Week 1 - H -Osteochondritis(Freiburg/Kohler/Keinbock/Panner/Scheuermann/Perthe&Osgood Schlatter/Sever)&Avascular Necrosis

Question 1

What similar end result do both osteochondritis and avascular necrosis share?

Answer 1

Osteochondritis and avascular necrosis have a similar end result in that an area of bone undergoes localised necrosis as a result of ischaemia from a reduction in blood supply

Question 2

Osteochondrosis is a family of disorders that affect bone growth in children and adolescents. What is affected in osteochondroses? What is osteochondritis?

Answer 2

Oseochondroses are characterised by the abnormal of endochondral ossification growth during childhood

Osteochondritis is a painful type of osteochondroses where cartilage and bone of a joint becomes inflamed and may die due to lack of bloof flow

Question 3

What age group may osteochondritis occur in? What may it be due to?

Answer 3

Osteochondritis tends to occur in children and young adults

It is thought that it may be due to increased physical activity with repetitive stress (compression or traction)

Question 4

How may the repetitive stress that occurs due to increased physical activity lead to osteochondtritis?

Answer 4

Impact or traction injuries cause bleeding and oedema within the bone resulting in capillary compression

This capillary compression can result in bone necrosis as a result of ischaemia from reduction in blood supply

Question 5

When there is fragmentation with separation of bone and cartilage within a joint, what is this known as?

Answer 5

Fragmentation with separation of bone and cartilage within a joint is known as osteochondritis dissecans.

Question 6

What may the bone necrosis that occurs in osteochonditis cause?

Answer 6

The bone necrosis may result compression, fragmentation or separation of bone (and overlying cartilage if intra-articular) which may cause flattening and incongruence of a joint

Pain and progression to arthritis at a young age if a joint is involved may follow

Question 7

There are common sites affected by compression of capillaries in osteochondritis each with an eponym (named after a person) In osteochondritis affecting the feet

* What is Freiburg’s disease?

* What is Koher’s disease?

Answer 7

Freiburg’s disease is compression of the capillaries to the 2nd metatarsal head

Kohler’s disease is compression of the capillaries to the navicular bone

Question 8

In Osteochondritis of the hand

What is Keinbock’s disease?

What is Panner’s disease? - what is this also known as?

Answer 8

Keinbock’s disease is compression of the capillaries supplying the lunate of the carpus

Panner’s disease is compression of the capillaries supplying the capitellum of the elbow (Osteochondiritis dissecans of the elbow as there is fragmentation and separtion of the bone and cartilage within the elbow joint)

Question 9

Vertebral compression can also form osteochondritis What is this known as? What is the mode of inheritance?

Answer 9

Vertebral compression in osteochondritis is known as Scheuermann’s disease

• characterised by abnormal endochondral ossification of the thoracic vertebra causing a dorsal kyphosis

It is an autosomal dominant condition

Question 10

Perthe’s disease of the hip is also thought to be a compression osteochondiritis

What happens in Perthe’s disease?

Answer 10

Perthes disease is a rare childhood condition that affects the hip.

It occurs when the blood supply to the rounded head of the femur (thighbone) is temporarily disrupted

Question 11

We have discussed different compression osteochondritis

Where does traction osteochondirits occur at?

Answer 11

Traction osteochondritis occurs at an apophysis - a bony tubercle where a tendon attaches

Question 12

What does the traction osteochondritis known as Osgood-Shclatter;s disease affect?

What doesthe traction osteochondritis known as Sever’s disease affect?

Answer 12

Osgood schlatters disease is a tibial tuberosity apophysitis where there is traction from the insertion of the patellar tendon

Sever’s disease is a calcaneal apophysitis where there is traction from the insertion of the calcaneal tendon

Question 13

Quick recap on the osteochondritis. State where each affects * Freiburg’s disease * Kohler’s disease * Keinbock’s disease * Panner’s disease * Scheurman’s disease * Perthe’s disease * Oshood Schlatter’s disease * Sever’s disease

Answer 13

Compression osteochondritis

• Freiburg’s disease - 2nd metatarsal head
• Kohler’s disease - navicular bone
• Keinbock’s disease - lunate of the carpus
• Panner’s disease - capitellum of the elbow
• Scheurman’s disease - vertebral compression
• Perthe’s disease - femoral head

Traction osteochondritis

• * Oshood Schlatter’s - tibial tuberosity aophysitis
• * Sever’s disease - calcaneal apophysitis

Question 14

How may compression osteochondritis be treated?

Answer 14

Compression types of osteochondritis may settle with few or no ongoing problems.

Restriction of activities may be enough and splintage may help in the wrist or foot.

Question 15

How are traction osteochondritis treated?

Answer 15

Traction osteochondritis is self‐limiting and settles with rest.

NSAIDs may help with painful symptoms

Question 16

If a joint is damaged from osteochondirits, what can be done?

Answer 16

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 (especially knee or Freiburg’s disease (2nd metatarsal head))

Question 17

As stated earlier, Fragmentation with separation of bone and cartilage within a joint is known as osteochondritis dissecans

What sites are particularly predisposed to osteochondritis dissecans?

Answer 17

Lateral side of medial femoral condyle in the knee is the typical patient

Also,

* Anteromedial talar dome

* Superomedial femoral head

* Humeral capitellum (Panner’s disease)

Question 18

What are the symptoms of osteochondritis dissecans?

Answer 18

Pain and effusions after exercise and locking may occur

MRI scan reveals articular surface defects / loose bodies

Question 19

What is the treatment of osteochondritis dissecans?

Answer 19

Stable lesions are treated conservatively as spontaneous healing can occur

Unstable lesions can be treated by pinning or removal of detached fragments

Question 20

What is avascular necrosis? What is avascular necrosis also known as?

Answer 20

Avascular necrosis is an ischaemic necrosis of bone predominantly in adults due to an interruption in blood supply

It is also Known as osteonecrosis or bone infarction

Question 21

What sites are particular prone to avascular necrosis?

Answer 21

Several sites are particularly prone to avascular necrosis

* The femoral head (hip)

* The femoral condyles (knee)

* The head of the humerus (shoulder)

* The capitellum of the humerus (elbow)

* PRoximal pole of scaphoid

* Proximal part of talus

Question 22

Name different fractures that avascular necrosis can be secondary to

Answer 22

Femoral neck fractures

Proximal humerus fractures

Waist of scaphoid fractures

Talar neck fractures

The fractures disrupt the blood supply to an entire portion of bone

Question 23

Many cases of AVN are idiopathic where no cause is found

What are the two most commonly identified causes of avascular necosis? How do they lead to AVN?

Answer 23

Alcoholism and steroid (ab)use are two of the commonest identifiable causes found.

Alcoholism and corticosteroids alter fat metabolism which can result in mobilisation of fat into the circulation *

This can sludge up the capillary system and promote coagulation within prone areas of bone

* The increased fat content of the marrow can compress venous outflow from the bone causing stasis and ischaemia

Primary hyperlipidaemia can also result in AVN in the same way.

Question 24

Aside from fractures, alcoholism and steroids, what are other causes of avascular necrosis?

Answer 24

Other causes include

* Thrombophilia

* Sickle cell disease

* Anti-phospholipid deficiecy

* Decompression sickness - nitrogen gas bubbles form in the circulation after too rapid a depressurisation after deep sea diving - N2 bubbles accumulate in the fat and therefore in marrow

Question 25

AVN results in necrosis of a segment of bone resulting in patchy sclerosis before subchondral collapse and irregularity of the articular surface occurs. Secondary OA ensues.

What is the treatment of avascular necrosis

* Early vs late detection

Answer 25

Treatment

* Early detection on MRI before the articular surface has collapsed - (usually the femoral head) - core decompression treatment by drilling to decompress the bone, prevent further necrosis and help healing

* Late detection - articular surface has collapse - total joint replacement