What is the likely diagnosis and initial management for a 65-year-old woman with hypertension who has left heel, medial malleolar and arch pain worsened by dorsiflexion and eversion?

Posterior Tibial Tendon Dysfunction (PTTD)

This clinical presentation—left heel, medial malleolus, and arch pain worsened by dorsiflexion and eversion in a 65-year-old woman—is highly consistent with posterior tibial tendon dysfunction (PTTD), also known as adult acquired flatfoot deformity. 1

Clinical Diagnosis

The posterior tibial tendon functions as a dynamic arch stabilizer, and injury to this structure causes a painful flat-footed deformity with hindfoot valgus and midfoot abduction. 1 Key examination findings to confirm this diagnosis include:

• Pain location: Medial ankle pain along the posterior tibial tendon course from behind the medial malleolus extending toward the navicular insertion, combined with medial arch pain. 1
• Provocative maneuvers: Pain with dorsiflexion and eversion specifically stresses the posterior tibial tendon, making this presentation classic for PTTD. 1
• "Too many toes" sign: When viewing the patient from behind while standing, excessive forefoot abduction causes more toes to be visible on the affected side compared to the normal side. 1, 2
• Single-limb heel rise test: Inability to perform or pain with single-leg heel raise on the affected side indicates posterior tibial tendon insufficiency. 1

The condition predominantly affects middle-aged women and results from degenerative tendinosis rather than acute inflammation—histopathology reveals mucinous degeneration, fibroblast hypercellularity, and disrupted collagen bundle structure. 3, 4

Initial Management Algorithm

Begin with conservative treatment for 6-8 weeks before considering subspecialty referral. 5, 6

First-Line Conservative Measures (Weeks 0-6):

• Activity modification: Reduce weight-bearing activities that exacerbate pain, but avoid complete immobilization to prevent muscle atrophy. 5, 6
• NSAIDs: Oral anti-inflammatory medication for pain relief and inflammation control. 5, 6
• Orthotic devices: Over-the-counter or custom arch supports to redistribute weight and support the medial longitudinal arch. 5, 6
• Structured stretching exercises: Calf muscle and plantar fascia stretches performed 3-5 times daily. 6, 1
• Appropriate footwear: Shoes with proper arch support, cushioning, and adequate width. 6
• Ice therapy: Apply through a wet towel for 10-minute periods to reduce pain and inflammation. 6

If No Improvement After 6-8 Weeks:

• Immobilization: Consider a cast or fixed-ankle walker-type device for 2-3 weeks in refractory cases. 7, 6
• Advanced imaging: MRI without contrast to evaluate the degree of posterior tibial tendon damage and spring ligament integrity, which guides surgical planning. 5, 4
• Subspecialty referral: Refer to a podiatric foot and ankle surgeon for consideration of bracing with ankle-foot orthoses or surgical intervention. 5, 7, 6

Diagnostic Imaging Recommendations

• Initial imaging: Weight-bearing radiographs of the foot and ankle are the gold standard for diagnosing adult acquired flatfoot deformity, with 85% sensitivity and 95% specificity. 5
• Advanced imaging indications: If pain persists beyond 1 week despite treatment or if surgical planning is needed, MRI without contrast is the preferred modality to assess tendon integrity and spring ligament damage. 5, 4

Critical Pitfalls to Avoid

• Never inject corticosteroids near the posterior tibial tendon or Achilles tendon: This significantly increases the risk of tendon rupture. 5, 7, 6
• Do not assume isolated plantar fasciitis: The combination of medial malleolar pain with arch pain and pain provoked by dorsiflexion/eversion distinguishes PTTD from plantar fasciitis. 5, 7
• Avoid complete immobilization initially: This leads to muscular atrophy and deconditioning; structured activity modification is preferred. 6
• Recognize the progressive nature: PTTD is a degenerative condition that worsens without treatment, potentially causing significant disability and requiring debilitating surgery if left untreated. 2, 3

When to Refer Immediately

• No improvement after 6-8 weeks of appropriate conservative treatment. 5, 7, 6
• Severe deformity with significant hindfoot valgus or forefoot abduction visible on examination. 1, 2
• Inability to perform single-limb heel raise, indicating advanced tendon insufficiency. 1
• Need for ankle-foot orthoses fitting or consideration of surgical intervention. 7, 2