Neuropathic Bone disease

Question 1

define charcot foot

Answer 1

Charcot foot is a progressive condition characterized by joint dislocation, pathological fractures, and severe destruction of the pedal architecture

Question 2

6 Ds of charcot foot on xray

Answer 2

Destruction
Debris
Dislocation
Distention
Disorganization
Increased Density (subchondral sclerosis)

Question 3

most common etiology

Answer 3

diabetes (anything that can cause neuropathy)

Question 4

presence charcot in diabetics and in neuropathic pts

Answer 4

7.5% in Diabetic patients
29% in neuropathic patients
Mean age is 50.3 years

Question 5

Neurotraumatic theory

Answer 5

• Exaggerated overuse injury coupled with loss of protective sensation
• Can be initiated by acute trauma or repetitive microtrauma
• Lack of sensation allows continued tissue destruction resulting in fractures and dislocations

Question 6

neurovascular theory

Answer 6

• Vasomotor neuropathy in patients with intact blood flow
• Arteriovenous shunting leads to excessive bone resorption and bone weakening contributes to fractures and dislocations with continued weightbearing

Question 7

eichenholtz classification (stages)

Answer 7

0 - x ray normal, but high degree suspicion
I- acute red hot swollen, fragmentation on x ray
II- bony fragmentation becomes more solid
III - swelling gone, residual deformity

Question 8

brodsky classification (location)

Answer 8

type 1: lisfranc's
type 2:choparts/subtalar
type 3A: ankle
type 3B: calcaneus
type 4: multiple regions
type 5: forefoot

Question 9

s/s charcot

Answer 9

• red, hot, swollen foot
• temp difference (3-6 celsius)
• sensory neuropathy present
• pain doesnt match amount destruction
• bilateral 9-30% of the time

Question 10

keys for diagnosis of charcot

Answer 10

• red, hot, edematous
• cortical fractures, periosteal reaction, joint debris, deformity, dislocation
• lack of break in skin

Question 11

gold standard diagnosis osteomyelitis v. charcot

Answer 11

bone biopsy- bone and cartilage debris embedded in synovium (charcot)

pts. need to be off antibiotics for atleast 2 half lives

Question 12

what test has highest sensitivity and specificity in detecting osteo in neuropathic foot

Answer 12

In111

best approach is to do a combined scan

Question 13

+ Tec99

+ WBC scan

Answer 13

osteomyelitis

Question 14

+ Tec 99

- WBC scan

Answer 14

charcot

Question 15

• Tec 99

+ WBC scan

Answer 15

soft tissue infection

Question 16

MRI for charcot

Answer 16

T1 - decreased
T2 - increased
STIR - high signal marrow edema

Question 17

being able to probe to bone with metallic instrument is ____ positive for diagnosing osteomyelitis

Answer 17

89%

Question 18

tx charcot based on stages

Answer 18

I - keep nwb in total contact cast or boot until consolidation occurs and/or temp stabilized- may take months
II - increase protected weight bearing
III - custom orthotics or braces