FRACTURES OF THE DISTAL RADIUS

IN ADULTS

Dr. D. N. Bid

• The distal end of the radius is subject to many different types of fracture, depending on factors such as age, transfer of energy, mechanism of injury and bone quality.

• With any of these fractures, the wrist also can suffer substantial ligamentous injury causing instability to the carpus or distal radio-ulnar joint.

• These injuries are easily missed because the x-rays may

look normal.

COLLES’ FRACTURE

• The injury that Abraham Colles described in 1814 is a transverse fracture of the radius just above the wrist, with dorsal displacement of the distal fragment.

• It is the most common of all fractures in older people, the high incidence being related to the onset of post-menopausal osteoporosis.

• Thus the patient is usually an older woman who gives a history of falling on her outstretched hand.

Mechanism of injury and pathological anatomy

• Force is applied in the length of the forearm with the wrist in extension.

• The bone fractures at the cortico-cancellous junction and the distal fragment collapses into extension, dorsal displacement, radial tilt and shortening.

Clinical features

• We can recognize this fracture (as Colles did long before radiography was invented) by the ‘dinner-fork’ deformity, with prominence on the back of the wrist and a depression in front.

• In patients with less deformity there may only be local tenderness and pain on wrist movements.

• X-ray There is a transverse fracture of the radius at the corticocancellous junction, and often the ulnar styloid process is broken off.

• The radial fragment is impacted into radial and backward tilt.

• Sometimes there is an intra-articular fracture; sometimes it is severely comminuted.

Treatment

• UNDISPLACED FRACTURES• If the fracture is undisplaced (or only very slightly

displaced), a dorsal splint is applied for a day or two until the swelling has resolved, then the cast is completed.

• An x-ray is taken at 10–14 days to ensure that the fracture has not slipped; if it has, surgery may be required; if not, the cast can usually be removed after four weeks to allow mobilization.

• DISPLACED FRACTURES• Displaced fractures must be reduced under anaesthesia

(haematoma block, Bier’s block or axillary block).

• The hand is grasped and traction is applied in the length of the bone (sometimes with extension of the wrist to disimpact the fragments); the distal fragment is then pushed into place by pressing on the dorsum while manipulating the wrist into flexion, ulnar deviation and pronation.

• The position is then checked by x-ray.

• If it is satisfactory, a dorsal plaster slab is applied, extending from just below the elbow to the metacarpal necks and two-thirds of the way round the circumference of the wrist.

• It is held in position by a crepe bandage.

• Extreme positions of flexion and ulnar deviation must be avoided; 20 degrees in each direction is adequate.

• The arm is kept elevated for the next day or two; shoulder and finger exercises are started as soon as possible.

• If the fingers become swollen, cyanosed or painful, there should be no hesitation in splitting the bandage.

• At 7–10 days fresh x-rays are taken; redisplacement is not uncommon and should be treated, if the patient’s functional demands are high, by re-manipulation and internal fixation.

• However, in some elderly patients with low functional demands, modest degrees of displacement should be accepted because – (a) out-come in these patients is not so dependent upon

anatomical perfection, and – (b) fixation of the fragile bone can be very difficult.

• The fracture unites in about 6 weeks and, even in the absence of radiological proof of union, the slab may safely be discarded and exercises begun.

• IMPACTED OR COMMINUTED COLLES’ FRACTURES

• With substantial impaction or comminution in osteoporotic bone, manipulation and plaster immobilization alone may be insufficient.

• The fracture can some-times be reduced and held with percutaneous wires, but if impaction is severe even this may not be enough to maintain length; in that case, an external fixator is used to neutralize the compressive force of the 25 tendons crossing the wrist, and bone graft or bone substitute is placed into the gap.

• The fixator is attached to the dis-tal radius and the second metacarpal shaft.

• It should be used only as a neutralizing device; too much distraction will lead to stiffness.

• The fixation is removed after 5–6 weeks and exercises begun.

• Plate fixation is increasingly being used for some Colles’ fractures.

• The so-called ‘volar locking plate’ is applied to the front of the radius through the bed of flexor carpi radialis.

• The screws are fixed to the plate itself and are passed into the relatively stronger subchondral bone distally.

• These devices, which are flourishing in the orthopaedic marketplace, allow stable fixation and thus early mobilization of the forearm.

• Other devices, such as a locked intramedullary nail or crossed K-wires, are also suitable for the distal radius.

Outcome

• As Colles himself recognized, the outcome of these fractures in an older age group with lower functional demands is usually good, regardless of the cosmetic or the radiographic appearance.

• Poor outcomes can often be improved by performing a corrective osteotomy.

• The amount of displacement that can be accepted depends on patient factors such as age, co-morbidity, functional demands, handedness, and quality of bone, and treatment factors such as surgical skill and implants available.

• As a rule, shortening of more than 2 mm at the distal radio-ulnar joint, dorsal tilt of more than 10 degrees and dorsal translation of more than 30 per cent are likely to lead to a poor outcome and early correction should be considered.

• This advice applies to older osteopaenic fractures; in younger patients the tolerances are far less!

Complications• EARLY

• Circulatory problems The circulation in the fingers must be checked; the bandage holding the slab may need to be split or loosened.

• Nerve injury Direct injury is rare, but compression of the median nerve in the carpal tunnel is fairly common.

• If it occurs soon after injury and the symptoms are mild, they may resolve with release of the dressings and elevation.

• If symptoms are severe or persistent, the transverse ligament should be divided.

• Reflex sympathetic dystrophy This condition is probably quite common, but fortunately it seldom progresses to the full-blown picture of Sudeck’s atrophy.

• There may be swelling and tenderness of the finger joints, a warning not to neglect the daily exercises.

• In about 5 per cent of cases, by the time the plaster is removed the hand is stiff and painful and there are signs of vasomotor instability.

• X-rays show osteoporosis and there is increased activity on the bone scan.

• TFCC injury

TFCC injury is more common than is generally appreciated.

As the distal radius displaces dorsally, the TFCC is damaged; the ulnar styloid fracture which commonly accompanies a Colles’ fracture illustrates the forces which are transmitted to the TFCC, which attaches in part to it.

• LATE• Malunion Malunion is common, either because reduction

was not complete or because displacement within the plaster was overlooked. The appearance is ugly, and weakness and loss of rotation may persist.

• In most cases treatment is not necessary.

• Where the disability is severe and the patient relatively young, the lower 1.5 cm of the ulna may be excised to restore rotation, and the radial deformity corrected by osteotomy.

• Delayed union and non-union Non-union of the radius is rare, but the ulnar styloid process often joins by fibrous tissue only and remains painful and tender for several months.

• Stiffness Stiffness of the shoulder, elbow and fingers from neglect is a common complication.

• Stiffness of the wrist may follow prolonged splintage.

• Tendon rupture Rupture of extensor pollicis longus occasionally occurs a few weeks after an apparently trivial undisplaced fracture of the lower radius.

• The patient should be warned of the possibility and told that operative treatment is available.

Wrist Fractures video

Wrist Fracture Repair video

Distal Radius fracturevid

SMITH’S FRACTURE• Smith (a Dubliner, like Colles) described a

similar fracture about 20 years later.

• However, in this injury the distal fragment is displaced anteriorly (which is why it is sometimes called a ‘reversed Colles’).

• It is caused by a fall on the back of the hand.

Clinical features

• The patient presents with a wrist injury, but there is no dinner-fork deformity. Instead, there is a ‘garden spade’ deformity.

• X-ray There is a fracture through the distal radial metaphysis; a lateral view shows that the distal fragment is displaced and tilted anteriorly – the opposite of a Colles’ fracture.

• The entire metaphysis can be fractured, or there can be an oblique fracture exiting at the dorsal or volar rim of the radius.

Treatment

• The fracture is reduced by traction, supination and extension of the wrist, and the forearm is immobilized in a cast for 6 weeks.

• X-rays should be taken at 7–10 days to ensure the fracture has not slipped.

• Unstable fractures should be fixed with percutaneous wires or a plate.

Thank You……