As a Miami Bicycle Accident Lawyer and Cyclist, I can conclude that the collarbone is the most frequent bone to be broken in bicycle accidents. For cyclists, collarbones are made to be broken because during a crash the first part of their body to hit the ground is often a shoulder, elbow or wrist. The force can be transmitted up the arm to the collarbone, which is one of the body’s most vulnerable bones.
Elite cyclists are even more at risk because they carry as little upper-body muscle as possible, providing little protection to a bone that is already close to the surface.
The clavicle(collarbone) is an S-shaped long bone that acts as a strut to attach the shoulder to the axial skeleton. Its most anterior apex attaches to the sternum via the sterno-clavicular joint and at the posterior apex it broadens and flattens to attach to the acromion via the acromio-clavicular joint. The bone acts as an attachment point of several muscles such as the sternocleidomastoid, pectoralis major, and the sternohyoid muscles medially and on the lateral side the anterior deltoid, trapezius and the pectoralis major’s clavicular head.
As written by the Boulder Center For Sports Medicine, with respect to characterizing clavicle fractures we tend to divide the bone into thirds with a medial, middle and lateral portions.
Fracture to the medial third of the clavicle are rare and make up less than 3 percent of breaks, while the lateral third is the second most frequently involved portion and accounts for 15-30 percent of all fractures.
The middle third of the clavicle is the narrowest section of the bone and lacks the muscular and ligamentous attachment of the ends. These facts when taken together are thought to make it more susceptible to injury and it is indeed the most frequent site of fracture (70-80 percent of all clavicle fractures). See video below which illustrates injury and treatment options.
Displacement is a term that means the bony ends of a fracture do not align and these mid-shaft fractures tend to have high rate of displacement with an incidence found to be between 48-73 percent. This high rate is likely related to the muscular attachments at the ends of the clavicle pulling the fracture fragments of bone away from their normal anatomic alignment, along with the actual weight of the upper extremity itself contributing to this distraction in some cases.
In cases of clavicle fracture it is extremely important to assess for concomitant injuries to the lungs, the surrounding neurovasculature, and other musculoskeletal issues such as associated rib fractures, AC joint separation and other scapular injuries to name a few.
In these injuries the clinician’s goal from a management standpoint should be to heal the clavicle in a fashion that recreates its function as a solid support for the shoulder girdle to elicit the return of pain-free range of motion, normal strength and to avoid bony non-union and malunion (bone fragments heal together but there is persistent pain and or loss of shoulder function). The means of accomplishing this goal by bringing about the least risk and harm to the patient is ideal.
To operate or not?
Historically in regards to midshaft clavicle fractures it was thought that the best approach was non-operative management even in cases of large displacement with damage to vasculature/nerves, open fractures (bone fragments pierce the skin) and painful non-unions being the most common indications to proceed with operative intervention. Over the last decade this approach has come under increasing scrutiny, with newer studies of completely displaced fractures showing much higher patient dissatisfaction rates than previously thought in those treated with non-operative management. These rates were secondary to a markedly increased rate of non-union than formerly documented (up to 21 percent) as well as malunions causing considerable shoulder girdle dysfunction. Taking this into account with the improved surgical fixation techniques and much lower complication rates over the last decade, it has made operative interventions much more viable from a management standpoint.
The approach to the patient with clavicle fracture should be on a very individualized basis with age, activity level, personal preferences, fracture type and monetary/insurance concerns playing important roles in the decision process.