benign and malignant knee conditions

Question 1

what is an osteochondroma?

Answer 1

benign chondrogenic lesion derived from abherrent cartilage

Question 2

what are the X-ray findings for osteochondroma?

Answer 2

pedunculate lesion with the cortex of the lesion in continuity with the cortex of the native bone

points away from the joint

Question 3

what are the concerning features for malignancy of osteochondromas?

Answer 3

1. growth in adulthood - thickened cartilage >2cm is very concerning
   2.Multiple hereditary exostosis - 10% transformation to chondrosarcoma
2. pain and swelling
3. lysis in part of stork
4. intramedullary invasion of the underlying bone

Question 4

Treatment of osteochondroma?

Answer 4

• observe if asymptomatic
• marginal excision if symptomatic
• safety net for adulthood

Question 5

principles of excision of osteochondroma?

Answer 5

marginal resection:
* resect at base of stalk
* remove cartilage cap
* consider bone graft and fixation

Question 6

common sites of osteochondroma?

Answer 6

• distal femur
• proximal tibia
• proximal humerus

Question 7

what is pigmented villonodular synovitis?

Answer 7

A locally aggressive neoplastic synovial disease characterized by joint effusions, expansion of the synovium, and bony erosions

Question 8

what is the typical presentation of PVS?

Answer 8

• joint swelling
• tenderness - anterior knee pain
• erythema
• stiffness

Question 9

what are the xray findings for PVS?

Answer 9

cystic erosion with sclerotic margins on both sides of the joint

Question 10

what is the treatment algorithm for PVS?

Answer 10

• non-operative = asymptomatic
• Operative
  
  • arthroscopy – anterior disease
  • open – posterior/ extra-articular disease
  • total synovectomy and TKR – degenerative disease