What could be causing hip pain in an adult that worsens at night and improves with walking, and how should it be managed?

Hip Pain Worse at Night and Better with Walking

This presentation is highly suspicious for a stress fracture or bone tumor, both of which are red flag diagnoses requiring urgent imaging with plain radiographs followed by MRI if radiographs are negative. 1

Critical Red Flags to Exclude First

Night pain that improves with walking is an atypical pattern that should immediately raise concern for serious pathology rather than typical mechanical hip conditions:

• Stress fractures (femoral neck or pubic ramus) characteristically present with insidious onset, night pain, and focal tenderness over bone 1
• Bone tumors present with night pain, constitutional symptoms, and progressive worsening 1
• Infection (septic arthritis, osteomyelitis) manifests with acute onset, fever, severe pain at rest, and inability to bear weight 1

The fact that pain improves with walking argues against typical mechanical causes like osteoarthritis or greater trochanteric pain syndrome, which worsen with activity. This paradoxical improvement suggests either inflammatory conditions that respond to movement or serious bone pathology where rest increases intraosseous pressure.

Immediate Diagnostic Workup

Obtain AP pelvis and lateral hip radiographs immediately to exclude fractures, bone lesions, or other structural abnormalities 2, 1

If radiographs appear normal but clinical suspicion remains high:

• Order MRI of the hip without contrast to identify occult fractures, bone marrow edema, tumors, or early osteonecrosis 3
• MRI is particularly critical for detecting stress fractures not visible on plain films 3

Secondary Differential Considerations (After Excluding Red Flags)

If imaging excludes serious pathology, consider these less urgent diagnoses:

Inflammatory Arthropathies

• Inflammatory conditions (rheumatoid arthritis, ankylosing spondylitis) can cause night pain that improves with morning movement
• However, these typically present with morning stiffness lasting >30 minutes, not isolated night pain

Referred Pain from Lumbar Spine

• Lumbar spine pathology must be screened in all hip pain evaluations as it can refer sharp lancinating pain to the hip region 1
• Radicular pain may paradoxically improve with walking if it relieves nerve root compression
• Physical examination should include lumbar spine assessment 1

Atypical Presentations of Common Conditions

• Femoroacetabular impingement (FAI) syndrome typically causes groin pain with activity, not night pain that improves with walking 4, 1
• Greater trochanteric pain syndrome presents with lateral hip pain, not the pattern described 2

Clinical Pitfalls to Avoid

• Do not assume mechanical hip pain based on location alone - the night pain pattern is a critical distinguishing feature requiring investigation 1
• Do not delay imaging - stress fractures can progress to complete fractures if weight-bearing continues 1
• Do not miss referred pain - always examine the lumbar spine and pelvis as competing sources 4, 1
• Do not rely on imaging alone - combine symptoms, clinical signs, and imaging for accurate diagnosis 4, 2

Management Algorithm

1. Immediate plain radiographs (AP pelvis + lateral hip) 2, 1
2. If radiographs negative but high clinical suspicion: Order MRI 3
3. If stress fracture confirmed: Non-weight-bearing, orthopedic referral
4. If tumor suspected: Urgent oncology referral
5. If infection suspected: Emergent evaluation with labs (CBC, ESR, CRP) and possible joint aspiration
6. Only after excluding red flags: Consider inflammatory workup or spine evaluation