Radial head fractures are located 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.
A fracture to the radial head occurs in 20% of all elbow traumas and 33% of elbow dislocations in 20% of all elbow injuries. This pathology is the result of axial energy loading trough the radius when falling with outstretched hand mostly keeping the arm in a pronated position.
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)
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 of the 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.
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)
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.
Radial head fractures are frequent in individuals between 30-40 years of age, and particularly women who are active in recreational and competitive sports. In addition, 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 sport
Motor vehicle accidents
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
History of a previous elbow dislocation or elbow instability
Congenital joint laxity
Inappropriate sport training technique
Congenital malformation of the radial head (larger and rounder)
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)
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
Physical examination begins with the medical history including the mechanisms of injury leading to radial head fracture. The examiner looks for the presence of deformities and bruises around the elbow and changes in the range of movement to establish functional limitations and pain level when the elbow is moved passively in extension and supination. Neurovascular injuries are established by checking the pulses to exclude associated compromise to the brachial artery.
Assessment of the radial nerve
The radial nerve innervates the dorsal extrinsic muscles in the forearm and is the nerve that may be most likely damaged with a radial head fracture and an elbow dislocation. Severe injury of this nerve causes hand drop. Specific functional tests of the radial nerve will look for changes in motor and sensory function:
Extension of the wrist and metacarpo-phalangeal (MCP) joints with abduction and extension of the thumb
Flexion of the fingers at the MCP joints and adduction of the thumb
Dysesthesia or anaesthesia on the dorsum of the thumb.
X-rays are the first radiological method to evaluate the type and severity of the radial head fracture. A CT scan or MRI may provide further information on the position of the bone fragments to plan a possible surgical approach. With an elbow dislocation a closed reduction may need to take place immediately after the diagnosis.
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:
Application of ice pads
Administration of NSAIDs
Early physiotherapy to prevent reduction of range of movement
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 internal fixation (ORIF). This procedure minimises the risk of posttraumatic 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.
Radial head fractures may lead to a number of complications that can severely compromise the function of the elbow. They include:
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 vasculature and nerves
Initially after either conservative or surgical treatment a splint/brace is applied for a short period in most patients with radial head fracture. Returning to physical activity after radius head fracture can take weeks to months. Physical therapy will assist the patient to achieve a normal elbow function with the following methods:
Application of ice or heat pads
Use of a compression bandage
Avoid strenuous arm movements and weight lifting
Exercises to restore elbow strength and flexibility
Elbow taping and bracing
Activity modification advice
Return to sport/work plan
Avoiding any type of fall will reduce the incidence of radius head fractures and associated injuries. In addition it is recommended to follow simple instructions especially when an elbow injury has already occurred:
Use of taping and bracing to protect the elbow during sport or other physical activities
Physical exercise to strengthen the muscles of the arm and maintain elbow flexibility
Return to sport with training guided by a physiotherapist only when symptoms have subsided
Possible necessity to quit contact sports such as football and rugby