Elbow and Forearm - Anatomy & Problems

Question 1

Which 3 joints make up the elbow and what types are they?

Answer 1

UlnoHumeral - hinge joint, 1 axis - back and forth.
RadioHumeral - ball and socket, 2 planes - hinge and swivel.
Proximal RadioUlnar joint - trochoid (1 element rotates in own axis).

Question 2

The synovial hinge joint of the elbow is independent of the shoulder joint and can move the hand to and from the body in flexion and extension. What limits extension?

Answer 2

The olecranon fitting into the olecranon fossa.

Question 3

The elbow joint is lined by a capsule and covered by a synovial membrane, what is the alignment?

Answer 3

Carrying angle is not straight down and arms must clear the hip when walking.

Question 4

If the allignment of the know joint occurs, the forearm may be more vertical or the opposite. What is the name of these situations and which is more severe?
The deformities may occur if supraepicondylar fractures heal wrong.

Answer 4

More vertical - Cubitus Varus
More horizontal - Cubitus Valgus
Cubitus Valgus is more severe as it can result in more functional issues with the ulnar nerve stretching as a result leading to tardy ulnar nerve palsy, whereas Cubitus Varus is more of a cosmetic issue.

Question 5

Describe the ligaments of the elbow joint.

Answer 5

Medial collateral ligament (anterior, posterior and transverse parts).
Lateral collateral ligament (radial collateral and ulnar collateral).
Annular ligament - around head of radius.

Question 6

Which 3 things provide stability to the elbow? What happens to them when the elbow gets dislocated?

Answer 6

Capsule, ligaments, muscles.

In dislocation, joint surfaces are completely lost, so all ligament complexes are disrupted.

Question 7

What use is finding a fat pad on an X-ray of an elbow?

Answer 7

If there’s effusion on the joint, for instance because of bleeding from a fracture, fluid will collect in the capsule and the black fat pads will be pushed superiorly.

Question 8

The ulnohumeral joint is responsible for (concentric) flexion and (eccentric) extension of the forearm, which range of angles can be achieved?

Answer 8

-5 to 140 degrees.

Question 9

Which muscles (and so nerves) contribute to flexion of the forearm?

Answer 9

Biceps brachii (musculocutaneous N.) - main, long and short head
Brachialis (musculocutaneous N.)
Brachioradialis (radial N.)
Pronator teres (median N.)

Question 10

Which muscles (and so nerves) contribute to extension of the forearm?

Answer 10

Triceps brachii (radial N.) - long, lateral and medial heads
Aconius (radial N.)

Question 11

Which joint is responsible for to 90-90 degree pronation and supination of the forearm?

Answer 11

The upper/proximal radioHumeral joint.

Question 12

Which muscles (and so nerves) contribute to pronation of the forearm?

Answer 12

Pronator Teres (median N.)
Pronator quadratus (branch of median nerve - anterior interosseous N.)

Question 13

Which muscles (and so nerves) contribute to supination of the forearm?

Answer 13

Biceps brachii (musculocutaneous N.) - main
Supinator muscle (radial N.)

Question 14

In the forearm, the median nerve supplies 4 superficial muscles, which one branch supplying the deep group, name the 4, which can be absent in some people?

Answer 14

Pass fail pass fail:
Pronator Teres
Flexor carpi radialis
Palmaris longus - may be absent
Flexor carpi ulnaris

Question 15

Nerves and vessels are at risk during injury, what does the ulnar nerve pass behind at the elbow and which muscle does the radial nerve supply?

Answer 15

Medial epicondyle

Extensor muscle, so if damage to radial nerve in humeral fracture, loss of strength in elbow and risk extensors.

Question 16

Name 5 muscles coming from the common flexor pronator origin of the medial epicondyle and 3 deep flexor muscles.

Answer 16

Pronator Teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris and flexor digitorum superficialis.
Flexor digitorum profundus, flexor policies longus and pronator quadratus.

Question 17

Name 4 extensor muscles of the wrist and fingers - what are they innervated by?

Answer 17

Extensor carpi radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris and extensor digitorum communis.
All are supplied by the radial nerve.

Question 18

Name 5 flexor of the wrist and fingers, what are they innervated by?

Answer 18

Flexor pollicus longus, superficial flexor digitorum, palmaris longus, flexor carpi radialis - all supplied by the radial nerve.
Flexor carpi ulnaris (ulnar N.).

Question 19

What series of events causes Compartment syndrome?

Answer 19

If a fracture occurs, pressure builds up in a compartment, so veins collapse and arterial supply is eventually cut off, leading to necrosis.

Question 20

What does the cubical fossa contain?

Answer 20

Lateral to medial TAN: tendon, artery, nerve - biceps tendon, brachial artery, then median nerve.

Question 21

A fragment of bone may impair a vessel or stretch a nerve, what’s the point of bursae around the elbow?

Answer 21

A bursa is a potential sac that can fill with fluid in inflammation.

Question 22

There are 8 carpal bones. Name them.

Answer 22

Some lovers try positions that they can’t handle.
Scaphoid, lunate, triquetral, pisiform
Trapezium, trapezoid, capitate, hamate

Question 23

Information organisations can be key when presenting a patient, the order can be helped by the following phrase, meaning what?
In A Surgeon’s Gown A Physician Might Make More Progress

Answer 23

Incidence
Age
Sex
Geography
Aetiology
Pathogenesis
Macroscopic
Microscopic
Management
Prognosis

Question 24

Elbow dislocation:
Usually occurs in ______\ _______ after FOOSH. Could present with ____, _____ and _____ ___ ______.
Usually posterior or anterior and what other feature may be present?

Answer 24

Children/young adults
Pain, deformity, loss of function
Usually posterior and may present with or without fractures.

Question 25

Supracondylar fracture of the distal humerus:
FOOSH, which age group?
Present with what?
Neurovasculature ,may compromised, so check if there’s been any __________, can the patient perform the ‘_______’, _____ pulse and capillary ______.
What2 types are there?

Answer 25

5-7 years old
Pain, marked swelling, bruising, no function
Parathesiae, ‘ok sign’, radial pulse and capillary return.
Displaced/undisplaced.

Question 26

What does traction involve?

Answer 26

Non surgical intervention or putting and holding something where you want it, to let the body try and heal itself.

Question 27

Radial head/neck fractures are often caused by _____. They can lead to lateral _____, modest _____ and _____ of range. If _____ (hidden) fracture, a sail sign of a displaced ____ _____ will appear _____ on a X-ray.
When might there be potential to remodel?

Answer 27

FOOSH
Pain, swelling, loss
Occult
Fat pad, black
If bones are young or near a joint.

Question 28

What is commonly known as ‘pulled elbow’ or nursemaid’s elbow and why?

Answer 28

Subluxation of radial head - it’s pulled out of annular ligament mostly in 2-5 year olds. Reduced movement, lateral pain and ‘not using it’ may be symptoms.

Question 29

Stiffness may arise from elbow osteoarthritis. What is it, when does it occur and why is an elbow replacement unlikely?

Answer 29

A degenerative disease of articular cartilage. May be primary or secondary after trauma. M>F - 4:1, with many cases in manual workers. Symptoms are relatively rare and stiffness with loss of extension are tolerated well.
An elbow replacement is unlikely as it it not designed for heavy duty or lots of force to be put into it.

Question 30

What happens in elbow rheumatoid arthritis?

Answer 30

Systemic autoimmune disease, where an abnormal layer of fibrous tissue also known as a synovial pannus, can lead to joint destruction. It’s the commonest inflammatory arthropathy.
Symmetric polyarthropathy with prolonged morning stiffness on the small and large joints.

Question 31

What is tennis elbow, inaccurately sometimes known as lateral epicondylitis?

Answer 31

Lateral elbow tendinopathy. A degenerative tendinopathy at the common extensor origin, usually in a person’s 5th or 6th decade.

Question 32

Why be cautious when someone presents with ‘elbow pain’?

Answer 32

It may be radiating from the neck/shoulder.

Question 33

What is Golfe’s elbow, sometime inaccurately referred to as medial epicondylitis?

Answer 33

Medial elbow tendinopathy - a degenerative tendinopathy at the common flexor origin (10X less common than LET).

Question 34

What may cause swellings around the elbow?

Answer 34

Rheumatoid nodules - commonest extrarticular manifestations of Rhematoid Arthritis - in 20% of cases. In more aggressive disease, they may also appear on the fingers or the forearm and can be of cosmetic concern.

Question 35

Olecranon Bursitis is primarily of cosmetic concern, but can become infected. What’s it colloquially named as and what is the underlying cause? How is it distinguished?

Answer 35

‘Student’s elbow’, which is inflammation of the elbow bursa following trauma/friction.
It is soft, cystic and transilluminates.

Question 36

What is Gouty Tophi?

Answer 36

A disorder of nucleic acid metabolism leading to hyperurocaemia (monosodium urate crystals) - primary or secondary urate crystal deposition at joints with recurrent attacks of arthritis or soft tissues - ear, elbow and Achilles’ tendon.

Question 37

What is being described?
Caused by FOOSH.
Pain, swelling and ‘dinner fork deformity’.
Young vs old- high vs low energy, displaced or undisplaced.
Outcome depends on accuracy of reduction.
Need to think if there may be underlying osteoporosis as this implies risk of further fracture and morbidity.

Answer 37

Fracture of the distal radius/ulnar.

Question 38

What are the two types of fracture described:

1. Dorsal displacement of hand and angulation - shortening.
2. Palmar displacement and angulation - shortening.

Answer 38

Colles’ fracture

Smith’s fracture

Question 39

What is the most frequently fractured carpal bone, often caused by FOOSH? Occurs in teens and 20s. Leads to tenderness where? What are the consequences of it being hard to see initially?

Answer 39

Scaphoid bone fracture may need multiple views/a delayed X-ray and examination/MRI. Tenderness in anatomical snuff box.
Tenuous blood supply means poor healing and avascular necrosis with delayed presentations meaning a risk of arthritis.

Question 40

What is Cubital tunnel syndrome?

Answer 40

Ulnar nerve neuropathy. Compressive neuropathy of ulnar nerve at the elbow - ulnar 1 and a half digits affected. Also be aware of compression at the neck or wrist. Hypersensitive ‘funny bone’, parasthesiae, numbness and weakness.

Question 41

In general, when should surgery be considered?

Answer 41

After failure of a non operative treatment or if the outcome is probably going to be better than nature.