It is the only long bone of the body that lies horizontally and supports shoulders for free arm movements and transmits weight medially to the sternum.
- It is also called the beauty bone.
- It is the first bone to start ossification in a baby.
- Clavicle is divided into a central cylindrical shaft with 2 ends medial and lateral.
- Only long bone having 2 primary ossification centers and no medullary cavity.
- It forms 2 joints Sternoclavicular (SC) joint and acromo-clavicular (AC) joint.
- Lateral end is flat and the media end is quadrilateral.
- Bone is curved as convexity in the medial side and concavity in the lateral side.
- The inferior surface is grooved longitudinally in its middle one-third.
- A prominent tubercle is present on posterio-superior surface laterally.
The shaft is divided in medial 2/3rd and lateral 1/3rd
- Medial 2/3rd-
It is said to have four surfaces- anterior (convex forward); posterior (smooth in texture); inferior surface (medial side- rough oval impression and lateral side- subclavian groove).
b. Lateral 1/3rd-
- It has 2 borders- anterior (concave downwards) and posterior (convex backwards).
- It has 2 surfaces- superior and inferior (trapezoid ridge and conoid tubercle).
2. Lateral and medial end-
- Lateral (acromial) end- has a facet to articulate with acromion to form the acromo-clavicular joint.
- Medial (sternal) end- form sternoclavicular joint by articulating with manubrium sterni’s clavicular notch.
|Lateral end||Medial end||Lateral 1/3rd of shaft||Medial 2/3rd of shaft|
|Provide attachment to joint capsule||Provide attachment to fibrous capsule of SC joint||Anterior border- deltoid origin||Anterior surface- pectoralis major origin|
|Attaches interclavicular ligament superiorly||Posterior border- trapezius insertion||Superior surface- clavicular head of SCM|
|Coraco-clavicular ligament (conoid part on conoid tubercle and trapezoid part on trapezoid ridge)||Inferior surface (oval impression) – costoclavicular ligament|
|Subclavian groove – subclavius muscle|
|Posterior surface- sternohyoid origin|
- Primary center- It has 2 primary centers that appear at 5-6 week of intera-uterine life in the shaft and fuse in about 45th day).
- Secondary center- It has 1 secondary center at medial end, that appears at 15-17 years fusing with shaft between 21-22 years.
- There may be a possibility of a secondary center at the acromion end.
- Congenitally absent or inappropriately developed clavicle is called cleidocranial dysostosis in which the shoulder drops and gets approximated anterior to the chest.
- Clavicular fracture- by falling on an outstretched hand and generally occurring in between the two curvatures of the bone. Lateral fragment is pulled downwards by the weight of the limb as trapezius is unable to hold it in place alone and medial fragment displaced upwards by the pull of SCM.
- Dislocation of SC and AC joint
- Degeneration of clavicle
- Immobilization in a triangular sling or figure of 8 bandages for 10-14 days.
- During immobilization- isometric of muscles that are immobilized and full range of motion exercises for joints that are not immobilized with breathing exercises.
- TENS, IFT or thermotherapy for pain relief.
- Mobilization starts with Codmann’s pendular exercises progressing to activate assisted, active and then resisted movements.
- B.D. Chaurasia ( Human anatomy)
- Susan Standring (Gray’s Anatomy)
- Jayant Joshi and Prakash Kotwal ( Orthopedics and applied physiotherapy)
- J. Maheshwari and Vikram A. Mhaskar ( Essential orthopedics)