Bone and Joint Infection

Question 1

How does a paediatric septic hip present?

Answer 1

Infants

Not feeding

Irritable

Fever

Flexed hip

Question 2

How do children present with septic hips?

Answer 2

Acute pain (usually hip)

Unable to WB

Child unwell

Swinging Fever

Joint swelling

Movements restricted by pain or spasm

Question 3

How is a suspected case of sepsis in the hip managed and approached?

Answer 3

Pain Relief, Fluids, Resuscitation

Investigations:

Bloods

Blood Cultures

USS

MRI

+/- Aspiration

Question 4

In cases of sepsis what do blood and aspiration results show?

Answer 4

Bloods: ESR >40

WCC >12

Aspiration: Aspiration WCC > 50,000 (90% PMN)

Note: PMN = granulocytes (type of leukocyte)

Question 5

If a child is unable to weightbear on one leg what are the differential diagnoses?

Answer 5

Setpic hip

SUFE

Perthes

DDH

Question 6

DDH

Answer 6

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.

Question 7

Perthes

Answer 7

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.

Question 8

SUFE

Answer 8

Slipped upper femoral epiphysis - fracture through the growth plate (physis), which results in slippage of the overlying end of the femur (metaphysis).

Question 9

Associated bugs in septic hip infection:

Answer 9

Important to know:

Question 10

Which pathogen is the likely cause of a septic hip in a child aged under 12 months?

Answer 10

Staph

Group B strep

Question 11

Which pathogen is the likely cause of a septic hip in a child aged 1-5 years?

Answer 11

Staph

H. Influenza

Question 12

Which pathogen is the likely cause of a septic hip in a child aged 5-12 years?

Answer 12

Staph. Aureus

Question 13

Which pathogen is the likely cause of a septic hip in a child aged 12-18 years?

Answer 13

Staph. Aureus

N. Gonorrhoea

Question 14

What is the general approach in children to a suspected septic hip?

Answer 14

Don’t aspirate - head straight to surgery and wash out the joint.

• follow with a course of antibiotics.

Question 15

Hot joint presentation in an adult:

Answer 15

Question 16

What is the normal response to a hot joint?

Answer 16

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.

Question 17

What is the most common cause of a hot swollen joint?

Answer 17

Osteoarthritis.

Question 18

What are differential diagnoses of septic arthritis?

Answer 18

• Only a minority of adult patients with acute monoarthritis have joint sepsis.
• Majority have crystal (gout/pseudogout) or other inflammatory arthropathies.

Question 19

Summary of diagnosing a septic joint:

Answer 19

Question 20

What does aspiration of a joint show?

Answer 20

Provides information about which pathogen is present.

Question 21

Organisms that cause septic arthritis:

Answer 21

History is key e.g history of food poisoning hints to salmonella.

Question 22

What is osteomyelitis?

Answer 22

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.

Question 23

How does osteomyelitis (bone infection) present?

Answer 23

Pain

Fever

Discharge

Abnormal x-ray

Question 24

Chronic osteomyelitis

Answer 24

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.

Question 25

Peri-Prosthetic joint infection

Answer 25

Prosthetic joint infection (PJI), also referred to as periprosthetic infection, is defined as infection involving the joint prosthesis and adjacent tissue.

Question 26

How does PJI present?

Answer 26

Symptoms of PJI:

Pain

Joint swelling or effusion

Erythema or warmth around the joint

Fever

Drainage

Question 27

Risk factors of infection in PJI and surgery:

Answer 27

Revision srugery

High BMI

Immunocompromised

Poorly controlled DM

Alcohol / Smoking

Malnutrition

IVDU (intravenous drug user)

Question 28

Is S.Aureus Gram positive or Gram negative?

Answer 28

S. Aureus - Gram positive

Question 29

What is compartment syndrome?

Answer 29

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.

Question 30

What are the 5 P’s of compartment syndrome?

Answer 30

Pain and passive movement

Pallor

Paraesthesia

Paralysis

Pulselessness

(These are symptoms distal to the compartment affeted).

Question 31

What type of injury causes comparement syndrome?

Answer 31

Crush injuries - can be motor collisions.