What is the next best imaging test for an elderly patient with hip pain and osteopenia after a fall, with initial radiographs showing no fracture?

MRI of the Right Hip

MRI of the right hip without IV contrast is the next test that should be ordered for this elderly patient with persistent hip pain after a fall, negative radiographs showing only osteopenia, and inability to ambulate despite using a walker. 1

Rationale for MRI as the Definitive Next Step

The American College of Radiology's 2025 Acute Hip Pain guidelines explicitly state that MRI hip without IV contrast is rated 9 (usually appropriate) as the next imaging study when radiographs are negative or indeterminate but clinical suspicion for hip fracture remains high. 1 This patient has classic clinical features demanding advanced imaging:

• Persistent severe pain limiting ambulation despite walker use 1
• Pain with internal rotation of the hip (highly specific for hip pathology) 1
• Mechanism consistent with hip fracture (fall on right side in elderly patient with osteopenia) 1
• High-risk patient profile (elderly female with documented osteopenia) 1

Why MRI Over Other Modalities

MRI is Superior to CT in This Clinical Context

While CT without IV contrast is also appropriate (rated 9) for suspected hip fracture with negative radiographs, the ACR guidelines specifically note that patients with persistent clinical concern for hip fracture after a negative or equivocal CT will still need an MRI. 1 Given this patient's severe osteopenia visible on radiographs, MRI provides superior detection of:

• Occult femoral neck fractures (which carry high morbidity risk if missed) 1
• Insufficiency fractures in osteopenic bone (specifically addressed in ACR stress fracture guidelines) 1
• Bone marrow edema patterns that indicate impending fracture 1

The ACR Stress Fracture guidelines rate MRI hip without IV contrast as 9 (usually appropriate) for suspected stress/insufficiency fractures of the hip with negative radiographs, specifically noting that "because of the high risk of complications, it is not advisable to wait 10-14 days in most cases." 1

Bone Scan is Inadequate

Bone scan is rated only 6 (may be appropriate) and has significant limitations: 1

• Lower sensitivity than MRI (87% vs near 100% for MRI) 1
• Timing-dependent (may be falsely negative if performed too early after injury) 1
• Age-dependent accuracy (less reliable in elderly patients) 1
• Provides no anatomic detail for surgical planning 1

Ultrasound Has No Role

Ultrasound is rated 1 (usually not appropriate) for acute traumatic hip pain evaluation. 1 While two recent studies suggest potential utility for point-of-care ultrasound by expert emergency sonographers, the ACR states "there is insufficient evidence to support the use of US as the next imaging study for the evaluation of acute traumatic hip pain." 1

No Further Imaging is Dangerous

Forgoing additional imaging in this patient would be inappropriate and potentially catastrophic. The patient has:

• Inability to ambulate normally (can only reach bathroom with walker, refuses to walk due to pain) 1
• Positive provocative testing (pain with internal rotation) 1
• High pretest probability for occult fracture given mechanism, age, and osteopenia 1

Meta-analysis data shows that 39% of patients with clinically suspected hip fracture and negative radiographs have surgical hip fractures on MRI. 1 Missing an occult femoral neck fracture leads to:

• Increased mortality (delayed surgery beyond 24-48 hours significantly increases short-term and mid-term mortality) 1
• Risk of fracture displacement (converting a stable fracture to an unstable one) 1
• Avascular necrosis risk (prolonged immobility and delayed treatment) 1

Clinical Urgency

This MRI should be obtained urgently (within 24 hours) to enable surgical intervention within the critical 24-48 hour window if fracture is detected. 1 The ACR guidelines emphasize that "rapid diagnosis reduces the morbidity associated with acute hip fracture" and that "this imaging information benefits the patient by reducing potential delay in appropriate treatment and by hastening patient recovery." 1

Common Pitfalls to Avoid

• Do not wait 10-14 days for repeat radiographs in hip fractures due to high complication risk 1
• Do not rely on ability to ambulate to exclude fracture (some patients with hip fractures can walk) 2
• Do not dismiss vague pain patterns (hip fractures can present with buttock, knee, thigh, groin, or back pain) 2
• Do not order CT first unless MRI is contraindicated or unavailable, as you may still need MRI afterward 1