Compound fractures of the scapula usually result from violence, which at
the same time does serious injury to adjacent structures, and it then
becomes necessary to administer an expectant treatment, observing
general surgical principles and providing in so far as possible for the
comfort of the patient.


Scapulohumeral Arthritis.

Anatomy.--The scapulohumeral joint is an enarthrodial (ball and
socket) joint wherein the ball or humeral articulating head greatly
exceeds in size the socket or glenoid cavity of the scapula. The
capsular ligament surrounding this joint is very large and admits of
free and extensive movement of the articulation. There exist no lateral
or common ligaments jointing the scapula and humerus as in other joints,
but instead the tendinous portions of muscles perform this function. The
principal ones which are attached to the scapula and humerus that act as
ligaments are the supraspinatus (antea-spinatus), infraspinatus
(postea-spinatus) biceps-brachii (flexor brachii) and subscapularis
muscles.

Etiology and Occurrence.--Inflammation of the scapulohumeral
articulation results from injuries of various kinds, including punctures
which perforate the joint capsule, bruises from collars, metastatic
infections and involvement as a result of direct extension of infectious
conditions situated near the joint.

Classification.--Acute arthritis may be septic or aseptic, and there
seems to be a remarkable tendency for recovery in cases of septic
arthritis involving this joint in the horse.