Septic Arthritis

Question 1

Comm joints

Answer 1

Knee 50%
Hip
Shoulder
Elbow
Ankle
Sternoclavic jnt

Question 2

RFs

Answer 2

Over 80
PMH- DM, RA, cirrhosis, HIV, crystal arthropathy
Endocarditis or recent bacteraemia
IV drug use
Recent jnt surg
Prosthetic implant

Question 3

Bacterial seeding

Answer 3

Bacteraemia
Direct inoculation eg trauma, surg
Contig spread eg from adjacent osteomyelitis
Staph aureus in 50% cases. Also MRSA, staph epidermidis, N gonorrhoea, gram neg bacilli eg ecoli, strep etc. Pa in imm comprom.

Question 4

Pathol

Answer 4

Irrev cartil destruc due to proteolytic enx rel from inflamm cells

Question 5

px

Answer 5

Pain
Fever
Erythema
Effusion
Warm
Inabil to weight bear or tol passive ROM

Question 6

ix

Answer 6

XR show sequestrum in chronic
US
MRI can show marrow oedema in spine
WBC over 10K with left shift
ESR over 30
CRP over 5
Jnt fluid aspirate- WBC over 50K, culture, appearance, gram stain, gluc, crystals
Saline load test

Question 7

diffs

Answer 7

Gout, pseudogout
Cellulitis
Bursitis

Question 8

mx

Answer 8

IV AB broad spec then culture based
Surgic irrigat and drain, can be arthroscopic
Debridement and lavage fro chronic, maybe req synovectomy. Fill in gaps eg myoplasty, graft, cement.
Cultures and microbiol advice
Haemodynamic resus if toxic
PK, splintage

Question 9

Kocher criteria

Answer 9

Non weight bearing
Temp over 38.5
ESR over 40mm/hr
WBC over 12K cells/mm3

Question 10

Grade of tenderness

Answer 10

1 no wince but report pain
2 wince
3 retract
4 not let touch

Grade 4 means septic arth or gouty arth

Question 11

Complics

Answer 11

Necrosis

Septacaemia- active multip in blood

Question 12

Shock- end organ hypoperfusion

Answer 12

Haemodynam- haemorr, hypovol
Cardiogenic- HF
Septic- endo/exotox