Elbow dislocation, flexor tuberosity subluxation and ulnar hawkbone fracture. 1.Elbow triangle and elbow straight line: also known as Hater’s triangle and Hater’s straight line. When the normal elbow joint is flexed at 90″, the medial epicondyle, lateral epicondyle and ulnar eminence of the humerus form an isosceles triangle, called the elbow triangle. When the elbow joint is straight, the three points are in a straight line, called the elbow line. When the elbow joint is dislocated, the triangle shape changes and the three points are not in a straight line when the elbow is straightened. 2. Elbow extension test: The patient takes a sitting or standing position with the palm of the hand on the top of the head and then actively extends the elbow. If the patient cannot actively extend the elbow, it may be a posterior dislocation of the elbow joint, hawk fracture, flexor tuberosity subluxation, etc. If the patient cannot actively extend the elbow or if there is pain at the brachial plexus when extending the elbow, it is said to be positive for Bikbles’ sign, which may be brachial plexus neuritis or meningitis due to the significant pulling effect of extending the elbow on the brachial plexus nerve. Supracondylar fracture of the humerus. Condylar stem angle: also known as B, O, and Mapuche condyles on line. The normal long axis of the humerus is at a right angle to the line of the medial and lateral epicondyles; if the supracondylar fracture is displaced or congenitally deformed, this condylar stem angle changes to an acute or obtuse angle. Fracture of the radial tuberosity. Extensor extrusion test, if there is pain is positive, see the radial tuberosity fracture. External humeral epicondylitis. Mill’s sign: Ask the patient to straighten the elbow and flex the wrist, while rotating the forearm forward, if the humeral epicondyle feels pain, it is positive, which is significant for the diagnosis of humeral epicondylitis (tennis elbow). 2. Extensor tension test: also known as the Cozen test. The patient is asked to flex the wrist and fingers, and the examiner presses the hand against the dorsal side of each finger, and then the patient is asked to extend the fingers and wrist joint against resistance, and if there is pain in the humeral epicondyle, it is positive, mostly seen in tennis elbow. Internal epicondylitis of the humerus. Flexor tension test: Ask the patient to hold the examiner’s fingers (from the index finger to the little finger), forcefully extend the wrist and make a fist, and then ask the examiner to hold the patient’s fingers against the patient’s grip, if there is pain in the medial epicondyle, it is positive, mostly seen in medial humeral epicondylitis. Colles fracture. Straight ruler a test: when normal, place a ruler on the little finger and humeral epicondyle, this ruler does not touch the ulnar stem, when Colles fracture, the ulnar stem is in contact with the ruler. Fracture of the lower end of the flexor ulnar styloid process. 1, carpal triangle cartilage crush test: see carpal stop triangle cartilage injury. 2, Laugier (Laugier) sign: the tip of the flexor stem is longer than the tip of the ulnar stem about 1. 0 – 1. 5 cm is the normal anatomical relationship, if the fracture of the lower end of the flexor is displaced, the tips of the two can be at the same level, or even opposite, this phenomenon is called Laugier sign. Cartilage injury of the carpal triangle. Wrist triangle cartilage squeeze test: the examiner holds the lower end of the forearm with one hand and the affected hand with the other hand, so that the wrist joint palmar flexion and ulnar deviation, and then the affected hand is constantly bumped in the direction of the small head of the ulna. If it causes pain on the ulnar side of the wrist as positive, injury to the triangular cartilage and ulnar styloid fracture should be considered.