What is the best course of action for an adult patient with no significant medical history presenting with pain, swelling, or limited mobility in their left hand?

Left Hand X-Ray: Initial Imaging Approach

Start with plain radiographs of the left hand as the initial imaging study—this is the mandatory first step recommended by the American College of Radiology to establish baseline assessment, rule out fractures, arthritis, bone tumors, foreign bodies, and guide all subsequent diagnostic decisions. 1, 2

Standard Radiographic Protocol

• Order a minimum three-view examination: posteroanterior (PA) view, lateral view, and 45° semipronated oblique view of the left hand 3
• These views provide comprehensive evaluation of bone alignment, joint spaces, soft tissue swelling, and any underlying bony pathology 1
• Radiographs remain the cornerstone for differential diagnosis despite being normal in early infections (<14 days) or purely soft tissue pathology 1, 4

What Radiographs Will Reveal

Bony pathology assessment:

• Joint space narrowing, bone erosions, malalignment, and osteophytes indicating osteoarthritis 1, 5
• Periosteal reaction, bone sclerosis, or erosions suggesting osteomyelitis 1
• Fractures, bone tumors, or metabolic bone disease 1, 4, 6

Soft tissue findings:

• Soft tissue swelling, joint effusion, or effacement of fat planes indicating infection or inflammatory arthritis 1
• Gas in soft tissues or foreign bodies 1

Algorithm for Next Steps Based on Radiographic Results

If radiographs show definitive pathology (fracture, arthritis, tumor):

• Proceed with condition-specific management and consider specialist referral 1

If radiographs are negative or show only soft tissue swelling:

• Order ultrasound of the left hand as the next imaging modality—the American College of Rheumatology supports this for patients without definitive diagnosis presenting with pain, swelling, or mechanical symptoms 1, 2
• Ultrasound identifies synovitis, joint effusion, tenosynovitis, tendinopathy, tendon injury, carpal tunnel syndrome, and retained foreign bodies 1, 2
• Ultrasound is contributory to clinical assessment in 76% of all patients and 67% of patients without trauma history 1, 2

If infection is suspected (acute onset with pain, erythema, warmth):

• Obtain ultrasound or CT with IV contrast to assess for abscess, septic arthritis, or deep soft tissue infection 1, 2
• Consider image-guided aspiration for culture if fluid collection or joint effusion is identified 1

If ultrasound is non-diagnostic and symptoms persist:

• Order MRI of the left hand without IV contrast for comprehensive soft tissue evaluation 1, 2
• MRI demonstrates arthritis, tendinopathy, tenosynovitis, pulley injury, ligament injury, and chondral injury, changing clinical management in 69.5% of cases 1

Critical Pitfalls to Avoid

• Never skip initial radiographs, even when soft tissue pathology seems obvious clinically—underlying bony abnormalities must be excluded first 3, 2
• Never order MRI as the first imaging study for hand pain—this is not cost-effective and violates guideline-based imaging algorithms 3, 2
• Do not delay duplex ultrasound if unilateral swelling is present, as upper extremity DVT requires immediate anticoagulation 2
• Do not attribute symptoms to soft tissue pathology until radiographs exclude fracture, arthritis, bone tumor, or foreign body 2

Concurrent Laboratory Workup (If Inflammatory or Infectious Etiology Suspected)

• Order ESR and CRP to identify active inflammation and differentiate inflammatory arthritis from mechanical causes 2
• Obtain CBC with differential to identify infection, anemia of chronic disease, or thrombocytosis 2
• Consider rheumatoid factor and anti-CCP antibodies if inflammatory arthritis is suspected based on morning stiffness >30-60 minutes 2