Orthopaedic Infections

Question 1

Pathophysiology of diabetic foot ulcers

Answer 1

1) Neuropathy - reduced sensation (sensory), dry skin (autonomic), toe clawing (motor)

2) Vasculopathy

3) Immunopathy - infection by S.aureus, Pseudomonas

Question 2

Qns to ask in diabetic foot ulcer history

Answer 2

1) Ulcer characteristics, time course
2) Associated symptoms (eg. vasculopathy - claudication, neuropathy - numbness)
3) Diabetic control
4) Significant past medical history

Question 3

How to assess foot for diabetic neuropathy at bedside?

Answer 3

Motor: claw/hammer toe, Charcot’s foot

Sensory: glove&stocking sensory loss, protective sensory loss (monofilament test), loss of propioception

Autonomic: dry skin

*loss of propioception is the first to go in diabetic foot

Question 4

How to assess foot for vasculopathy at bedside?

Answer 4

Reduced peripheral pulses, cool peripheries, increased capillary refill time

Dry, shiny, hairless skin

Arterial doppler

Ankle-brachial pressure index

Question 5

What is a bone scan?

Answer 5

Bone scintigraphy - radionuclide scan that picks up areas of increased uptake, corresponding to increased osteoblastic activity

Question 6

Investigations in diabetic foot ulcer

Answer 6

1) Bedside: hypocount, HbA1c, monofilament test, ABPI

2) Biochemical: FBC, ESR, wound swab (to check for infection)

3) Imaging: X-ray ankle & foot, MRI
(to check for osteomyelitis, septic arthritis, gas gangrene, bony destruction)

Question 7

What is Charcot Arthropathy?

Answer 7

Chronic progressive degeneration of weight-bearing joint -> deformity of bone architecture and joint alignment

Question 8

Causes of Charcot joint

Answer 8

**Diabetes
Neurological: multiple sclerosis, peripheral neuropathy
Rheum: RA
Toxins: Alcoholism
Infections: Syphilis, leprosy, polio

Question 9

Clinical presentations of Charcot’s arthropathy

Answer 9

Inflammation - erythema, warmth, swelling, tenderness

Instability - hypermobility of joint

Deformity - Rocker-bottom deformity (medial arch collapse + soft tissue contracture)

Question 10

What does Xray show in Charcot Arthropathy? (O+6 Ds)

Answer 10

Atrophic - Osteolysis
Hypertrophic - debris, density increase (sclerosis), destruction, distended joint, dislocation, disorganisation

Question 11

Eichenholtz staging for ____. What are the stages?

Answer 11

Charcot Joint

Stage 0: inflammatory
Stage 1: Development (instability + inflammation)
Stage 2: Coalescence (deformity + inflammation)
Stage 3: Remodelling (deformity + no inflammation)

Question 12

Brodsky classification for ___. What are the types?

Answer 12

Charcot joint site

Type 1: tarsometatarsal joint/midfoot
Type 2: Subtalar joint/hindfoot
Type 3: Ankle joint/calcaneal fracture
Type 4: any combination
Type 5: forefoot

Question 13

make cards for cellulitis onwards (pg18)