The Elbow Flashcards
What joints are involved in elbow flexion?
Radiohumeral
Ulno-humeral
What type of cartilage covers the articular surface of the elbow joint?
Hyaline cartilage
What are the conditions and implications of supracondylar fracture of the humerus?
A transverse supracondylar fracture fractures the distal end of the humerus just above the epicondyle. The tricep pulls the fragment and its related tissues posteriorly. The brachial artery “bowstrings” across the fragment. Really bad for children. muscles of anterior compartment become ischemic (lose blood supply) and form severe contractions which reduce function of anterior compartment and flexor muscles.
Describe a pulled elbow. (Nursemaid’s elbow) and how to fix it.
Usually in children under 5 years old. A sharp pull of a child’s hand (usually up a curb), The undeveloped head of the radius slips out of the lax anular ligament. Extremely painful. Clinician supinates forearm and compresses the elbow joint to relocate.
What considerations need to be taken into account in the developmental changes of the elbow joint?
As the elbow develops in children, numerous secondary ossification centers appear before and around puberty. These are easily mistaken for a fracture. One must know the child’s age when reading a child’s radiograph.
How does one fracture the head of the radius? What functions are lost? There is a secondary way to identify a fractured radial head. What is it?
A typical injury from a fall on the outstretched hand. The force is transmitted to the radial head which fractures.
Lose full extension, and surgical reconstruction may require long periods of physiotherapy to obtain full range of movement at elbow joint.
Lateral radiographs may reveal elevation of the fat pads in the coronoid and olecranon fossae from fluid filling the synovial cavity.
Tennis elbow and Golfer’s elbow (epicondylitis). What is it?
Where does it occur? What is the surgical remedy?
- Overuse strain of the origins of the flexor and extensor muscle of the forearm.
- Lateral epicondyle and common extensor origin (tennis elbow), and medial epicondyle and common flexor origin (golfer’s elbow).
- If pain and inflammation persist, surgical division of the extensor or flexor origin from the bone may be necessary.
Describe osteoarthritis in the elbow.
Usually most severe in the dominant limb. When really bad, small bone fragments appear in the articular cavity. In the small space, the elbow can experience reduced flexion and extension and lodge within the olecranon and coronoid fossae.
Describe the cause of ulnar nerve injury at the elbow.
Posterior to the medial epicondyle of the humerus, the ulnar nerve is bound in a fibro-osseous tunnel by a retinaculum. Degenerative changes with age can compress the ulnar nerve when flexed. Over time, this can result in permanent injury. Accessory muscles and localized neuritis n this region secondary to direct trauma ay also produce ulnar nerve damage.
What 2 muscles form the cubital fossa? and its origination?
Brachioradialis muscle originating from lateral supracondylar ridge of the humerus.
Pronator teres muscle originating from the medial epicondyle of the humerus.
What muscle is primarily the floor of the cubital fossa?
Brachialis.
What are the 3 major contents of the cubital fossa from lateral to medial?
Tendon of the biceps brachii muscle.
Brachial artery.
Median nerve.
What does the brachial artery turn into? and what is the exception to this rule?
The brachial artery bifurcates into the radial and ulnar arteries in the apex of the fossa. This bifurcation may occur much higher in the arm, even in the axilla.
What protects the brachial artery and the median nerve as they pass through the cubital fossa? Describe this structure.
Bicipital Aponeurosis. THis flat connective tissue membrane passes between the medial side of the tendon of the biceps brachii muscle and deep to fascia of the forearm. The sharp medial margin of the bicipital aponeurosis can often be felt.
Where does the radial nerve travel in the forearm and how does it divide?
Travels just under the lip of the brachioradialis muscle. Divides into superficial and deep branches.
The deep branch passes between the two heads of the supinator muscle to access the posterior compartment of the forearm.
