Pathology cortex 2

Question 1

What is the similar end result of osteochondiritis and avascular necrosis (AVN)?

Answer 1

An area of bone undergoes localized necrosis as a result of ischaemia from a reduction in blood supply

Question 2

What is osteochondritis ?

Answer 2

Tends to occur in children and young adults and may be due to increased physical activity with repetitive stress (compression or traction)

(Recurrent) Impact or traction injuries cause bleeding and oedema within the bone, resulting in capillary compression. Bone necrosis ensues resulting in compression, fragmentation or separation of bone

Question 3

Match the sites commonly affected by osteochondritis, due to compression, to the name it is known by when osteochondritis affects these sites:

• 2nd metatarsal head
• capitellum of the elbow
• lunate of the carpus
• the navicular bone
• Vertebral compression

Freiburg’s disease, Kohler’s disease, Kienbock’s disease, Panner’s disease, Scheuermann’s disease

Answer 3

1. 2nd metatarsal head - Freiburg’s disease
2. capitellum of the elbow - Panner’s disease
3. lunate of the carpus - Kienbock’s disease
4. the navicular bone - Kohler’s disease
5. Vertebral compression - Scheuermann’s disease

Question 4

Describe the treatment of osteochondritis

Answer 4

• Compression and traction osteochondritis may settle
• If joint is damaged from osteochondritis, osteotomy (surgical realignment of a bone ) can shift the load in a joint from a damaged area to an undamaged area
• Osteochondritis dissecans (cracks form in the articular cartilage and the underlying subchondral bone.) can be treated by pinning of unstable fragments or removal of detached fragments.

Question 5

What is AVN?

Answer 5

Ischaemic necrosis of bone predominantly in adults

Question 6

What areas of bone are particularly at risk of AVN ?

Answer 6

• Femoral head,
• The femoral condyles,
• The head of the humerus, T
• he capitellum,
• The proximal pole of the scaphoid
• The proximal part of the talus.

Question 7

What are the causes of AVN ?

Answer 7

• Fractures
• Idiopathic
• Alcoholism and Steroid abuse (promote fat mobilisation into circulation which can promote coagulation

Question 8

What does AVN result in ?

Answer 8

Results in necrosis of a segment of bone resulting in patchy sclerosis before subchondral collapse

Question 9

Describe the treatment of AVN

Answer 9

If the articular surface has not collapsed in an amenable site (usually the femoral head) drilling can be performed under fluoroscopy to “decompress” the bone, prevent further necrosis and help healing.

If the articular surface has collapsed generally joint replacement is usually required

Question 10

Where does traction osteochondritis occur ?

Answer 10

Occurs at an apophysis (a bony tubercle where a tendon attaches)

Question 11

What are the common sites for traction osteochondritis and what are there subsequent names if it occurs in that site ?

Answer 11

• Osgood schlatters disease - occurs at the tibial tubercle
• Severes disease - occurs at the calcaneus