Anatomy of the Wrist and Hand

A healthy wrist and hand allow gripping, writing, grasping and fine motor tasks — the fundamental movements of daily life — without pain.

Distal Radius Fracture ("Wrist Fracture")

This is the most common fracture in adults. It usually results from a fall on an outstretched hand.

• Colles fracture: dorsally angulated; the most common type (particularly in women over 50)
• Smith fracture: volarly angulated; less common
• Barton fracture: an intra-articular partial fracture–dislocation
• Chauffeur's fracture: a fracture of the radial styloid (the tip)
• Non-displaced / displaced: according to the amount of displacement
• Intra-articular / extra-articular: according to whether the joint surface is involved

Ulna Fracture

This frequently accompanies a distal radius fracture; isolated fractures are uncommon. An ulnar styloid fracture is the most common type and most are treated non-operatively. Fractures of the distal ulna are usually unstable and may require surgery.

Scaphoid (Navicular) Fracture

This is the most commonly fractured carpal bone. Tenderness in the anatomical snuffbox after a fall on an outstretched hand is the characteristic finding. Because the blood supply enters distally and travels proximally, proximal pole fractures carry a high risk of avascular necrosis, and surgery is required if displacement exceeds 2 mm.

• Distal pole fracture: healing is generally good; treated in a cast if there is no displacement
• Waist fracture: the most common type; surgery is required if displacement exceeds 2 mm
• Proximal pole fracture: high risk of non-union and avascular necrosis

Metacarpal Fractures

These are fractures of the palm bones. A punching injury is the most common mechanism.

• Boxer's fracture: a fracture of the neck of the fifth metacarpal (from punching); the most common metacarpal fracture
• Bennett fracture: an intra-articular fracture–dislocation of the base of the first metacarpal
• Rolando fracture: a comminuted intra-articular fracture of the base of the first metacarpal
• Metacarpal shaft or neck fractures
• Metacarpal head fractures (uncommon)

Phalangeal (Finger) Fractures

These are fractures of the finger bones, usually caused by a direct blow or a crush injury.

• Proximal, middle or distal phalangeal fracture
• Mallet fracture: avulsion of the extensor tendon from the dorsal surface of the distal phalanx (the fingertip cannot be straightened)
• Jersey finger: avulsion of the flexor tendon from the volar surface of the distal phalanx
• Intra-articular fractures (condylar and plateau fractures)
• Open fractures (uncommon; may occur with a nail bed injury)

Symptoms

• Pain: at the fracture site, increasing with movement
• Swelling and bruising: oedema developing within the first hours
• Restricted movement: difficulty moving the wrist or fingers
• Deformity: visible in displaced fractures (for example the "dinner fork" deformity of a distal radius fracture)
• Tenderness: pain that increases on palpation of the fracture site
• Weakness of grip: particularly in hand and finger fractures
• Altered sensation: particularly median nerve compression (carpal tunnel-like symptoms in a distal radius fracture)
• Bruising of the nail bed: in distal phalangeal fractures

Mechanisms of Injury

• Fall on an outstretched hand (FOOSH): the most common mechanism for distal radius and scaphoid fractures
• Punching: typical of a boxer's fracture (fifth metacarpal neck)
• Direct blow or crush injury: for phalangeal and metacarpal fractures
• Sports injuries: cycling, skiing, football, volleyball
• Osteoporotic falls: typical of distal radius fractures in older women

Diagnosis

Diagnosis is based on a detailed history, physical examination and imaging. Examination assesses swelling, deformity, points of tenderness, range of motion, grip strength, tendon function (particularly for mallet or jersey finger), neurovascular status (median, ulnar and radial nerves; capillary refill) and skin integrity. Anatomical snuffbox tenderness is specific for a scaphoid fracture.

Plain radiographs are the first-line investigation; anteroposterior, lateral and oblique views are standard. Dedicated scaphoid views are obtained where a scaphoid fracture is suspected; if the initial films are normal they are repeated after 10–14 days, or MRI is used to look for an occult fracture — particularly of the scaphoid. CT is used for surgical planning in intra-articular fractures (especially intra-articular distal radius fractures). MRI is preferred for assessing occult scaphoid fractures, cartilage and soft-tissue damage and tendon injuries.

Non-operative (Conservative) Treatment

Stable, non-displaced fractures — or those brought into an acceptable position by closed reduction — are treated in a cast or splint. Typical candidates are non-displaced distal radius fractures; isolated ulnar styloid fractures; non-displaced scaphoid distal pole or waist fractures; non-displaced or successfully reduced metacarpal neck fractures (a degree of angulation is acceptable in a boxer's fracture in particular); and non-displaced phalangeal fractures. The duration of immobilisation varies by type: 4–6 weeks for the distal radius, 8–12 weeks for the scaphoid and 3–4 weeks for metacarpal and phalangeal fractures.

Surgical Treatment (ORIF / Percutaneous Fixation)

Surgery is the standard treatment for displaced or unstable fractures and for those that disturb the joint surface. Typical candidates are displaced intra-articular distal radius fractures; unstable distal radius fractures (where position cannot be maintained after closed reduction); displaced scaphoid fractures and particularly proximal pole fractures; metacarpal and phalangeal fractures that are displaced or show rotational deformity; Bennett and Rolando fractures; intra-articular phalangeal fractures; and open fractures. The fundamental aims of treatment are anatomical reduction, rigid fixation and early movement.

Advantages

The principal advantage is anatomical restoration of the fracture with rigid fixation. This reduces the risk of malunion, loss of grip strength, rotational deformity of the fingers and post-traumatic arthritis in the long term. Whereas prolonged casting in non-operative treatment can lead to wrist and finger stiffness, surgery allows early movement.

• Anatomical reduction: the joint surface and any extra-articular angulation are corrected with millimetre precision
• Early motion: stable fixation allows wrist or finger range-of-motion exercises to begin within 1–7 days after surgery, reducing the risk of stiffness
• Operative time: 60–90 minutes for a distal radius volar plate; 30–60 minutes for metacarpal or phalangeal fixation; shorter for percutaneous techniques
• Most cases are performed as day cases (discharged the same day)
• Hand function is better preserved in the long term; the risk of post-traumatic arthritis is higher after non-operative treatment of displaced intra-articular distal radius fractures

Disadvantages

There are surgery-specific risks: wound infection, deep infection, implant irritation, rare nerve injury (particularly the median nerve, superficial branches of the radial nerve and the digital nerves) and rare tendon injury, together with rare anaesthetic complications.

• Implant irritation: plates and K-wires placed close to the skin may cause irritation; some patients require hardware removal
• Carpal tunnel syndrome: median nerve compression is common after a distal radius fracture or its surgical treatment (temporary or permanent numbness, night pain)
• Wrist or finger stiffness: may develop despite surgery; additional immobilisation or a late start to movement increases the risk, and intensive physiotherapy may be required

Why Surgery?

The wrist and hand are critical to almost every activity of daily life. Incongruity of 1–2 mm in the distal radius joint surface, or angulation of more than 10°, leads to cartilage wear and post-traumatic arthritis in the long term. In metacarpal and phalangeal fractures, rotational deformity can prevent the fingers from closing properly ("scissoring" — the fingers crossing over one another). Because of their blood supply, scaphoid fractures can lead to non-union and, in the long term, wrist arthritis (SNAC wrist); early surgery reduces the risk of avascular necrosis in displaced or proximal pole fractures. The surgeon therefore prefers surgical treatment where the fracture is displaced and unstable, or where the functional outcome is threatened.

Who is a Candidate?

Surgery is performed for displaced or unstable wrist and hand fractures and for those that disturb the joint surface.

• Displaced intra-articular distal radius fractures; distal radius fractures that are unstable after reduction
• Displaced or proximal pole scaphoid fractures (including non-displaced scaphoid fractures in patients who want early healing and a rapid return to sport)
• Metacarpal and phalangeal fractures with rotational deformity or marked angulation
• Bennett and Rolando fractures; intra-articular phalangeal fractures
• Open fractures
• Mallet or jersey fractures with an associated active tendon injury
• Non-operative treatment: stable, non-displaced fractures, or those that can be brought into an acceptable position by closed reduction

Expected Outcomes

Most patients with a correctly treated wrist or hand fracture achieve a pain-free, functional hand. After a distal radius fracture most return to daily activities within 6–12 weeks, with complete recovery taking up to 6 months. Metacarpal and phalangeal fractures usually heal in 6–8 weeks. Scaphoid fractures take longer to heal (8–16 weeks) and may take longer still for proximal pole fractures. Mild stiffness and a small loss of grip strength may persist, but most patients return to a functional level of use.

Risks Specific to Non-operative (Cast/Splint) Treatment

• Inadequate reduction / secondary displacement: fragments shifting within the cast; further surgery may be required
• Pressure sores and friction beneath the cast
• Wrist or finger stiffness: due to prolonged immobilisation
• Loss of grip strength
• Malunion: angulation of the distal radius, or rotational deformity of a metacarpal or phalanx
• Complex regional pain syndrome (CRPS): particularly after distal radius fractures

Risks Specific to Surgery — Common (Under 5%)

• Superficial wound infection (usually treated with antibiotics)
• Postoperative pain, swelling and temporary bruising
• Temporary wrist or finger stiffness — resolves with regular physiotherapy
• Transient symptoms related to anaesthesia such as nausea and dizziness
• Scar discomfort
• Local irritation at K-wire exit sites (with percutaneous techniques)

Risks Specific to Surgery — Less Common

• Deep infection: 1–2%; may require revision and antibiotics
• Median nerve sensitivity / carpal tunnel syndrome: common after distal radius surgery; temporary numbness and night pain
• Injury to the superficial branch of the radial nerve (with dorsal approaches)
• Tendon injury or rupture: particularly rupture of flexor pollicis longus (FPL) after volar plate fixation of the distal radius; irritation of the extensor tendons by long screws
• Complex regional pain syndrome (CRPS)
• Heterotopic ossification (bone formation in soft tissue; rare)
• K-wire migration or breakage

Long-term Complications

• Malunion: ulnocarpal impingement from distal radius angulation; "scissoring" of the fingers from rotational deformity
• Non-union: common in scaphoid fractures in particular (20–30% in displaced and proximal pole fractures); increased by smoking and delayed diagnosis
• Avascular necrosis: death of the bone due to loss of blood supply in scaphoid proximal pole fractures
• Post-traumatic osteoarthritis: may develop years later after intra-articular fractures; SLAC/SNAC wrist is seen particularly with scaphoid non-union
• Persistent wrist or finger stiffness; persistent loss of grip strength
• Chronic pain
• Distal radioulnar joint (DRUJ) instability

Implant-related Problems

• Implant irritation close to the skin: prominence of K-wires beneath the skin; irritation of the tendons by screws
• Need for implant removal: K-wires are usually removed at weeks 3–6 and plates or screws after 6–12 months
• Tendon irritation after a distal radius volar plate (particularly extensor pollicis longus and flexor pollicis longus)

Factors that Increase Risk

• Smoking (the single most important factor for scaphoid non-union)
• Poorly controlled diabetes; osteoporosis
• Immunosuppressive therapy and rheumatological disease
• Advanced age; high-energy or open fracture
• Delayed diagnosis (particularly in scaphoid fractures)
• Active or recently treated infection
• Prolonged immobilisation (the determining factor for stiffness)

Contact Your Doctor Immediately If You Have

• Sudden increase in pain or swelling
• Fever above 38 °C
• Discharge, malodour or separation of the wound
• Increasing numbness, tingling or weakness in the hand or fingers
• Bruising, coldness or pallor of the fingers (suspected vascular problem)
• Excessive tightness or unbearable pain within the cast or splint (suspected compartment syndrome)
• Wound edge separation or exposed hardware
• Severe, burning pain in the fingers (suspected complex regional pain syndrome)

Long-term Outcomes

With accurate diagnosis, appropriate treatment and compliant rehabilitation, the great majority of wrist and hand fractures heal without problems. Most patients return to daily activities within 2–4 months. Mild stiffness and a small loss of grip strength may persist for 6–12 months.

Scaphoid fractures may take longer to heal; delayed diagnosis increases the risk of non-union and of wrist arthritis in the long term. Stopping smoking, early diagnosis and disciplined rehabilitation are critical to long-term outcome.