INJURIES IN THE REGION OF THE ELBOW AND FOREARM
Surgical Anatomy--Examination of injured elbow--FRACTURE OF LOWER END OF HUMERUS: _Supra-condylar_; _Inter-condylar_; _Separation of epiphysis_; _Fracture of either condyle alone_; _Fracture of either epicondyle alone_--FRACTURE OF UPPER END OF ULNA: _Olecranon_; _Coronoid_--FRACTURE OF UPPER END OF RADIUS: _Head_; _Neck_; _Separation of epiphysis_--DISLOCATION OF ELBOW: _Both bones_; _Ulna alone_; _Radius alone_--FRACTURE OF FOREARM: _Both bones_; _Radius alone_; _Ulna alone_.
The injuries met with in the region of the elbow-joint include the various fractures of the lower end of the humerus, and upper ends of the bones of the forearm, including the olecranon; and dislocations and sprains of the elbow-joint. The differential diagnosis is often exceedingly difficult on account of the swelling and tension which rapidly supervene on most of these injuries, the pain caused by manipulating the parts, and the difficulty of determining whether movement is taking place _at_ the joint or _near_ it.
#Surgical Anatomy.#--The medial epicondyle of the humerus is more readily felt through the skin than the lateral. The two epicondyles are practically on the same level, and a line joining them behind passes just above the tip of the olecranon when the arm is fully extended. On flexing the joint, the tip of the olecranon gradually passes to the distal side of this line, and when the joint is fully flexed the tip of the olecranon is found to have passed through half a circle. The head of the radius can be felt to rotate in the dimple on the back of the elbow just below the lateral epicondyle. The coronoid process may be detected on making deep pressure in the hollow in front of the joint. As the line of the radio-humeral joint is horizontal, while that of the ulno-humeral joint slopes obliquely downwards, the arm forms with the fully extended and supinated forearm an obtuse angle, opening laterally--the "carrying angle." This angle is usually more marked in women, in harmony with the greater width of the female pelvis. The ulnar nerve lies in the hollow between the olecranon and the medial condyle, and the median nerve passes over the front of the joint, with the brachial artery and biceps tendon to its lateral side. The radial nerve divides into its superficial and deep (posterior interosseous) branches at the level of the lateral condyle.