis and rule out other conditions 2

Common Pitfalls to Avoid

• Do not rely solely on initial radiographs to exclude stress fractures, as symptoms often precede radiographic findings 1, 2
• Always reexamine 3-5 days post-injury if initial examination is limited by excessive swelling and pain 2
• Consider rare causes (tumors, infections, vascular compromise) if pain is constant at rest, progressively worsening, or accompanied by systemic symptoms 1, 2
• Recognize that patients often report increased walking activity before stress fracture symptom onset 1, 2