What is the initial approach for managing continued ankle pain with no swelling and a normal X-ray?

Management of Continued Ankle Pain with Normal X-ray and No Swelling

For patients with continued ankle pain, normal X-rays, and no swelling, MRI without IV contrast is the most appropriate next imaging study to evaluate for occult injuries such as ligamentous tears or osteochondral lesions. 1

Diagnostic Approach

Initial Assessment

• If the patient meets any Ottawa Ankle Rules criteria (inability to bear weight immediately after injury, point tenderness over malleoli/talus/calcaneus, or inability to ambulate 4 steps), radiographs should have already been performed 1
• Normal radiographs rule out most fractures but not soft tissue injuries or occult bone injuries 1
• Persistent pain beyond 1-3 weeks with normal radiographs requires further evaluation 1

Next Diagnostic Steps

• MRI without IV contrast is the preferred next imaging study for patients with persistent ankle pain (>1 week but <3 weeks) with negative initial radiographs 1
• CT ankle without IV contrast is an alternative but less sensitive for soft tissue injuries 1
• The absence of swelling may suggest chronic rather than acute injury, but does not eliminate the possibility of significant pathology 2, 3

Common Causes of Persistent Ankle Pain with Normal X-rays

• Ligamentous injuries (especially lateral ankle ligaments) 4, 2
• Osteochondral lesions not visible on plain radiographs 2, 5
• Peroneal tendon injuries or tendinopathy 2, 3
• Syndesmotic injuries (high ankle sprains) 1, 2
• Anterior or lateral ankle impingement syndromes 2, 5
• Sinus tarsi syndrome 3

Management Algorithm

Step 1: Initial Conservative Management (0-6 weeks)

• Activity modification and avoidance of aggravating activities 1, 2
• Physical therapy focusing on strengthening and proprioceptive exercises 2, 3
• NSAIDs for pain control 1
• Functional bracing rather than complete immobilization 3
• Weight loss if indicated 1

Step 2: If No Improvement After 6 Weeks

• Obtain MRI without IV contrast to evaluate for occult injuries 1
• Consider referral to podiatric foot and ankle surgeon or orthopedist 1, 6
• Additional treatments may include:
  • Customized orthotic devices 1
  • Immobilization with cast or fixed-ankle walker-type device for more severe cases 1
  • Limited corticosteroid injections (with caution, avoiding the Achilles tendon) 1

Step 3: Refractory Cases (No Improvement After 2-3 Months)

• Surgical consultation for consideration of:
  • Arthroscopic evaluation and treatment for osteochondral lesions or impingement 2, 5
  • Ligament reconstruction for chronic ankle instability 4, 2
  • Other targeted interventions based on specific diagnosis 2, 3

Important Considerations and Pitfalls

• The absence of swelling does not rule out significant pathology; many chronic ankle conditions present without visible swelling 2, 3
• Continued ankle pain despite normal X-rays should not be dismissed as minor 4, 2
• Even with negative MRI findings, patients with clinical evidence of ankle instability may benefit from surgical intervention 4
• Inadequate rehabilitation is a common cause of persistent pain after ankle injury 2
• Early functional rehabilitation is preferred over complete immobilization to prevent muscle atrophy 3
• Consider less common causes if standard treatments fail, including referred pain from proximal sources 6