MSK CATs Flashcards
1
Q
Types of Disturbed fracture healing
A
Delayed union
- takes longer
Non-union (pseudoarthrosis)
- healing not occuring within 6-9 months
- common sites: scaphoid, femoral neck, tibial shaft
Malunion
- Healing in non-anatomical position
Refracturing
2
Q
Causes of insufficiency fracture
A
Osteoporosis (most common)
3
Q
Osteochondral injury staging system
A
Stage 3
- Detached but not displaced
- MRI shows high signal around the osteochondral fracture “rim sign” but not displaced
Stage 4
- fragment displaced
Stage 5
- subchondral cyst formation
4
Q
mnemonic for causes of diffuse bony sclerosis is:
A
M: Myelofibrosis, Metastases, Lymphoma, Leukemia
S: Sickle cell disease
P: Pagets
R: Renal osteodystrophy
O: Osteopetrosis
F: Fluorosis
5
Q
What is Primary myelofibrosis characterised by
A
extramedullary haematopoiesis
progressive splenomegaly
anaemia
variable change in the number of granulocytes and platelets including thrombocytopenia
6
Q
Complications of Myelofibrosis
A
Gout: from hyperuricaemia due to increased haematopoietic turnover
Complications with splenomegaly
- infarction, rupture
- splenic vein thrombosis
- portal HTN
Bleeding due to thrombocytopenia
Thromboembolic event
- PE
- DVT
7
Q
Stages of FICAT for AVN
A
Stage 2
- plain radiograph: mixed osteopenia and/or sclerosis and/or subchondral cysts, without any subchondral lucency (crescent sign: see below)
- MRI: geographic defect
- bone scan: increased uptake
Stage 3
- plain radiograph: crescent sign and eventual cortical collapse
- MRI: same as plain radiograph
Stage 4
- plain radiograph: end-stage with evidence of secondary degenerative change
- MRI: same as plain radiograph
8
Q
Why femoral neck fracture prone to AVN?
A
Most of the femoral head blood supply is done by the extracapsular arterial ring, which is formed by the lateral femoral circumflex and the medial femoral circumflex arteries.
The femoral circumflex arteries arise from the deep femoral artery. Between them, the medial femoral circumflex artery supplies most of the blood to the head of the femur.
In cases of trauma proximal to the extracapsular arterial ring, such as femoral neck fractures, there is a considerable chance of avascular necrosis of the femoral head due to disruption of proper blood supply.
9
Q
Which part of the bone is affected most by Bone Infarct and Why ?
A
Convex articular surfaces.
Because convex articular surfaces have smaller diameter of terminal vessels and the lack of collateral vascularisation**
10
Q
Causes of Bone infarct ?
A
(Same causes as AVN)
- Trauma
- Sickle cell disease (rigid sickle cells leading to vaso-occlusive crises)
- vessel occlusion by nitrogen bubbles (caisson disease)
- Gaucher disease
11
Q
Complications of Bone infarct ?
A
- MFH (most common)
- Osteogenic sarcoma
- Fibrosarcoma of bone
- Osteomyelitis
- Angiosarcoma of bone (super rare)
12
Q
Nuclear medicine scan to do for bone infarct ?
A
Bone scan
- No uptake (photopenia) where blood supply absent
- Mildly increased uptake at periphery during acute phase
13
Q
Define acute vs chronic osteomyelitis
A
Acute OM
- symptoms are present for <2 weeks
Chronic OM
- symptoms present for >4 weeks
14
Q
Do cultures often yield positive for OM ?
A
No, low culture yields (only yield in ~35%). Often false-negative results
15
Q
OM complications
A
- SCC (Marjolin ulcer)
- Osteosarcoma
- Pathological fracture
- Secondary Amyloidosis
16
Q
Which of the following important features favours the diagnosis of osteomyelitis over neuropathic osteoarthropathy?
A
transcutaneous spread of disease — correct!
Explanation
>90% of cases of osteomyelitis spread through a transcutaneous route. Therefore, subcutaneous fat is usually involved.
Neuropathic osteoarthropathy is an aggressive form of degeneration therefore it is common to see subchondral cysts and bone erosions. It usually involves multiple joints with an articular epicenter. However, in osteomyelitis, there is a marrow epicenter.
17
Q
How to diagnose early osteomyelitis in a diabetic foot with discordant bone marrow signal ?
A
A bone marrow to joint fluid signal intensity ratio of ≥53% on T2/STIR sequences
18
Q
What is the most common location of osteomyelitis?
A
Lower limb
19
Q
What are the 2 forms of Necrotizing fasciitis ?
A
Polymicrobial (Type 1)
- most common
- involves anaerob and aerobic organisms
- forms gas - due to anaerobes
Monomicrobial (Type 2)
- less common
- involves “Group A Strep” - flesh eating bacteria
- complicated by “Toxic shock syndrome”
- will not form gas, because group A strep dont form gas
20
Q
Management of Necrotizing fasciitis
A
- Urgent surgical fasciotomy with aggressive debridement of the necrotic tissue
- Urgent empiric broad-spectrum antibiotics including anaerobic is recommended
21
Q
Most common sites of septic arthritis in IV drug users ?
A
In intravenous drug users, the sternoclavicular and sacroiliac joints are more frequently affected.
22
Q
Risk factors for septic arthritis
A
- Advanced age
- Bacteremia
- Sexually active
- Immunocompromised
- Rheumatoid arthritis
- Prosthetic joints
- Intraarticular injections
23
Q
Ankylosing spondylitis associations
A
- Uveitis
- IBD
- Interstitial lung disease
- Psoriasis
- Cauda equina syndrome
24
Q
DISH associations ?
A
- OPLL (accompanies around 50% of cervical DISH cases)
- Metabolic syndrome, obesity and diabetes mellitus
- Ossification of the stylohyoid ligament and Eagle syndrome
24
Ankylosing spondylitis genetics ?
HLA-B27 (+)
RF (-)
25
What are the 2 forms of Neuropathic arthropathy ?
1. Atrophic
- most common
- acute progression
- No osteophytes
- Resorptive
2. Hypertrophic
- slow progression
- have osteophytes
- Fragmentations/Debris
- No osteoporosis
26
Neuropathic arthropathy causes for:
- foot and ankle
- shoulder
- hips
- knee
- spine
Foot / ankle
- Diabetes
Shoulder
- Syringomyelia
Hip
- Alcoholism, tabes dorsalis
Knee
- Neurosyphilis / Tabes dorsalis
Spine
- Trauma
27
Useful MRI features that support superimposed osteomyelitis on a Charcot joint include:
Sinus tract
Diffuse marrow signal abnormality
Replacement of soft tissue fat*
Thick rim enhancement
Joint erosion
Ghost sign (poor definition of the margins of a bone on non-contrast T1)
28
Aetiology of Pagets disease
- Paramyxovirus
- Disease of Osteoclasts
29
Markers of Pagets disease
Increased ALP
Increased Hydroxyproline
Normal Calcium
30
Findings of Renal osteodystrophy
1. Osteomalacia (adults) or rickets (children)
2. Secondary hyperparathyroidism: abnormal calcium and phosphate metabolism
- subperiosteal resorption
- bone sclerosis: rugger jersey
- brown tumours
- salt and pepper skull
- soft tissue calcifications
- looser zones insufficiency fracture
31
Causes of gout
Under secretion
- CKD
- Hyperparathyroidism
Overproduction
- Myeloproliferative disorder
- Hemolysis
32
Complication of HADD
When intra-articular, calcium apatite crystals can cause joint destruction. Any joint can be involved; the shoulder is most commonly affected, resulting in Milwaukee shoulder
32
Causes of CPPD
Idiopathic
Hereditary: AD with ANKH gene
Secondary:
- hemochromatosis
- hyperparathyroidism
- hypothyroidism
- hypermagnesaemia
33
Transient osteoporosis of the hip (TRO Transient regional osteoporosis) seen more commonly in what demographic ?
- Higher incidence during third trimester of pregnancy
- But still more common in man (M:F ratio 3:1)
34
Transient osteoporosis of the hip features (TRO Transient regional osteoporosis)
- Femoral head marrow oedema without features of AVN
- Indistinctiveness of the femoral head cortex (virtually pathognomonic; present in only 20% of cases after 4-8 weeks from symptom onset)
- Osteopenia of the femoral head and neck region (late)
- Joint effusion may be present
- Joint space always preserved
35
Transient osteoporosis of the hip if bilateral or if it migrates then its called ?
Regional migratory osteoporosis
36
Which is NOT a typical MRI feature of myositis ossificans at 4 weeks after suspected inciting trauma?
During the active phase, myositis ossificans is associated with prominent surrounding muscular oedema which can be a useful sign (in addition to peripheral calcification and history of trauma) in confidently differentiating it from sarcomas, which typically induce very little if any surrounding oedema.
37
What are the 3 types of osteochondromatosis ?
Para-articular Chondroma (intracapsular chondroma)
- most common in Hoffa's fatpad of knee
- if seen calcifications (then cannot be PVNS)
Synovial osteochondromatosis
- appear as multiple intra-articular nodules in contrast to the solitary lesion of para-articular chondroma
- contains synovial cells
- It must be remembered that, in a minority of cases, the bodies in SC are not calcified enough to be visible on radiographs.
Soft tissue osteochondromatosis
38
Inheritance of Maffuci's and Ollier's
Sporadic*
39
Ollier and Maffuci associations ?
- Chondrosarcoma
- Pancreatic and Juvenille granulosa cell tumor of the ovary
- Gliomas
40
Ollier + osteochondromas =
metachondromatosis.
41
Clinical signs of malignant transformation of Ollier and Maffuci
- if pain occurs when child is OLDER (pain is normal during periods of rapid growth)
- Pathological fracture also present with pain
42
Management of Maffuci and Ollier
If extensive involvement, it might cause growth impairment, deformity (such as leg length discrepancy or Madelung deformity of the forearm), and functional impairment and these may require corrective surgery.
43
Maffucci syndrome genetic mutation ?
IDH1 or IDH2
44
Location and distribution of Maffuci / Ollier
Phalanges of Hands and Feet
Bilaterally Asymmetrical
45
Chondrosarcoma subtypes
- Conventional
- Clear cell
- Mesenchymal
- Dedifferentiated
46
Chondrosarcoma associated with
- Hyperglycemia due to paraneoplastic syndrome
- Hereditary Multiple Exostosis
- Ollier
- Maffucci
47
Chondrosarcoma management
- Usually surgery, unless it's Mesenchymal type, then Chemo + Radiation therapy*
48
Fibrous Dysplasia genetic mutation
GNAS
49
Non-Ossifying fibroma most common location ?
metaphyses of long bones.
- giant cell rich bone tumours
50
Non-ossifying fibroma associations
NF-1
Jaffe Campanacii syndrome
51
Macrodystrophia lipomatosa pathology
- Can be thought of as lipomatosis of nerve resulting in visible deformity.
- Considered a progressive form of macrodactyly growth halts at puberty
52
Macrodystrophia lipomatosa associations
syndactyly
clinodactyly
polydactyly
53
Lipoma arborescens location
- affecting synovial linings of the joints and bursae
- can be seen in the setting of osteoarthritis, collagen vascular disorders, or previous traum
54
Lipoma arborescens associated findings
- Joint effusion (very common)
- Degenerative change (common)
- Meniscal tears (common)
- Synovial cysts (uncommon)
55
Types of liposarcoma ?
- Well differentiated (most common)
- De-differentiated
- Myxoid liposarcoma
- Pleomorphic liposarcoma
- Mixed liposarcoma
56
Prognosis of Liposarcoma in extremity vs retroperitoneum
Extremity (most common)
- indolent
- lower rate of recurrence
- better prognosis
Retroperitoneum (less common)
- high rate of recurrence
- tend to be high grade
57
Osteoid osteoma composition
Lucent Nidus
- represents neoplastic process
- releases prostaglandins (via the enzymes cyclo-oxygenase-1 and cyclo-oxygenase-2), resulting in pain
Fibrovascular rim
Surrounding reactive sclerosis
58
Osteoid osteoma treatment
- Radiofrequency ablation
59
Why is Aspirin contraindicated in Osteoid osteoma in children?
Aspirin is contraindicated in children <12 years old due to risk of Reye syndrome
60
When osteoid osteoma intra-capsular, what can it mimic ?
When intracapsular, the presentation is more atypical and more likely to mimic inflammatory arthropathy or synovitis.
Joint effusion is often present
61
When osteoid osteoma/osteoblastoma in spine, what does it cause ?
Classic cause of painful scoliosis
62
Complications of Osteoblastoma intra-operatively
Lesions are prone to extensive intraoperative bleeding due to intrinsic vascularity
63
Primary vs Secondary osteochondromatosis
Primary synovial chondromatosis:
- Predominantly monoarticular disorder of unknown aetiology
Secondary synovial chondromatosis:
- Intra-articular loose bodies from Trauma, osteoarthrosis and neuropathic arthropathy*
- Large nodules vary in size vs small and uniform size in primary
64
What are the 3 phases of Primary osteochomdromatosis
Initial phase: metaplastic formation of cartilaginous nodules in the synovium
Transitional phase: detachment of those nodules and formation of free intra-articular bodies
Inactive phase: resolution of synovial proliferation, but loose bodies remain in the joint, and may increase in size obtaining nourishment from the joint fluid by diffusion
65
Diagnostic criteria for Hereditary Multiple Exostosis ?
essential: ≥2 radiological osteochondromas at the juxtaepiphyseal region of the long bones and positive family history and/or EXT gene germline mutation
66
Complications of Hereditary Multiple Exostosis ?
vascular impingement
neural impingement
fracture
bursitis
deformity and ankylosis
malignant transformation
67
Features of osteochondroma malignant (sarcomatous) transformation
more common than in sporadic cases*
G: growth after skeletal maturity
L: lucency (new)
A: additional scintigraphic activity
D: destruction (cortical)
P: pain after puberty
a: and
S: soft tissue mass
T: thickened cartilage cap >1.5 cm
68
How to approach planning to biopsy a potential sarcoma
The treating surgeon should be consulted to plan the biopsy track as this will require excision to reduce the chance of seeding. A poorly planned track that crosses compartments can result in a more extensive resection, potentially with poor outcomes for the patient.
69
Complication of parosteal osteosarcoma
Might progress to a high-grade sarcoma including other osteosarcoma variants, undifferentiated spindle cell sarcoma or rhabdomyosarcoma
70
Rhabdomyosarcoma 3 types
embryonal rhabdomyosarcoma (most common)
alveolar rhabdomyosarcoma: 20%
pleomorphic rhabdomyosarcoma: 5%
Rhabdomyosarcoma (RMS) is a malignant tumour with skeletal muscle cell morphology. It is one of the tumours of muscular origin.
71
What type of tumour is Ewing sarcoma ?
- Small round blue cell tumor
72
Ewing sarcoma closely related to what other tumours
- pNET
- Askin tumour
- Neuroepithelioma
All referred to as Ewing sarcoma family of tumors
73
Ewing sarcoma labs ?
ESR and serum LDH levels are elevated
74
Imaging features on MRI to differentiate giant cell tumor from aneurysmal bone cyst ?
Enhancing solid components can help to distinguish giant cell tumours with haemorrhagic areas and aneurysmal bone cyst-like changes from a pure aneurysmal bone cyst.
75
What is a useful nuclear study scan to do for Giant cell tumor, Aneurysmal bone cyst and Simple bone cyst (cystic lesions)
On bone scintigraphy, most giant cell tumours demonstrate increased uptake on delayed images, especially around the periphery, with a central photopenia (doughnut sign).
Increased blood pool activity is also seen, and can be seen in adjacent bones due to generalised regional hyperaemia (contiguous bone activity).
76
Treatment of benign metastasizing GCT / unresectable disease ?
Denosumab
77
inferior shoulder dislocation caused by?
- Sudden forceful hyperabduction
- Direct force on an abducted arm
- Humeral head forced against the acromion, leading to inferior glenohumeral capsule rupture and rotator cuff disruption
78
What injuries are SLAP tears associated with ?
- Bankart lesion (in young patient <40)
- Rotator cuff injury (in older patient >40)
79
SLAP tears vs ALPSA and Bankart
Unlike Bankart lesions and ALPSA lesions, they are uncommonly (20%) associated with shoulder instability
80
What is a Perthes lesion ?
One of the types of anterior glenohumeral injury in which the anterior inferior labrum is torn and lifted from the edge of the glenoid but still attached to the intact lifted periosteum from the anterior aspect of the glenoid.
Although the labrum may be normally positioned, functionally it no longer provides any stability to the humeral head, mainly as a result of impairment of the normal stabilising influence of the "inferior glenohumeral ligament"
81
What is Glenolabral articular disruption (GLAD) lesion ?
Superficial anterior inferior labral tear + anterior inferior glenoid articular cartilage injury.
Not tend to associate with "shoulder instability"*
82
What positoin can help visualize labral tears better on MR arthrography ?
ABER
- ABduction and External Rotation.
83
What is anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesion ?
similar to a Bankart lesion, in that it too is usually due to anterior shoulder dislocation and involves the anterior inferior labrum.
- Detachment of the anteroinferior labrum + labrum remains attached to the periosteum
(Bankart lesion in which the labrum and glenoid periosteum are avulsed from the underlying glenoid)
84
Where is the cirtical zone of rotator cuff tear ?
8-20 mm proximal of the insertion site.
85
Indirect signs of Full-thickness tear
Subdeltoid bursal effusion, medial dislocation of biceps, fluid along biceps tendon, and diffuse loss of peribursal fat planes.
Muscle atrophy and fatty replacement is seen in chronic cases and can be graded using the Goutallier classification, or assessed with the tangent sign or scapular ratio
86
Supraspinatus tear associations (same as infraspinatus tear)
- posterosuperior tear extension into the infraspinatus tendon and muscle and the rotator interval
- ACJ osteoarthritis
- Proximal biceps tendon injury
- SLAP lesion
87
Full thickness tear of the supraspinatus tendon will lead to loss of what function
- Shoulder abduction
88
What are the Three patterns of subscapularis tendon tears
- Supraspinatus tear involvement (80%)
- "Rotator cuff interval" extension: Potentially involving the "superior glenohumeral ligament (SGHL)" and "coracohumeral ligament (CHL)" and can lead to "biceps instability", especially when superior tears are present.
- Isolated (rare): most commonly traumatic in the setting of anterior glenohumeral instability
**almost always (>90%) start as articular-sided partial-thickness tears superomedially and progress inferolaterally
**entire tendon can be torn but the overlying superficial fascia and transverse humeral ligament can be intact
89
Subscapularis tear associations
Subcoracoid impingement (narrowing of the coracohumeral interval (space between the tip of the coracoid and the humerus)
SLAP tears in the context of biceps pulley injury
90
What are some signs of subscapularis tear
comma sign: full-thickness superior subscapularis tears along with SGHL and CHL tears retracted superiorly
axial plane: long head of biceps (LHB) tendon subluxation
sagittal oblique plane: subscapularis muscle belly atrophy
lesser tuberosity bone marrow oedema and cysts especially when combined with muscle belly fatty atrophy is indicative of chronic tears.
if the LHB is normally positioned in the bicipital groove (i.e. not subluxed), there is a low likelihood of a full-thickness subscapularis tear**
91
What are the types of Shoulder impingement ?
subacromial impingement: most common
- os acromiale
- type 3 acromium
- osteophytes
subcoracoid impingement: affects subscapularis, long head of biceps
- reduced coraco-humeral interval due to trauma or prior rotator cuff repair*
posterosuperior impingement: involves infraspinatus (rare)
- occurs when the shoulder is abducted and externally rotated (ABER position).
92
Complications of subacromial impingement ?
rotator cuff tear
subacromial bursitis
biceps tendinopathy
93
What structures do lateral epicondylitis affect (tennis elbow) ?
overuse syndrome of the common extensor tendon and predominantly affects the extensor carpi radialis brevis (ECRB) tendon.
- best clue for the diagnosis of lateral epicondylitis is abnormal thickening and increased signal intensity within the common extensor origin from the lateral epicondyle
- associated radial nerve entrapment may occur in 5% of cases
94
Complications of Scaphoid fracture
Osteonecrosis (Most common)
- proximal portion due to arterial supply entering distally
SNAC wrist
- Scaphoid non-union advanced collapse
- proximal fragment remains at the lunate while the distal fragment begins to rotate into flexion creating abnormal contact in the radio-scaphoid compartment that will progressively get worse.
SLAC wrist
- Scapholunate advanced collapse
- widening of the scapholunate interval, over time, this leads to increase load over the radial aspect of the radioscaphoid joint causing osteoarthritic changes.
- capitate to migrate proximally and ultimately cause degeneration of the capitulate joint and further displacement of the lunate ulnarward
Delayed union
95
Bennett fracture
Epibasal fracture
Rolando fracture
Reverse Bennett fracture-dislocation
Boxer fractures
Bennett
- Base of 1st MC fracture
- intra-articular
- 2 piece
Epibasal fracture
- extra-articular fractures through the first metacarpal base
Rolando fracture
- comminuted intra-articular fracture through the first metacarpal base
Reverse Bennett fracture-dislocatoin
- fracture-dislocation of the base of the 5th metacarpal bone. It is pathologically and radiographically analogous to the Bennett fracture of the thumb.
Boxer fracture
- minimally comminuted, transverse fractures of the 5th metacarpal neck
96
Perilunate dislocation + Scaphoid fracture = ?
Trans-scaphoid perilunate dislocation
97
Perilunate dislocation injures what structures
- Radioscaphocapitat ligament
- Scapholunate interosseous ligament
- Lunotriquetral interosseous ligament
98
Describe midcarpal dislocation
A dislocation where neither the capitate or the lunate is aligned with the distal radius.
99
What is the classification used for carpal instability ?
Mayfield classification of carpal instability:
Stage I: scapholunate dissociation (rotatory subluxation of the scaphoid)
- disruption of the scapholunate ligament with resultant Terry Thomas sign
- exacerbated on clenched-fist views
- associated with DISI and VISI
stage II: perilunate dislocation
- the lunate remains normally aligned with the distal radius, and the remaining carpal bones are dislocated (almost always dorsally)
- the capitolunate joint is disrupted, and the lunate projects through the space of Poirier
- 60% are associated with scaphoid fractures
stage III: midcarpal dislocation
- lunotriquetral interosseous ligament disruption or triquetral fracture*
- neither the capitate or the lunate is aligned with the distal radius
stage IV: lunate dislocation
- dorsal radiolunate ligament injury*
- dislocation of the lunate in a palmar direction
- tipped teacup appearance
100
Madelung deformity associations
- Turner syndrome
- Hereditary multiple exostosis
- Ollier disease
- Achondroplasia
101
Ulnar impaction syndrome and its association
Painful degenerative wrist condition caused by the ulnar head impacting upon the ulnar-sided carpus (lunate) with the injury to the triangular fibrocartilage complex (TFCC).
- majority of cases occur in association with positive ulnar variance
102
Ulnar impingement syndrome and its association
- caused by a shortened distal ulna impinging on the distal radius proximal to the sigmoid notch.
- results in contraction of the extensor pollicis brevis, abductor pollicis longus, and pronator quadratus muscles which prevents normal buttressing of the radioulnar joint
- Most commonly, the syndrome is caused by surgical resection of the distal ulna as part of the management of wrist trauma, rheumatoid arthritis, or Madelung deformity. Less commonly, ulnar impingement may occur in de novo negative ulnar variance.
103
Scapholunate dissociation injured ligaments ?
scapholunate interosseous ligament (SLIL):
- Dorsal (strongest, most important)
- Intermediate
- Volar
scapholunate interval >3 mm on PA view
104
When does TFCC injury require surgery
- medial tears are in the vascularised zone and a surgical repair is a treatment option whereas central tears are in the avascular zone and are typically debrided
- TFCC degenerations are intrinsically high signal not extending to the articular surface
105
MRI wrist arthrogam, how to tell if TFCC injury ?
The injected wrist joint capsule and distal radioulnar joint (DRUJ) only communicate if there is a tear in the triangular fibrocartilage complex (TFCC).
As shown, contrasts opacifies the DRUJ, indicating a TFCC tear.
106
Mallet finger ?
Avulsion of the Common extensor tendon on the dorsal aspect of the distal phalanx at the DIP joint.
Due to sudden hyperflexion
107
Mallet finger complications
- Dorsal skin ulcer
- Nail deformity
- Swan neck deformity
- Secondary osteoarthritis
108
Jersey finger ?
Avulsion of the flexor digitorum profundus (FDP) from the volar aspect of the distal phalanx base
Due to sudden hyperextension
109
Which finger does Jersey finger typically affect, and why ?
It most commonly affects the 4th digit because the FDP insertion into the ring finger is anatomically weaker than the middle finger
110
Complications of Jersey finger ?
- Unstable DIP joint
- Development of secondary osteoarthritic changes
- DIP flexion contracture or quadrigia
111
Management of Jersey Finger
Conservative for partial tear (i.e. splinting, NSAIDs, physical therapy)
All complete flexor tendon injuries should be surgically repaired
112
Seymour fracture
- Clinically important subtype of mallet finger type injury.
- The Seymour fracture is comprised of a distal phalanx physeal fracture that has an associated nail bed injury commonly with ungual subluxation.
113
Complications of Seymour fracture
osteomyelitis
delayed union, malunion, non-union
disturbance of distal phalanx bone growth
- Hence early review and treatment by a specialist hand (plastic/orthopaedic) surgeon are recommended
- Delayed radiograph done to look for the above
114
Köhler disease's adult version ?
An eponymous term referring to childhood-onset osteonecrosis of the navicular in the foot.
Müller-Weiss syndrome is the adult counterpart of navicular osteonecrosis
115
Four main forces have been described in high-energy blunt force trauma that results in "unstable pelvic fractures"
Anteroposterior: Open book fracture
Lateral compression: Windswept pelvis (unilateral sacral compression fracture + contralateral SI joint diastasis)
Vertical shear: Bucket Handle fracture (fracture through ipsilateral superior and inferior pubic rami with contralateral sacroiliac joint disruption/dislocation)
Combined mechanical: occur when two different force vectors are involved and result in a complex fracture pattern
116
What does posterolateral ligamentous complex consist of
lateral (fibular) collateral ligament
arcuate ligament
popliteofibular ligament
posterior third of the lateral capsule
117
Arcuate sign ?
- Avulsion fracture of the proximal fibula at the site of insertion of the arcuate ligament complex (posterolateral ligamentous complex)
- fracture fragment is attached to the lateral (fibular) collateral ligament, the biceps femoris tendon, or both.
Associations:
Cruciate ligament injuries
- especially posterior cruciate ligament
Bones bruises
- anteromedial femoral condyle: 50%
- anteromedial tibial plateau: 28%
Meniscal tears
Popliteus injury
MCL injury
118
Primary and secondary signs of ACL tear
Primary
- empty notch
- fiber discontinuity
- disruption of intercondylar (Blumensaat) line
Secondary
- Anterior tibial translocation >0.7cm
- Coronal LCL sign
- Bone contusion: lateral femoral condyle and posterolateral tibial plateau
- Uncovering posterior horn
119
ACL tear associations
O'Donoghue unhappy triad
Segond fracture
posteromedial corner injury of the knee
meniscocapsular separation
120
PCL tear associations
ligamentous injury (~40%)
- ACL
- MCL
- LCL
meniscal tears
posterolateral corner injury (ACL is posteromedial corner)
bone contusion (80%) or avulsion fracture (<10%)
knee joint effusion
121
PCL MRI features
- Posterior tibial translation (>0.3cm)
- PCL usually remains contiguous (70%)
- Enlarged and swollen PCL
122
PCL tear prognosis ?
- Can spontaneously heal but can result in early degenerative change
123
posteromedial corner structures ?
Posterior oblique ligament (injury in virtually all cases with associated instability)
Oblique popliteal ligament
Meniscotibial ligament
Semimembranosus tendon
Medial meniscus: posterior third
124
What are the types of ACL repair ?
Autograft reconstruction:
- Hamstring (Semitendinosis, Gracilis)
- Quadriceps
Allograft reconstruction
Synthetic graft reconstruction
125
Name ACL repair complications
Graft impingement
- ACL graft impinged by bony/soft tissue structures at the intercondylar notch
Arthrofibrosis
Intra-articular body (loose body)
Femoral or tibial tunnel cyst
- benign ganglion cysts that develop in or around the osseous tibial tunnel made during ACL reconstruction
Graft stretching
Graft rupture
126
Proximal tibiofibular joint dislocation MRI findings
- proximal tibiofibular ligament injury
- Posterolateral corner injury (almost always)
- Common peroneal nerve injury (common fibular nerve, forms the lateral part of the sciatic nerve and supplies the leg)
127
Insall-Salvati index
Insall-Salvati index: patella tendon length to the length of the patella.
ratio >1.2 is diagnostic of patella alta and <0.8 is diagnostic of patella baja.
128
Baker cyst complications
dissection: the cyst usually dissects inferomedially but can dissect proximally, anteriorly, intermuscularly or intramuscularly
rupture: leaking of cyst fluid into the popliteal fossa, between fascial planes and surrounding the hamstrings and medial gastrocnemius muscles; moreover, there is oedema of the soft tissue and irregularity of the cyst wall
compression: of the popliteal vessels and tibial nerve
compartment syndrome: can be either anterior or posterior
129
Achilles tendon ruptures where in a young pt ?
Critical zone: 2-6 cm proximal to insertion
When a plantaris muscle is present then its tendon is usually spared due to its more anterior insertion on the calcaneum.
(Plantaris inserts anterior to Achilles tendon)
130
Lateral ankle sprain associations
Anterior talofibular ligament injury (common - 75%)
Calcaneofibular ligament injury (common as well - occurs with ATFL injury in lateral ankle sprain)
Deltoid ligament (if ATFL + calcaneofibular ligament injury, special scrutiny should be placed on the deltoid ligament to look out for additional deltoid ligament injury as well as on a possible associated subtalar injury)
posterior talofibular ligament injury (uncommon)
talocrural joint capsule injury
subtalar joint injury
131
What are the Types of injuries to anterior part of the deltoid ligament:
type 1: proximal tear or avulsion of the ligament
type 2: intermediate tear of the ligament
type 3: distal tear or avulsion of the deltoid and spring ligaments
132
Plantar fasciitis can arise from ?
Mechanical stress due to repetitive trauma (most common)
Degenerative
Seronegative spondyloarthropathies:
- AS
- reactive arthritis
- psoriatic arthritis
133
Plantar fasciitis MRI findings
Plantar fascial thickening
Increased T2 of proximal plantar fascia
Oedema of medial calcaneal tuberosity
Oedema of adjacent fatpad and underlying soft tissue
134
Posterior tibialis tear leads to ?
Pes Planus
135
Posterior tibialis tear associations
spring ligament injury
sinus tarsi syndrome
plantar fasciitis
136
Where does Posterior tibialis insert ?
Navicular and Medial Cuneiform
137
Describe the 2 types of Tarsal Coalition
Calcaneonavicular
- anterior process of calcaneus
- associated with talus hypoplasia
- best seen on oblique view
- anteater sign
Talocalcaneal
- middle facet calcaneus
- best seen on lateral view
- C-sign: Complete posterior ring around talus and sustentaculum tali
- Talar beak sign
138
Tarsal coalition features and types
- Coalition may be fibrous, cartilaginous or osseous
- Associated with pes planus
- 50% are bilateral
139
Locations of Morton's neuroma
The 3rd web space (between 3rd and 4th metatarsal heads) is the most commonly affected site.
The 2nd webspace is less often involved while the remaining web spaces are rarely involved.
Occasionally specific terms are used when occurring in certain spaces
- 1st intermetatarsal space: Heuter neuroma
- 4th intermetatarsal space: Iselin neuroma
140
What causes Morton's Neuroma ?
due to Chronic entrapment of the nerve by the intermetatarsal ligament (distal common plantar nerve)
141
What is the sign to elicit pain for Morton Neuroma ?
Mulder sign
142
Differential for Mortons Neuroma
Intermetatarsal bursa/bursitis
- extruding out in between the metatarsal bones on the plantar aspect of the foot
- compressible
143
Define Jones fracture
5th metatarsal base
transverse fracture 1.5-2 cm from tip of proximal tuberosity
- High risk of nonunion due to being in a vascular watershed zone*
- Indications for non-operative management include undisplaced fractures and fractures in patients with limited activity (i.e. recreational athletes)
144
Avulsion fractures of the calcaneal tuberosity association
- Diabetes
- Osteoporosis
- Renal osteodystrophy
- Hyperparathyroidism
145
Clinical presentation of Fong's disease (Nail-Patella syndrome)
- Absent or Hypoplastic Nails
- Recurrent knee dislocations and flexion contractures
- Renal dysfunction
- Bilateral Posterior iliac horns ("Fong prongs") - pathognomonic
146
Features of SLE skeletal manifestations
1. Hands and feet (Non-erosive arthropathy)
- due to "ligamentous laxity" and not articular destruction
- Seen on Nogaard view* but reduces on PA
- Interphalangeal joint swan neck and boutonniere deformities with ulnar deviation at MCP joints
- Subluxation of 1st Metacarpophalangeal joint
- Hallux valgus, widened foot
- Often reducible, hence deformities are seldom disabling
2.Myositis
3. Femoral head osteonecrosis (most common site)
4. Atlanto-axial dislocation
5. Tendinopathies
6. Calcifications
147
SLE diagnostic criterias
- Malar rash
- Discord rash
- Oral ulcers
- Non-erosive arthropathy
- proteinuria
- Pleuritis or pericarditis
- Photosensitivity
- Positive antinuclear antibodies
- Neuropsychiatric manifestations
148
Extra-articular findings of Psoriatic arthritis
gastrointestinal: inflammatory bowel disease
cardiac: rhythm disturbances (e.g. left bundle branch block)
urogenital: urethritis, prostatitis, balanitis, cervicitis, vaginitis
149
Scleroderma associations
CREST syndrome
other connective tissue disorders
- systemic lupus erythematosus (SLE)
- polymyositis
- dermatomyositis
150
Markers for Scleroderma
- ESR
- RF
- ANA (also seen in SLE**)
151
Dermatomyositis associations
- Interstitial lung disease
- Malignancy: can occur as part of a paraneoplastic syndrome (e.g. lung cancer)**
152
Complication of Dermatomyositis
Increased risk for malignancy (same as polymyositis).
Multiple risk factors for malignancy development identified:
- >60 yo
- male
- dysphagia
- increased CK
- increased CRP and ESR
- skin necrosis
153
Differentials of Dermatomyositis
- Polymyositis (does not affect skin)
- Anti-synthetase syndrome
- Immune-mediated necrotising myopathy
154
Which MRI sequence useful to guide muscle biopsy ?
MRI T2-weighted sequences are useful to guide muscle biopsy:
areas of oedema related to the active inflammatory process
non-specific end-stage fatty atrophic muscle should be avoided
155
Anti-synthetase syndrome
an idiopathic inflammatory myopathy that is characterised by inflammatory myositis, polyarthritis, interstitial lung disease, and anti-synthetase autoantibodies. It is considered a distinct entity to dermatomyositis.
156
Which auto-anti body most commonly relates to Anti-synthetase syndrome
anti-JO-1: most common anti-synthetase autoantibody
157
What does SAPH consists of ?
S: synovitis
A: acne
P: pustulosis
H: hyperostosis
O: osteitis
158
Morel-Lavallée lesion location and imaging appearance
Location: Superficial to the deep fascia
- can have solid components or septa
- may present long after trauma
- may present as enlarging mass
- may get infected
159
What is Still's disease
Systemic onset of Juvenile Rheumatoid Arthritis
- Fever with RA
- Migratory salmon skin
- Hepatosplenomegaly
- Lymphadenopathy (see PET)
Image
- Wrist: involved in 74% of case
- Pericapitate narrowing, ankylosis (midcarpal and carpometacarpal) disease is classic, but any pattern of carpal involvement may be seen
RF+
160
Differentials for HPOA
- Thyroid Acropachy
- hypervitaminosis A
- chronic venous insufficiency (look for phleboliths)
161
Pseudohypoparathyroidism due to ?
Pseudohypoparathyroidism occurs when there is end-organ resistance to parathyroid hormone (PTH).
162
Imaging findings of radiation necrosis
Radiograph: Osteopenia, Coarsening of trabeculation, Cortical irregularity, Heterogeneous bone density
MRI: Spine will have fatty marrow replacement, other parts show new heterogeneous signal within marrow
163
Complications of osteonecrosis
- Tumor recurrence
- Radiation induced sarcoma
- Osteomyelitis developing
164
Treatment for Bisphosphonate Insufficiency fracture
- Stop Bisphosphonate
- Intramedullary nailing
- Recombinant human parathyroid hormone (rhPTH)
- Imaged contralateral femur (usually bilateral)
165
Nodular fasciitis can be categorized as ?
myxoid, cellular, or fibrous.
This histologic diversity likely accounts for the variable MR imaging appearance of the lesions
166
Features of Nodular faciitis ?
Location: Deep subcutaneous region or in the fascia. Most common volar aspect of the forearm, the lower extremity, and the chest and back. It typically manifests as a rapidly growing mass.
MRI:
hypercellular lesions appear nearly isointense to that in skeletal muscle on T1WI and hyperintense to that in adipose tissue on T2WI
highly collagenous lesions have hypointense signal on all sequences
contrast enhancement is typically diffuse but may be peripheral
167
On MRI, for low T2 signal masses without characteristic blooming artifact consider..
- PVNS (absence of blooming artifact does not exclude, but calcification excludes)
- Tendon sheath fibroma (no blooming)
- Gout tophi
- Nodular fascitis (subcutaneous location)
- Synovial chondromatosis
167
What is the pathognomonic pathological findings for Chondroblastoma ?
pericellular lace-like "chicken-wire calcification"
168
Chondroblastoma management ?
Benign lesion
- Surgical curettage with or without bone grafting.
- Consider adjuvant treatment such as cryotherapy to reduce recurrence risk.
- Follow-up imaging for early detection of recurrence.
169
Pathology of Chordoma ?
Chordomas are malignant bone tumors derived from notochordal remnants.
Characterized by physaliferous cells (large cells with vacuolated cytoplasm).
Tumor cells are embedded in a myxoid matrix.
S100 and brachyury are positive on immunohistochemistry.
170
What are the 3 subtypes of Chordoma and what does the truly malignant form contain ?
Conventional chordoma (most common)
Chondroid chordoma (best prognosis)
Dedifferentiated chordoma (least common, worst prognosis)
True malignant forms most often contain fibrosarcoma**
171
Chordoma treatment and prognosis
surgical resection has been the first line of treatment when feasible, with radiotherapy offered for recurrent cases.
Prognosis is typically poor due to the locally aggressive nature of these tumours, with overall 10-year survival of approximately 40%.
172
What's unique about Synovial sarcoma histological pattern ?
Synovial sarcoma can be Biphasic or Monophasic.
- Does not contain synovialcytes instead of epithelial cells
172
Good prognostic factors for Synovial Sarcoma
small size (<5cm)
located in the extremity
younger age <20 years of age
solid homogeneous mass
presence of calcification
173
Synovial sarcoma often mets ?
- Yes, frequently mets
- most commonly to the lungs as cannonball metastases (~80%)
174
Highest risk factor for MFH ?
Radiotherapy
175
MFH commonly seen on a background of what disease ?
Paget disease
Secondary transformation into malignant sarcomas (including undifferentiated pleomorphic sarcoma) has also been reported in fibrous dysplasia, giant cell tumour, enchondroma, chronic osteomyelitis, and osteonecrosis
176
MFH prognostic factors
Tumour size: smaller being better
Location:
- superficial is better
- distal is better
Histological subtype: the myxoid subtype has a better prognosis compared to the storiform-pleomorphic subtype
177
Causes of Carpal Tunnel syndrome
- Osteoarthritis
- Mechanical overuse
- Trauma
- Ganglion cysts, nerve sheath tumor
- Bifid median nerve
178
Imaging feature of Carpal tunnel syndrome
- Palmar bowing of the flexor retinaculum (>2 mm beyond a line connecting the pisiform and the scaphoid)
- Distal flattening of the nerve
- Enlargement of the nerve proximal to the flexor retinaculum (most sensitive)
179
What are the carpal tunnel contents
The carpal tunnel contains the following structures, from superficial to deep:
CONTENTS:
- flexor digitorum superficialis tendons (four) (with middle and ring finger more superficial to the index and little finger)
- median nerve (laterally)
- flexor pollicis longus tendon (laterally)
- flexor digitorum profundus tendons (four)
EXLUDED:
Flexor carpi radialis
180
Location of Guyon's canal and content
Guyon’s canal
- superficial and slightly proximal to the flexor retinaculum.
- spanning from the proximal aspect of the pisiform to the hook of hamate.
CONTENTS
- ulnar nerve: bifurcates within the canal into the deep (more radial) and superficial (more ulnar) branches
- ulnar artery and ulnar vein
- veins associated with the ulnar nerve
- fat
181
Clinical presentation of Guyon's canal syndrome
pain and altered sensation in the ulnar half of the 4th digit and the complete 5th digit (sensory supply of the deep branch of the ulnar nerve)
weakness in flexion, abduction and opposition of the little finger (innervation to the hypothenar muscles)
weakness in digit adduction and abduction (innervation to the interossei)
extension of the MCP and flexion of the PIP (innervation to the third and fourth lumbricals) resulting in the characteristic ulnar claw
182
What is Quadrilateral space syndrome
neurovascular compression syndrome of the posterior humeral circumflex artery (PHCA) and/or the axillary nerve or in the quadrangular space.
183
How to differentiate Quadrilateral space syndrome vs. Parsonage-Turner syndrome
Parsonage-Turner syndrome:
- may be distinguished from quadrangular space syndrome on MRI by the usual involvement of more than one muscle or even more than one nerve distribution
184
Parsonage-Turner syndrome involvements
In almost all cases (97%) the suprascapular nerve is involved and is the only nerve involved in 50% of cases. The axillary nerve and subscapular nerve are also sometimes involved, either in combination or alone.
The most frequently involved muscles are supraspinatus and infraspinatus (innervated by the suprascapular nerve) followed by deltoid (innervated by the axillary nerve).
185
Explain quadrilateral nerve syndrome
Quadrangular space syndrome is a neurovascular compression syndrome of the
- posterior humeral circumflex artery (PHCA)
- axillary nerve or one of its major branches in the quadrangular space.
186
Explain bisphosphonate insuffiency fracture
1. Impaired ability to repair microdamage
- Bisphosphonates work by inhibiting osteoclasts, which are responsible for bone resorption. Over time, this suppresses the bone remodeling process, reducing bone turnover. While this is beneficial for reducing fractures in conditions like osteoporosis, it also impairs the bone's ability to repair microdamage.
2. Brittle bone
- Bisphosphonates lead to increased bone mineralization and density but at the expense of bone quality. The bone becomes more brittle and less resilient to mechanical stresses, particularly in areas like the femoral shaft that endure high mechanical loads.
3. Impaired Bone Healing
- Once an insufficiency fracture starts, the healing process is also impaired in bisphosphonate-treated bone because of the suppression of osteoclast activity. Osteoclasts are essential not only for resorption but also for initiating the repair of fractured bone. This results in delayed or non-union of fractures in patients on long-term bisphosphonate therapy.
187
How does magic angle artefact work ? how to fix it ?
Magic Angle Artifact:
The magic angle artifact occurs when collagen-rich structures (like tendons) are imaged at an angle of approximately 55 degrees to the main magnetic field (B0) in MRI.
This angle causes altered signal intensity in sequences with short echo times (TE), like T1-weighted or proton density (PD) sequences, making the tendon appear more hyperintense (brighter), which can be mistaken for tendinopathy or a partial tear.
How to Avoid It:
Use longer echo time (TE) sequences
Oblique imaging planes: If the tendon is aligned close to 55 degrees relative to the magnetic field, try imaging the tendon in a different plane (oblique coronal or sagittal), which may alter the angle and reduce the artifact.
Correlate with clinical findings
Assess other signs of a true tear
188
Stages of adhesive capsulitis and treatment ?
1.Painful stage
2. Transitional stage
3. Thawing stage
Treatment:
- Corticosteroids injection
- Glenohumeral joint hydrodilatation
- NSAIDS
189
"What steps should be taken to reduce the risk of radiation-induced injury during interventional radiology procedures?"
Collimation, use of pulsed fluoroscopy, limiting fluoroscopy time, and optimizing beam positioning.
190
What measures should be taken in a CT protocol to reduce the risk of radiation-induced injury, especially in pediatric patients?"
Focuses on dose optimization techniques such as automatic tube current modulation, low kVp settings, and using appropriate diagnostic reference levels (DRLs) for pediatric patients.
191
Explain cause for Radiation necrosis ?
Radiation necrosis is caused by delayed radiation-induced damage to cells, blood vessels, and surrounding tissues.
It results from a combination of direct DNA damage, vascular injury, and chronic inflammation, leading to tissue hypoxia and necrosis.
Management typically includes steroids, hyperbaric oxygen therapy, anti-VEGF, surgical resection.
192
Explains the zones of the meniscus
Red zone
- Peripheral
- vascular supplied by genicular arteries
- surgery, as can heal
Red-white zone
- Mid portion
- limited vascular supply, gets some from genicular
- surgery if stable tear, have potential to recover
White zone
- Inner most
- no vascular supply, relies on synovial fluid for nutrition
- menisectomy
193
Explain particles disease
Granulomatous reaction occurs in response to small particles of prosthetic components (eg metal, cement, or polythene) breaking off from implant wear and tear, leading to osteolysis, prosthesis loosening and failure
194
"How would you differentiate transient osteoporosis of the hip from avascular necrosis (AVN) on imaging?"
TOH presents as diffuse bone marrow edema without subchondral fracture or collapse. In contrast, AVN shows focal signal changes with subchondral bone involvement, often leading to collapse.
195
Explain Distal compartment syndrome
Tenosynovitis of the EPL as it crosses over the 2nd dorsal carpal compartment. just distal to "Lister's tubercle"
Tenosynovitis of the
- Extensor pollicis longus (EPL) tendon (3rd extensor compartment), where it crosses the extensor carpi radialis longus (ECRL) and brevis (ECRB) tendons (2nd extensor compartment)
It is distinct from intersection syndrome which occurs more proximally in the forearm at the intersection of the first and second extensor compartments.
196
De Quervain tenosynovitis
Washerwoman's sprain/strain
- Tenosynovitis of the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendons.
- Thickening of the "extensor retinaculum" and tendons from acute or repetitive trauma restrains normal gliding within the sheath.
- first extensor compartment at the "radial styloid"
- There is an intertendinous septum between APL and EPB in 10% of patients => worse prognosis for healing, may require surgical decompression.
- The absence of a septum is associated with very high rates (almost 100%) of complete symptom resolution with conservative management.
197
Occipital condyle fracture important factors to check
Role of imaging is foremost to evaluate for occipita-atlantal dislocation:
If stable or unstable
Stable (Anderson and Montesano types, type I and II)
- alar ligament and tectorial membrane are preserved
- conservative tx
Unstable (Anderson and Montesano types, type III)
- posterior occipitocervical fusion
198
Jefferson fracture
- C1 anterior and posterior arch fracture
- If there is an injury to the transverse atlantal ligament, the atlantodental interval (ADI) increases (see avulsed fragment*)
- The normal ADI in the adult population is less than 0.3 cm
199
What is a classification of Odontoid fracture ?
Anderson and D'Alonzo classification
Type 1
- fracture of tip
- potentially unstable
- rare
Type 2
- fracture at the base
- unstable
- high risk non-union
Type 3
- fracture body
- best prognosis for healing
200
hangman’s fracture
- C2 pars interarticularis fracture
Practical points
check for an extension to the transverse foramina and, if present, vertebral artery injury should be considered
201
Describe burst fracture and most common location
- Any axial compression fracture involving an endplate and the posterior cortex regardless of retropulsion
- L1 (most common site)
202
Burst fracture next step ?
- All patients require a CT to assess the injury and evaluate the extent of the retropulsed fragments which may enter the spinal canal, and a percentage of spinal canal narrowing should be reported
- Hence often have neurological deficits of lower limb*
203
Chance fracture
AKA "seatbelt fractures"
- flexion-distraction type injuries of the spine that extend to involve all three spinal columns.
- These are unstable injuries and have a high association with intra-abdominal injuries (pancreas, duodenum, and abdominal aorta)
204
Compression fracture
Single-column (i.e. stable) wedge fracture.
Typically, these fractures are insufficiency fractures secondary to osteoporosis, although some are pathological secondary to a focal bone lesion. A small proportion is due to trauma in patients with normal underlying bone
205
Limbus fracture
Bony fractures of the vertebral body rim at the site of attachment of the "Sharpey fibres" of the intervertebral disc (Not to be confused with a limbus vertebra which is a normal anatomic variant).
206
Flexion teardrop fractures
Severe axial/flexion injury of the cervical spine.
- fracture of the anteroinferior lip of vertebral body
- posterior displacement of the posterior vertebral body relative to the intact inferior cervical column
Important to recognise because they indicate extensive underlying ligamentous injury and spinal instability. Associated spinal cord injury is common, especially anterior cervical cord syndrome and quadriplegia.
They should not be confused with extension teardrop fractures, which tend to occur higher within the cervical spine and are considered less severe injuries
207
DISH associations
- OPLL
- Diabetes, metabolic syndrome, obesity
- Ankylosing spondylitis (co-existing condition and ddx)
- Ossification of stylohyoid ligament
208
Explain CAM morphology
loss of sphericity of the femoral head
leads to a restriction in range of motion especially during hip flexion, internal rotation and adduction with associated shear at the chondrolabral junction
209
Explain PINCER morphology
Acetabular overcoverage is due to an increased acetabular depth such as coxa profunda or protrusio acetabuli, if focal it can be due to acetabular retroversion, a prominent posterior rim, or an acetabular ossicle
210
What are some x-ray views to do for FAI ?
- Dunn 45° and 90° views
- Meyer lateral
- frog-leg lateral
- Lequesne's false profile
- cross-table lateral
211
What are some radiographic signs of FAI
lateral center-edge angle, acetabular index: to confirm acetabular overcoverage
ilioischial line: coxa profunda, protrusio acetabuli
crossover sign, ischial spine sign: acetabular retroversion
posterior wall sign: prominent posterior wall or acetabular retroversion
pistol grip deformity: cam morphology
212
What muscles inserts onto the greater trochanter ?
Gluteus medius, gluteus minimus, Piriformis
213
Predisposing factors for Patellar rupture
1. Prior ACL repair
2. Repetitive microtrauma (Jumpers knee)
3. Diabetics
214
Predisposing factors for Quadriceps rupture
1. Connective tissue disorder (SLE, RA, Gout)
2. Renal impairment
3. Steroid use
4. TKR complication
215
Discoid meniscus more common medial or lateral
Lateral meniscus (way more common)
216
How to classify discoid meniscus
complete vs incomplete
- 80% coverage of the tibial plateau is often used as the cut-off between incomplete and complete
stable vs unstable
- stable: normal peripheral attachments with an intact posterior meniscofemoral ligament
- unstable (also known as a Wrisberg variant): lack or tear of a posterior meniscocapsular (in particular meniscopopliteal) ligaments with an attachment only from the meniscofemoral ligament of Wrisberg
217
Discoid meniscus MRI diagnostic signs
- On coronal imaging, meniscal body width of 15 mm or more
- On sagittal imaging, the body of meniscus seen on 3 or more adjacent slices
218
Discoid meniscus complications
meniscal tears
intrasubstance mucoid degeneration
early bony degenerative change
219
What are potential sites of compression for Ulnar nerve neuropathyy
At the cubital tunnel: passes through elbow (most common site)
At the "Arcade of Struthers": against the medial epicondyle - proximal to cubital tunnel
Between the humeral and ulnar heads of the "flexi carpi radialis" - distal to cubital tunnel
220
Ulnar nerve neuropathy findings
- Oedema or atrophy of the "flexor carpi ulnaris" and "flexor digitorum profundus muscles"
- Ulnar nerve thickening + oedema
221
Cause for Cubital tunnel syndrome - ulnar nerve neuropathy
Accessory anconeus epitrochlearis muscle
- bridges olecranon and medial humeral epicondyle
- lies superficial to the nerve nerve. (most common structural abnormality of the cubital tunnel causing ulnar neuropathy)
Ganglion
Subluxation/dislocation of ulnar nerve
Overuse
222
Trigger finger
- type of stenosing tenosynovitis involving the flexor digitorum superficialis at the level of the A1 pulley.
It develops due to repetitive microinjury from frequent flexion-extension movements of the fingers and/or thumb.
- Thickening of the A1 pulley that overlies the metacarpal heads and alteration in echotexture of the flexor tendons that pass through the digital tunnel. There may be synovial sheath effusion around the tendons
223
What ligaments connects the anterior and posterior horns of the medial and lateral menisci ?
- Transverse ligament (anterior)
- Ligament of Wrisberg and Humphrey (posterior)
224
What are causes of sausage digits ?
- Psoriasis
- TB
- Sickle cell anemia
225
Stages of SAPHO
1. costoclavicular ligament ossification
2. arthropathy of the sternoclavicular joint, osteitis of the medial end of the clavicle, first rib and sternum as well as hypertrophy of the costal cartilages
3. osteitis, hyperostosis and hypertrophy of the medial ends of the clavicles, sternum and upper ribs and ultimately ankylosis
226
Diffuse Marrow Infiltration and Replacement causes?
Mnemonic
M: metastases, multiple myeloma
L: lymphoma
M: myelofibrosis, mastocytosis
L: leukaemia
Focal infiltration is seen in metastases and lymphoma.
The diffuse pattern is seen more commonly in multiple myeloma, mastocytosis, myelofibrosis, and leukaemia.
227
Focal marrow infiltration vs replacement
Focal marrow infiltration has residual and admixed fatty elements
Focal marrow replacement has no residual fat
228
What are causes of Increased or Decreased Marrow Cellularity (red vs yellow marrow ratio)
Red marrow converts when theres increased hematopoietic demand:
↑ red marrow occurs with
- Marrow reconversion: otherwise normal patients confronting new stress = athlete, high altitude
- Chronic anemia: sickle cell disease, thalassaemia
- Marrow stimulation: treatment with granulocyte &/or red cell stimulating factors
↓ red marrow occurs with (increased fatty marrow)
- Advanced age: diffuse marrow depletion
- Severe depletion: aplastic anemia (global)
- Radiation: focal cellular marrow depletion
229
red marrow reconversion pattern?
Axial, then proximal appendicular skeleton.
In the tubular bones, conversion begins in the proximal metaphysis --> distal metaphysis --> diaphysis --> epiphysis.
230
Felty syndrome
Felty syndrome (FS): triad of
- Rheumatoid arthritis (RA)
- Splenomegaly
- Neutropenia
231
Clear cell chondrosarcoma imaging appearance ?
- EPIPHYSEAL, Lytic
- Femoral head (most common)
- Need to differentiate from chondroblastoma
- Absent periosteal reaction (c.f. chondroblastoma)
- Absent adjacent marrow oedema (c.f. chondroblastoma)
232
What consists of the lateral collateral ligament complex
1. annular ligament
2. radial collateral ligament
3. lateral ulnar collateral ligament (lies distal to the common extensor) - torn in elbow dislocation
233
Associated injuries of elbow dislocation (terrible triad)
elbow dislocation (usually postero-lateral)
coronoid process fracture
radial head fracture
234
Anconeus Epitrochlearis runs where and impinges what ?
- Runs over the roof of the cubital tunnel
- impinges on the ulnar nerve
235
Image findings of Hypothyroidism
Congenital hypothyroidism (cretinism)
Delayed skeletal development
Absent or small epiphyses; stippled epiphyses
Short and thick bones, delayed closure of fontanelles
SCFE
236
Differentials of Liposarcoma in thigh
Hibernoma
- rare benign fatty tumors that arise from the vestiges of fetal brown fat and are named “hibernoma” because they resemble brown fat in hibernating animals
237
Guyon's canal syndrome causes ?
- Hook of hamate fracture
- Ganglion cyst (can check statdx images)
238
Distal radioulnar joint (DRUJ) instability
refers to excessive painful mobility in the distal radioulnar joint usually as a result of a previous traumatic injury or bony malunion.
Distal radioulnar joint instability is associated with the following:
- acute distal radioulnar joint dislocation
- distal radial fractures
- triangular fibrocartilage complex injuries
- fracture malunion
239
Femoroacetabular impingement syndrome risk factors
coxa profunda, protrusio acetabuli
acetabular retroversion
previous slipped capital femoral epiphysis or Perthes disease
240
Femoroacetabular impingement syndrome CT measurements ?
alpha angle: >55° in anterior and >60° in anterosuperior position indicate cam morphology
femoral head-neck offset: <6-7 mm in anterosuperior position indicates cam morphology
acetabular retroversion: (normal 12-20°) as an indicator for pincer morphology
241
Complications of FAI
labral tear
chondrolabral separation
chondral injury e.g. carpet lesion
osteoarthritis of the hip
242
What are some vertebral body mass ?
Non-neoplastic
- ABC
- Brown tumor
- Vertebral hemangioma (can enhnace with mass-effect complications, such as neural impingement and extraosseous extension)
- If internal fat => Intraosseous lipoma, Paget disease
Neoplastic
- Mets (most common)
- Multiple Myeloma / Plasmacytoma
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Spinal AVM / DAVF Tx
surgery and angioembolisation
endovascular occlusion
- performed with either cyanoacrylate glue or Onyx after superselective catheterisation of the radiculomeningeal artery supplying the fistula
- endovascular treatment is contraindicated if the radicular artery also supplies the anterior spinal artery; embolisation of a fistula that supplies a posterior spinal artery remains controversial
surgery
- surgical occlusion consists of a targeted laminectomy and intradural exploration with coagulation or disconnection of the draining vein; occlusion rates as high as 98% have been reported
Notably, patients may worsen if initially treated with corticosteroid therapy, which may have been given if an inflammatory pathology such as transverse myelitis was initially suspected
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Spinal epidural hematoma causes
- Spontaneous (most common)
- Trauma
- Spinal AVM
- Iatrogenic (LP)
T1: isointense or hyperintense to spinal cord
T2: heterogeneously hyperintense to spinal cord with hypointense foci
SWI/T2*: blooming artifact
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Atlantooccipital Dislocation measurement ?
On X-ray only:
- Basion-Dense interval < 12mm (normal)
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Periprosthetic fracture classification system ? what parameters does it use ?
Vancouver classification:
Parameters: **fracture site, the status of the femoral implant, and the quality of the surrounding femoral bone stock.
type A: fractures involve the trochanteric area
type B: around the stem or just below it
type C: well below the stem
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Classification for Tibial plateau fracture ?
Schatzker I: wedge-shaped lateral plateau fracture
Schatzker II: wedge-shaped lateral plateau fracture with compression fracture of ipsilateral plateau
Schatzker III: compression fracture of the lateral plateau
Schatzker IV: medial plateau fracture with a split or compressed portion
Schatzker V: wedge fracture of both plateaus
Schatzker VI: transverse tibial metadiaphyseal fracture, along with any type of tibial plateau fracture
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What is Distal biceps tendon repair
refers to the direct surgical fixation of an injured distal biceps tendon to restore elbow flexion and/or supination power and is the surgical procedure of choice in the acute setting.
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Complications of distal biceps tendon repair with endobutton ?
Lateral antebrachial cutaneous nerve injury being the most common.
Posterior interosseous nerve injury.
- nerve compression neuropathy of the posterior interosseous branch of the radial nerve, which affects the innervation of the forearm extensor compartment.
superficial radial nerve injury.
heterotopic ossification.
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What is the differences in approach for biopsying a lymphomatous lesion vs. sarcomatous lesion ?
1. Biopsy Technique:
Lymphomatous Lesion: Excisional biopsy or punch biopsy is often preferred, especially for cutaneous lymphomas, to obtain sufficient tissue for immunohistochemical and molecular studies. Fine needle aspiration (FNA) is generally insufficient for diagnosis.
Sarcoma: Core needle biopsy is typically preferred to obtain enough tissue for histologic analysis while minimizing disruption to surrounding structures. Fine needle aspiration is usually avoided because it may not provide enough tissue for grading and subtype classification.
2. Risk of Seeding:
Lymphoma: lower risk of tumor cell seeding along the biopsy tract
Sarcoma: higher risk of local seeding. Therefore, the biopsy tract must be planned carefully, ideally along the shortest, most direct route, to allow for resection if needed.
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Where does ACL attach ? Arterial supply ? Nerve supply ?
Attachments:
- anteromedial aspect of the intercondylar tibial plateau
- posteromedial aspect of the lateral femoral condyle
Arterial:
- middle genicular artery
Nerve supply:
- tibial nerve
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ACL mucoid degeneration clinical presentation vs ACL tear ?
ACL mucoid degeneration
- Typically patients present with knee pain or restricted movement, although often other potential causes for the patient's symptoms are found.
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ACL mucoid degeneration treatment
No treatment is usually required.
If arthroscopy is performed, the ligament may appear entirely normal, especially using the standard anterior portal approach. A posterior approach will allow for the detection of changes by probing the ligament and mucoid material can be expressed.
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Mucoid degeneration associated with ?
ganglion cysts
osteoarthritis
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Management of tibial plateau fracture ?
The goal of therapy is to reduce the fracture and begin early mobilisation. If the patient is immobilised for a lengthy period (>3 weeks), the joint will not return to the full range of movement.
Depression of a tibial plateau that is inadequately corrected results in a varus or valgus deformity and accelerated osteoarthritis.
Unappreciated ligamentous injury causes greater than normal stress on the remaining support structures of the joint, malalignment, and the development of premature osteoarthritis.
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Secondary Causes of protrusio acetabuli
Paget disease
psoriatic arthropathy
rheumatoid arthritis
ankylosing spondylitis
osteomalacia / rickets
osteogenesis imperfecta
Marfan syndrome
trauma
iatrogenic, e.g. complication of hip hemiarthroplasty
haemophilia (in advanced arthropathy)
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Shoulder fracture classification system ?
Neer classification
- The Neer system divides the proximal humerus into four parts and considers not the fracture line, but the displacement as being significant in terms of classification (>1 cm).
The four parts are:
humeral head
greater tubercle
lesser tubercle
humeral shaft
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Humeral surgical neck fracture considered how many parts ?
2 part
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Scaphoid fracture classification system
Mayo classification of scaphoid fractures
divides scaphoid fractures into three types according to the anatomic location of the fracture line:
middle (70%)
distal (20%)
proximal (10%)
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Thoracic spine fracture-dislocation, and what levels are good prognosis ?
Vertebral fracture concomitant with dislocation of facet joints and/or the intervertebral disc space. They are mechanically unstable and are associated with a high risk of spinal cord injury.
Good prognosis:
- Those fracture-dislocations with preservation of neurological function tend to occur between T6 to T10.
- This is due to the fact that spinous processes extend farther inferiorly in this region. Consequently, strong shear forces would be concentrated in the middle column leading to pedicle fractures and spontaneous spinal decompression (relieving deformities that narrow the spinal canal).
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Thoracic spine fracture dislocation bad prognosis ?
Vertebral body translation >3.5 mm is correlated with higher risk of injury to the posterior ligamentous complex and greater motor deficits
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Thoracic spine fracture dislocation classification ?
AO classification
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Thoracic spine fracture management ?
Maintaining spinal immobilization precautions is imperative in these patients.
The main treatment goals are realignment and fixation of involved vertebrae to avoid any further neurological deficits 3. The neurologic prognosis depends on the initial neurologic evaluation (e.g. ASIA impairment scale for spinal injury) and early course in rehabilitation.
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Spinal subdural hematoma management and prognostic factors ?
Conservative treatment with watchful waiting (i.e. follow-up with serial MRIs) is acceptable for small collections. In case of significant neurologic defects, laminectomy with clot evacuation is done.
Cervical and thoracic SSDH are associated with a worse outcome than lumbar SSDH, as is coexisting spinal subarachnoid haematoma (SSAH).
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is PET good for staging of Myxoid liposarcoma ?
FDG PET is the staging test of choice for most sarcomas. Myxoid liposarcoma however often shows little to no uptake and the study can be falsely reassuring.
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Pathophysiology of ilio-tibial band syndrome ? What patients usually gets this ?
- iliotibial band rubs against the lateral femoral epicondyle irritating the fat and connective tissue as well as an advential bursa in between.
commonly affects young, physically active patients, most often long-distance runners or cyclists.
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Predisposing factors of iliotibial band syndrome ?
Limb length discrepancy
genu varum
overpronation
hip adductor weakness
myofascial restriction
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Clinical presentation of ilio-tibial band syndrome
- Pain over greater trochanter or at the lateral knee joint is the
- Point tenderness 1-2 cm above the lateral joint line.
- Pain is usually worse with downhill running and increases throughout an episode of activity
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How does bone scan appear for medial tibial stress syndrome ?
Bone scintigraphy is relatively sensitive (~75%) and may demonstrate high uptake in the affected region, characteristically along the posteromedial tibial aspect on lateral views.
On the 3-phase isotope bone scan there will be typically normal appearances on the arterial and blood pool phases but longitudinal uptake on the delayed images. (cf. stress fracture which will show early phase uptake).
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Treatment for SNAC and SLAC
four-corner arthrodesis
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Posterior ankle impingement (PAI) syndrome causes
- Stieda process
- Os Trigonum
- Haglund deformity
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How to differentiate SLAP (superior labral anterior posterior tear) to Sublabral sulcus or foramen ?
SLAP: will see high signal extending between the glenoid and labrum posteriorly to the biceps anchor
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