What X-ray (radiographic) views are recommended for a patient with knee pain suspected of having gout and osteoarthritis?

Recommended X-ray Views for Knee Pain with Suspected Gout and Osteoarthritis

For a patient with knee pain suspected of having gout and osteoarthritis, obtain weight-bearing anteroposterior (AP) and lateral views as the mandatory initial imaging, with strong consideration for adding a weight-bearing posteroanterior (PA) flexed view (Rosenberg/tunnel view) and tangential patellar view to maximize diagnostic yield. 1, 2

Standard Initial Views

Mandatory Views

• Weight-bearing anteroposterior (AP) view: This is the foundational view recommended by the American College of Radiology as the initial imaging modality for chronic knee pain 1, 2
• Lateral view: Essential component of the standard knee radiographic examination 1, 2

Strongly Recommended Additional Views

• Weight-bearing PA flexed view (Rosenberg or tunnel view): This view with the knee in 45 degrees of flexion significantly improves detection of joint space narrowing, particularly in the medial compartment, compared to standard AP views alone 3, 4, 5
• Tangential patellar (skyline) view: Critical for evaluating patellofemoral compartment involvement, which is characteristically affected in pseudogout and may be missed on AP views alone 1, 6

Rationale for Each Condition

For Suspected Gout

• Radiography is the initial imaging method as recommended by the American College of Radiology, as imaging findings are often characteristic 1
• X-rays can demonstrate joint effusion, which if present, justifies ultrasound-guided aspiration for crystal analysis (the definitive diagnostic test for gout) 2, 7
• Standard views can identify erosions and tophi in advanced disease 1

For Suspected Osteoarthritis

• Weight-bearing views are essential because they maximize visualization of joint space narrowing, the hallmark of osteoarthritis 3, 4, 8
• The combination of AP and tunnel views significantly increases detection of joint space narrowing in both medial (p=0.006) and lateral (p<0.001) compartments compared to AP alone 5
• The tunnel view detects 43% more cases of radiographic osteoarthritis not visualized on standard AP views 5
• Multiple views detect compartmental distribution: Using PA, lateral, and skyline views together identifies 98.7% of radiographic osteoarthritis cases, compared to only 56.7% with PA view alone 6

Optimal Imaging Algorithm

1. Obtain weight-bearing AP and lateral views first as the mandatory baseline 1, 2
2. Add weight-bearing PA flexed (Rosenberg/tunnel) view to improve sensitivity for joint space narrowing, particularly in the medial compartment where osteoarthritis commonly occurs 3, 4, 5
3. Include tangential patellar view to evaluate the patellofemoral compartment, which is characteristically involved in pseudogout (calcium pyrophosphate deposition disease) 1, 6
4. If radiographs show joint effusion and gout remains suspected, the effusion finding justifies ultrasound-guided aspiration for definitive crystal analysis 2, 7

Critical Pitfalls to Avoid

• Never skip radiographs and proceed directly to advanced imaging (MRI, CT, or ultrasound), as this violates evidence-based guidelines and wastes resources—approximately 20% of patients inappropriately receive MRI without recent radiographs 2, 9
• Do not rely on AP view alone: Using only the standard AP view misses 43% of radiographic osteoarthritis cases that would be detected with additional views 5, 6
• Do not overlook patellofemoral compartment: Pseudogout characteristically involves the patellofemoral joint, which requires a tangential patellar view for adequate visualization 1
• Ensure proper positioning: The Rosenberg/tunnel view requires 45 degrees of knee flexion with weight-bearing to maximize joint space narrowing detection 3, 4
• Document specific laterality (right vs. left knee) to improve diagnostic clarity and reimbursement 2, 7

When to Consider Advanced Imaging

If radiographs are normal or show only effusion but pain persists, MRI without contrast is the next appropriate step to evaluate for soft tissue pathology, early cartilage damage, and bone marrow lesions not visible on plain films 9. However, always obtain and review radiographs first before proceeding to MRI 2, 9.