With clavicle fractures, you will want to know a little bit about the ligaments that support the clavicle. These ligaments are known as the Coracoclavicular ligaments, or the CC ligaments. There are two ligaments, the conoid—which is medial and inserts about 4.5 cm from the end of the clavicle, and the trapezoid—which is lateral and inserts about 3 cm from the end of the clavicle (Figure 1). These ligaments are the primary stabilizers to superior or vertical translation of the distal clavicle. The middle third of the clavicle is the most common place for fractures, occurring approximately 80-85% of the time, followed by the lateral third (10-15%), and the medial third (5%) (Figure 2).
The Neer’s classifies lateral clavicle fractures into three types based on the integrity of the CC ligament complex and involvement of the AC joint.
Type I fractures (Figure 3) occur when the conoid and trapezoid ligament are intact to the medial fragment. The fracture is lateral to the ligament and the medial fragment is stable because it is supported by the ligaments.
Type II fractures (Figure 4) occur when the medial fragment is not supported by the CC ligaments. The CC ligaments are either torn or the fracture is medial to the ligaments. With Type II fractures, the lateral fragment may contain the ligaments entirely and the medial fragment displaces superiorly. Lateral clavicle fractures are a different breed. This fracture type is displaced and has disruption of the CC ligaments. It is the least stable fracture type and has the highest risk of nonunion (may not be symptomatic). Surgery for Type II displaced fractures should be considered.
With Type III fractures, the fracture will extend into the AC joint. (Figure 5)
The typical deformity that occurs in clavicle fractures is when the sternocleidomastoid muscle pulls on the medial fragment superiorly and the pectoralis muscle, with gravity and the weight of the arm will pull the distal fragment inferiorly (Figure 6).
During the physical examination, you will check the patient for deformities and tenting of the skin—there may be an impending open fracture. You will watch for a distracted clavicle—which may have scapulothoracic dissociation. It is important to check for a possible neurovascular deficit or a brachial plexus injury. Be aware that the neurovascular bundle is very close to the clavicle (subclavian vessels are about 1 cm from the clavicle) (Figure 7).
When ordering an x-ray, you will want one of both shoulders. A bilateral panoramic view is used to measure the shortening (Figure 8). I usually get an AP and a 20° cephalad upshot view x-ray of the shoulder, especially in the operating room. In the x-rays, you are going to look for shortening, displacement, comminution, and the Z-type fracture.
Risk factors for nonunion include: displacement and comminution, older females, and smokers. Another risk factor is a fracture of the lateral third of the clavicle with displacement of the medial fragment. Nonunion occurs in up to 50% of these cases.
Absolute indications for surgery include: open fractures, a vascular injury, or if the fragment is tenting the skin. Injury to the brachial plexus is NOT an absolute indication for surgery! The majority of patients improve spontaneously.
Most clavicle fractures can be treated without surgery. It is very difficult to reduce and maintain reduction in clavicle fractures. Patients with nondisplaced clavicle fractures usually heal well and healing will occur despite the degree of displacement. If the fracture is significantly displaced, then there is a higher incidence of nonunion. This displaced fracture can cause significant persistent weakness and disability even if the fracture heals. Conservative treatment is used for minimally or nondisplaced fractures of the clavicle and typically consists of the patient using a sling or figure 8 wrap for support (Figure 9). You will remove the sling and start range of motion in about 4-6 weeks. The fracture will probably heal with a small bump (callus of healing). A sling is not a bad option for treatment and there is no difference in treating the fracture with a sling or a figure 8 strap. Movement of the shoulder and the arm is not a risk factor for nonunion.
Relative indications for surgery include: a comminuted fracture (use buttress plate), segmented fracture, Z-type fracture, (Figure 10) fracture shortening more than 2 cm, and fracture displacement more than 100%. Nonoperative treatment in these cases will lead to decreased endurance and strength, but the range of motion will remain the same in operative or nonoperative cases.
Surgery is usually not as easy as you think, and begins by defining the location of the AC joint. Surgery is also dependent on getting good x-rays in the operating room. When surgery is necessary, there are a few options for hardware or implants for fixation. Plates are used in two techniques. You can use Superior plate fixation or anteroinferior plate fixation (Figure 11). In displaced fractures, make sure to treat the healthy, active, young patients between 16-60 years of age.
With superior plate fixations, there is no dissection of the deltoid muscle from the clavicle. The superior plate has a mechanical advantage being on the tension surface of the clavicle. You have to be careful when you drill through the inferior border of the clavicle because a neurovascular bundle injury may occur. It is also important to be careful when inserting the depth gauge because the hardware is usually felt by the patient. With anteroinferior plate fixation, you will have the advantage of using longer screws with a safe screw trajectory and less hardware prominence. However, there is the disadvantage of deltoid dissection from the clavicle. An Anteroinferior plate may be better tolerated by the patient, especially those who carry loads on their shoulders, such as a back pack. Each fixation has their own advantages and it is better to use a contoured plate! I personally use a superior plate fixation and plates with locking screw capabilities. About 30% of the clavicle fixation plates are removed after the fracture has completely healed.
Another treatment involves the intramedullary nail or screw through the clavicle, but you will need to watch out for migration of this hardware. A hook plate can be used in distal fractures. A small fragment plate fixation with possible CC ligament reconstruction can be used in very distal fractures. Sometimes, lag screws and a neutralization plate are used for fracture stabilization with three screws per segment. After the fixation of the clavicle fracture, you will close the incision in two layers. The patient should be given a sling for comfort and the patient should avoid contact sports for about 3 months. The plate can be removed after about a year.
The main complications of clavicle fractures include nonunion and malunion but there are complications that can occur due to fixations as well. Symptomatic hardware is the most common complication due to fixation, and this will need reoperation. The most common complication is infraclavicular numbness, which occurs due to injury of the supraclavicular nerve. There are three supraclavicular branches: the lateral, medial, and intermediate. These three branches span out to cover the entire clavicle subcutaneous surface. Injury to these branches may cause numbness to the chest wall below the incision. Injury to these branches may occur due to the incision or from traction during surgery. The location of each branch is variable. Medical professionals haven’t discovered a way to save them, it is just best to avoid them. There are small safe areas medially and laterally about 2 cm from the sternoclavicular join and about 2 cm from the AC joint. The surgeon must be very careful while working in between these two safe areas to prevent transection of these branches (Figure 12). There is no real safe zone between the medial and lateral branches of the supraclavicular nerve.
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