A patient has had six weeks of swelling around the ankle involving the talus, lateral malleolus, and medial side of the joint with mild tolerable pain; what is the likely diagnosis and recommended evaluation and management?

Six-Week Ankle Swelling: Chronic Ankle Instability or Occult Pathology

This presentation most likely represents chronic ankle instability (CAI) from an inadequately treated lateral ankle sprain, which develops in approximately 40% of patients and requires MRI evaluation to exclude occult bone or ligamentous pathology, followed by supervised exercise-based rehabilitation. 1

Most Likely Diagnosis

The six-week duration with persistent swelling and tolerable pain strongly suggests chronic ankle instability rather than an acute injury. 1 This condition develops when initial lateral ankle sprains receive inadequate treatment, leading to ongoing lateral pain, swelling, and functional limitations. 1

However, at this timepoint, you must also consider:

• Occult osteochondral lesions of the talus, which can accompany ankle injuries and cause persistent symptoms 2
• Syndesmotic injury involving the anterior and posterior tibiofibular ligaments, particularly if the mechanism involved dorsiflexion with eversion 1
• Malunion of an unrecognized lateral malleolus fracture, which can present with chronic symptoms even years later 1

Critical Physical Examination Findings to Elicit

Perform these specific maneuvers:

• Palpate systematically along the lateral malleolus, distal fibula, anterior tibiofibular ligament, and medial malleolus for focal tenderness 1
• Anterior drawer test to assess lateral ligament integrity (sensitivity 84%, specificity 96% when performed after acute swelling resolves) 1
• Crossed-leg test: apply pressure on the medial knee while the affected leg is crossed over the opposite knee—pain at the ankle indicates syndesmotic injury 1
• Assess medial structures carefully: tenderness, bruising, or swelling medially suggests deltoid ligament involvement or occult medial pathology 3, 4

Imaging Algorithm for Six-Week Symptoms

Order MRI without contrast as the primary imaging study for this chronic presentation. 1 Here's why:

• MRI has 93-96% sensitivity and 100% specificity for chronic ligamentous injuries and occult bone pathology 1
• Standard radiographs may have been normal initially but missed occult injuries 2
• Weight-bearing radiographs should also be obtained to measure medial clear space (normal <4mm) and assess for dynamic instability 1, 4

The British Journal of Sports Medicine emphasizes that MRI is the study of choice for persistent symptoms beyond the acute phase, as it can identify osteochondral lesions, bone edema, ligamentous tears, and synovial pathology that plain films miss. 1

Treatment Approach Based on Findings

Primary Treatment: Exercise-Based Rehabilitation

Supervised exercise-based programs are strongly preferred over passive modalities as they stimulate recovery of functional joint stability. 1 This approach is superior to immobilization for reducing morbidity and improving quality of life. 3

Specific interventions include:

• Lace-up ankle supports or semirigid braces, which are superior to elastic bandages for functional treatment 1
• Structured proprioceptive and strengthening exercises under supervision 1
• NSAIDs used cautiously and briefly for symptom control—they reduce pain and swelling but may suppress natural healing with prolonged use 1

Surgical Consideration

Reserve surgery only for cases that do not respond to thorough and comprehensive exercise-based treatment. 1 The British Journal of Sports Medicine is clear that conservative management should be exhausted first, as successful reconstruction is achievable even years post-injury (average presentation at 6 years for symptomatic malunion). 1

Critical Pitfalls to Avoid

• Failing to recognize occult malunion or inadequately assessing associated deltoid ligament injury in remote lateral malleolus injuries 1
• Missing osteochondral lesions of the talus, which occur in up to 42% of ankle injuries and cause persistent symptoms 2
• Underestimating syndesmotic involvement, which requires different management than simple lateral ligament injuries 1
• Assuming all chronic ankle pain is "just a sprain" without imaging—rare vascular injuries like pseudoaneurysms can present with persistent swelling and pain 5

Expected Outcomes and Follow-Up Timing

The British Journal of Sports Medicine reports that 5-33% of patients will have persistent pain and instability at 1 year, and 3-34% will experience recurrent ankle sprains. 3 Early aggressive rehabilitation addressing pain level, workload, and activity modification improves recovery outcomes. 3

If MRI reveals significant pathology (large osteochondral defect, complete ligament disruption, bone edema), adjust the treatment plan accordingly—some lesions may require arthroscopic debridement or ligament reconstruction. 1, 6