Brant & Helms / Book Ques Flashcards
What distinguishes an insufficiency # from a pathological fracture through a met?
On MRI the typical appearance is a T1 low signal fracture line associated with surrounding oedema (low T1 / high T2).
Fx that support an insufficiency fracture:
- A sharp margin between normal and abnormal marrow within the affected vertebral body.
- Lack of posterior element involvement
- Absence of a paraspinal soft tissue
Causes of a high riding shoulder include?
- Rheumatoid arthritis
- Calcium pyrophosphate dihydrate deposition disease (CPPD)
- Torn rotator cuff
What are the key fx of gout
Well-defined erosions (sclerotic margins with over hanging edges.
Soft tissue nodules - these can become calcified in the presence of renal failure
Random distribution
No osteoporosis
Where does calcification tend to happen in CPPD ?
Knee
Triangular fibrocartilage of wrist
Symphysis pubis
Can calcium hydroxyapatite be differentiated from CPPD on radiographs ?
When CPPD crystals are deposited in the soft tissues, such as in the rotator cuff of the shoulder, a radiograph cannot differentiate between CPPD and calcium hydroxyapatite, which occurs in calcific tendinitis.
Calcium hydroxyapatite does not occur in the joint cartilage except in extremely unusual cases; therefore, all chondrocalcinosis can be
considered to be secondary to CPPD.
The joint destruction or arthropathy of CPPD is
virtually indistinguishable from that of DJD. In fact, it is DJD. It is caused by CPPD crystals eroding the cartilage.
What is the main distinguishing fx of the DJD caused by CPPD that will help distinguish it from DJD caused by trauma or overuse?
The main difference is location.
The DJD of CPPD has a proclivity for the:
- shoulder,
- the elbow
- the radiocarpal joint in the wrist
- the patellofemoral joint of the knee
- the metacarpophalangeal joints in the hand
These are areas of wear and tear not normally involved by DJD (such as in the DIPJs of the hand, the hip, and the medial compartment
of the knee).
When DJD is seen in the joints that CPPD tends to involve, a search for chondrocalcinosis should be made.
If necessary, a joint aspiration for CPPD crystals may be required to confirm the
diagnosis.
What conditions are associated with calcium pyrophosphate dihydrate disease?
Primary hyperparathyroidism
Gout
Haemochromatosis
The collagen vascular diseases are sometimes referred to as the non-erosive arthropathies. What are diseases involved?
Scleroderma,
systemic lupus erythematosus,
dermatomyositis,
mixed connective tissue disease
What are the key features of SLE arthropathy?
Marked soft tissue wasting - this can appear as concavity in the hypothenar eminence
Ulnar deviation of the phalanges, seen primarily in the Rt hand
No erosions
What are the fx of scleroderma in the hands?
1: acro-osteolysis
2: periarticular osteoporosis
3: joint space narrowing
4: erosions
Soft tissue changes including:
1: subcutaneous and periarticular calcification
2: atrophy especially at tips of fingers
3: flexion contractures
What are the typical radiographic features of Myositis Ossificans ?
Circumferential calcification with a lucent centre
How can you distinguish Myositis Ossificans from a tumour ?
Tumours tend to have: - An ill-defined periphery and - A calcified or ossific centre Note: Periosteal reaction can be seen with myositis ossificans or with a tumour
Cystic geodes can occur with ?
Degenerative disease Trauma Rheumatoid CPPD AVN
