Orthopaedic

2. septic arthritis
 is an inflammatory joint disease
caused by bacterial, viral, and
fungal infection.

3. Route of infection
 Dissemination of pathogens via the blood, from
distant site…. (most common)
 Dissemination from an acute osteomylitic focus
 Dissemination from adjacent soft tissue infection,
 Entry via penetrating trauma
 Entry via iatrogenic means

5. Etiology
 The causal organism is usually Staphylococcus aureus.
 In children under the age of 3 years Haemophilus
influenzae is fairly common
 gram-negative bacilli (a group of bacteria, including
Escherichia coli, or E. coli)
 streptococci (a group of bacteria that can lead to a
wide variety of diseases)

6. Pathology
 There is an acute synovitis with a purulent joint effusion
and Synovial membrane becomes edematous, swollen and
hyperemic, and produces increase amount of cloudy
exudates contains leukocytes and bacteria
 As infection spread through the joint, articular cartilage is
destroyed by bacterial and cellular enzymes.
 If the infection is not arrested the cartilage may be
completely destroyed.
 Pus may burst out of the joint to form abscesses and
sinuses.
 The joint may be become pathologically dislocated.

7. With healing there will be:
 Complete resolution and return to normal.
 Partial loss of cartilage and fibrosis.
 Bone ankylosis
 Bone destruction and permanent deformity.

8. Clinical presentation
 Typical features are acute pain and swelling in a single
large joint ,commonly the hip in children and the knee in
adults, however any joint can be affected.
 The most commonly involved joint is the knee (50% of
cases), followed by the hip (20%), shoulder (8%), ankle
(7%), and wrists (7%). interphalangeal, sternoclavicular,
and sacroiliac joints each make up 1-4% of cases.

9. 1. Symptoms in newborns or infants:
 The emphasis is on septicemia rather than joint pain.
 Irritability ,Fever, refuses to feed, rapid pulse.
 Unable to move the limb with the infected joint
(pseudoparalysis) .
 Cries when infected joint is moved (diaper changing)
 Infection is usually suspected ,but it could be anywhere
so the joints should be carefully felt and moved to elicit
the local signs of warmth ,tenderness and resistance to
movement.
 Umbilical cord or the site of injection should be
examined for possible source of infection.
 If the baby is distressed and wont move his/her leg think
of hip infection.

10. 2. In children:
 Acute pain in single large joint.
 The joint is swollen (if superficial), warm
and tender.
 Fever.
 All movements are restricted due to muscle
spasm (Pseudo paresis).

11. 3. In adult:
 Intense joint pain .
 Joint swelling .
 Joint redness .
 Unable to move the limb with the infected
joint .
 Low-grade fever.

12. Physical examination
1. Decreased or absent rang of motion.
2. Signs of inflammation: joint swelling, warmth,
tenderness and erythema.
3. Joint orientation as to minimize pain (position
of comfort):
 Hip: abducted, flexed and externally rotated.
 Knee, ankle and elbow: partially flexed.
 Shoulder: abducted and internally rotated

13. Investigation
Lab studies:
 The diagnosis can usually be confirmed by joint aspiration
and immediate microbiological investigation of the fluid.
 Blood culture may be positive in about 50% of proven
cases.
 Non specific features of acute inflammation-
leucocytosis,ESR,CRP-are suggestive but not diagnostic .

14. Ask for:
gram stain, culture, leukocyte count with
differential, and crystal examination
 leukocyte count:
o generally higher than 50,000/µL, with a predominance
of neutrophils more than 75%
gram stain:
are positive in approximately 75% of patients with
staphylococcal infections; however, results are positive in only
50% of patients with gram-negative infections

15.  crystal examination:
 exclude crystal-induced arthritis (may coexist)
 culture:
 The definitive method
 for aerobic and anaerobic organisms.
 are positive in 85-95%
• Synovial fluid glucose, protein, and lactic acid
concentration not specific.

17. Imaging studies
1-Plain x-ray:
 The appearance of significant x-ray findings depends upon
the duration and virulence of infection.
 Plain radiography findings are generally nonspecific and
may reveal only soft tissue swelling ,widening of the joint
space ( due to the effusion), and periarticular osteoporosis
during the first 2 weeks.
 Later ,when the articular cartilage is attacked ,the joint
space is narrowed.(persistent subluxation, destructive
arthritis).

18. Septic arthritis of the hip following group B strep psoas abscess

20. Septic arthritis
of the ankle

22. 2-Ultrasonography
 This study is very sensitive in detecting joint effusions
generated by septic arthritis.
 Ultrasound can be used to define the extent of septic arthritis
and help guide treatment.
 Ultrasound helps to differentiate septic arthritis from other
conditions (e.g., soft tissue abscesses, tenosynovitis) in which
treatment may differ.

23.  3-Radio-isotope bone scan:
 Show increase uptake of the isotope in the region of the
joint. (may help in difficult site as sacroiliac &
sternoclavicular joints
4- CT scan:
 This study may help to diagnose sternoclavicular or
sacroiliac joint infections.
5-MRI:
 MRI is most useful in assessing the presence of
periarticular osteomyelitis as a causative mechanism.

24. DIFFERENTIAL DIAGNOSIS
 Osteomyelitis: near a joint may be indistinguishable from septic
arthritis ;the safest is to assume that both are present.
 An acute haemarthrosis :either post-traumatic or due to a
haemophilic bleed ,can closely resemble infection. The history is
helpful and joint aspiration will resolve any doubt.
 Transient synovitis(irritable joint) in children: causes
symptoms and signs which are less acute ,but there is always the that
this is the beginning of an infection.
 Gout and pseudogout in adults :aspirated fluid may look turbid
but the presence of urate or pyrophosphate crystals will confirm the
diagnosis.
 Rheumatic fever

25. complication
 Dislocation: a tense effusion may cause dislocation
 Epiphyseal destruction: in neglected infants the largely
cartilaginous epiphysis may be destroyed ,leaving an unstable
pseudarthrosis.
 Growth disturbance: physeal damage may result in shortening or
deformity
 Ankylosis: if articular cartilage is eroded healing may lead to
ankylosis
 Secondary osteoarthritis
 Osteomyleitis/abcess/sinus

26. Treatment
 General Measures:
The first priority is to aspirate the joint and examine the
fluid, treatment is then started without further delay.
 Analgesics and splinting of the involved joint in the
position of maximal comfort alleviate pain.
 Fluid replacement and nutritional support may be
required.
 Other foci of infection and any coexisting medical
conditions must be identified and treated appropriately.

27.  Intravenous antibiotics should be given empirically and
started as soon as joint fluid and blood sample have been
taken for culture.
 If gram –positive organisms are identified ,Flucloxacillin is
suitable . If in doubt ,a third generation cephalosporin will
cover both game+ and gram- organisms.
 Children less than 4 yr( if suspicion of H.Infl) treated with
Ampicillin.
 Once the bacterial sensitivity is known the appropriate
drug is substituted.
 Intravenous administration is continued for several weeks
and is followed by oral antibiotics for a further 2 or 3 weeks.

28. Drainage:
Indication of Surgical Drainage:
1-Joints that do not respond to antimicrobial therapy and
daily arthrocentesis
2-. Any joint with limited accessibility, including the
sternoclavicular or the hip joint
3-Patients with underlying disease, including diabetes,
rheumatoid arthritis, immunosuppression, or other
systemic symptoms, should be treated more aggressively
with earlier surgical intervention

29. Thank you