What is the appropriate workup and management for a patient presenting with left hand swelling over the metacarpal?

Left Hand Swelling Over Metacarpal: Diagnostic Workup and Management

Begin with standard three-view radiographs (posteroanterior, lateral, and oblique) of the hand as the initial imaging study, which will establish the diagnosis in most cases. 1

Initial Clinical Assessment

Key Clinical Features to Identify:

• Examine for soft tissue swelling versus bony enlargement – inflammatory conditions produce soft, boggy joint swelling from synovitis, while non-inflammatory osteoarthritis causes hard, bony enlargement from osteophytes 2
• Assess for morning stiffness duration – stiffness lasting more than 30 minutes strongly indicates inflammatory arthritis and warrants urgent rheumatology referral within 6 weeks 2
• Perform the "squeeze test" – lateral compression of metacarpophalangeal joints causing pain helps identify inflammatory joint involvement 3
• Document pain characteristics, duration of symptoms, history of trauma, and functional limitations – tuberculosis should be suspected in cases of long-standing pain and swelling (4-17 months duration) 4
• Examine for joint deformities, range of motion restrictions, and associated skin changes 2

Essential Laboratory Workup

Order the following tests immediately:

• C-reactive protein (CRP) – preferred over ESR as it is more reliable and not age-dependent 3, 2
• Erythrocyte sedimentation rate (ESR) – for baseline inflammatory marker assessment 3, 2
• Rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA/anti-CCP) – RF has 70% specificity with moderate sensitivity, while ACPA has 90% specificity with 60% sensitivity 2
• Complete blood count with differential – to assess for cytopenias before starting treatment 2
• Comprehensive metabolic panel – including liver function tests, renal function, glucose, and urate levels 2
• Urinalysis – part of standard initial workup 2

Conditional testing based on clinical presentation:

• Antinuclear antibodies (ANA) – if diagnosis remains uncertain to screen for other connective tissue diseases 2
• HLA-B27 – if spondyloarthropathy is suspected (axial or entheseal involvement) 2

Imaging Algorithm

First-line imaging:

• Standard three-view radiographs (PA, lateral, oblique) are the most appropriate initial study and sufficient for diagnosis in most cases 1, 5
• Look for specific radiographic features:
  • Inflammatory arthritis: periarticular osteopenia, uniform joint space narrowing, marginal erosions 2
  • Osteoarthritis: asymmetric joint space narrowing with osteophytes and subchondral sclerosis 2
  • Tumor: expanded and lytic mass (giant cell tumor affects metacarpals in only 2% of cases) 6
  • Tuberculosis: bone destruction with periosteal reaction 4

Advanced imaging when radiographs are normal or equivocal:

• Ultrasound with Power Doppler – superior to clinical examination for detecting synovitis (75% more accurate than physical examination alone) and useful when patients do not meet diagnostic criteria 1, 2
• MRI without IV contrast – more sensitive than ultrasound in early stages, detects bone marrow edema (osteitis) which is the best single predictor of future disease progression 1, 2
• CT without contrast – useful for diagnosing carpometacarpal joint fracture dislocations and complex injuries, but cannot evaluate ligamentous injuries 1

Do not order MRI or CT initially unless radiographs are normal, as this adds cost without diagnostic benefit. 5

Differential Diagnosis Framework

Inflammatory Arthritis (if morning stiffness >30 minutes, symmetric involvement, elevated CRP/ESR):

• Rheumatoid arthritis – symmetric involvement of MCPs, PIPs, and wrists; DIP joints typically spared 2
• Psoriatic arthritis – can present with polyarticular involvement including hands, elevated CRP, and negative RF 2
• Crystalline arthropathy – though normal uric acid effectively excludes gout 2

Non-inflammatory Conditions:

• Thumb carpometacarpal (trapeziometacarpal) osteoarthritis – affects approximately 33% of postmenopausal women, with 20% requiring treatment 7
• Metacarpophalangeal joint osteoarthritis – less common than inflammatory causes in this location 8

Neoplastic/Infectious (if long-standing swelling, 4-17 months duration):

• Giant cell tumor – rare in metacarpals (2% incidence), presents as expanded lytic mass 6
• Osteochondroma – rare in metacarpals, consider alongside enchondroma 9
• Tuberculosis – suspect with long-standing pain and swelling, mild ESR elevation, no active pulmonary disease 4

Management Algorithm Based on Diagnosis

If Inflammatory Arthritis Confirmed:

First-line conservative management:

• Splinting – use full splint covering both thumb base AND wrist (NNT=4 for improving daily activities), superior to thumb-only splints 5
• Topical NSAIDs – preferred pharmacological treatment for mild-moderate pain, equivalent efficacy to oral NSAIDs (effect size 0.77) without increased GI complications 5

Second-line pharmacological options:

• Oral paracetamol (up to 4g/day) if topical NSAIDs insufficient, best safety profile 5
• Oral NSAIDs at lowest effective dose with gastroprotection (PPI or H2-blocker) in patients with GI risk factors; avoid COX-2 inhibitors in patients with cardiovascular risk 5

Disease-modifying therapy (if rheumatoid arthritis):

• Methotrexate 15-30 mg/week as anchor drug, started immediately without delaying for complete serologic workup 2
• Short-term low-dose glucocorticoids as bridge therapy while awaiting DMARD effect 3
• Target: sustained remission (SDAI ≤3.3) or low disease activity (SDAI ≤11) 2
• Refer to rheumatology within 6 weeks of symptom onset – early treatment prevents irreversible joint damage 2

Interventional treatment:

• Intra-articular corticosteroid injection for painful flares, though evidence shows short-term benefit (one month) with limited persistence 1, 3
• Intra-articular hyaluronan as alternative with potentially more prolonged benefit than corticosteroid 1, 3

If Trapeziometacarpal (Thumb Base) Osteoarthritis:

Conservative management sequence:

1. Full splint (thumb base AND wrist) plus topical NSAIDs 5
2. Oral paracetamol or oral NSAIDs with gastroprotection if inadequate response 5
3. Intra-articular corticosteroid or hyaluronan injection for persistent symptoms 5

Surgical intervention:

• Consider surgery when conservative treatments fail AND patient has marked pain/disability affecting quality of life 5
• Trapeziectomy alone is the recommended surgical approach – combination procedures (trapeziectomy with ligament reconstruction and tendon interposition) provide no additional benefit but cause significantly more complications (RR 2.12,95% CI 1.24-3.60) 5

If Tuberculosis Suspected:

• Open biopsy for definitive diagnosis – based on clinical picture, radiographic features, and histopathology 4
• 4-drug regimen for 2 months, followed by 2-drug regimen for 10 months – no patient requires bony debridement or arthrodesis to control infection 4
• Mean follow-up 30 months shows all lesions heal with no recurrence and satisfactory functional results 4

If Neoplastic Process (Giant Cell Tumor, Osteochondroma):

• MRI for confirmation and surgical planning 6, 9
• Surgical intralesional excision with reconstruction using synthetic bone graft for giant cell tumor 6
• Surgical excision for osteochondroma 9

Critical Pitfalls to Avoid

• Do not dismiss inflammatory arthritis based on normal ESR/CRP – acute phase reactants are poor predictors and can be normal even in active disease 2
• Do not delay treatment waiting for positive serology – seronegative RA accounts for 20-30% of cases with similar prognosis 2
• Do not use thumb-only splints when full splint including wrist provides superior pain control 5
• Do not proceed directly to oral NSAIDs without first trying topical NSAIDs, which have equivalent efficacy with better safety profiles 5
• Do not perform complex surgical procedures when simple trapeziectomy provides equivalent outcomes with fewer complications 5
• Do not order advanced imaging (MRI/CT) initially unless radiographs are normal or show only nonspecific findings 1, 5

Monitoring and Follow-up

For inflammatory arthritis:

• Repeat CRP/ESR every 4-6 weeks after treatment initiation to monitor disease activity 2
• Measure composite disease activity (SDAI or CDAI) at each visit 2
• Repeat hand, wrist, and foot X-rays at 6 and 12 months to monitor radiographic progression 2

For tuberculosis:

• Mean follow-up 30 months with clinical and radiographic assessment 4

For post-surgical cases:

• Initial splinting, wire removal at 6 weeks post-op, adequate physiotherapy 6
• 3-month follow-up to assess range of motion and graft uptake 6