AR TICL'I.A TIONS.LIGAMEN XX 4;,i 



The inferior scapular ligament extends from the glenoid margin to the 

 spine. . Under it pass the infraspinatous divisions of the suprascapular 



and nerves. (Fig. 249.) 



THE STEKNO-CLAVICULAR ARTICULATION. 



1. Class. Diarthrosis, since capsule and motion are present. 



2. Subdivision. Arthrodia simple gliding articular surfaces. 



3. Tcclwical Name. Sterno-clavicular articulation. 



4. Osteological Units. Sternum and clavicle. 



5. Subdivisional Parts. Manubrium and sternal end of clavicle. 



6. Articular Surfaces. Sternal of clavicle, clavicular of sternum. 



7. Basis. A capsule lined by synovial membrane. 



8. Local Subdivisions. Should be none. 



9. Strengthening Bands. None. Periosteal purely. 



10. Incorporated Tendons. None. 



1 1. Bony Limitations. Manubrium and first rib. 



1 2. Nen'e-supply. Brachial plexus by nerve to subclavius. 



13. Ligamentous Muscles. Subclavius and sterno-mastoid. 



Rhomboid 

 ligament 

 Anterior 

 aterno- 

 olavicular 

 ligament 



Edge of 

 interartieular 

 IntercUvicular cartilage 

 ligament 



FIG. 300. ANTERIOR VIEW OK STERNO-CLAVICULAR JOINT. 



(The capsule is cut into on the left side to show the interartieular fibro-cartilage dividing the joint 



into two cavities.) 



1 . Name all the ligaments of this articulation. 



The capsidar, the basis of the joint. The interclavicular binds the clavicles to 

 the sternum. The costo-clavicular, or rhomboid. The interartieular fibro- 

 cartilage. 



2. HOT.V many synovial cavities has the articulation .' 



Two, separated from each other by the interartieular fibro-cartilage. This 

 cartilage is attached to the capsule like others of its class, as the temporo-man- 

 dibular and the inconstant acromio-clavicular interartieular fibro-cartilage. 



3. In practical dissection, when yon wish to remove the clavicle, wlwtisthe most 

 difficult structure to divide / 



The costo-clavicular ligament binding the clavicle very firmly to the first rib. 



4. What muscle do you find under the clavicle, and what is its surgical impor- 

 tance .' 



The subclavius muscle, arising in front of the costo-clavicular ligament I 

 the first rib. It is inserted into the middle third of the clavicle on the under sur- 

 face of the bone. In fracture of the clavicle in the middle or outer third, the 



