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Sternoclavicular Joint
From WikiSM
The sternoclavicular joint[1]
- Joint created by articulation of Sternum and Clavicle
- Diarthrodial, saddle-type synovial joint
- Inherently unstable due to poor osseus articulation
- Less than 50% of the medial clavicle articulates with the corresponding manubrium
- Ligaments
- Costoclavicular Ligament (sometimes referred to as rhomboid ligament)
- Anterior fasiculus: resists superior rotation and lateral displacement
- Posterior fasiculus: resists inferior rotation and medial displacement
- Interclavicular ligament
- Sternoclavicular ligaments
- Anteriot and Posterior
- Capsular Ligaments
- Anterior and Posterior
- Strongest ligamentous stabilizers[2]
- Fibrocartilagenous disc
- Attached to the anterior and posterior SC ligaments and capsule
- Divides SJC into two synovium-lined cavities
- Degenerates over time and by age 70-80 is incomplete[3]
- Subclavius Muscle
- arises from the first rib just lateral to the costoclavicular ligament and inserts onto the inferior surface of the clavicle.
- It is believed to have a protective function with regards to the stability of the SCJ by reducing the rate of upward displacement of the clavicle when it is under lateral compressive loads
- Stability from intrinsic and extrinsic ligamentous structures[4]
- Only bony articulation between axial skeleton, upper extremity[5]
- Clavicle is first bone to ossify in utero, last to fuse occuring between ages 23-25[6] This can make distinguishing physeal injuries from sternoclavicular dislocations challenging.
Contents
Biomechanics
- All shoulder girdle movement results in some degree of movement at the SCJ
- Every 10° of shoulder flexion results in 4° elevation of the clavicle[7]
- Shoulder retraction: SCJ translates anteriorly
- Shoulder protraction: SCJ translates posteriorly
- Subsequently, clavicle can rotate up to 40° in long axis
Origin
Insertion
Actions
Artery
Nerve
Clinical Significance
See Also
- ↑ Image courtesy of orthobullets.com, "Sternoclavicular Join"
- ↑ Spencer EE, Kuhn JE, Huston LJ, Carpenter JE, Hughes RE. Ligamentous restraints to anterior and posterior translation of the sternoclavicular joint. J Shoulder Elbow Surg. 2002;11:43–47.
- ↑ van Tongel A, MacDonald P, Leiter J, Pouliart N, Peeler J. A cadaveric study of the structural anatomy of the sternoclavicular joint. Clin Anat. 2012;25:903–910.
- ↑ Sewell MD, Al-Hadithy N, Le Leu A, Lambert SM. Instability of the sternoclavicular joint: current concepts in classification, treatment and outcomes. Bone Joint J. 2013;95-B:721–731.
- ↑ Spencer EE, Kuhn JE, Huston LJ, Carpenter JE, Hughes RE. Ligamentous restraints to anterior and posterior translation of the sternoclavicular joint. J Shoulder Elbow Surg. 2002;11:43–47.
- ↑ Wirth MA, Rockwood CA. Acute and Chronic Traumatic Injuries of the Sternoclavicular Joint. J Am Acad Orthop Surg. 1996;4:268–278.
- ↑ Inman VT, Saunders JB, Abbott LC. Observations of the function of the shoulder joint. 1944. Clin Orthop Relat Res. 1996;(330):3–12.