Metabolic and Arthritis Flashcards
What is cupital tunnel syndrome?
Where there is pressure or stretching of the ulnar nerve
Patient presents with reduced sensation in ring and little fingers
What are the causes of cubital tunnel syndrome?
Accessory muscle called Aconeus epitrochleris
Can cause compression on the ulnar nerve
Seen on MRI
Can be surgically released
What conditions do bone demineralisation (osteopenia) occur in?
HORSE
Haemophilia
Osteomalacia
Rheumatoid
Scleroderma
SLE
What conditions does osteopenia demineralisation NOT occur in?
PONGS
Psoriatic arthritis
Osteomyelitis
Neuropathic joints
Gout
Sarcoidosis
What are tthe features of complex regional pain syndrome?
Patient develop pain in an area of previous minor injur
Burning in sensation
Plain film: juxta articular osteopenia and subperiosteal bone resorption (osteoporosis)
Nuclear Med scans: increased flow with increased uptake OR decreased flow with decreased uptake
Where does enteropathic arthritis typically affect?
Seen in crohns/UC/whipples/salmonella
Sacroiliitis and spondylitis are typical
Other areas affected: hands, uveitis, feet, calcaneal enthesitis
What is diagnosis in patient with sternoclavicular hyperostosis and osteitis, and unilateral sacroilitis?
SAPHO
Synovitis, Acne, Palmoplantar pustolisis, hyperostosis, osteitis
Middle aged adults
- Hyperostosis, ankylosis of sternoclaviular joint is classical*
- progresses to involve medial clavicles and costal cartilages and upper ribs
- 1/3 of patients have spinal involvement with osteosclerosis*
- Unilateral sacroilitis can be seen*
Where does Psoriatic arthropathy typically affect?
‘Erosive change with bone proliferation’
- Pencil in cup deformity*
- Mouse ears*
- Ankylosis*
Usually prefers DIPs over MCPs
Affects:
- spine
- SI joints
-Bony erosions
-Periosteal new bone formation
What is rheumatoid arthritis distribution?
Characterised by:
- osteoporosis
- -soft tissue swelling*
- -marginal erosions*
- -uniform joint space narrowing*
Often Bilateral and symmetric
**Spares the DIP joints
**5th metaTARsal is the first place in foot to be affected
Good differentiator for RA/Psoriatic vs OA is that OA will always affect first CMC joint first (in RA and psoriatic it will be the last of the carpals to be affected
Distal radioulnar joint
Radiocarpal joint
MCPs & PIPs
What are the 5 features of charcot joint?
What is main cause of a charcot shoulder?
Compromise to the senosry nerves to the area compromise normal protective mechanisms
Affected joints can be Atrophic (bony destruction and little sclerosis) which is most common or Heterotrophic (fragmentation and debris with alot of sclerosis)
- Destruction*
- Dislocation*
- Density (heterotrophic)*
- Disorganisation*
- Debris*
Loose bodies
Most common cause of shoulder charcot is Syringomyelia
Other causes of charcot:
- Diabetes
- Leprosy (hansen disease)
- Poliomyelitis
- Neurosyphilis
- MS
How to differentiate charcot vs osteomyelitis?
TCharcot is a neuopathic process and usually affects midfoot. Can affect multiple joints at once
Osteomyelitis tends to be over area of ulcer or infection and involve isolated joint. Tend to prefer pressure points in the feet. Effusion is common. High T2 signal in the bone.
What is Osteopetrosis?
Hereditary disorder
Abnormal osteoclasts result in thick and sclerotic bone
-Poorly formed therefore high propensity for fractures
Features: appear as bone within bone appearance
highly dense appearing bones
What is name of condition which appears as multiple sclerotic bone islands oval in shape?
Osteopoikilosis
Mild uptake on NM bone scan
How to differentiate cam type vs pincer FAI?
Cam - bony overgrowth of femoral neck
- more frequently in men in 30’s
- predisposing conditions: SUFE, DDH
- femoral retroversion
Pincer: -overcoverage of the femoral head by bony protruberance of anterosuperior acetabulum
- acetabular retroversion
- more common in women around 40 years
What ligament damage causes VISI (volar intercalated segmental instability?
VISI - Lunotriquetral
Injury to this ligament also causes midcarpal dislocation
SLAC & DISI - Scapholunate ligament injury
Perilunate dislocation = Capitolunate ligament injury
Lunate dislocation = Dorsal radiolunate ligament injury
What is name given to dripping candle wax apperance on bone?
Melorrheostosis
Resembles dripping of solid candle wax on a bone
Can cross joints and bones
Appears as dense sclerosis
Can cause flexion contractures
FIbrosis of overlying skin
Usually affects just one joint
What is Lipoma arborescens?
How is it different to PVNS? (below)
Fatty deposition in the synovium of the knee
Due to chronic inflammation of synovium
Older patients 50 - 70 years
Assc with OA/RA/prev trauma
Plain film will show joint effusion
MR will show high T1 and T2
Tx: Synovectomy
If there is nodular thickening in the synovium with frond like villonodular appearance in suprapatellar region (Low T1 and Low T2) - this is due to Pigmented villonodular synovitis (has haemosiderin deposition also)
-if patient is male, haemophilicarthropathy is differential
What causes bilateral symmetric sacroilitis?
- Psoriatic arthritis
- Ankylosing spondylitis
What causes bilateral asymmetric sacroilitis?
- Psoriatic arthritis
- Gout
- Reactive arthritis
What is alkaptonuria? (also known as ochronosis)
What are features?
Excessive homogenistic acid which has an affinity for collagen where it accumulates
Features
-Chondrocalcinosis
- -Calcification and destruction of intervertebral joints*
- -Premature osteoarthritis of hands, feet shoulder, hips, knees*
- -Depositon in heart and kidneys leads to heart and renal failure*
Where does pseudogout typically effect?
The patellofemoral joint – joint space loss here can be extremely striking with almost complete preservation of the joint space at the medial and lateral compartments of the knee
Triangular fibrocartilatinous complex of the wrist – calcification
Radiocarpal joints – degenerative changes without involvement of the DIPs and PIPs
Soft tissue calcification is common and chondrocalcinosis is also classical. The formation of unusually large subchondral cysts is often seen and sometimes these can be so large that they are mistaken for giant cell tumours.
What are features of enteropathic arthritis?
This occurs in a subsect of patients with inflammatory or infective bowel disease. Roughly 10-20% of patients with Crohn’s or ulcerative colitis suffer from enteropathic arthropathy. Like chronic reactive arthropathy, it can also occur in the context of salmonella, shigella and yersinia infections. Appearances are very similar to those of ankylosing spondylitis; the two can be very difficult to separate radiologically.
- Bilateral symmetrical sacroillitis
- Enthesopathy
- Vertebral syndesmophytes
- Fusion of spinous processes
What is Osteomalacia?
Soft bone due to Vitamin D or phosphate deficiency of various causes
- -Appears as diffuse osteopenia*
- -blurred appearance to trabeculae*
- -poor corticomedullar differentiation*
Loosers Zones
Insufficiency fractures that appear as wide lucent bands that traverse bone at right angle to cortex
There is sclerosis surrounding the lucency
Classic places - pubic rami and femoral necks (can happen anywhere though)
When you see these = think rickets of osteomalacia
Transient osteoporosis of the hip
What is typical presentation and in whom?
Typically pregnant woman in 3rd trimester with involvement of the left hip
Will have loss of subchondral cortex of the femoral head and neck region.
-No joint space narrowing
-Joint effusion
Increased uptake on Bone scan
Plain film - Osteopenia
MRI - Oedema
What are features of a vertebral met/tumour?
There wont be a vertebral body fracture until almost all of the VB is infiltrated by tumour
If low on T1 (lower than disc) and involvement of posterior cortex, think met
Its helpful to look at rest of spine as mets are often multiple
What is Osteochondral Dissecans?
Occurs in males under age 18 usually
It is separation of an osteochondral fragment (most common in medial femoral condyle) which can result in fragmentation of the articular surface and secondary OA.
Commonly due to trauma e.g. repetitive stress/gymnastics
Can occur in capitellum of elbow, ankle.
MRI - may see a T2 line between bone and osteochondral defect signifying instability and detachment
What are classic appearances of Osteomyelitis on plain film?
Destruction of bone and periosteal new bone foramation
Chronic Osteomyelitis
Where osteomyelitis has persisted for longer than 6 weeks
Classic sign is sequestrum (area of necrotic bone surrounded by granulation tissue best seen on CT)
- Draining sinus tracts are a risk factor for SCC*
- On MRI Osteomyelitis will be Low T1 and high STIR*
What is Potts Disease?
What is spared in Potts?
What are assc findings?
What is a Gibbus deformity?
TB of the spine
Spares the disc spaces
Gibbus deformity is a destructive kyphosis
Pagets Disease
Excessive bone remodelling - disease of osteoclasts
3 stages: Lytic – Mixed — Sclerotic
- ‘Expanded bone with coarsened trabecular pattern’*
- Affects:*
- -Spine*
- -Skull*
- -Pelvis*
- -Proximal long bones*
Elevated ALP
Normal calcium and phosphate
Spine: picture frame sign denotes sclerosis of VB cortex rim on all 4 sides (rugger jersey is top and bottom only)
Cotton wool appearance to skull (lytic and sclerotic lesions)
Osteoporosis circumscripta (well defined lucent lesions in skull)
Pattern of destruction in RA vs OA at hips
RA vs Psoriasis
What are differences?
Ankylosing Spondylitis
Where is first affected?
Where in the peripheral skeleton can be involved?
What can occur post hip replacement?
SI joints are first places affected
- When there is involvement of peripheral skeleton hips and shoulders are most common*
- Heterotrophic ossification (bone growth in soft tissues around hip) can occur post hip replacement - can often need NSAIDS or radiotherapy*
Asymmetric vs Symmetric involvement of SI joints
What causes bilateral symmetric?
Gout
What are features?
- Earliest sign is joint effusion*
- -SPARES joint space until late on*
- -Juxt-aarticular erosions away from joint*
- -Overhanging edges*
- -Punched out lytic lesions*
- -Soft tissue tophi*
What is Osteopathia striata?
Logitudinal striations in the metaphysis of long bones
Bone looks like celery
Inherited or sporadic
What is Dolichocephaly?
Head is disproportionaltey long and narrow
Le fort fractures
Hepatosplenomegaly, metaphyseal flaring (widened metaphysis and narrow diaphysis),
What is diagnosis?
Gauchers
Erlenmeyer flask deformity
