Distal radius fracture consists of a fracture of the larger bone of the forearm, the radius, in proximity of the wrist joint on the inner side of the forearm.
The radius bone bears 80% of the energy load of the wrist and is therefore easily subject to injury. A fracture of the distal radius is the most frequent fracture amongst adults and elderly people (15% of all fractures) due to the high incidence of falls and osteoporosis.
In younger individuals, it often results from high-energy impacts and is associated to other injuries to smaller wrist bones such as ulnar fracture, scaphoid fracture, other carpal bone fractures and carpal tunnel syndrome.
In children, a distal radius fracture may involve the growth plate and potentially impair bone growth.
The fractures of the distal radius are defined with various classification systems including the AO (Arbeitsgemeinschaf fuer Osteosynthese) system. They relate to the mechanisms of injury and bone fracture characteristics and provide a guideline towards suitable treatments. The most frequent types of distal radius fracture are:
Colle's fracture is the most common type of fracture in which the distal bone of the radius tilts upwards following an outer bending of the wrist as it happens when falling on the hand or reversed
Smith's fracture or reversed Colle's fracture occurs when the distal portion of the radius tilts downwards following the inward bending of the wrist
Barton fracture is an intra-articular fracture of the distal radius with dislocation of the radiocarpal joint
Chauffeur fracture is an intra-articular fracture of the radial styloid process, also known as Hutchinson fracture or backfire fracture.
Intra-articular fracture extends to the wrist joint (or articulation)
Extra-articular fracture is located outside of the wrist joint
Open fracture when bone fragments perforate the skin
Comminuted fracture when the bone breaks into multiple fragments
Non-displaced when the anatomical alignment of the bone is maintained or displaced when the bone fragments move apart.
Melone’s classification describes the characteristics of intra-articular fractures of the radius:
i Stable fracture
ii Unstable "die-punch"
iii Spike fracture
iv Split fracture
v Explosion injuries
A distal radius fracture mostly occurs with a traumatic weight bearing force through the wrist particularly when falling with an outstretched hand onto a hard surface (hyperextension type fracture) or in a roll over (hyperflexion type injuries). It is common in sports such as skateboarding and snowboarding and after car and bike accidents.
Intensive sport activities in the younger population and falls in the elderly suffering from degenerating bone conditions are prominent risk factors for a distal radius fracture. Postmenopausal women are more frequently affected than men. Additional risk factors are:
Chronic inflammatory diseases: rheumatoid arthritis, gout (accumulation of uric acid in the joint)
Septic arthritis (infection of the joint)
Poor muscle training
The fracture of the distal radius causes an immediate variety of symptoms including:
Tenderness at touch
Deformity and hanging of the wrist
Reduced range of movement
Wound in case of open fractures
Clinical examination begins by discussing the medical history including the causes leading to a distal radius fracture. The main scope of the diagnosis is to identify the type of fracture in order to develop a suitable treatment plan.
It is critical for the examiner to assess potential damage caused to the nerves and the vasculature. The examiner palpates the wrist and performs gentle movements to assess pain level, joint instability and possible grinding noise. The presence of open fractures is determined by examining the skin around the wrist. Other elements of the examination include:
Associated injuries to the forearm, elbow and shoulder
Changes in the range of movement of elbow and shoulder
Vascular damage by testing pulses
Nerve damage via loss of sensation, e.g. drop hand
The diagnosis is confirmed with X-rays, CT scan and MRI in case of more complex (displaced, comminuted) fractures.
Conservative treatment is recommended in uncomplicated distal radius fracture (undisplaced and stable) or when bone quality is compromised in elderly patients. This approach includes:
Closed reduction under anaesthesia to reposition the bone in case of minor displacement
Traction of the fracture with a Chinese finger trap (see figure)
Plaster above elbow that is replaced as swelling subsides
Monitoring fracture healing with X-rays every 3 weeks to confirm a correct bone alignment
Cast removal and rehabilitation after 6 weeks
If the fracture is complicated surgery is necessary. This achieves a reposition of the bone fragments into a correct and functional anatomy to prevent secondary complications such as arthritis, nerve and vascular damage and bone necrosis, among others. Several surgical techniques are available for the treatment of distal radius fracture:
Open reduction and internal fixation (ORIF) using plates and screws
Screws in unstable fracture of the radial process styloid
Dorsal plate with bone graft for unstable fractures
External fixator in open fractures with severe soft tissue damage (screws inserted from the skin into the radius)
Joint replacement with artificial joint or wrist arthroplasty
A number of complications can occur following distal radius fracture such as:
Damage to blood vessels and bleeding
Compression or injury to the median nerve at the carpal tunnel (temporary or permanent)
Chronic Regional Pain Syndrome (CRPS) of the fractured area with persisting symptoms
Defects in fracture healing: mal-union when closure and alignment of the fracture fail
Damage to the cartilage leading to arthritis of the wrist joint (stiffness, pain) possibly requiring surgery
Wrist fusion consequent to chronic arthritis, meaning fusion of the radius with carpal and metacarpal bones
Anatomical reduction of bone fragments to minimise the risks of post-traumatic arthritis arising from mechanical grinding
Development of avascular necrosis of the fractured bone(s).
Early after distal radius fracture, the rehabilitative therapy focuses on:
Arm elevation (to reduce swelling/pain)
Pain management with NSAIDs or morphine for a few days, if pain is severe
Ice or heat pads
Antibiotics in case of open fractures
Replacement of cast when swelling subsides to keep the arm firm
Intensive physical therapy one to two months after cast removal or surgery and includes:
Activity modification advice
Return to sport/work plan
Gentle exercise to improve flexibility and strength.
Vigorous exercises can commence after three to six months from injury. Full recovery is expected after one year or longer in more complex fractures or in case of poor bone healing. Although most patients return to normal activities after radius head fracture, some may suffer some degree of pain, which will decrease over two years.
In older osteoporotic patients, assessment of bone density and administration of calcium and Vitamin D may be necessary to help preventing bone fractures. Reducing the risk of falls in elderly patients remains an efficacious prevention for future distal radius fractures and other injuries. In young individuals, wearing a wrist brace or taping is advised especially when sport is resumed after the fracture.