import { HighYieldBox, ExamCheatSheet, Tabs, Tab, ComparisonTable, VivaScenario, ContentSection, SpecialTestCard , MedicalImage} from '@/components/content' # Rheumatoid Hand Examination Rheumatoid hand examination requires systematic identification of classic deformities and functional assessment. Examiners expect you to recognize the pattern of joint involvement, identify tendon ruptures, and understand the pathophysiology behind each deformity. Always assess function, not just appearance. ## Quick Reference One-Pager ## Pattern of Joint Involvement **Characteristic Pattern (Bilateral Symmetric):** - MCP joints (most common in hand) - PIP joints - Wrist (radiocarpal, midcarpal) - MTP joints (feet) **Spared Joints in RA:** - DIP joints (usually osteoarthritis) - CMC of thumb (may have secondary OA) **Key Differentiator:** - RA: MCP and PIP - OA: DIP and CMC **Pathophysiology of RA Hand:** 1. Synovitis → Joint destruction → Deformity 2. Synovitis → Tendon attrition → Rupture 3. Ligament laxity → Subluxation/dislocation 4. Muscle imbalance → Fixed deformities **Order of Tendon Ruptures (Vaughan-Jackson):** Little → Ring → Middle → Index (EDC over ulnar head) ## Observation **Look From Dorsal:** - Swelling (synovitis, effusion, nodules) - Muscle wasting (interossei, thenar) - Deformities (ulnar drift, subluxation) - Scars (previous surgery) - Skin (thin, fragile - steroids) - Nodules (extensor surfaces) **Look From Lateral:** - Swan neck deformity - Boutonnière deformity - Z-thumb deformity **Look From Palmar:** - Thenar wasting - Palmar nodules (flexor tenosynovitis) - Carpal tunnel scars **Caput Ulnae:** - Prominent dorsal ulnar head - Due to DRUJ destruction and supination of carpus ## Classic Deformities **Swan Neck Deformity:** - PIP hyperextension - DIP flexion - Terminal tendon attenuates as lateral bands sublux dorsally **Causes in RA:** - MCP synovitis → intrinsic tightness - PIP volar plate laxity - FDS rupture or attenuation **Classification (Nalebuff):** | Type | Description | |------|-------------| | I | Full PIP flexion in all MCP positions | | II | PIP flexion limited by intrinsic tightness (MCP extension limits) | | III | Limited PIP flexion in all MCP positions | | IV | Stiff, arthritic PIP (fixed) | **Key Test:** Intrinsic tightness test (Bunnell) **Boutonnière Deformity:** - PIP flexion - DIP hyperextension - Central slip attenuates, lateral bands slip volar **Causes in RA:** - PIP synovitis → central slip attenuation/rupture - Lateral bands migrate volar - Become flexors of PIP, hyperextend DIP **Classification (Nalebuff):** | Type | Description | |------|-------------| | I | Supple, passively correctable | | II | Moderate, limited passive extension | | III | Fixed flexion deformity | **Key Test:** Elson test (central slip integrity) **Ulnar Drift (MCP Level):** - Fingers deviate ulnarly at MCP joints - Usually with volar subluxation **Pathophysiology:** - Radial collateral ligament laxity - Radial sagittal band attenuation - EDC subluxates into ulnar valleys - Extrinsic muscle forces (ulnar pull) - Loss of intrinsic balance **Assessment:** - Active extension: Observe drift and subluxation - Passive correction: Is it flexible? - EDC subluxation: Watch tendons during extension **Z-Thumb (Boutonnière Thumb):** - MCP flexion - IP hyperextension - Similar mechanism to finger boutonnière **Causes:** - MCP synovitis → EPB attenuation - Volar plate laxity at MCP - FPB shortens, EPL hyperextends IP **Types:** - Type I: MCP flexion, IP hyperextension (most common) - Type II: MCP hyperextension, IP flexion (swan neck pattern) - Type III: Combined with CMC subluxation ## Tendon Examination **Vaughan-Jackson Syndrome:** - EDC ruptures over dorsally subluxed ulnar head - Attritional rupture from caput ulnae - Order: Little → Ring → Middle → Index **EPL Rupture:** - Usually at Lister's tubercle - Cannot extend thumb IP (retropulsion) - May occur with distal radius fracture or RA **Testing Each Extensor:** - EDC: Extend MCP against resistance for each finger - EPL: Lift thumb off flat surface (retropulsion) - EDM: May mask little finger EDC rupture **Mannerfelt Syndrome:** - FPL rupture over scaphoid osteophyte - Cannot flex thumb IP - Important functional loss **FDP Ruptures:** - Usually over carpal osteophytes - Test each finger (DIP flexion with PIP extended) **FDS Function:** - Test by holding other fingers extended - May compensate for FDP loss ## Wrist Assessment **Observe:** - Caput ulnae (dorsal prominence of ulna) - Radial deviation of wrist (compensates for ulnar drift) - Extensor tenosynovitis (boggy swelling) - Volar subluxation of carpus **Palpate:** - DRUJ stability (piano key test) - Extensor tendon synovitis - Carpal tenderness **Move:** - Range of motion (often limited) - Crepitus **DRUJ Destruction:** - Caput ulnae = supinated carpus, prominent ulnar head - Piano key sign positive - Attritional tendon ruptures ## Functional Assessment **Critical Functional Tests:** 1. **Grip Strength:** Dynamometer if available 2. **Pinch Strength:** Key pinch, tip pinch 3. **Key Grip (Froment):** Hold paper between thumb and index 4. **Opposition:** Touch thumb to little finger 5. **Fine Motor:** - Pick up coins - Button and unbutton - Write name - Turn key in lock **Document:** - Dominant hand - Impact on daily activities - Walking aid requirements (affects wrist loading) ## Extra-Articular Features **Skin:** - Rheumatoid nodules (extensor surfaces, olecranon) - Thin, fragile skin (steroid use) - Vasculitic lesions (nail fold infarcts) **Eyes:** - Dry eyes (secondary Sjögren's) - Scleritis, episcleritis **Always Examine:** - Cervical spine (atlantoaxial instability) - Elbows (nodules, flexion contracture) - Feet (MTP involvement, similar deformities) **Ask About:** - Systemic symptoms (fatigue, weight loss) - Pulmonary involvement - Cardiovascular risk **Cervical Spine in RA:** ALWAYS ask about and assess cervical spine: - Atlantoaxial instability in 25-50% of RA patients - Myelopathy symptoms: Hand clumsiness, gait disturbance - Neck pain, occipital headache - Important for surgical planning (anesthetic risk) **Pre-operative Cervical Spine X-rays:** Essential before any surgery ## Assessment Summary ## Summary Presentation ## Examination Sequence 1. **Observation**: Swelling, deformities, muscle wasting, scars 2. **Extra-Articular**: Nodules, nail fold infarcts, skin quality 3. **Specific Deformities**: Name each deformity present 4. **Tendons - Extensors**: EDC (each finger), EPL, EDM 5. **Tendons - Flexors**: FDS, FDP, FPL 6. **Wrists**: ROM, DRUJ (piano key), caput ulnae 7. **Intrinsic Testing**: Bunnell test, interossei 8. **Function**: Grip, pinch, fine motor, ADLs 9. **Cervical Spine**: Range of motion, neurology 10. **Complete**: Examine elbows, feet if time permits ## Examiner Tips