Valgus and varus deformity of the elbow, including post-traumatic and growth-related cubitus valgus
10 questions2 source pages1 fact-check flags
Images appear with the first
question taken from each source page — tap a question to open it.
10 questions
Q1What is the normal carrying angle of the elbow?▸
Male: 5-10 degrees
Female: 15-20 degrees
Q2What are the causes of cubitus varus?▸
Static (malreduction) or dynamic (growth) causes
Supracondylar fracture malunion (varus, IR, extension)
Lateral condyle fracture - fishtail deformity, overgrowth of lateral condyle (50% regardless of treatment)
Transphyseal injury; bilateral causes include HME
Q3What is the incidence of cubitus varus after supracondylar fracture and how does the patient present?▸
3% after pinning, 14% after casting
Complaint is cosmetic; seldom causes functional deficit
Q4What is a fishtail deformity after lateral condyle fracture?▸
Type 1: malunion of lateral condyle causing under development of lateral crista
Type 2: AVN of the medial crista of the trochlea
One cause of cubitus varus
Q5What corrective osteotomy options are available for cubitus varus?▸
Timing: till skeletal maturity
French osteotomy, lateral closing wedge with step cut, medial opening wedge, computer assisted
Q6Describe the French osteotomy for cubitus varus.▸
Lateral closing wedge with correction of rotation
Screws inserted from lateral: proximal screw posterior, distal screw anterior
Figure-of-8 wire loop tightening
Q7A child develops cubitus valgus after a lateral condyle fracture. What is the mechanism, and what other causes should be considered?▸
AVN with physeal arrest of the lateral condyle after fracture
Other unilateral causes: OA, HME
Bilateral causes: congenital dislocation of the radial head, HME
Q8List the causes of radial head subluxation.▸
Congenital (nail-patella syndrome)
Synostosis
MHE
Arthrogryposis; achondroplasia
Post-traumatic
Q9Describe the blood supply of the distal humerus.▸
Lateral condyle: from posterior, just lateral to origin of the capsule
Trochlea: lateral crista supplied from the lateral condyle; medial crista has dual supply
Lateral supply crosses the posterior surface of the distal humeral metaphysis and is an end artery; medial supply comes from multiple vessels
Q10What is the complication of cubitus valgus and how is it treated?▸
Tardy ulnar nerve palsy
Treatment: supracondylar osteotomy after skeletal maturity
Fact check
Normal carrying angle is 5-10 degrees in males and 15-20 degrees in females — imprecise - values vary widely — Commonly quoted normal values are about 11 degrees in men and 13 degrees in women (Orthobullets); studies report means of roughly 9-14 degrees in men and 11-16 degrees in women. — (medium confidence) — source