Sternoclavicular Joint

Original Editor - Tyler Shultz

Top Contributors - Naomi O'Reilly, Tyler Shultz, Redisha Jakibanjar, Mariam Hashem and Kim Jackson  

Description

The Sternoclavicular Joint (SC joint) is formed from the articulation of the medial aspect of the clavicle and the manubrium of the sternum. The SC joint is the only true articulation connecting the upper limb to the axial skeleton, and that it’s the least constricted joint in the human body[1]. It is one of four joints that compose the Shoulder Complex.  The SC joint is generally classified as a plane style synovial joint and has a fibrocartilage joint disk.[2]  The ligamentous reinforcements of this joint are very strong, often resulting in a fracture of the clavicle before a dislocation of the SC joint.[3]

Anatomy

SC Joint.jpg

The SC joint is formed by the articulation of three bones[4]:

  • Manubrium, which means handle in Latin. The Manubrium is joined with the sternum.
  • The clavicle
  • The articulation between the first rib costal cartilage

Joint Capsule

The SC Joint capsule is fairly strong but is dependent on the ligaments for the majority of its support.

Joint Disk 

The inter-articular fibrocartilage disc separates the joint into two compartments[4][5]. The first compartment lies between the manubrium and the disc and the second lies between the disc and the clavicle.

The SC Joint is surprisingly incongruent, and because of this incongruency, a joint disk is present to enhance joint curvature and contact of the joint surfaces. Similar to the meniscus of the knee, the SC Joint disk increases joint congruence and acts to absorb forces that may be transmitted along the clavicle. The disk is attached to the upper and posterior margin of the clavicle, and to the cartilage of the first rib, which functions to help prevent medial displacement of the clavicle. Greater movement occurs between the disk and the clavicle than between the disk and the manubrium. [2][6]

Ligaments 

LIGAMENT

DESCRIPTION ATTACHMENT ROLE

Anterior

Sternoclavicular

Ligament [6][2]


Broad band of fibers, covering anterior surface of SC Joint running obliquely from proximal clavicle to sternum in a downward and medial direction

Superior & Anterior Aspect of

Sternal End of the Clavicle to the Anterior Superior Aspect

of manubrium

  • Reinforces the capsule anteriorly
  • Limits anterior translation of the clavicle
  • Checks anterior movement of the head of the clavicle

Posterior

Sternoclavicular
Ligament [6][2]

Broad band of fibers, covering posterior surface of SC Joint

Weaker than the Anterior Sternoclavicular Ligament.

Superior & Posterior Aspect

Sternal End Clavicle to Posterior Superior Aspect

of Manubrium

  • Reinforces the capsule Posteriorly
  • Limits the posterior translation of the Clavicle
  • Checks the posterior movement of the head of the clavicle

Costoclavicular

Ligament [6][2]

Anchors Inferior Surface of the Sternal End of the Clavicle to the 1st Rib & its Costal Cartilage


Orientation allows this ligament to act as the Primary Restraint for the SC Joint

Anterior lamina: laterally from first rib to the clavicle

Posterior lamina: medially from first rib to the clavicle

  • Limits the elevation of the pectoral girdle
  • Acts as a fulcrum for elevation-depression & protraction-retraction
  • Checks the clavicular elevation and superior glide of the clavicle

Interclavicular

Ligament [6][2]

Connects Sternal Ends of Each Clavicle with the Capsular Ligaments and Upper Manubrium

Produces a Bilateral Depression Force

Sternal end of one clavicle to sternal end of the other clavicle.
  • Strengthens the capsule superiorly
  • Resists excessive depression or downward glide of the clavicle


Ligaments-of-the-Sternoclavicular-Joint-1024x312.png

Muscles

There are no muscles that act directly on the SC Joint.  However, the SC Joint motions closely mimic the reciprocal motions of the scapula.  In addition, the following muscles have an attachment of the clavicle and therefore may produce movement of the clavicle: 

Function

Motions Available & Range of Movement

The SC Joint has 3 Degrees of Movement

Elevation and Depression  

During elevation, the clavicle rotates upward on the manubrium and produces an inferior glide to maintain joint contact. The reverse actions happen when the clavicle is depressed. The motions are usually associated with elevation and depression of the scapula.[7] The elevation is assumed to be 45 degrees and the depression to be 10 degrees. [8]

The elevation is limited by the tension of the costoclavicular ligament and the subscapularis muscle. Depression is limited by the superior sternoclavicular ligament, the interclavicular ligament, and by the bony contact with the first rib[4].

Elevation (0-45 degrees)

Depression (0-10 degrees)

Muscles Nerve supply Muscles Nerve supply
Levator Scapulae

Dorsal Scapular Nerve C5

Cervical Nerves C3-C4 

Pectoralis Minor Medial Pectoral C8-T1
Trapezius - Upper

Spinal Accessory Motor CN XI

Cervical Nerves C3-C4 

Trapezius Lower

Spinal Accessory Motor CN XI

Cervical Nerves C3-C4 

Rhomboids Dorsal Scapular Nerve C4-C5 Serratus Anterior - Inferior

Long Thoracic C5-C6-C7 


Protraction and Retraction

During protraction, the concave surface of the medial clavicle moves on the convex sternum, producing an anterior glide of the clavicle, and anterior rotation of the lateral clavicle. With retraction, the medial clavicle articulates with a flat surface and tilts or swings, causing an anterolateral gapping, and a posterior rotation at the lateral end. These movements are usually associated with abduction (protraction) and adduction (retraction) of the scapula since the scapula is attached to the distal end of the clavicle.[9][2]

The anterior movement is limited by tension in the costoclavicular and anterior and posterior ligaments. And the posterior movement is limited by tension in the anterior and posterior sternoclavicular ligaments[4].

Protraction

0° - 15° / 30°

Retraction

0° - 15° / 30°

Muscles Nerve supply Muscles Nerve supply
Pectoralis Minor Medial Pectoral C8-T1 Trapezius - Middle

Spinal Accessory Motor CN XI

Cervical Nerves C3-C4 

Serratus Anterior Long Thoracic C5-C6-C7 Latissimus Dorsi

Thoracodorsal Nerve C6 - C8 

Rhomboids

Dorsal Scapular NerveC4-C5

Axial Rotation

When the arm is raised over the head by flexion the clavicle rotates passively as the scapula rotates approximately around 40-50degrees.[8] This is transmitted to the clavicle by the coracoclavicular ligaments. this movement is allowed by the relative slackness of the ligaments in this position[4].  

Rotation Elevating Glenoid Cavity

0° - 40° / 50°

Axial Rotation Depressing Glenoid Cavity

0° - 40° / 50°

Muscles Nerve supply Muscles Nerve supply
Trapezius - Upper (Descending) Suprascapular Nerve C5-6 Levator Scapulae

Dorsal Scapular Nerve C5

Cervical Nerves C3-C4 

Trapezius - Lower Axillary Nerve C5-6 Latissimus Dorsi

Thoracodorsal Nerve C6 - C8 

Serratus Anterior - Inferior Long Thoracic C5-C6-C7 Pectoralis Minor

Medial Pectoral C8-T1 

Rhomboids

Dorsal Scapular Nerve C4-C5 


Video

[10]

Closed Packed Position

  • Maximum Shoulder Elevation

Open Packed Position

  • Arm is resting by Side

Resources References

References will automatically be added here, see adding references tutorial.

  1. Van Tongel A, MacDonald P, Leiter J, Pouliart N, Peeler J. A cadaveric study of the structural anatomy of the sternoclavicular joint. Clinical Anatomy. 2012 Oct;25(7):903-10.
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Levangie, P.K. and Norkin, C.C. Joint structure and function: A comprehensive analysis (4th ed.). Philadelphia: The F.A. Davis Company;2005
  3. ALLMAN JR FL. Fractures and ligamentous injuries of the clavicle and its articulation. JBJS. 1967 Jun 1;49(4):774-84.
  4. 4.0 4.1 4.2 4.3 4.4 Horsley I. Sternoclavicular joint disorders Course. Physioplus 2020
  5. Negri JH, Malavolta EA, Assunção JH, Gracitelli ME, Pereira CA, Neto RB, Croci AT, Neto AF. Assessment of the function and resistance of sternoclavicular ligaments: A biomechanical study in cadavers. Orthopaedics & Traumatology: Surgery & Research. 2014 Nov 1;100(7):727-31.
  6. 6.0 6.1 6.2 6.3 6.4 Dutton M. Orthopaedic: Examination, evaluation, and intervention(2nd edition). New York: The McGraw-Hill Companies, Inc, 2008.
  7. Brody, L.T.:Shoulder. In: Wadsworth, C.(ed.)(2001). Current concepts of orthopedic physical therapy: Home study course. LaCrosse, WI: Orthopaedic Secion, APTA, Inc.
  8. 8.0 8.1 Neumann DA. Kinesiology of the musculoskeletal system; Foundation for rehabilitation. Mosby & Elsevier. 2010.
  9. Anna M.Conway, M.S.,Movements at the sternoclavicular and acromioclavicular joints. Physical Therapy,June 1961; 41(6): 421-432. Available from: https://doi.org/10.1093/ptj/41.6.421
  10. Catalyst University. The Sternoclavicular (SC) Joint | Anatomy and Function. Available from: https://youtu.be/q_wIlZsP3b8. [last accessed on: 2020/05/31]