Orthopaedics Flashcards
What is subluxation?
Incomplete or partial dislocation
What three injuries comprise the unhappy triad?
- ACL tear
- MCL tear
- Medial meniscal tear
Why is the medial meniscus more commonly injured than the lateral meniscus?
It is relatively immobile, being attached to the MCL and joint capsule
Why is the ACL more commonly torn than the PCL?
The PCL is shorter and stronger
On physical examination, what manoeuvre will reproduce the pain of Osgood-Schlatter disease?
Knee extension against resistance
Explain the pathophysiology of Osgood-Schlatter disease
- The tibial tuberosity develops separately from the proximal tibia
- Normally it ossifies with the tibia
- With repeated tension on the patellar ligament, the tuberosity avulses
- This avulsed fragment continues to grow and the intervening space fills with new bone or connective tissue
What is osteochondritis dissecans?
Necrosis of subchondral bone in which a bone-cartilage fragment detaches and becomes displaced in the joint space
A popping and locking sensation in the knee is characteristic of an injury to which structure?
Menisci
What is the most sensitive and specific test for meniscal tears?
Thessaly test
Clicking/locking/catching with rotation
What is the characteristic MRI finding of a meniscal tear?
Hyperdense line
What are the 6 P’s of acute limb ischaemia?
- Pain
- Pallor
- Paraesthesias
- Poikilothermia (inability to regulate temperature)
- Pulselessness
- Paralysis
What is the major complication of acute forearm compartment syndrome?
Volkmann contracture
What upper limb injury is particularly prone to the development of a Volkmann contracture?
Fractures around the elbow, particularly supracondylar humeral fractures due to compression of the brachial artery
Which nerve is most commonly affected by compartment syndrome in the lower limb?
Deep peroneal nerve
What are the 5 types of Salter-Harris fractures?
- S - straight across
- A - above
- L - lower
- T - through/two
- ER - Erasure
When in a child’s life are Salter-Harris fractures most common?
Growth spurts at the beginning of puberty
11-12 for females
12-14 for males
Where on a bone is the metaphysis, epiphysis and physis?
What is the difference between adult and child periosteum and what is the clinical significance of this in terms of fractures?
Children have thicker and stronger periosteum
- Limits fracture displacement
- Reduces the likelihood of open fractures
- Maintains fracture stability
What type of collagen predominates in bone?
I
What is an avulsion fracture?
Injury to the bone in a location where a tendon or ligament attaches to bone
The tendon or ligament pulls of a piece of the bone
What is a comminuted fracture?
More than 2 fracture fragments
What is a segmental fracture?
A type of comminuted fracture in which a completely separate segment of bone is bordered by fracture lines
What is a greenstick fracture?
Bone that is bent with a fracture line that does not extend completely through the width of the bone
(common in children)
What is a torus/buckle fracture?
Incomplete fractures of the shaft of a long bone that is characterised by bulging of the cortex. They result from trabecular compression from an axial loading force along the long axis of the bone.
List 3 potential complications of a fracture at the surgical neck of the humerus
- Axillary nerve damage
- Posterior circumflex humeral artery damage → necrosis of the humeral head
- Suprascapular nerve damage
- Adhesive capsulitis
What is the major complication of humeral shaft fractures?
Radial nerve damage
(triceps muscle is spared)
What is a Galeazzi fracture?
Radius fracture + dislocation of the distal radioulnar joint
What is a Smith fracture?
Palmar displacement of the distal radius fragment
What is a Monteggia fracture?
Ulna fracture + dislocation of the radial head
What test is used the assess the function of the supraspinatus?
Empty can test/Jobe’s test
What test is used to assess the function of the infraspinatus?
External rotation against resistance
What test is used to assess the subscapularis?
Internal rotation against resistance
What test can be used to assess the function of the teres minor?
Position the arm in 90° of abduction and bend the elbow to 90°
Passively externally rotate the shoulder to its maximum degree
During shoulder abduction, pain through during which arc is suggestive of glenohumeral impingement?
60-120 degrees
During shoulder abduction, pain through during which arc is suggestive of acromioclavicular impingement?
170-180
May also be due to osteoarthritis
Which two test can be used to assess a biceps tendon rupture?
Speed’s test - elbow flexion against resistance
Yergason’s test - forearm supination against resistance
What is the sail sign?
Wide anterior fat pad
Suggests an occult fracture (hidden, does not appear clearly on x-ray)
What is the significance of a posterior fat pad on an x-ray of the elbow?
Suggests an effusion caused by significant trauma
What is neuropraxia?
Temporary loss of nerve function due to compression/stretch of the nerve. There is no structural damage to the nerve, but to the myelin sheath
Which branch of the median nerve is most commonly injured in supracondylar humeral fractures?
Anterior interosseous (AION)
What are the features of an injured anterior interosseous nerve?
No sensory changes (AION lacks a superficial sensory component)
Hand weakness, weak “OK” sign
Proximal forearm pain
How are supracondylar humeral fractures graded?
I. Undisplaced
II. Angulated with intact posterior cortex
III. Displaced distal fragment posteriorly with no cortical contact
What does radial head malalignment on x-ray suggest?
Radial head should point towards the capitellum
Lateral condylar fracture
Monteggia fracture
What is the significance of the anterior humeral line in x-rays of supracondylar humeral fractures?
In a normal elbow, a line drawn through the anterior cortex of the humerus intersects the capitellum in its middle third
The anterior humeral line passes through the anterior third of the capitellum or fails to intersect it if the humerus is posteriorly displaced
How are ligamentous injuries of the knee graded?
- No tear, no instability
- Partial tear, reduced stability
- Complete tear, poor stability
Which tendons are most commonly used as native grafts for ACL tears?
Patellar tendon
Hamstring tendon
Quadriceps tendon
How do you differentiate rotator cuff impingement from a tear?
Tears are associated with weakness
What are the 5 Ottowa knee rules?
A knee x-ray series is only required for knee injury patients with any of these findings:
- Age 55 or older
- Isolated tenderness of the patella
(No bone tenderness of knee other than patella)
- Tenderness of the head of the fibula
- Cannot flex to 90 degrees
- Unable to bear weight both immediately and in the emergency room department for 4 steps
(Unable to transfer weight twice onto each lower limb regardless of limping)
What is the management for a rotator cuff tear < 50% of the tendon’s thickness?
Arthroscopic debridement
What is the management for a rotator cuff tear >50% of the tendon’s thickness?
Arthroscopic repair (sutures)
How do you perform the Hawkin’s Kennedy test?
The clinical stabilises the shoulder with one hand and, with the patient’s elbow flexed at 90 degrees, internally rotates the shoulder using the other hand
Pain = positive test
Assesses shoulder impingement
What are 3 potential complications of a proximal humeral fracture?
- Avascular necrosis of the humeral head (circumflex artery)
- Axillary nerve palsy
- Suprascapular nerve palsy
- Adhesive capsulitis
What is a floating shoulder injury?
Fracture of the clavicle and glenoid neck
Which two conditions are most strongly associated with adhesive capsulitis?
- Diabetes mellitus
- Thyroid disease
What is a bankart lesion?
Detachment of the anterior inferior labrum from the glenoid due to an anteriorly dislocated humeral head
What’s the difference between a strain and a sprain?
Strain: overstretching/tearing of LIGAMENTS
Sprain: overstretching/tearing of MUSCLES or TENDONS
Which shoulder conditions may cause pain at night?
Impingement
Adhesive capsulitis
What is the conservative treatment of proximal humeral fractures?
Immobilisation with a sling (no splinting needed)
Ice, analgesia, mobilisation
What is the Neer classification of proximal humeral fractures?
Fractures are classified according to how many of the four major segments of the proximal humerus are displaced
- Anatomical neck
- Surgical neck
- Greater tuberosity
- Lesser tuberosity
Displacement exists when a segment is angulated more than 45 degrees or displaced more than one centimetre from a normal anatomic position.
What is the management of non-complicated clavicular fractures of the middle third?
Sling for 2 weeks (children)
Figure 8 can be used but they may be less comfortable and there is little evidence to show increased efficacy
What is the most common complication of a scaphoid fracture?
Avascular necrosis
Pain with pressure on the anatomic snuffbox suggests what injury?
Scaphoid fracture