What is the appropriate workup for a 47-year-old female (f) with leg pain, considering the differential diagnosis (ddx)?

Workup for 47-Year-Old Female with Leg Pain

Begin with a focused history targeting pain characteristics (location, quality, timing, exacerbating/relieving factors) and perform a comprehensive lower extremity vascular examination including bilateral pulse palpation (femoral, popliteal, dorsalis pedis, posterior tibial), followed by ankle-brachial index (ABI) testing if peripheral artery disease (PAD) is suspected based on clinical findings. 1

Initial Clinical Assessment

Critical History Elements

Pain Characterization:

• Location specificity: Determine if pain is in buttock, thigh, calf, ankle, or foot to narrow differential 1
• Claudication features: Ask about aching, burning, cramping, or fatigue that occurs with walking; typical claudication resolves within <10 minutes of rest 1
• Atypical exertional symptoms: Assess for leg weakness, numbness, or fatigue during walking without pain, or muscular discomfort requiring >10 minutes rest to resolve 1
• Rest pain: Determine if pain occurs at rest, suggesting critical limb ischemia 1
• Positional factors: Ask if symptoms improve with leg elevation (venous), lumbar flexion (spinal stenosis), or change in position (nerve root compression) 1

Risk Stratification for PAD: This 47-year-old female warrants PAD evaluation if she has diabetes plus one additional atherosclerotic risk factor, or if she has known atherosclerotic disease elsewhere 1

• Assess for diabetes, smoking history, dyslipidemia, hypertension, chronic kidney disease, or family history of PAD 1

Physical Examination Protocol

Vascular Assessment (remove all lower extremity garments, shoes, and socks): 1

• Pulse palpation: Grade all four pulses bilaterally (femoral, popliteal, dorsalis pedis, posterior tibial) as 0=absent, 1=diminished, 2=normal, 3=bounding 1
• Presence of all four pedal pulses bilaterally (dorsalis pedis and posterior tibial) indicates low likelihood of PAD 1
• Auscultation: Listen for bruits over epigastric, periumbilical, and groin regions 1
• Ischemic signs: Examine for elevation pallor/dependent rubor, asymmetric hair growth, nail bed changes, calf muscle atrophy 1
• Wound assessment: Inspect for nonhealing wounds or gangrene 1

Neurologic and Musculoskeletal Assessment:

• Evaluate for peripheral neuropathy, especially if diabetic 1
• Assess gait pattern and localize tenderness 1

Diagnostic Testing Algorithm

First-Line Testing

If PAD is suspected based on history/physical findings: 1

• Resting ABI is the initial diagnostic test (Class I recommendation, Level B-NR evidence) 1
• ABI <0.90 confirms PAD diagnosis 1

Differential Diagnosis Considerations

The broad differential requires systematic exclusion: 1

Vascular causes:

• PAD/claudication: Aching/cramping with exertion, relieved quickly (<10 min) with rest 1
• Venous claudication: Tight, bursting pain in entire leg (worse in calf), subsides slowly with rest, relieved faster with leg elevation; history of deep vein thrombosis, edema, venous stasis signs 1

Musculoskeletal causes:

• Hip arthritis: Lateral hip/thigh aching after variable exercise, not quickly relieved, improved when not bearing weight 1
• Foot/ankle arthritis: Ankle/foot/arch pain after variable exercise or at rest, may be relieved by not bearing weight 1

Neurologic causes:

• Nerve root compression: Sharp lancinating pain radiating down leg, induced by sitting/standing/walking, often present at rest, improved by position change; history of back problems 1
• Spinal stenosis: Bilateral buttocks/posterior leg pain and weakness, may mimic claudication, variable relief taking long time, relieved by lumbar flexion, worse with standing/extending spine 1

Other causes:

• Baker's cyst: Pain behind knee down calf with swelling/tenderness, present with exercise and at rest, not intermittent 1
• Chronic compartment syndrome: Tight, bursting calf pain after strenuous exercise, subsides very slowly with rest; typically in heavy-muscled athletes 1

Additional Testing Based on Initial Findings

If ABI is abnormal or PAD confirmed and further anatomic detail needed for revascularization planning: 1

• Duplex ultrasound of lower extremities 1
• CT angiography (CTA) pelvis with runoff 1
• MR angiography (MRA) pelvis with runoff 1

If initial vascular workup is normal but symptoms persist:

• Consider plain radiographs of symptomatic area to evaluate for arthritis, fracture, or bone lesions 1
• MRI without contrast for suspected soft tissue, nerve, or musculoskeletal pathology 1

Common Pitfalls to Avoid

• Do not assume all exertional leg pain is claudication: Only one-third of PAD patients present with typical claudication; most have atypical symptoms 1
• Do not skip bilateral pulse examination: Presence of all four pedal pulses bilaterally makes PAD unlikely and redirects workup 1
• Do not order imaging before clinical assessment: History and physical examination should guide targeted testing 1
• Do not overlook positional factors: Relief patterns distinguish vascular (rest), neurogenic (position change), and venous (elevation) causes 1