Bone And Soft Tissue Infection Flashcards
Risk factors for acute osteomyelitis?
Age (child),
Male,
History of trauma,
Other disease (DM, rheum arthritis, immune compromise, long term steroid, sickle cell)
Source of infection of acute osteomyelitis?
Haematogenous spread,
Local spread from contiguous site of infection,
Secondary to vascular insufficiency
Common source of infection of acute osteomyelitis in infants?
Infected umbilical cord
Common sources of infection of acute osteomyelitis in children?
Boils, tonsillitis, skin abrasions
Common sources of infection of acute osteomyelitis in adults?
UTI,
Arterial line
Common organisms in acute osteomyelitis in infants <1yr?
Staph aureus,
Group B streptococci,
E.coli
Common organisms in acute osteomyelitis in older children?
Staph aureus,
Strep pyogenes,
Haemophilus influenzae
Common organisms in acute osteomyelitis in adults?
Staph aureus,
Coagulate negative staphylococci,
Mycobacterium tuberculosis,
Pseudomonas aeroginosa
Other organisms cause of acute osteomyelitis
Salmonella (if caused by sickle cell disease),
Mycobacterium marinum (in fishermen and filleters),
Candida (HIV AIDS)
In what bones in acute osteomyelitis common?
Distal femur,
Proximal tibia,
Proximal humerus,
Joints with intra-articular metaphysis
Stages of acute osteomyelitis
There is vascular stasis,
Followed by acute inflammation which raises pressure,
Causing suppuration to release the pressure,
Followed by sequestrum,
Involucrum,
Resolution or not
What is sequestrum?
Necrosis of bone
What is involucrum?
New bone formation
Clinical features of acute osteomyelitis in infants?
Failure to thrive, Drowsy, Irritable, Metaphysical tenderness and swelling, Decreased ROM, Positional change
Clinical features of acute osteomyelitis in children?
Severe pain, Reluctant to move, Not weight bearing, Swinging pyrexia, Tachycardia, Malaise, Toxaemia
Clinical features of primary acute osteomyelitis in adults?
Backache,
History of UTI or urological procedure,
Elderly, diabetic, immunocompromised
Where is primary osteomyelitis seen commonly in adults?
Thoracolumbar spine
Investigations of acute osteomyelitis?
FBC, ESR,CRP. Blood cultures, U&Es, X-ray, US, Aspiration, Isotope bone scan, Labelled white cell scan, MRI
Differential diagnosis of acute osteomyelitis?
Cellulitis, Erysipelas, Necrotising fasciitis, Gas gangrene, Toxic shock syndrome, Acute septic arthritis, Acute inflammatory arthritis, Trauma, Transient synovitis, Sickle cell crisis, Rheumatic fever
What isotope bone scans are used in acute osteomyelitis?
Tc-99,
Gallium-67
What labelled white cell scans are used in acute osteomyelitis?
Indium-111
Treatment of acute osteomyelitis?
Supportive treatment,
Rest and splintage,
Antibiotics
Duration and type of antibiotics used in acute osteomyelitis?
4-6 weeks,
Flucloxicllin,
Benzylpen
Antibiotic failure causes?
Drug resistance, Bacterial persistence, Poor host defences, Poor drug absorption, Drug inactivation by host flora, Poor tissue penetration
Surgery indications in acute osteomyelitis?
Aspiration of pus for diagnosis and culture,
Abscess drainage,
Debridement of dead/ infected/ contaminated tissue
Complications of acute osteomyelitis?
Septicaemia, Death, Metastatic infection, Pathological fracture, Septic arthritis, Altered bone growth, Chronic osteomyelitis
Risk factors of chronic osteomyelitis
Operation, Open fracture, Immunocompromised, Diabetics, Elderly, Drug abusers
Common organisms causing chronic osteomyelitis?
Staph aureus,
E.coli,
Strep pyogenes,
Proteus
Pathological causes of chronic osteomyelitis?
Cavities,
Sinuses,
Retained sequestra,
Involucrum
Complications of chronic osteomyelitis?
Chronically discharging sinus/ flare up, Ongoing infection, Pathological fracture, Growth disturbance, Growth deformities, Squamous cell carcinoma
Treatment of chronic osteomyelitis?
Long term antibiotics, Eradicate bone infection, Deformity correction, Massive reconstruction, Treat soft tissue problems, Amputation
Route of infection of acute septic arthritis
Haematogenous,
Eruption of bone abscess,
Direct invasion (eg penetrating wound, intra-articular injury, arthroscopy)
Organisms that cause acute septic arthritis?
Staphylococcus aureus,
Haemophilus influenzae,
Streptococcus pyogenes,
E.coli
Pathology of acute septic arthritis?
Acute synovitis with purulent joint effusion,
Articular cartilage attacked by bacterial toxin and cellular enzyme,
Complete destruction of the articular cartilage
Outcome options of acute septic arthritis?
Complete recovery,
Partial loss of articular cartilage and subsequent OA,
Fibrous or bony ankylosis
Acute septic arthritis presentation in neonate?
Present as septicaemia:
Irritability,
Resistant to movement,
Ill
Acute septic arthritis presentation in child/adult?
Acute pain in single large joint, Reluctant to move the joint, Pyrexia, Tachycardia, Increased tenderness
Acute septic arthritis presentation in adult?
Pain in superficial joint
Investigations of acute septic arthritis?
FBC, WBC, ESR, CRP, Blood cultures, Xray, US, Aspiration
What is the most common cause of acute septic arthritis in adults?
Infected joint replacement
Differential diagnosis in acute septic arthritis?
Acute osteomyelitis, Trauma, Irritable joint, Haemophilia, Rheumatic fever, Gout, Gaucher’s disease
Treatment of acute septic arthritis
Supportive measure,
Antibiotics (3-4 weeks),
Surgical drainage and lavage,
Infected joint replacements
Classification of Tuberculosis bone and joint?
Extra-articular,
Intra-articular,
Vertebral body
Clinical features of TB of the bone and joint?
Insidious onset and general ill health, Contact with TB, Pain, Night pain, Swelling, Loss of weight, Low grade pyrexia, Joint swelling, Decreased ROM, Ankylosis, Deformity
Presentation of TB of the spine?
Little pain,
Abscess or kyphosis
Markers of TB of the bone and joint?
Single joint involvement,
Marked thickening of the synovium,
Marked muscle wasting,
Periarticular osteoporosis
Investigations of TB of the bone and joint?
FBC, ESR, Mantoux test, Sputum/ urine culture, XRAy, Joint aspiration and biopsy
TB of bone and joint differential diagnosis?
Transient synovitis, Monoartcular RA, Haemorrhagic Arthritis, Pyogenic Arthritis, Tumour
Treatment of TB of bone and joint?
Chemotherapy,
Initial- Rifampicin, Isoniazid, Ethambutol for 8 weeks,
Then- Rifampicin and Isoniazid for 6-12 months,
Rest and splintage,
Operative drainage