What is the proper order for a hip x-ray (anteroposterior, AP, and lateral views)?

Proper Order for Hip X-ray

The proper order for hip x-ray evaluation should include an anteroposterior (AP) view of the pelvis with approximately 15 degrees of internal rotation and a cross-table lateral view of the affected hip. 1, 2

Standard Hip X-ray Protocol

Primary Views

• AP view of the pelvis - Allows visualization of both hips for comparison
• Cross-table lateral view of the affected hip - Provides orthogonal assessment

Key Points About the Protocol

• The cross-table lateral view is preferred over the frog-leg lateral view in cases of suspected fracture due to the potential risk of fracture displacement with the frog-leg positioning 1
• Many institutions include both an AP view of the pelvis and a dedicated AP view of the symptomatic hip, along with the cross-table lateral view 1
• The AP view should be taken with approximately 15 degrees of internal hip rotation to optimize visualization 1, 2

Rationale for This Protocol

1. Complete Assessment: The combination of AP and lateral views provides complementary information for complete evaluation of the hip 2

2. Diagnostic Accuracy: This standard protocol detects approximately 90% of proximal femoral fractures 2

3. Clinical Importance: Delays in diagnosis and treatment of hip fractures are associated with increased complications, longer hospital stays, and higher mortality rates 1, 2

4. Comparison Value: Including the pelvis in the AP view allows for comparison with the contralateral hip, which can be valuable in detecting subtle abnormalities 1, 2

Common Pitfalls to Avoid

1. Omitting the cross-table lateral view: Even when the AP view clearly shows a fracture, the lateral view should not be omitted as it can change treatment decisions in some cases 1, 2

2. Using frog-leg lateral instead of cross-table lateral in trauma: The cross-table lateral is preferred in suspected fractures as the frog-leg positioning may cause fracture displacement 1

3. Excluding the pelvis from initial imaging: This is not recommended as associated pelvic fractures are common in patients with suspected proximal femur fractures 2

4. Relying solely on one view: While some research suggests one view might be adequate in certain scenarios 3, the current guidelines strongly recommend both AP and lateral views for comprehensive assessment 1, 2

In summary, the standard hip x-ray protocol should include an AP view of the pelvis with internal rotation and a cross-table lateral view of the affected hip, which provides the optimal balance of diagnostic accuracy and patient safety.