Lecture 9: Neurotrophic Arthropathy

Question 1

What is neurotrophic arthropathy like in the spine?

Answer 1

• Most common in Lx
• Hypertrophic pattern
  
  • IVD loss of height
  • Sclerosis
  • Osteophytes
  • Vacuum phenomenon.
• Vertebral fragmentation and misalignment (jigsaw vertebrae)

Question 2

What % of DM patients develop neurotrophic arthropathy?

Answer 2

5%

Question 3

What is neurotrophic arthropathy secondary to?

Answer 3

Impaired or absent sensory or proprioceptive function in the joints

Question 4

What is neurotrophic arthropathy like in the foot?

Answer 4

• Subtalar joint shows early hypertrophic change
• Talocalcaneal joint sees collapse of inferior talar cortex
• Talar destruction (involvement of entire tarsus)
• Malleolar fractures, tibiotalar destruction with sclerosis, fragmentation and misalignment
• Forefoot see trophic changes
• Metatarsal shaft and neck fractures; occasional fracrture near metatarsal bases
• Atrophic changes in the metatarsals and adjacent phalanges
• Metatarsals spread apart as soft tissue support is destroyed

Question 5

What can cause neurotrophic arthropathy?

Answer 5

Any condition resulting in decreased peripheral sensation, propriception and fine motor control. (pretty much anything that impairs vascular or neurological supply to the joint)

Question 6

What is neurotrophic arthropathy like in the knee

Answer 6

• Hypertrophic pattern
• Early stage joint effusion and DJD
• May fracture easily (esp. medial tibial plateau)
• Later see subchondral sclerosis as far as adjeacent metaphyses
• Prominent feature: joint debris
• Articular surface destruction (esp. tibial plateau)
• Severe misalignment: tibia and fibula laterally displaced
• Lateral dislocation of the patella

Question 7

What does neurotrophic arthropathy usually result in?

Answer 7

Excessive traumatic DJD

Results in severe instability, and joint destruction

Question 8

What are the clinical features of neurotrophic arthropathy?

Answer 8

Altered gait patterns

Joint enlargement and crepitus

Relatively painless instability of affected joint

Question 9

What is the pathological process of neurotrophic arthropathy?

Answer 9

General agreement is neurotraumatic theory, whereby destructive joint changes occur as the sequeala to an ineffective protective neurological mechanism

Question 10

What are the radiological findings of a charcots joint?

Answer 10

Early:

• Chronic, painless effusion.
• DJD and spontaenous #

Six D’s:

• Density of subchondral sclerosis
• Destruction of bone
• Debris within joint
• Dislocation due to chronic and severe instability
• Disorganisation of all joint elements
• Distention of the joint

Question 12

What is neurotrophic arthropathy also known as?

Answer 12

Charcots joints