# Clinical Cases: Upper Limb - Hand

## Case 1: Scaphoid Fracture

### Clinical Image
![Scaphoid Fracture](case_01_image.jpg)
*Source: [Wikimedia Commons - Scaphoid Fracture](https://commons.wikimedia.org/wiki/File:Scaphoid_fracture.jpg) - CC BY-SA 3.0*

### Case Presentation
An 18-year-old college student presents to urgent care 2 days after falling off his skateboard. He landed on his outstretched right hand and has had persistent wrist pain since. He initially thought it was "just a sprain" but the pain has not improved. He reports pain at the base of his thumb that worsens with gripping and thumb movement. Physical examination reveals tenderness in the anatomical snuffbox (bordered by the extensor pollicis longus medially and extensor pollicis brevis/abductor pollicis longus laterally), as well as pain with axial loading of the thumb and tenderness over the scaphoid tubercle on the volar wrist. Initial radiographs, including scaphoid views, appear normal without obvious fracture. Given the high clinical suspicion, a thumb spica splint is applied and he is scheduled for repeat X-rays in 2 weeks. Follow-up radiographs reveal a nondisplaced fracture through the scaphoid waist with early resorption at the fracture line. MRI is obtained which confirms the waist fracture without evidence of avascular necrosis. He is placed in a thumb spica cast for 8 weeks, and follow-up imaging confirms union.

### Key Learning Points
- The scaphoid is the most commonly fractured carpal bone, typically from a fall on an outstretched hand (FOOSH)
- The anatomical snuffbox is the classic location of tenderness for scaphoid fractures
- Initial radiographs may be negative in up to 20% of scaphoid fractures; follow-up imaging or early MRI is essential
- The scaphoid blood supply enters distally, placing proximal pole fractures at high risk for avascular necrosis
- Delayed diagnosis leads to nonunion, avascular necrosis, and scaphoid nonunion advanced collapse (SNAC) arthritis

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## Case 2: Carpal Tunnel Syndrome

### Clinical Image
![Carpal Tunnel Anatomy](case_02_image.jpg)
*Source: [Wikimedia Commons - Carpal Tunnel](https://commons.wikimedia.org/wiki/File:Carpal_Tunnel_Syndrome.png) - CC BY-SA 4.0*

### Case Presentation
A 52-year-old woman presents with a 6-month history of numbness and tingling in her right hand that wakes her from sleep several times per week. She reports the symptoms are worst in her thumb, index, and middle fingers, and improve when she shakes her hand (flick sign). She works as a data entry clerk and notes worsening symptoms with prolonged computer use. Over the past month, she has noticed weakness when opening jars and occasionally drops objects. Physical examination reveals decreased two-point discrimination in the median nerve distribution (thumb, index, middle finger, and radial half of ring finger). There is thenar muscle atrophy with weakness of thumb abduction and opposition. Tinel sign is positive at the wrist (tapping over the carpal tunnel reproduces paresthesias). Phalen test is positive (sustained wrist flexion for 60 seconds reproduces symptoms). Nerve conduction studies confirm severe median neuropathy at the wrist with prolonged distal motor and sensory latencies. Given the moderate to severe findings with thenar atrophy, she undergoes carpal tunnel release surgery with complete resolution of nighttime symptoms at 6-week follow-up.

### Key Learning Points
- The carpal tunnel is bounded by carpal bones dorsally and the flexor retinaculum (transverse carpal ligament) volarly
- Nine flexor tendons (FDS x4, FDP x4, FPL) and the median nerve pass through the carpal tunnel
- Compression of the median nerve causes sensory symptoms in the thumb, index, middle, and radial ring finger
- Motor findings include weakness of thumb abduction (APB) and opposition (opponens pollicis), with thenar atrophy
- The palmar cutaneous branch of median nerve is superficial to the retinaculum and is typically spared

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## Case 3: Dupuytren's Contracture

### Clinical Image
![Dupuytren's Contracture](case_03_image.jpg)
*Source: [Wikimedia Commons - Dupuytren's Contracture](https://commons.wikimedia.org/wiki/File:Dupuytren%27s_contracture.jpg) - CC BY-SA 3.0*

### Case Presentation
A 65-year-old man of Northern European descent presents with progressive inability to fully straighten his right ring and small fingers over the past 2 years. He first noticed a firm nodule in his palm several years ago that has gradually enlarged. He is a retired carpenter with a history of diabetes and moderate alcohol consumption. He now has difficulty placing his hand flat on a table, putting on gloves, and reaching into his pocket. Physical examination reveals palpable nodules and cords in the palmar fascia overlying the ring and small finger metacarpals. The metacarpophalangeal (MCP) joint of the ring finger has a 45-degree fixed flexion contracture, and the proximal interphalangeal (PIP) joint has a 30-degree contracture. The small finger MCP has a 35-degree contracture. The overlying skin is dimpled and adherent to the underlying fascia. Tabletop test is positive (cannot place palm flat on table). There is no triggering, and finger flexion strength is normal. The patient undergoes limited fasciectomy with good correction of the contractures.

### Key Learning Points
- Dupuytren's contracture is fibromatosis of the palmar fascia causing progressive finger flexion contracture
- The palmar aponeurosis has longitudinal pretendinous bands extending to each digit that become pathologically thickened
- Risk factors: Northern European ancestry, male sex, age >50, diabetes, alcohol use, smoking, family history
- The ring and small fingers are most commonly affected; MCP contractures are most common, followed by PIP
- Treatment indications include MCP contracture >30 degrees, any PIP contracture, or positive tabletop test