Definition

Radial head fractures occur at the proximal end or head of the radius, one of the forearm bones that articulates with the distal humerus to form the elbow  joint.

Pathology

In adults, a fracture to the radial head is seen in 20% of all elbow injuries, in 33% cases concomitant with elbow dislocations and 8% in children. This pathology is the result of axial energy loading trough the radius when falling with outstretched hand usually while keeping the arm in a pronated position.

Associated injuries

A radial head fracture may be present as an isolated pathology, simultaneously to elbow dislocations or combined with more complex fractures to the neck of the radial head, proximal forearm bones, the distal humerus (coronoid) and the wrist (carpal injuries). It can also be associated with soft tissue injuries to:

Ligaments (medial collateral ligament)

Nerves, more often the radial nerve, causing drop hand

Vessels (brachial artery)

Classification

The fracture of the radial head is classified according to its complexity:

Type I: undisplaced small fracture that does not alter the anatomy of the radius and elbow joint. It can be overseen with X-rays.

Type II: more severe fracture involving a larger portion ofthe radial head. With minimal displacement no surgery is required. When small bone fragments are released into the joint they are removed with surgery; larger bone parts are fixed with pins, screws or implants. In older patients a complex radial head fracture may require the removal of portions or the entire head

Type III: the most complex form comminuted and displaced that includes multiple fractures of the radial head compromising its surgical reconstruction. The bone fragments are removed surgically and the soft tissue, if damaged, repaired. Prosthesis of the radius head may be needed to restore the anatomy and function of the elbow

Type IV: combines radial head fracture with elbow dislocation.

Associated injuries

A radial head fracture may be present as an isolated pathology, simultaneously to elbow dislocations or combined with more complex fractures to the neck of the radial head, proximal forearm bones, the distal humerus (coronoid) and the wrist (carpal injuries). It can also be associated with soft tissue injuries to:

Ligaments (medialcollateral ligament)

Nerves, more often the radial nerve, causing drop hand

Vessels (brachial artery)

Causes

Radial head fractures are frequent in individuals between 30-40 years of age, and particularly women who are active in recreational and competitive sports.

Congenital radial head dislocation ensues with a bilateral malformation of the radio-capitellar joint including a shorter development of the ulna causing abnormality of the radio-ulnar joint. However, most common causes leading to radial head fracture result from trauma and include:

Fall on the outstretched arm with or without elbow dislocation

Direct blow to the elbow in high impact sports

Motor vehicle accidents

Risk factors

Exposure to radial head fracture is most likely related to sport and other activities facilitating falls and elbow dislocations. These are the typical risk factors for a radial head fracture:

Tendency to fall

Sport

Epilepsy

History of a previous elbow dislocation or elbow instability

Congenital joint laxity

Congenital malformation of the radial head (larger and rounder)

Inappropriate sport training technique

Symptoms

These are the main symptoms of radial head fracture:

Sudden severe pain on the outer side of the elbow at time of injury

Deformed elbow (with dislocation and associated fractures)

Swelling

Bruising

Tenderness at touch

Patient inability to straighten or rotate the arm  

Changes in sensation of the areas innervated by the radial nerve

Changes in motor function of thumbs and fingers controlled by the radial nerve

Treatment

Nonoperative treatment

Conservative treatment is sufficient in case of simpler fractures when bone fragments are not displaced or minimally displaced and when they do not impact on the joint function. This treatment approach involves a closed reduction of the dislocated elbow by an orthopaedic surgeon to position the radius head in the joint socket. This procedure is followed by the immobilisation of the elbow using a splint, a cast or a brace above the elbow. In simple fracture the splint is generally worn for a 1-2 weeks whereas in more complex fractures it is recommended to use a cast for 6 to 8 weeks. Additional conservative treatment includes:

Rest

Application of ice pads

Administration of NSAIDs

Pain killers

Early physiotherapy to prevent reduction of range of movement

Surgical treatment

Surgery is recommended in radial head fractures Type II and III.

Firstly, the bone parts if dislocated are repositioned within the elbow joint (reduction) then fracture fixation is achieved with screws and pins with a method defined open reduction and internalfixation (ORIF). This procedure minimises the risk of post-traumatic arthritis due to mechanical grinding of the bones forming the joint. In more severe cases of radial head fracture the surgeon may perform a partial excision or total resection of the radial head. If the radial head is not salvageable it is replaced with an artificial prosthesis. Surgery is also used to repair possible damage to ligaments and vasculature.

Complications

Radial head fractures may lead to a number of complications that can severely compromise the function of the elbow. They include:

Elbow instability

Elbow stiffness and persistent pain

Non-union or failure of the fracture to heal

Mal-union or loss of bone alignment

Reduction in the range of movement, often requiring a second surgery

Osteoarthritis of the elbow joint caused by damage to the articular cartilage

Avascular necrosis of part or the entire radial head

Injury to the vessels and nerves