Musculoskeletal and trauma Flashcards
1
Q
- A 17 year old girl presents with pain in the distal forearm which has worsened over
the last six to eight weeks. Plain films show an eccentric lytic radiolucency in the distal
radius with a soap-bubble appearance. The most likely pathology is:
a. Enchondroma
b. Aneurysmal bone cyst
c. Simple bone cyst
d. Fibrous dysplasia
e. Chondroblastoma
A
- b. Aneurysmal bone cyst
Aneurysmal bone cyst is most common in females and 75% occur under 20 years of age.
The classic presentation is of pain of relatively acute onset with a rapid increase in severity
over 6–12 weeks. Common locations include the spine, with a slight preponderance for the
posterior elements, and the metaphysis of long bones – femur, tibia, humerus and fibula.
The lesion is usually expansile with thin internal trabeculations giving it the characteristic
soap-bubble appearance.
2
Q
- A 35 year old man presents with increasing stiffness in his knee and soft-tissue swelling
around the joint. Plain films show multiple areas of irregular cyst-like radiolucencies
in the distal femur. There are no areas of abnormal calcification and there is no evidence
of periarticular osteoporosis. MR shows a low signal joint effusion on both T1 and T2
sequences. The most likely diagnosis is:
a. Synovial osteochondromatosis
b. Pigmented villonodular synovitis
c. Osteoarthritis
d. Reiter’s syndrome
e. Osteomyelitis
A
- b. Pigmented villonodular synovitis
Pigmented villonodular synovitis is a relatively rare condition which usually presents in the
third or fourth decade. It is a monoarticular, painful disease which causes a decreased range
of movement at the affected joint. It is most common at the knee (80%) followed by the hip,
ankle, shoulder and elbow. Haemorrhagic ‘chocolate’ effusion is characteristic. Low signal
effusion on all sequences at MR is characteristic. There is no calcification or osteoporosis,
and joint space narrowing is a late feature.
3
Q
- A 56 year old motorcyclist has a trauma series of plain films following a road traffic
accident. On evaluation of the lateral cervical spine film, which of the following softtissue
parameters would be a concerning feature?
a. Predental space of 3mm
b. Nasopharyngeal space of 7mm
c. Retropharyngeal space of 10mm
d. Retrotracheal space of 20mm
e. Decreased disc space at the C5/6 level
A
- c. Retropharyngeal space of 10mm
This is too wide for the retropharyngeal space. The correct acceptable limits for soft-tissue
measurements are as follows:
Predental space 3mm in adults, 5mm in children.
Nasopharyngeal space (anterior to C1) 10 mm.
Retropharyngeal space (C2–C4) 5–7 mm.
Retrotracheal space (C5–C7) 22 mm.
Disc spaces should be roughly equal throughout the cervical spine. Narrowing of a disc
space is usually due to degenerative change, but widening would be a more concerning
feature.
4
Q
- A 20 year old man presents with an increasingly painful right thigh which is worse at
night. Plain films of the area show a lucent area measuring approximately 8–9mm in
the distal femur surrounded by extensive sclerosis. The most likely diagnosis is:
a. Osteoblastoma
b. Giant cell tumour
c. Brodie’s abscess
d. Osteoid osteoma
e. Chondroblastoma
A
- d. Osteoid osteoma
This most commonly presents in the second and third decades. The male:female ratio is
2.5:1. Classically it presents with increasing pain which is worse at night and often relieved
with aspirin. Spinal lesions often lead to painful scoliosis. Almost any site in the body may
be affected but the most common regions are the lower limb and spine.
5
Q
- In a 65 year old woman with a fracture of the neck of the humerus, which of the
following classification systems to describe the fracture would be useful in guiding the
surgical management?
a. Garden classification
b. Neer classification
c. Weber classification
d. Fryman system
e. Crosby–Fitzgibbon system
A
- b. Neer classification
The Neer classification system is used to grade humeral neck fractures. This system
describes four parts – greater tuberosity, lesser tuberosity, humeral head and shaft of
humerus. According to Neer, a fracture is displaced if there is more than 1 cm of displacement
and 45 angulation between any two segments. Two-part fractures involve any of the
four parts and include one fragment that is displaced. Three-part fractures include a
displaced fracture of the surgical neck in addition to either a displaced greater tuberosity
or lesser tuberosity fracture. Four-part fractures include displaced fractures of the surgical
neck and both tuberosities.
6
Q
- A 60 year old woman presents to her GP with renal colic and hypercalcaemia. She has
the following findings on plain film: subperiosteal bone resorption of the proximal
phalanges of the hands, chondrocalcinosis of the articular cartilage at the knee joints,
and a well-defined lytic lesion in the body of the mandible. The most likely unifying
diagnosis is:
a. Parathyroid adenoma
b. Parathyroid carcinoma
c. Renal osteodystrophy
d. Osteomalacia
e. Myeloma
A
- a. Parathyroid adenoma
Parathyroid adenoma would be the most likely cause of primary hyperparathyroidism.
Parathyroid carcinoma would produce a similar radiographic picture but is much less
common. Brown tumours are seen in both primary and secondary hyperparathyroidism
and are most common in the mandible, ribs and pelvis; they have a variable appearance on
MRI and may simulate primary or secondary neoplasms
7
Q
- In a 21 year old man with symptoms of chronic back pain, pain in his feet, particularly
the great toe and metatarsophalangeal joints, and bilateral sacroiliitis on plain films, the
most likely diagnosis is:
a. Ankylosing spondylitis
b. Gout
c. Inflammatory bowel disease-related arthropathy
d. Reiter’s syndrome
e. Psoriatic arthritis
A
- d. Reiter’s syndrome
Reiter’s syndrome is the association of urethritis, conjunctivitis and mucocutaneous
lesions. Sacroiliitis is usually bilateral but often persists asymmetrically. There is an
association with the HLA B27 antigen. Reiter’s has a predeliction for the great toe and
metatarsophalangeal joints.
8
Q
- A 45 year old woman falls onto her outstretched hand. The following findings on PA
and lateral wrist plain films indicate which pathology? A scapholunate angle of 70,
a capitolunate angle of less than 20, and a 4mm gap between scaphoid and lunate
on PA view.
a. Normal appearances
b. Scapholunate dissociation
c. Volar intercalated segment instability (VISI)
d. Dorsal intercalated segment instability (DISI)
e. Perilunate dislocation
A
- b. Scapholunate dissociation
In scapholunate dissociation the scapholunate angle is >60 and there is a >3mm gap
between the scaphoid and lunate on AP view of the wrist. In VISI, capitolunate angle is
increased and there is volar angulation of the lunate. In DISI, both scapholunate and
capitolunate angles are increased and there is dorsal angulation of the lunate.
9
Q
- A young man presents to A&E following a fall onto his outstretched right arm. Plain
films of the right forearm show a fracture of the distal forearm with volar angulation
of the distal fragment with no intra-articular component. The carpal bones remain
well aligned. Which of the following injuries has he sustained?
a. Smith’s fracture
b. Barton’s fracture
c. Monteggia fracture
d. Galeazzi fracture
e. Colles fracture
A
- a. Smith’s fracture
This description is of a Smith’s fracture. More common is a Colles fracture, which is
a fracture of the distal radius with dorsal angulation of the distal fragment. A Monteggia
fracture is fracture of the ulnar with dislocation of the radial head. A Galeazzi fracture is
a fracture of the radius with dislocation of the distal ulnar. Barton’s fracture is a fracture of
the distal radius with dislocation of the distal radiocarpal joint
10
Q
- A 24 year old man injured his left knee whilst skiing. He presents with pain and
swelling over the lateral aspect of the knee joint. AP plain radiographs demonstrate an
avulsion fracture of the lateral aspect of the proximal tibia below the articular surface.
A joint effusion is also seen. The most likely associated ligamentous injury is to which
of the following structures?
a. Posterior cruciate ligament
b. Anterior cruciate ligament
c. Medial collateral ligament
d. Lateral collateral ligament
e. Ligament of Humphry
A
- b. Anterior cruciate ligament
The fracture described is a Segond fracture, originally documented by Dr Paul Segond in
1879 after a series of cadaveric experiments. The Segond fracture occurs most commonly
in association with anterior cruciate ligament injuries (75–100%) and medial meniscal
injuries. Due to the high rate of associated injuries, a patient who sustains a Segond fracture will require further imaging, usually by way of MRI, in order to specifically investigate the
ligaments and menisci.
11
Q
- A 22 year old man presents to his GP with pain in his right knee which is gradually
worsening in severity and is relatively resistant to analgesia. MRI of the knee demonstrates
an area of geographic bone destruction in the distal femur with a wide zone of
transition. There is marked aneurysmal dilatation of the bone and a fluid-fluid level is
present within the lesion. The most likely diagnosis is:
a. Plasmacytoma
b. Simple bone cyst
c. Giant cell tumour
d. Telangiectatic osteosarcoma
e. Parosteal osteosarcoma
A
- d. Telangiectatic osteosarcoma
With the MRI finding described, the most likely explanation is that the lesion is a
telangiectatic osteosarcoma. This is a rare type of osteosarcoma with a mean age at
presentation of 20 years. The most common site is around the knee (62%). Fluid-fluid
levels are also seen in giant cell tumours and aneurysmal bone cysts.
12
Q
- A 32 year old footballer sustains an avulsion injury to the anterior superior iliac spine
during training. Which of the following muscles is likely to be affected?
a. Sartorius
b. Gracilis
c. Iliopsoas
d. Rectus femoris
e. Semimembranosus
A
- a. Sartorius
Sartorius has its origin at the anterior superior iliac spine and inserts into the pes anserinus.
A sartorius muscle injury can therefore cause an avulsion fracture of the anterior superior
iliac spine. Gracilis has its origin at the inferior pubic ramus, and rectus femoris has its
origin at the anterior inferior iliac spine
13
Q
- A middle-aged woman undergoes an MRI of the lumbar spine for longstanding lower
back pain. She has no specific neurological signs and is otherwise well. MRI shows
some lower lumbar spine facet joint arthropathy and a 22 cm well-defined rounded
lesion in the L3 vertebral body. This displays high signal on both the T1 and T2
sequences. The most likely explanation for this lesion is:
a. Discitis
b. Lymphoma
c. Myeloma
d. Metastatic deposit
e. Haemangioma
A
- e. Haemangioma
This is most likely to be a benign haemangioma. These are relatively common lesions seen as
incidental findings on spinal imaging. High signal on T1 imaging is indicative of the presence
of fat within the lesion. All the other conditions would give a low-signal lesion on T1 imaging.
14
Q
- A 21 year old long-distance runner complains of increasing right groin pain.
Plain films show no acute bony injury, but demonstrate a pistol grip deformity
of the femoral head, an osseous bump deforming the femoral head–neck junction
and an alpha angle of 70. The acetabulum appears normal. The most likely
diagnosis is:
a. Hip dysplasia
b. Pincer-type acetabular impingement
c. Cam-type acetabular impingement
d. Sportsman’s hernia
e. Avascular necrosis
A
- c. Cam-type acetabular impingement
Femoroacetabular impingement (FAI) occurs as a result of repetitive microtrauma due to
an anatomic conflict between the proximal femur and the acetabular rim at the extremes of
motion. An osseous bump at the femoral head–neck junction is present in 50% of cam-type
FAI and only 33% of pincer-type FAI. An alpha angle of >55 is indicative of cam-type FAI.
The alpha angle, drawn on the AP pelvis radiograph, is formed by a line drawn from
the centre of the femoral head through the centre of the femoral neck, and a line from the
centre of the femoral head to the femoral head–neck junction, found by the point by which
the femoral neck diverges from a circle drawn around the femoral head. A normal patient’s
alpha angle is around 45, whereas for patients with FAI it may be around 70.
15
Q
- A 24 year old rugby player attends A&E following a tackle during which he felt his left
shoulder dislocate. Initial plain radiographs confirm an anterior inferior dislocation
of the left shoulder. Which of the following statements is true?
a. The humeral head lies inferior and lateral to the glenoid on the AP view
b. The presence of a Hill–Sachs defect indicates previous dislocation
c. Hill–Sachs lesions are more common than Bankart lesions
d. Anterior dislocation accounts for 50% of shoulder dislocations
e. A Hill–Sachs lesion affects the inferior aspect of the humeral head
A
- c. Hill–Sachs lesions are more common than Bankart lesions
A Hill–Sachs lesion affects the postero-superior aspect of the humeral head and whilst it
does often indicate a previous dislocation, this is not necessarily the case and it can be
present after a single episode. A Bankart lesion affects the inferior glenoid. Almost 95% of
all shoulder dislocations are anterior.
16
Q
- In a 26 year old woman with sickle cell disease, which one of the following would not
be considered a typical musculoskeletal manifestation of the disease?
a. Osteopaenia and trabecular thinning
b. ‘Bone within bone’ appearance
c. Avascular necrosis of the femoral head
d. Posterior vertebral scalloping
e. Fish deformity of the vertebrae
A
- d. Posterior vertebral scalloping
Posterior vertebral scalloping is not a feature. The remainder are all classic features of sickle
cell anaemia, along with ‘hair-on-end’ appearance of the skull due to coarse granular osteoporosis and widening of the diploe. Osteomyelitis is a feature and is due to salmonella in over 50% of cases.
17
Q
- A 74 year old woman presents with back pain and no history of recent trauma.
Lateral plain radiographs show partial collapse of the L2 vertebral body. Which of
the following findings would be more suggestive of osteoporotic collapse than
malignancy?
a. Complete replacement of the normal marrow signal within the vertebral body
on T1 imaging
b. Bilateral pedicular involvement with expansion of the right pedicle
c. Bulging and convex appearance to the vertebral body
d. Nodular irregular epidural mass
e. Intervertebral vacuum phenomenon
A
- e. Intervertebral vacuum phenomenon
Intervertebral vacuum phenomenon is highly specific for osteoporotic collapse, although it
is not common. The other features are all more suggestive of malignancy than osteoporotic
collapse. Pedicular destruction occurs in 50% of cases of malignant collapse but in less than
1% of osteoporotic collapse.
18
Q
- A 23 year old man sustains a Jefferson fracture to his cervical spine following an injury
in which he dived into a shallow swimming pool, hitting his head on the bottom.
Which of the following regarding his injury is incorrect?
a. Displacement of the lateral masses of C1 relative to the dens on an odontoid view
indicates a transverse ligament rupture
b. Associated C2 fracture will be present in up to 30% of cases
c. Jefferson fractures are usually associated with a neurological deficit
d. Up to 50% are associated with a further cervical spine injury
e. There may be associated vertebral artery injury
A
- c. Jefferson fractures are usually associated with a neurological deficit
Jefferson fractures are not usually associated with neurological deficit. Although there may
be retropulsion of fragments into the vertebral canal, spinal cord injury is rare due to the
large dimensions of the canal at this level. Vertebral artery injury, however, must be
considered and if there is concern either CTA or MRA imaging should be considered.
19
Q
- A 50 year old woman presents with a mass on the plantar aspect of her right foot.
Ultrasound reveals a small oval-shaped lesion between the plantar portions of the
metatarsal heads. MRI characteristics of the lesion are low-to-intermediate signal
on T1 and low signal intensity on T2. Which of the following is the most likely
diagnosis?
a. Lipoma
b. Morton’s neuroma
c. Plantar fibromatosis
d. Giant cell tumour of the tendon sheath
e. Ganglion cyst
A
- b. Morton’s neuroma
The description is that of a Morton’s neuroma. This occurs most commonly in the third
metatarsal space and less commonly in the second space. There is often an associated
metatarsal bursitis which is a high signal on STIR imaging. Ultrasound is usually the first
imaging modality; squeezing the metatarsal heads together during scanning will usually
make the lesion more prominent.
20
Q
- Following a traumatic left elbow fracture, a young man complains of paraesthesia in
his left ring and little fingers. He also starts to notice weakness of his left hand.
A diagnosis of ulnar nerve entrapment is made. Which of the following muscles will
not be affected?
a. Abductor digiti minimi
b. Abductor pollicis brevis
c. Adductor pollicis
d. Flexor carpi ulnaris
e. Flexor digiti minimi
A
- b. Abductor pollicis brevis
Abductor pollicis brevis is supplied by the median nerve and would therefore not be affected
in an ulnar nerve injury. Due to the anatomic location of the ulnar nerve at the elbow, it can
often be damaged leading to denervation and paralysis of the muscles supplied by the nerve.
This includes the intrinsic muscles of the hand, which can be very debilitating. Injury to the
ulnar nerve at the wrist would lead to severe muscle denervation sparing only the opponens
pollicis, the superficial head of the flexor pollicis brevis and the lateral two lumbricals
21
Q
- A routine pre-operative chest X-ray in a 62 year old woman shows bilateral erosion of
the distal clavicles. Which one of the following conditions might be responsible?
a. Hypoparathyroidism
b. Rheumatoid arthritis
c. Langerhans’ cell histiocytosis
d. Ankylosing spondylitis
e. Sarcoidosis
A
- b. Rheumatoid arthritis
Myeloma, hyperparathyroidism, metastases, cleidocranial dysplasia and Gorlin basal cell
nevus syndrome all cause absence of the outer end of the clavicle. Destruction of the medial
end of the clavicle is caused by metastases, infection, lymphoma, eosinophilic granuloma,
rheumatoid arthritis and sarc
22
Q
- A 74 year old woman with back pain presents to her GP. Initial plain radiographs of
her spine show multiple sclerotic metastatic lesions. The most likely primary tumour
would be:
a. Renal cell carcinoma
b. Melanoma
c. Bronchial carcinoid
d. Bladder
e. Colorectal carcinoma
A
- c. Bronchial carcinoid
The most likely from the above list is a bronchial carcinoid. In men the most likely cause
would be prostate. All the other conditions are more likely to produce lytic metastases
than sclerotic.
23
Q
- An elderly gentleman complaining of generalised aching in his lower limbs is shown to
have bilateral distal tibial periostitis. There is no underlying bone lesion identified.
Which of the following would be the most likely explanation?
a. Arterial insufficiency
b. Thyroid acropachy
c. Trauma
d. Pachydermoperiostosis
e. Hypertrophic pulmonary osteoarthropathy
A
- e. Hypertrophic pulmonary osteoarthropathy
The most likely explanation is hypertrophic osteoarthropathy. Thyroid acropachy changes
usually occur in the upper limb. Venous stasis is a cause of periostitis rather than arterial
insufficiency. Trauma would be unlikely to be bilateral unless there was a specific history.
Pachydermoperiostitis is the idiopathic form of hypertrophic osteoarthropathy, it usually
presents around adolescence and is usually associated with clubbing.
24
Q
- A 28 year old man is brought into the emergency department following an assault during
which he was stabbed in the left flank. He has a 1.3 cm wound just below the left costal
margin in the mid-axillary line. No information regarding the knife has been obtained.
His renal function is within normal limits and he has no contrast allergies. The optimal CT
protocol for scanning his abdomen would include the following contrast:
a. IV contrast only
b. Oral contrast and rectal contrast
c. IV contrast and oral contrast
d. Oral, rectal and IV contrast
e. IV contrast and rectal contrast
A
- d. Oral, rectal and IV contrast
A triple contrast technique has been advocated in penetrating trauma where there may be
concern regarding small bowel or colon trauma. If no oral or rectal contrast are given then
a small bowel or colon injury can easily be missed.