What is the most appropriate next step in evaluating a 79-year-old woman with acute right hip pain localized over the hip after three days of exercise?

Initial Plain Radiography of the Hip

The most appropriate next step is to obtain plain radiographs of the right hip, including an anteroposterior (AP) view with 15 degrees of internal hip rotation and a cross-table lateral view of the affected hip 1.

Rationale for Immediate Radiography

In a 79-year-old woman with acute hip pain following exercise, the primary concern is an occult hip fracture, which carries significant morbidity and mortality risk in elderly patients. The 2025 ACR Appropriateness Criteria explicitly designates radiography as the initial imaging modality of choice for acute traumatic hip pain 1. This approach is critical because:

• Delays in hip fracture diagnosis increase mortality: Surgical delays beyond 12 hours significantly increase 30-day mortality risk in patients over 50 years 1
• Over 300,000 hip fractures occur annually in the U.S., predominantly in elderly patients with osteoporosis 1
• Radiographs are rapid and accessible: They can be obtained quickly without moving the patient, reducing fracture-related morbidity 1

Specific Radiographic Views Required

The standard hip radiographic series must include 1:

• AP view with 15 degrees of internal hip rotation
• Cross-table lateral view (NOT frog-leg lateral, which risks fracture displacement)
• AP pelvis view for hip symmetry assessment (commonly included)

If Radiographs Are Negative But Clinical Suspicion Persists

If radiographs are negative or indeterminate but clinical concern for fracture remains high, proceed immediately to CT hip without IV contrast 1. This is the recommended next imaging study because:

• CT detects 24.1% of occult fractures after negative radiographs and changes management in 20% of cases 1
• CT has 94% sensitivity and 100% specificity for radiographically occult hip fractures 1
• CT is faster than MRI or bone scan, supporting rapid diagnosis to reduce fracture-related morbidity 1
• 39% of patients with negative radiographs but clinical suspicion have surgical hip fractures 1

Critical Pitfalls to Avoid

• Do not use frog-leg lateral views initially: Risk of fracture displacement 1
• Do not skip imaging based on ability to walk: Physical examination alone cannot definitively exclude hip fracture 1
• Do not order bone scan: No evidence supports its use as initial or follow-up imaging 1
• Do not order CT or MRI with IV contrast: No evidence supports contrast use for this indication 1
• Do not delay imaging: Each hour of delay increases morbidity and mortality risk 1

If CT Is Also Negative

If CT remains negative or equivocal but clinical suspicion persists, MRI hip without IV contrast is the definitive study to detect occult fractures 1.