Orthopaedics

Question 1

Compartment syndrome

Answer 1

A: Occurs when pressure in muscle compartment exceeds that of capillary blood supply. Eventually leading to muscle oedema and ischaemia.
Usually from open/closed fracture (tibial most common), crush injury, burns, penetrating injury, vascular injury or iatrogenic (dressings, IM injection)

S: Pain out of proportion with the injury, Paraesthesia and diminished pulses are late signs.

D: Clinical, but compartment pressure can be measured with an external probe.

T: Remove dressings, immediate fasciotomy and decompression

Question 2

Cauda equina syndrome

Answer 2

A: Spinal cord terminates at L1-L2, the cauda equina extends below this and can become compressed.
Central disc prolapse, tumour, trauma (spinal anaesthesia, fractures, penetrating injury), spinal stenosis, spinal inflammatory conditions.

S: Reduced lower limb power, reduced anal tone, reduced/absent reflexes, saddle anaesthesia, bilateral leg pain, incontinence, urinary retention.

D: Urgent MRI lumbar spine.

T: Surgical decompression within 48 hours of symptom onset.

Question 3

Median nerve injury (carpel tunnel)

Answer 3

S: Loss of thumb abduction and opposition. Loss of sensation in thumb, index finger, middle finger and radial aspect of ring finger.

D: Phalen’s test (inverted prayer sign), Tinel’s sign (tapping over wirst), nerve conduction studies.

T: Rest, splinting, steroid injection, carpel tunnel decompression.

Question 4

Ulna nerve injury

Answer 4

A: Usually compressed at medial epicondyle as it passes the elbow.

S: Ulna claw hand (little and ring fingers), loss of sensation in little finger and in medial half of ring finger and on corresponding palm below.

D: Forment’s sign (paper held between thumb and forefinger, when trying to pull paper away the thumb has to flex due to muscle weakness).

T: Rest, fix fracture, surgical decompression.

Question 5

Radial nerve injury

Answer 5

A: Usually mid-shaft humeral fractures.

S: Wrist drop, loss of sensation over anatomical snuff box (below thumb tendon)

D: Nerve conduction studies.

T: Splinting, physio.

Question 6

Bachial plexus injury

Answer 6

A: Shoulder trauma, tumours and inflammation.

S: Erb’s palsy - “waiter’s tip” position (c5-c6)
Klumpke’s palsy - claw hand, paralysis of intrinsic hand muscles (c8-t1)

D: NCS

T: Physio, nerve transfer if severe.

Question 7

Lateral cutaneous nerve of thigh injury

Answer 7

A: Injured by entrapment or compression as it passes between the ilium and inguinal ligament near the ASIS. Known as meralgia paraesthetica.
Compressed by seatbelts, tight clothing, obesity.

S: Pain, loss of sensation over outer thigh

D: NCS

T: Analgesia, weight loss, nerve decompression if severe.

Question 8

Sciatic nerve

Answer 8

A: Arises from L4-S3. Compression can be from lumbar disc herniation, lumbar spinal stenosis, piriformis syndrome.

S: Pain, altered sensation, weakness in lower back radiating down buttox, posterior thigh and leg.

D: Lasegue test (straight leg raise) positive if sciatic pain produced between 30-70 degrees.
MRI spine.

T: Underlying cause, analgesia, discectomy.

Question 9

Common peroneal nerve injury

Answer 9

A: Damaged as it winds around the neck of the fibula.

S: Foot drop, sensory loss to dorsal surface of foot.

D: Clinical.

T: Rest, fix fracture.

Question 10

Colles’ fracture

Answer 10

A: Extra-articular distal third radius fracture with displacement dorsally.
Fall onto outstretched hand, elderly population.

S: Pain, “dinner-fork” deformity (ie arm curved upwards)

D: XR

T: Closed reduction in A & E with application of backslab.
Open reduction and internal fixation (ORIF).

Question 11

Smith’s fracture

Answer 11

A: Extra-articular distal third radius fracture with voral (downwards) displacement.
Fall onto flexed wrist (ie back of hand), elderly population.

S: Garden spade/reverse dinner fork defomity, pain.

D: XR

T: Closed reduction in A & E with application of backslab.
ORIF.

Question 12

Barton’s fracture

Answer 12

A: Intra-articular distal third radial fracture with dislocation of radiocarpal joint - may be volar or dorsal.

S: Pain, deformity.

D: XR

T: ORIF

Question 13

Galleazzi fracture

Answer 13

A: Middle to distal third radius fracture associated with an intact ulna and disruption of the distal radio-ulna joint.
Fall onto outstretched hand, peak incidence 9-12 years.

S: Swelling about distal third of ulna.

D: XR

T: Closed reduction with arm held in supination by long arm cast. If closed reduction not possible, ORIF.

Question 14

Monteggia fracture

Answer 14

A: Proximal third ulna fracture with associated dislocation of radial head.
Peak incidence 4-10 years. Either direct blow on back of upper forearm or fall onto outstretched hand in the hyperpronated position.

S: Elbow swelling and deformity, painful movement especially pronation/supination and crepitus.

D: XR

T: Conservative, ORIF.

Question 15

Scaphoid fracture

Answer 15

A: Most common mechanism is fall onto an outstretched hand with forced dorsi-flexion.

S: Tenderness over anatomical snuffbox, positive scaphoid shift test positive, pain and swelling at the base of the thumb.

D: XR can be initially non-diagnostic in 25% of fractures, so follow up in 1-2 weeks may be needed. If still negative but suspected, CT/MRI can be used.

T: Immobilisation in a thumb spica cast or operative ORIF.

Question 16

Bennett’s fracture

Answer 16

A: Fracture of base of first metacarpal extending into the carpo-meta-carpal joint. Often from axial load on thumb from either punching a hard object or falling onto the thumb.

S: Tenderness, swelling and bruising over the base of the thumb.

D: XR

T: All need to be immobilised in a thumb spica cast for 4-6 weeks, some need closed reduction or ORIF.

Question 17

Boxer’s fracture

Answer 17

A: Transverse neck fracture of 5th metacarpal. Typically sustained when an inexperienced fighter throws a punch and sustains most of the force through the 5th knuckle.

S: Localised swelling and pain, loss of 5th knuckle contour.

D: XR

T: If minimal splinting in the Edinburgh position, may not operative reduction.

Question 18

ACL tear

Answer 18

A: ACL stabilizes the knee when it is in extension. Caused by deceleration followed by sudden change in direction or twisting knee on landing.

S: Sudden pop, knee locks or buckles, pain bending knee.

D: Anterior drawer test positive.
MRI confirms

T: RICE, knee brace, arthroscopic repair.

Question 19

PCL tear

Answer 19

A: Direct blow to the flexed knee displacing the tibia posterior to the femur (eg. hitting the dashboard).

S: Pain, instability.

D: Posterior drawer test positive,
MRI confirms

T: Arthroscopic repair.

Question 20

Meniscal tear

Answer 20

A: Menisci are c-shaped pads of fibrocartilage between femoral condyles and tibial plateau.
Trauma due to twisting of a flexed knee.

S: Pain on loading, swelling, mechanical symptoms (locking, clicking, catching or giving way). Tender over joint line.

D: Mcmurray’s test positive, Thessaly’s test positive, MRI confirms.

T: Conservative - analgesia, quadriceps strengthening.
Surgical - arthroscopic repair or removal

Question 21

Salter-Harris fractures

Answer 21

A: Epiphyseal injuries in immature bones.

I; Slipped - Seperation of physis (growth plate)
II; Above - fracture above physis (most common)
III; Lower - fracture below physis
IV; Through - fracture through the metaphysis, physis and epiphysis
V; Rammed - crushed physis

Question 22

Elbow - supracondylar fracture

Answer 22

A: Common in 5-15 year olds, fall onto outstretched hand causing elbow hyperextension, fracture runs through distal humerus above epicondyles.

S: Pain, swelling, unable to move elbows.

D: XR - anterior sail sign and posterior fat pad sign due to effusion suggest a fracture.

T: Depending on severity - immoblisation for 2-3 weeks, closed reduction or ORIF.

Important to monitor neurovascular status as they are commonly affected by these types of fractures.

Question 23

Osgood-Schlatter disease

Answer 23

A: Irritation of the patella tendon at the tibial tuberosity. Often in active children 9-16 years, coincides with growth spurts.

S: Knee pain exacerbated with exercise.

D: XR may show calcification over tibial tuberosity.

T: RICE - self limiting and resolves in 2-3 months.

Question 24

Cervical spondylosis

Answer 24

A: Degeneration of the intervertebral discs causing compression of the cord and nerve roots as the neck is flexed/extended.

S: neck stiffness, crepitus on neck movement, arm/wrist movement, neurological symptoms.

D: MRI

T: Immobilisation in collar.

Question 25

Baker’s cyst

Answer 25

A: Benign posterior bulge if knee joint capsule, can be secondary to osteoarthritis.

S: Painless swelling in popliteal fossa, non-pulsatile. Beware of popliteal aneurysm.

D: US

T: Not needed, analgesia can be given. Aspiration can reduce size.