What is the recommended evaluation and stepwise management for chronic medial ankle pain?

Chronic Medial Ankle Pain: Evaluation and Management

Initial Imaging

Start with plain radiographs (AP, lateral, and mortise views) as the most appropriate initial imaging study for all chronic medial ankle pain. 1 Chronic ankle pain is defined as symptoms persisting >6 weeks. 1, 2

• Radiographs may reveal osteoarthritis, osteochondral abnormalities, stress fractures, ossific fragments indicating ligamentous injury, or periostitis adjacent to tenosynovitis. 1
• Weight-bearing radiographs are preferred when possible, as they reveal dynamic abnormalities like joint malalignment or subluxation not apparent on non-weight-bearing images. 3
• Pay special attention to areas of point tenderness, as avulsion fractures may be overlooked in 40-50% of cases on routine radiographs. 3

Subsequent Imaging Based on Clinical Suspicion

If radiographs are normal and medial ankle pain persists, order MRI ankle without IV contrast as the next study. 1 MRI globally evaluates all anatomic structures including ligaments, tendons, cartilage, and bone marrow. 1

Specific Clinical Scenarios:

• Suspected tendon pathology (posterior tibial tendon dysfunction): Either MRI without IV contrast OR ultrasound are appropriate. 1 Ultrasound has higher resolution than MRI for evaluating tendon pathology and allows dynamic evaluation during specific movements. 1, 2

• Suspected deltoid ligament injury: MRI without IV contrast OR MR arthrography should be ordered when ankle instability is suspected. 1 Deltoid ligament injuries significantly impact ankle stability but are frequently overlooked, especially when concurrent lateral ligament injuries exist. 4

• Suspected stress fracture: MRI without IV contrast is most sensitive for detecting occult fractures and bone marrow edema patterns. 3 Alternatively, technetium bone scanning or SPECT/CT can detect stress fractures when radiographs are negative. 1, 2

• Suspected nerve entrapment (tarsal tunnel syndrome): Ultrasound or MRI can evaluate peripheral nerve symptoms, with ultrasound offering higher resolution. 1, 2 Consider US-guided nerve blocks for diagnostic purposes and surgical planning. 1

Key Differential Diagnoses for Medial Ankle Pain

The medial ankle pain differential includes:

• Deltoid ligament complex injury: Results from pronation or supination-external rotation injuries; frequently underdiagnosed and can lead to chronic instability and posttraumatic arthritis if untreated. 4, 5
• Posterior tibial tendon dysfunction: Usually associated with spring ligament or flexor retinaculum injury; presents with medial gutter pain and valgus/pronation foot deformity. 4, 6
• Tarsal tunnel syndrome: Nerve compression causing medial ankle pain with neurologic symptoms. 4
• Accessory flexor muscles or subtalar coalition: Should be considered in chronic cases. 4
• Medial ankle impingement: MRI without IV contrast should be ordered when impingement syndrome is suspected. 1

Conservative Management

Initiate NSAIDs to reduce swelling and pain, which may decrease time to return to activities (Grade B recommendation). 2

• Semirigid or lace-up ankle supports are recommended as functional treatment (Grade B recommendation). 2
• Activity modification: Reduce or temporarily cease activities involving repetitive ankle loading. 2
• Graded exercise regimens with proprioceptive elements (such as ankle disk training) reduce risk of recurrent injury (Grade B recommendation). 2

Surgical Considerations

For chronic deltoid instability or posterior tibial tendon dysfunction failing conservative treatment, surgical reconstruction is usually needed. 5, 6

• Reconstruction of all involved ligaments (medial and lateral if necessary) should be considered for symptomatic medial instability. 6
• In cases of progressed foot deformity or bilateral valgus/pronation deformity, additional calcaneal lengthening osteotomy may be required. 6

Red Flags Requiring Urgent Evaluation

• Acute inability to bear weight 2, 3
• Significant swelling or deformity 2
• Point tenderness over specific osseous structures 2
• Neurovascular compromise (coldness or numbness in the foot) 2, 3
• In patients with diabetes or peripheral neuropathy, fractures may be present despite minimal pain or ability to walk, requiring higher index of suspicion. 3

Critical Pitfalls to Avoid

• Never inject corticosteroids near the Achilles tendon as this increases rupture risk. 2
• Do not rely solely on radiographs to rule out fractures in high-risk patients (diabetics, elderly). 3
• Avoid missing subtle avulsion fractures that appear as small bone fragments adjacent to ligamentous attachments. 3
• Do not skip imaging in favor of serum testing; structural pathology is far more common than systemic disease. 7
• Avoid ordering comprehensive autoimmune panels without specific clinical indicators, as this leads to false positives and unnecessary anxiety. 7