What are the causes and treatment options for ankle pain in a patient with possible underlying conditions such as arthritis, diabetes, or peripheral artery disease?

Ankle Pain: Diagnostic and Treatment Approach

Initial Diagnostic Workup

Begin with plain radiographs (anteroposterior, lateral, and mortise views) as the first-line imaging study for all patients presenting with ankle pain. 1

Radiographs can identify:

• Osteoarthritis - the most common cause of chronic ankle pain in non-traumatic cases 1
• Osteochondral lesions and fractures 1
• Calcified intra-articular bodies 1
• Evidence of prior trauma or stress fractures 1
• Ankle effusions (53-74% accuracy) 1

Key Clinical Distinctions

Chronic ankle pain (>6 weeks duration) has multiple etiologies requiring targeted examination: 1

• Osteoarthritis: Progressive joint space narrowing, typically post-traumatic; primary ankle OA is rare and warrants investigation for hemochromatosis 2
• Tendon pathology: Achilles insertional tendonitis presents with posterior heel pain aggravated by shoes but relieved barefoot 1
• Ligament instability: History of recurrent sprains with persistent lateral ankle pain 3
• Impingement syndromes: Anterior or lateral ankle pain with specific provocative maneuvers 1

Advanced Imaging When Indicated

If radiographs are normal but clinical suspicion remains high, proceed to MRI as it globally evaluates all anatomic structures including ligaments, tendons, cartilage, and bone. 1

MRI is particularly useful for:

• Soft-tissue abnormalities (tendon and ligament tears) 1
• Osteochondral lesions 1
• Synovitis and impingement lesions 1
• Early inflammatory arthritis 1

CT is reserved for detailed osseous evaluation when surgical planning is needed, not as first-line imaging. 1

Treatment Algorithm

Conservative Management (First 6 Weeks)

Initiate immediate conservative treatment with: 1, 4

• Regular calf-muscle stretching exercises 1
• Cryotherapy/ice massage 1
• Over-the-counter heel cushions and arch supports 1
• NSAIDs for pain and inflammation 1
• Activity modification - avoid flat shoes and barefoot walking 1
• Weight loss if indicated 1
• Padding and strapping of the foot 1
• Corticosteroid injections in appropriate patients (avoid near Achilles tendon) 1, 4

Escalation at 6 Weeks Without Improvement

Refer to a podiatric foot and ankle surgeon while continuing initial treatments and adding: 1

• Customized orthotic devices 1
• Night splinting 1
• Limited corticosteroid injections if not previously used 1
• Cast immobilization or fixed-ankle walker device 1

Escalation at 2-3 Months Without Improvement

Continue all initial measures and consider: 1

• Cast immobilization if not previously used 1
• Extracorporeal shock wave therapy 1
• Surgical intervention (plantar fasciotomy or other procedures based on diagnosis) 1

Special Considerations for Underlying Conditions

Diabetes Mellitus

Perform annual comprehensive foot examination including inspection and assessment of foot pulses in all diabetic patients. 1

Critical risk factors requiring heightened surveillance: 1

• Loss of protective sensation (LOPS) 1
• Foot deformities 1
• History of prior ulcers or amputation 1
• Patients on dialysis 1

Refer diabetic patients with insensate feet, structural abnormalities, or history of ulcers to foot care specialists for ongoing preventive care and lifelong surveillance. 1

Peripheral Arterial Disease (PAD)

Screen for PAD with history of claudication and assessment of pedal pulses; obtain ankle-brachial index (ABI) if suspicion exists. 1

PAD-related ankle pain characteristics: 1

• Exertional pain that resolves with rest (claudication) 1
• Rest pain in severe cases (critical limb ischemia) 1
• Diminished or absent pulses 1
• ABI <0.40 suggests severe ischemia 1

Patients with significant claudication or positive ABI require vascular surgery referral for consideration of exercise therapy, medications, and surgical options. 1

Inflammatory Arthritis

New presentations of inflammatory mono/oligoarthritis involving the ankle are more likely due to undifferentiated arthritis or spondyloarthritis than rheumatoid arthritis. 2

Primary ankle osteoarthritis is uncommon; investigate for underlying causes, especially hemochromatosis. 2

MRI can assess disease activity and detect subclinical pathology in early inflammatory arthritis. 1

Critical Pitfalls to Avoid

• Never inject corticosteroids directly into or near the Achilles tendon - risk of rupture 1, 4
• Do not delay imaging in patients with stress fracture history 4
• Avoid missing critical limb ischemia - patients with diabetes, neuropathy, chronic renal failure, or infection who develop acute limb symptoms represent vascular emergencies requiring immediate specialist assessment 1
• Do not assume all ankle arthritis is osteoarthritis - consider inflammatory, crystalline, and infectious etiologies 2