Carpal injuries

The most commonly injured carpal bone is the scaphoid. Scaphoid fractures are common, especially in young. They occur due to fall on outstretched hand, and are classified according to Herbert. Symptoms include swelling, pain, and tenderness of the anatomical snuffbox. These fractures are not always visible on x-ray acutely, and so conservative treatment is usually performed despite x-ray evidence if the clinical suspicion is high, to prevent the high risk of complications.

Perilunate dislocation refers to dislocation of the carpus relative to the lunate. It’s a rare but serious injury which is often overseen initially. Treatment is surgical.

Etiology

Scaphoid fracture and perilunate dislocation occur due to fall on an outstretched dorsiflexed hand.

Classification

Scaphoid fractures are classified by the Herbert classification:

Type	Description
Type A	Acute, stable
Type B	Acute, unstable
Type C	Delayed union
Type D	Nonunion

Clinical features

Scaphoid fracture involves localised swelling and tenderness of the anatomical snuff box. There’s also pain when axially compressing the thumb.

Perilunate dislocation causes swelling, pain, and loss of function of the wrist. The dislocation can be palpated.

Diagnosis and evaluation

Scaphoid fractures may not always be visible acutely on x-ray. However, an untreated scaphoid fracture may cause complications. As such, if there is a clinical suspicion for scaphoid fracture, we should either treat conservatively and make another x-ray two weeks later (at which point the fracture will be visible) or make a CT/MRI to completely rule out fracture.

Diagnosis of perilunate dislocation is visible on x-ray as an empty lunate fossa, a triangularly shaped lunate bone, and misplacement of all carpal bones.

Treatment

Treatment of scaphoid fractures is mostly conservative, with thumb fixation with a cast. In case of dislocated fractures, ORIF with screw is performed.

Treatment of perilunate dislocation is surgical with ORIF.

Complications

Untreated scaphoid fracture has high risk of pseudoarthrosis due to avascular necrosis, nonunion, etc.

Metacarpal injuries

There are multiple named injuries of the metacarpal bones:

Bennet fracture is a partial intraarticular fracture of the base of the 1st metacarpal. Rolando fracture is a comminuted intraarticular fracture of the 1st metacarpal. They’re due to axial force on the thumb. Treatment is surgical.

Rolando fracture is a comminuted intraarticular fracture of the 1st metacarpal (multiple bone fragments).

Gamekeeper’s thumb is a torn medial collateral ligament of the thumb.

Boxer’s fracture is a fracture of the neck of the 5th metacarpal. Treatment may be conservative or surgical depending on the presence of dislocation or rotational malalignment.

Etiology

Bennet and Rolando fracture occurs due to axial force on the thumb, often sustained during a fist fight.

Gamekeeper thumb occurs due to abduction trauma of the MCP joint, for example due to fall while downhill skiing.

Like the name implies, a boxer’s fracture occurs due to direct trauma with closed fist to a hard object.

Clinical features

Typical fracture features. The patient must be examined for rotational malalignment.

Diagnosis and evaluation

X-ray.

Treatment

Fractures of the first metacarpal are treated surgically with ORIF and a cast.

Fractures of the fifth metacarpal may be treated conservatively or operatively, depending on whether there’s dislocation or not. In any case metacarpal fracture, if there is rotational malalignment, the patient should be considered for surgery.

Immobilisation of the hand requires fixation of it in a functional (resting) position with special casts. The exact position depends on the joint to be immobilised.

If one finger should be immobilised, it can often be fixated to the adjacent finger. As an example, for 5th metacarpal fractures, the 4th and 5th fingers are often fixated to each other for stability.