Clavicle fracture
A clavicle fracture, also known as a broken collarbone, is a partial or complete break of the clavicle bone. Symptoms typically include pain and tenderness at the site of the break and a decreased ability to move the affected arm. Other symptoms may also include reports of a cracking sensation during the injury, swelling, and deformity over the injury site. Complications can include a collection of air in the pleural space surrounding the lung, injury to the nerves or blood vessels in the area, and an unpleasant appearance.
It is most often caused by a fall directly onto a shoulder, direct trauma to the bone, or a fall onto an outstretched arm. The fracture can also occur in a baby during childbirth. Rare causes of clavicle fractures include muscle contractions during seizures and minimal trauma in the setting of pathologic bone conditions. The middle section of the clavicle is most often involved. Diagnosis is typically based on symptoms and trauma then confirmed with X-rays.
Clavicle fractures can be treated operatively or non-operatively. Operative treatment involves alignment and stabilization of the fracture with plates and screws or an intramedullary device. Non-operative treatment consists of immobilization by putting the arm in a standard sling for three to four weeks. Pain medication such as paracetamol may be useful. It can take up to five months for the strength of the bone to return to normal. Reasons for surgical repair include an open fracture, involvement of the nerves or blood vessels, tenting of the skin, or severe displacement in a high-demand individual
Clavicle fractures most commonly occur in people under the age of 25 and those over the age of 70. Among the younger group males are more often affected than females. In adults they make up about 5% of all fractures while in children they represent about 13% of fractures.
Signs and symptoms
- Pain, particularly with arm movement or on the front part of upper chest
- Swelling
- Deformity of the clavicle area sometimes with a sharp bone end pressing up from below the skin creating the appearance of a tent held up by poles
- Often, after the swelling has subsided, the fracture can be felt through the skin
- Sharp pain when any movement is made
- Referred pain: dull to extreme ache in and around clavicle area, including surrounding muscles
- Possible nausea, dizziness, and/or spotty vision due to extreme pain
- Tachypnea if the underlying lung is affected
- Arm weakness if the underlying neurovascular structures are damaged
Mechanism
Due to the anatomy of the clavicle, 80% of fractures occur in the middle third of its length which is its weakest point. When a clavicle fracture occurs, the sternocleidomastoid tends to pull the proximal portion of the clavicle upwards toward the head while the conoid and trapezoid ligaments, pectoralis minor muscle, and overall weight of the arm pull the distal portion of the clavicle downwards, away from the head. This creates the typical "S" shaped deformity most often seen with clavicle injuries.
Anatomy
The clavicle serves as a strut and the only bony attachment between the trunk of the body and the bones of arm which are otherwise connected to the trunk through a series of muscles and ligaments. A clavicle is located on each side of the front, upper part of the chest and it is located directly above the first rib. The clavicle consists of a medial end, a shaft, and a lateral end. The medial end connects with the manubrium of the sternum and gives attachments to the fibrous capsule of the sternoclavicular joint, articular disc, and interclavicular ligament. The lateral end connects at the acromion of the scapula which is referred to as the acromioclavicular joint. The clavicle forms a slight S-shaped curve where it curves from the sternal end laterally and anteriorly for near half its length, then forming a posterior curve to the acromion of the scapula. The clavicle widens and flattens at both ends while taking a hollow tubular shape through its middle segment with limited medullary bone resulting in a relative weak point where most fractures occur.Diagnosis
If a clavicle fracture is suspected, the initial method to evaluate for a clavicle fracture is by an AP or PA X-ray of the affected clavicle to determine the fracture type and extent of injury. When an AP or PA view of the clavicle is taken, the xray beam is horizontal versus the body and the first rib and other structures overlap the clavicle which can make it more difficult to assess the clavicle, to avoid the overlap of other structures an xray of the clavicle can be obtained with a 20-30 degree cephalad to isolate the clavicle. Although the degree of shortening of the clavicle can be often be assessed from the AP or PA dedicated clavicle images, additional AP or PA views of the chest can be taken to compare both clavicles for length or evaluate for other injuries that may be present such as rib fractures. In cases where the physician suspects the fracture may involve the joint surfaces of the clavicle, to differentiate an epiphyseal injury from a sternoclavicular joint dislocation, or to evaluate injury to underlying neurovascular structures they may order a computerized tomography scan. Diagnosis through ultrasound imaging performed in the emergency room may be utilized in children.Classification
A clavicle fracture can be classified and described based on its location, displacement, angulation, pattern, and comminution. The most common classification system for these fractures is the Allman classification system which broadly divides these fractures based upon their location along the clavicle divided into thirds along its length.Allman Classification
Group I
Fractures of the middle third of the clavicle. The most common type of clavicle fracture which both ends of the clavicle stablized and secured by muscular and ligamentous attachments.Group II
Fractures of the distal third of the clavicle. Second most common type of clavicle fracture. Can be further subdivided based upon fracture relative location to coracoclavicular ligaments as this can inform the presense of involvement of the acromioclavicular joint surface, ligamentous involvement, and fracture stability.Group III
Fractures of the proximal third of the clavicle. These fractures need to be assessed for epiphyseal injury in pediatric patients. These fractures can be further subdivided based on displacement of the fracture, articular surface involvement, epiphyseal involvement, and comminution.Treatment
The treatment of clavicle fractures depends on the type of fracture based upon which third of the clavicle length is affected, the degree of fracture displacement, patient goals, and the presence of complications. Based upon these factors, clavicle fractures may be treated nonoperatively with immobilization and activity limitation or operatively. Medication may be prescribed for pain. It is unclear if surgery or conservative management is superior. Antibiotics and tetanus vaccination may be used if the bone breaks through the skin; however, this is uncommon.Nonoperative
Current practice for simple fractures without great displacement is generally to provide a sling, and pain relief, and to allow the bone to heal itself, monitoring progress with X-rays every week or few weeks if necessary. Surgery is employed in 5–10% of cases. However, a meta-analysis of 2 144 midshaft clavicle fractures supports primary plate fixation of completely displaced midshaft clavicular fractures in active adult patients.The arm is usually supported by an external immobilizer to keep the fracture stable and decrease the risk of further damage and pain. The two most common types of fixation are the figure-of-eight splint that wraps the shoulders to keep them forced back and a simple broad arm sling. The primary indication is pain relief. Type of sling used does not seem to affect the results as far as healing is concerned but patient satisfaction is lower with the figure-of-eight bandage due to discomfort and skin irritation. No difference in functional outcome has been reported between the two types of immobilization.
There is a lack of consensus on nonoperative vs operative treatment for minimally displaced middle third clavicle fractures with operative treatment possibly leading to lower rates of nonunion and residual deformity but potentially leading to the need for future hardware removal. If the fracture is at the lateral end, the risk of nonunion is greater than if the fracture is of the shaft. However, it seems that this does not affect the functional outcomes in most patients, indicated by recent systematic reviews.
Surgical
In children, breaks in the middle of the clavicle treated with surgery resulted in faster recoveries but more complications. The evidence for different types of surgery for breaks of the middle part of the clavicle is poor as of 2023.Surgery may be considered when one or more of the following is presents
- Comminution with separation
- Skin penetration
- Associated nervous and vascular trauma
- Nonunion after several months
- Displaced distal third fractures
- Although shortening has often been suggested as an indication for surgery, a review found that people treated without surgery for shortening of mid shaft clavicle fractures did not affect outcomes.