Forearm fractures
Left: normal forearm bones, right: radius fracture with callus formation

Definition

The fracture of the forearm refers to the break of one or both forearm bones, the radius and ulna.

X-ray of a normal forearm which depicts the anatomical structure where fractures can occur

Pathology

In adults, the fracture of the forearm accounts for most arm fractures. They frequently involve both the radius and ulna. If only one bone is broken, it is usually the ulna. In children it is critical to evaluate the fracture in relation to the growth plate (or physis) of the radius and ulna, as injury to the growth plates can compromise full bone growth. The classification of forearm fractures differs in adults and children and consequently their treatment management.

‍Drawings of child's forearm fractures: non-displaced left, displaced centre, Greenstick fracture right. Note the growth plates at either end of the radius and ulna

Classification

The fractures of the forearm are classified according to the location of the break, whether occurring close to the elbow (proximal), near the wrist (distal) or in the length between these joints (also named shaft or diaphysis). They are also defined by the specific characteristics of the fracture. Below some of the most used classification systems:

Closed fracture, when the extremities of the fractured bone are contained within the soft tissue and the skin is intact

Open fracture, when the extremities of the bone protrude through a wound

Simple fracture, when the bone break maintains the bone anatomical alignment

 

This classification of forearm fractures is often used in adults and children:

Growth plate fracture: occurs in children and refers to a fracture including the physis (growth plate at either end of the bone where cartilage grows and becomes ossified bone)

Greenstick fracture: is a partial fracture of the bone only found in children. The periost (skin covering the bone) around the fracture is intact

Torus fracture (buckle fracture): compression of the top layer of bone with bending of the opposite bone side. The broken bones are undisplaced

Metaphyseal fracture: is a fracture of the upper or lower section of the bone shaft, outside the growth plate 

The Orthopaedic Trauma Association classification of radial and ulna diaphyseal (shaft) fractures includes:

Type     A:     Simple fracture of ulna (A1), radius (A2), or both (A3)

Type     B:     wedge fracture of ulna (B1), radius (B2), or both (B3)

Type     C:     complex fractures

Associated injuries

Forearm fractures often occur together with other injuries to the wrist and elbow and are also associated with soft tissue injuries to nerves, more likely the radial nerve, which may result into drop hand. Injury to vessels may involve the radial and ulnar arteries. As a consequence of a fracture the patient may develop a compartment syndrome, which consists of increased swelling and pressure of the soft tissues around the forearm fractures.

Left: Distal radius intraarticular, displaced fracture; Middle: Older distal radius fracture with callus formation; Right: Distal radius and ulna fracture, extraarticular and displaced

No 2.

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

Acetabular fracture of the pelvis

Acetabular fractures

These fractures are divided into:

Anterior pillar (not weight bearing part of joint)

Posterior pillar (often associated with dislocation of the hip including the weight bearing part of joint)

Transverse

Comminuted involving both column type 

Sacral / coccygeal fractures

The sacrum is a triangular-shaped bone formed by 5 fused vertebrae, which provide a posterior wall to the pelvic ring. At each side of the sacrum, the ala structures articulate with the ilium bones forming the sacro-iliac joints. Sacral fractures are usually parallel to the spine and can involve the ala. Less frequently sacral fractures may display an “H” shape, including a transversal fracture uniting both sides of the sacrum. Three zones are described where sacral fractures can occur that are along vertical lines relative to the alignment of the foramina. Sacral fractures may result in sacral instability and require treatment via sacroplasty (injection of bone glue into the fracture). Surgery is necessary in case of associated neurological symptoms.

Fractures of the coccyx involve the tailbone, the terminal portion of the spine situated below the sacrum formed by 3 to 5 fused vertebrae. Coccyx fractures occur when falling on a seated position. They are more common in elderly women and seldom require surgical treatment.

Accidents while maneuvering industrial machines can cause forearm fractures

Causes

Fractures to the forearm can be produced by high-energy trauma or low energy falls. Forearm fractures are more frequent in males. The main causes are:

Fall on a hard surface with outstretched arm

Motor vehicle accidents

Direct blow to the forearm (nightstick, baseball bat)

Forceful twisting of the forearm pushing the elbow beyond its normal range of movement caused by automobile and motorbike accidents

Machinery accidents

Cancer metastases to the bones (pathological fracture)

Gun shot

Sports like skateboarding increase the risk for forearm fractures

Risk factors

A number of recreational sports and ageing constitute typical factors that increase the risk of forearm fractures:

Sports (skate-/snow-boarding)

Contact sports (football, rugby, soccer)

Motor vehicle and motor bicycle driving

Manoeuvring of farming and industrial machines

Elderly individuals prone to falls

Postmenopausal women

Osteoporotic bones

Congenital bone conditions

Presence of bruises may indicate the presence of a forearm fracture

Symptoms

The typical symptoms of forearm fracture are: 

Acute, sharp pain in the forearm at time of injury

Pain increasing with movement

Swelling around the fractured bone(s)

Deformation of the arm, flopping arm

Bleeding

Feeling of bone fragments when moving the forearm

Patient inability to straighten or rotate the arm as a consequence of the fracture

Medical examination for the diagnosis of a forearm fracture

Diagnosis

The diagnosis begins with the clinical history and the description of the mechanisms of injury leading to a forearm fracture. Medical examination will focus on:

Detection of skin lacerations, bruises, open fractures in the forearm

Examination of the shoulder, upper arm, wrist and hand to assess the possibility of concomitant injuries

Palpation of the injured area to test for tenderness and pain

Detection of pulses for associated injuries to blood vessels

Neurological testing for damage to the radial nerve

The examiner employs specific tests to establish changes in the range of movement. X-rays under the antero-posterior and lateral planes are used to evaluate the type and severity of the fractures to the ulna and/or radius. CT scan and MRI are taken to provide further information on the position of the bone fragments and soft tissue damage as well as to plan for suitable treatment. Angiography and Doppler ultrasonography may be useful when injury to the vascular system is suspected.

Treatment

Conservative treatment of undisplaced forearm fracture with a cast

Nonoperative treatment

Early management of forearm fractures is usually provided at the Emergency Department. If fractured bone fragments are not displaced or minimally displaced and do not impact on elbow or wrist joint movement, conservative treatment is recommended. This comprises an early closed reduction performed by an orthopaedic surgeon to realign the fractured bone(s), followed by the immobilisation using a splint, a cast or a brace above the elbow. A splint is worn for 6 weeks in the more simple cases and a cast between 6 and 10 weeks in more complex fractures. Additional conservative treatment aims at reducing swelling, pain and inflammation with:

Arm elevation

Ice pads

Analgesics (pain killers)

Administration of NSAIDs

Left: ORIF of single radius fracture, centre: ORIF of radius and ulna fractures; right: ORIF of the radius and intramedullar nailing of the ulna with a cast

Surgical treatment

Surgery is necessary in significantly displaced, comminuted and / or open fractures or in case of high instability when both forearm bones are fractured. The option of surgery will also depend on the age, general health and the osteoporotic nature of the bone. Several approaches are available to fix the fractures of the forearm, including:

Open reduction and internal fixation (ORIF) consists of a large skin incision, a plate inserted along the fracture length that is fixed with screws. It is the most common method. It may require the employment of bone graft especially with bone loss due to comminuted or open fractures

Intramedullary rod or nail, a metal introduced in the bone shaft canal and fixed on the outer bone extremities with screws. The rod can be introduced either from the proximal or distal end of the bones

External fixation via percutaneous screw fixation is used to maintain bone alignment while the fracture is healing. This is often followed by permanent internal fixation within 14 days after the injury. This method is used in situations where an immediate internal fixation cannot be performed, eg. multiple injured patients and in open fractures with high risk of infection transmitted to the bone. In rare cases the external fixator remains in place until the fracture has healed.

Ultrasound treatment

Rehabilitation

Return to physical activity after forearm fracture can take weeks to months. Physiotherapy assists the patient to achieve wrist and elbow function following weeks of immobilisation and reduce residual symptoms with the following methods:

Soft tissue massage

Joints mobilisation

Exercises to restore muscle strength

Ultrasound

Use of a compression bandage

Forearm taping and bracing

Activity modification

Graduated return to activity plan

Complications

As in all bone fractures, complications can also occur after forearm fracture. The main complications include:

Infection of the bone and soft tissue (after surgery and in open fractures)

Compartment syndrome

Non-union of the fracture when the gap between the bone extremities is not closed

Arm shortening

Mal-union when the fracture heals with abnormal bone alignment

Damage to the radial nerve

Vascular injury and bleeding

Refracture if the plate is removed before complete bone healing

Wearing elastic bands can protect the arm while practicing sports and prevent fractures

Prevention

A number of preventive measures will reduce the incidence of forearm fractures and recidivism after a primary fracture:

Removal of metals only after complete fracture repair

Wear forearm and wrist guards when practicing sport (skating, biking) or driving motorbikes

Avoid falls in elderly individuals

Prevention and treatment of osteoporosis