Conditions Of The Elbow Flashcards
What is the most common mechanism of a supracondylar fracture of the distal humerus? 1️⃣
-FOOSH from a moderate height (with hyperextended elbows)
E.g child falling off monkey bars
[less common mechanism is falling onto a flexed elbow. ‘Flexion supracondylar fractures’ occur most often in the elderly]
In what patient group are supracondylar fractures of the distal humerus most common seen in? 1️⃣
90% seen in children <10yrs. Peak of 5-7yrs. Occur most commonly in boys
How does a child with a supracondylar fracture of the distal humerus present? 1️⃣
- pain
- deformity
- loss of function
How do supracondylar fractures usually look on an X-ray? 1️⃣
-fracture line is usually extra-articular (joint not involved) and distal fragment usually displaced posteriorly
State 3 main complications of supracondylar fractures of the distal humerus 1️⃣
- malunion, resulting in cubits varus. ‘Gunstock deformity’
- nerve damage to median nerve, radial nerve or ulnar nerve
- ischaemic contracture
How can supracondylar fractures of the distal humerus result in ischaemia of muscles? 1️⃣
- brachial artery passes very close to the fracture site
- can be damaged or occluded by a displaced fracture
-if reflex spasm of the collateral circulation around the elbow also occurs, there will be ischaemia of the muscles in the anterior compartment of the forearm
What does ischaemia of the muscles in the anterior forearm result in? 1️⃣
- oedema
- rise in compartment pressure (compartment syndrome)
-> further exacerbated the ischaemia as it impedes arterial inflow, and if untreated, the muscle bellies undergo infarction
How does Volkmann’s ischaemic contracture arise? 1️⃣
- during repair phase following infarction, dead muscle tissue is replaced by scar tissue through fibrosis
- fibrotic tissue contracts, eventually resulting in a flexion contracture
Describe the appearance of the Volkmann’s ischaemic contracture 1️⃣
- wrist typically flexed
- fingers extended at MCPJs
- fingers flexed at IPJs
- forearm pronated
- elbow flexed
What should be done in order to minimise the risk of the complications of supracondylar fractures of the distal humerus? 1️⃣
- prompt neurovascular examination conducted
- if any compromise then emergency reduction and fixation of the fracture is required
When does elbow dislocation usually occur? 2️⃣
-when a person, often a child, FOOSH with elbows partially flexed
Most common joint to dislocate in children and second most in adults (after shoulder) due to high frequency of FOOSH
Why is the elbow dislocation most likely to occur in mid-flexion? 2️⃣
- the configuration of the bones contributes most to stability of the elbow in full extension
- the stability of the elbow in mid flexion is more reliant on the ligaments
What type of elbow dislocation is most common? 2️⃣
Posterior elbow dislocation 90% cases
- distal end of the humerus is driven through the joint capsule anteriorly
- the ulnar collateral ligament is usually torn and there can be associated fracture and/or ulnar nerve involvement
What are anterior (10% cases) usually the result of? 2️⃣
-a direct blow to the posterior aspect of a flexed elbow
Associated fractures of the olecranon are commonly seen due to high degree of force required
What is a pulled elbow? (‘Nursemaids elbow’) 3️⃣
Subluxation of the radial head
(Subluxation= partial disruption of a joint with some remaining but abnormal apposition of the articular surfaces. I.e. an incomplete dislocation)
In what patient group does a pulled elbow commonly occur? 3️⃣
Children 2-5yrs
How does a child with a pulled elbow present? 3️⃣
- with reduced movement of the elbow
- pain over the lateral aspect of the proximal forearm
- parent often states that there are ‘not using their arm’
What is the classical described mechanism of injury for a pulled elbow? 3️⃣
-when longitudinal traction is applied to the arm with the forearm pronated
E.g tugging an uncooperative child or swinging a child by their arms
Other mechanisms include falls or overreaching for an object
Why does a pulled elbow injury most commonly occur in pronation? 3️⃣
- annular ligament is taut in supination and more relaxed in pronation so easier for subluxation to occur
- longitudinal traction on the radial head tears the distal attachment of the annular ligament from where it is loosely attached to the neck of the radius
- radial head is then displaced distally through the torn ligament
(Annular ligament strengthens as child ages)
What do radial head and neck fractures usually result from? 4️⃣
FOOSH when radial head impacts on the capitellum of the humerus
Commonest type of elbow fracture in adults
How does a patient with radial head and neck fractures present? 4️⃣
- pain in lateral aspect of proximal forearm
- loss of range of movement
- swelling
How does the fracture appear on an X ray? 4️⃣
-often quite difficult to see
-‘fat pad sign’ (‘sail sign’) indicates that an effusion is present
Trauma likely to be due to a haemarthrosis secondary to an intra-articular fracture. The sign is caused by displacement of the anterior fat pad which appears black as it is relatively radio-lucent
Why is OA of the elbow relatively uncommon? 5️⃣
Because of the well-matched joint surfaces and strong stabilising ligaments
Therefore it can tolerate large forces without becoming unstable. So there is leads wear and tear with age
In what patient groups is OA of the elbow commonly seen? 5️⃣
- men than women
- manual workers and athletes who engage in sports involving throwing
What do patients with elbow OA usually report? 5️⃣
- crepitus
- locking (caused by loose fragments of cartilage)
- swelling occurs relatively late and is due to an effusion
- osteophytes can impinge on the ulnar nerve, causing paraesthesia and or muscle weakness.
- stiffness
- loss of extension
What is rheumatoid arthritis? 6️⃣
An autoimmune condition in which autoantibodies, known as rheumatoid factor, attack the synovial membrane
The inflamed synovial cells proliferate to form a pannus, which penetrates through the cartilage and adjacent bone, leading to joint erosion and deformity
What joints are particularly affected by rheumatoid arthritis? 6️⃣
-MCPJ
-PIPJ
Of the hands
- joint of the feet
- joints of the cervical spine
What does the autoimmune process in RA also lead to? 6️⃣
- damage to other organs including the eyes, skin, lungs, heart, blood vessels and kidneys
- have anaemia of chronic disease
What patient group is affected by RA? 6️⃣
Peak ones is 40-50 years but there is a juvenile form affecting children
Women twice as more likely to be affected
State 4 key x-ray features of RA 6️⃣
- joint Spain narrowing
- periarticular osteopenia
- juxta-articular bony erosions (marginal erosion) in non-cartilage protected bone
- subluxation and gross deformity
How is RA managed? 6️⃣
- predominantly managed medically than surgically through prescription of disease-modifying medication
- in severe cases, surgery required to relieve pain and improve mobility. May need a total elbow replacement
How does lateral elbow tendinopathy (‘tennis elbow’) present? 7️⃣
Presents with pain at the site of the common extensor origin at the lateral epicondyle
How does lateral elbow tendinopathy arise? 7️⃣
-extensors carpi a radialis brevis normally helps stabilise wrist when elbow is straight
E.g during a tennis groundstoke
- when ECRB is weakened from overuse, microscopic tears form in the tendon where it attaches to the lateral epicondyle
- this leads to inflammation and pain
What do patients with lateral elbow tendinopathy typically experience? 7️⃣
-pain over the lateral epicondyle during wrist extension, especially if against resistance
Who is particularly prone to lateral elbow tendinopathy? 7️⃣
- tennis players
- painters
- plumbers
- carpenters
How is lateral elbow tendinopathy managed? 7️⃣
- patients advised to modify their activities to give tendon an opportunity to heal
- disorder usually self limiting
- sometimes physiotherapy and bracing are required
- small number of patients may need injections or surgery
What is affected in medial elbow tendinopathy (‘golfer’s elbow’)? 8️⃣
-affects the common flexor origin at the medial epicondyle
Who is prone to getting medial elbow tendinopathy? 8️⃣
- golfers
- sports people
Place valgus stress on the elbow
Also in bowlers, archers and weightlifters
What is the most common site of pathology in medial elbow tendinopathy? 8️⃣
The interface between the pronator teres and the flexor carpi radialis origins
How do patients with medial elbow tendinopathy present? 8️⃣
- aching pain over the medial elbow, often noticed during the acceleration phase of throwing
- pain on resisted flexion or pronation of the wrist
- ulnar nerve symptoms present in 20% cases due to proximity of the ulnar nerve to the medial epicondyle
State the 3 common causes of swellings around the elbow
- olecranon bursitis
- rheumatoid nodules
- gouty tophi
what is olecranon bursitis (‘student’s elbow’)? 9️⃣
-inflammation of the olecranon bursa usually due to repeated minor trauma
Results in a soft and cystic (fluid filled) swelling and transilluminates
How is olecranon bursitis treated? 9️⃣
- conservative treatment with compression bandaging with or without aspiration
- hydrocortisone injection is sometimes necessary in chronic cases
What is septic bursitis and how is it treated? 9️⃣
Bursitis due to an infection of a bursa e.g following minor penetration injury to the elbow
- requires aspiration, compression and antibiotics
- occasionally require surgical drainage and washout under anaesthetic to resolve the infection
What are rheumatoid nodules? 🔟
-firm subcutaneous lumps that are the commonest extra-articular manifestation of RA (20% of RA cases)
Which patients tend to develop rheumatoid nodules? 🔟
Patients tend to be smokers and tend to have more aggressive joint disease
-> these patients are also more prone to other extra-articular manifestations of RA, including vasculitis and lung disease
Where do rheumatoid nodules tend to occur? 🔟
-over espoused regions that are subjected to repeated minor trauma
- elbow region
- fingers
- forearms
- occasionally over the back of the heel
Usually non-tender although the overlying skin can occasionally ulcerate and become infected
How are rheumatoid nodules treated? 🔟
Treatment is by improving medical control of the underlying rheumatoid disease
What is gout and how does it arise? 1️⃣1️⃣
- inflammatory condition resulting from defective purine metabolism, leading to an increased production of uric acid
- as uric acid concentration increases in blood, supersaturation and precipitation occurs, forming crystals of monosodium urate in the synovial cavity of joints, in tendons and in the surrounding tissues
- these urate crystals trigger and immune response leading to acute inflammation
How is gout treated? 1️⃣1️⃣
- treated medically with NSAIDs during the acute phase
- once acute attack of gout has resolved, xanthine oxidase inhibitors e.g allopurinol (purine analogue) can then be prescribed to reduce the production of uric acid and reduce risk of further attacks
[gout can also increase long term risk of secondary OA due to damage it causes to the articulate cartilage]
What are tophi? 1️⃣1️⃣
nodular masses of monosodium urate crystals deposited in soft issues
They are a late complication of hyperuricaemia and develop in >50% of patients with untreated gout
What are the complications of tophi? 1️⃣1️⃣
- pain
- soft tissue damage
- deformity
- joint destruction
- nerve compression
What are the most common sites of gouty tophi? 1️⃣1️⃣
-fingers and ears
Can also be found in olecranon bursa and subcutaneous tissues of the elbow where they can resemble the appearance of rheumatoid nodules
What do gouty tophi contain? 1️⃣1️⃣
-white, pasty material
What happens to gouty tophi as they enlarge? 1️⃣1️⃣
Work their way towards the skin surface to drain, either forming a sinus tract or a continuously draining ulcer
What lies in the cubital tunnel? 1️⃣2️⃣
The ulnar nerve as it passes behind the medial epicondyle of the humerus to enter the forearm. It is therefore in close proximity to the elbow joint
What is cubital tunnel syndrome? 1️⃣2️⃣
Compression of the ulnar nerve
Describe the common site for cubital tunnel syndrome1️⃣2️⃣
Where the ulnar nerve passes beneath the tendinous arch (arch that unites the 2 heads of the flexor carpi ulnaris) to enter the cubital tunnel
What does minor trauma to the ulnar nerve in the cubital tunnel cause? 1️⃣2️⃣
(E.g. banging elbow on desk)
Causes a sharp transient pain radiating from elbow to the cutaneous territory of the ulnar nerve
Often people refer to this as ‘catching their funny bone’
What can compression of the ulnar nerve in the cubital tunnel result in? 1️⃣2️⃣
- paraesthesia of the cutaneous territory of the ulnar nerve
- weakness in muscles supplied by ulnar nerve
How is ulnar nerve compression treated? 1️⃣2️⃣
‘Decompress’ the nerve
-> surgically release it and transpose it anterior to the medial epicondyle
What are the characteristic mechanisms of injury to the musculocutaneous nerve? 1️⃣3️⃣
- penetrating trauma to the axilla e.g stabbing
- anterior dislocation of the shoulder
- injury during shoulder surgery
What does injury to the musculocutaneous nerve result in? 1️⃣3️⃣
- paralysis of the coracobrachialis, biceps brachii and brachialis muscles
- weakened flexion at shoulder and elbow
- weakened supination
- loss of sensation over radial side of the forearm
