Bone and Joint Infection Flashcards
How does a paediatric septic hip present?
Infants
Not feeding
Irritable
Fever
Flexed hip
How do children present with septic hips?
Acute pain (usually hip)
Unable to WB
Child unwell
Swinging Fever
Joint swelling
Movements restricted by pain or spasm
How is a suspected case of sepsis in the hip managed and approached?
Pain Relief, Fluids, Resuscitation
Investigations:
Bloods
Blood Cultures
USS
MRI
+/- Aspiration
In cases of sepsis what do blood and aspiration results show?
Bloods: ESR >40
WCC >12
Aspiration: Aspiration WCC > 50,000 (90% PMN)
Note: PMN = granulocytes (type of leukocyte)
If a child is unable to weightbear on one leg what are the differential diagnoses?
Setpic hip
SUFE
Perthes
DDH
DDH
Developmental dysplasia of the hip (DDH) is a condition where the “ball and socket” joint of the hip does not properly form in babies and young children.
Perthes
Perthes disease is a rare childhood condition that affects the hip. It occurs when the blood supply to the rounded head of the femur (thighbone) is temporarily disrupted. Without an adequate blood supply, the bone cells die, a process called avascular necrosis.
SUFE
Slipped upper femoral epiphysis - fracture through the growth plate (physis), which results in slippage of the overlying end of the femur (metaphysis).
Associated bugs in septic hip infection:
Important to know:
Which pathogen is the likely cause of a septic hip in a child aged under 12 months?
Staph
Group B strep
Which pathogen is the likely cause of a septic hip in a child aged 1-5 years?
Staph
H. Influenza
Which pathogen is the likely cause of a septic hip in a child aged 5-12 years?
Staph. Aureus
Which pathogen is the likely cause of a septic hip in a child aged 12-18 years?
Staph. Aureus
N. Gonorrhoea
What is the general approach in children to a suspected septic hip?
Don’t aspirate - head straight to surgery and wash out the joint.
- follow with a course of antibiotics.
Hot joint presentation in an adult:
What is the normal response to a hot joint?
If there aren’t signs of sepsis, aspirate to identify bug causing the infection so antibiotic treatment can be appropriately tailored.
If there are signs of sepsis immediate intervention and antibiotic treatment.
What is the most common cause of a hot swollen joint?
Osteoarthritis.
What are differential diagnoses of septic arthritis?
- Only a minority of adult patients with acute monoarthritis have joint sepsis.
- Majority have crystal (gout/pseudogout) or other inflammatory arthropathies.
Summary of diagnosing a septic joint:
What does aspiration of a joint show?
Provides information about which pathogen is present.
Organisms that cause septic arthritis:
History is key e.g history of food poisoning hints to salmonella.
What is osteomyelitis?
Osteomyelitis is an infection in a bone. Infections can reach a bone by traveling through the bloodstream or spreading from nearby tissue. Infections can also begin in the bone itself if an injury exposes the bone to germs.
How does osteomyelitis (bone infection) present?
Pain
Fever
Discharge
Abnormal x-ray
Chronic osteomyelitis
Chronic osteomyelitis is a severe, persistent, and sometimes incapacitating infection of bone and bone marrow. It is often a recurring condition because it is difficult to treat definitively. This disease may result from the following: Inadequate treatment of acute osteomyelitis.
Peri-Prosthetic joint infection
Prosthetic joint infection (PJI), also referred to as periprosthetic infection, is defined as infection involving the joint prosthesis and adjacent tissue.
How does PJI present?
Symptoms of PJI:
Pain
Joint swelling or effusion
Erythema or warmth around the joint
Fever
Drainage
Risk factors of infection in PJI and surgery:
Revision srugery
High BMI
Immunocompromised
Poorly controlled DM
Alcohol / Smoking
Malnutrition
IVDU (intravenous drug user)
Is S.Aureus Gram positive or Gram negative?
S. Aureus - Gram positive
What is compartment syndrome?
Compartment syndrome occurs when the pressure within a compartment increases, restricting the blood flow to the area and potentially damaging the muscles and nearby nerves. It usually occurs in the legs, feet, arms or hands, but can occur wherever there’s an enclosed compartment inside the body.
What are the 5 P’s of compartment syndrome?
Pain and passive movement
Pallor
Paraesthesia
Paralysis
Pulselessness
(These are symptoms distal to the compartment affeted).
What type of injury causes comparement syndrome?
Crush injuries - can be motor collisions.
