Flashcards in Session 5 Anatomy Deck (6)
What is Subcutaneous Olecranon Bursitis?
Bursa is exposed to injury during falls on the elbow and infection from abrasions of the skin covering the olecranon.
Repeated excessive pressure and friction e.g. In wrestling may cause inflammation, produce a friction subcutaneous olecranon bursitis e.g. "student's elbow/miner's elbow".
Occasionally the bursa becomes infected and area over the bursa becomes inflamed.
What is Subtendinous Olecranon Bursitis?
Much less common than subcutaneous olecranon bursitis.
Results from excessive friction between the triceps tendon and olecranon due to repeated flexion-extension of the forearm.
The pain is most severe during flexion of the forearm because of pressure exerted on the inflamed subtendinous olecranon bursa by the triceps tendon.
Describe avulsion of the medial epicondyle
Forced separation of the medial epicondyle can result from a fall that causes severe abduction of the extended elbow, an abnormal movement of this articulation.
The resulting traction on the ulnar collateral ligament pulls the medial epicondyle distally.
Thus occurs because the epiphysis for the medial epicondyle may not fuse with the distal end of the humerus until up to age 20 (normally fusion is complete radiographically at age 14 in females and age 16 in males).
Traction injury of the ulnar is a frequent complication - the ulnar nerve is stretched because it passes posterior to the medial epicondyle before entering the forearm.
Describe subluxation and dislocation of radial head
Preschool children, particularly girls, are vulnerable to transient subluxation of the head of the radius ('pulled elbow').
Typical history: child is suddenly lifted by the upper limb while the forearm is pronated (e.g. Lifting a child).
The sudden pulling of the upper limb tears the distal attachment of the annular ligament where it is loosely attached to the neck of the radius.
The radial head then moves distally, partially out of the "socket" formed by the annular ligament - muscle pulls the radial head superiorly.
The proximal part of the torn ligament may become trapped between the head of the radius and the capitulum of the humerus.
The source of the pain is the pinched annular ligament, treatment of the subluxation consists of supination of the child's forearm while the elbow is flexed.
The tear in the annular ligament heals when the limb is placed in a sling for 2 weeks.
Describe dislocation of elbow joint
Posterior dislocation of the elbow joint may occur when children fall on their hands with their elbows flexed.
Dislocations of the elbow may also result from hyperextension or a blow that drives the ulna posterior or posterolateral.
The distal end of the humerus is driven through the weak anterior part of the fibrous layer of the joint capsule as the radius and ulna dislocate posteriorly.
The ulnar collateral ligament ligament is often torn and an associated fracture of the head of the radius, coronoid process or olecranon process of the ulna may occur.
Injury to the ulnar nerve may occur resulting in numbness of the little finger and weakness of flexion and adduction of the wrist.