Clavicle: Anatomy, Injuries, and Function Quiz

The Clavicle: Structure, Function, and Common Injuries

Introduction

The clavicle, also known as the collarbone, is a flat, horizontal bone located between the sternum and acromion. It serves as the primary connection between the axial skeleton and the upper limb, providing mechanical stability and facilitating movements such as flexion, extension, and rotation of the arm.

Anatomy

The clavicle is composed of three parts: the sternal end, the middle third, and the acromial end. The bone is approximately 20 cm long and 1 cm wide, making it an essential component of the upper extremity skeleton.

Blood Supply

The clavicle's periosteal vascularization is primarily supplied by the middle part of the suprascapular artery along the posteroinferior surface and anastomosing vessels connecting the medial clavicular physis to the acromion.

Muscle Attachment

The muscle footprint anatomy of the clavicle varies widely due to its unique structure, which encourages the use of fixation plates or intramedullary devices that respect the muscle footprints.

Growth and Development

Contrary to popular belief, the clavicle continues to grow during adolescence and early adulthood, with growth rates varying among different age groups. In male patients aged 12 to 15 years, clavicular growth is approximately 4.9 mm/year; from ages 16 to 19 years, growth decreases to 3.2 mm/year; and from ages 20 to 25 years, growth further reduces to 1.7 mm/year. Female clavicles exhibit similar patterns but with slightly lower growth rates.

Common Injuries

Clavicle fractures are common injuries, particularly in young adults involved in sports activities and older adults experiencing falls. They typically occur in the middle third of the bone, followed by the distal third. Most fractures heal with conservative treatment methods such as immobilization and pain management. However, complications like delayed union or nonunion may arise in some cases.

Conclusion

The clavicle plays a vital role in the biomechanics of the upper extremity skeleton, facilitating movement while also maintaining stability. Understanding its structure, blood supply, muscle attachment, growth patterns, and common injuries helps provide insight into its function and clinical implications.