This document discusses septic arthritis, including its definition, risk factors, common causative organisms, modes of infection, pathogenesis, clinical features, investigations, treatment, and approaches to joint aspiration and drainage. The key points are: - Septic arthritis is a joint infection caused by bacterial invasion of the synovial membrane. It commonly affects the knee, hip, shoulder and ankle. - Risk factors include rheumatoid arthritis, prosthetic joints, IV drug use, and diabetes. Common organisms include Staphylococcus aureus and gram-negative bacilli. - Treatment involves joint drainage, IV antibiotics based on culture and sensitivity results, and splinting the joint. Surgical drainage is often needed if

1. SEPTIC ARTHRITIS
DR. DEBESH SHRESTHA
1ST YEAR PG RESIDENT
DEPARTMENT OF ORTHOPEDICS
GANDAKI MEDICAL COLLEGE
POKHARA, NEPAL

3. Definition
• Septic arthritis is an inflammation of synovial
membrane with purulent effusion into the
joint capsule due to infection.
• Also referred to as Infectious Arthritis
• Considered as an orthopedic emergency

4. • Acute septic arthritis can occur at any age but
young children and elderly adults are most
susceptible
• Male = female
• The lower extremity weight bearing joints are
predominantly affected (61-79%)
• However any joint can be involved
• Multiple joint infections do occur

5. Risk factors
• Rheumatoid arthritis
• Osteoarthritis
• Prosthetic joint
• IV drug abuse
• Alcoholism
• Diabetes
• Low socioeconomic status
• Previous I/A corticosteroid injection
• Cutaneous ulcers

6. Organisms found in common clinical
settings of infectious arthritis
Patient age
o Neonate : Staph. aureus
o <2 yr : H.influenzae, S.aureus
o >2 yr : S.aureus
o Young adults : Neisseria gonorrhoea
(sexually active)
o Elderly adults : S.aureus(50%), Streptococci,
gram negative bacilli

7. Structural abnormalities
o Aspiration or injection : S. Aureus
o Trauma : gram negative bacilli, anaerobes,
S. aureus

8. Prosthesis
o Early infection : S. epidermidis
o Late infection : gram positive cocci,
anaerobes

9. Medical conditions
o Injecting drug use : atypical gram negative bacilli
(eg. Pseudomonas species)
o Rheumatoid arthritis : S.aureus
o SLE, sickle cell anemia : Salmonella species
o Hemophilia : S.aureus(50%), streptococci, gram
negative bacilli
o Immunosuppression : S.aureus, Mycobacterium
species, fungi

10. Modes of infection
1. Hematogenous spread from a distant site- most
common
2. Direct invasion through a penetrating wound, intra-
articular injection or arthroscopy
3. Direct spread from adjacent bone
o Can develop from osteomyelitis especially in infants in
whom transphyseal vessels allow proximal spread into
the joint in joints with an intra-articular metaphysis
(hip, elbow, shoulder, ankle)

13. Pathogenesis
• The usual trigger is a hematogenous infection
which settles in the synovial membrane
• There is an acute inflammatory reaction with a
serous or seropurulent exudate and an
increase in synovial fluid

14. • As pus appears, articular cartilage is eroded
and destroyed, partly by bacterial enzymes
and partly by proteolytic enzymes released
from synovial cells, inflammatory cells and pus
• Spread to the underlying bone or burst out of
the joint to form abscesses and sinuses

15. With healing there may be
1. Complete resolution and a return to normal
2. Partial loss of articular cartilage and fibrosis
of the joint
3. Loss of articular cartilage and bony ankylosis
4. Bone destruction and permanent deformity
of the joint

17. Clinical features
In neonates
o Emphasis on septicemia rather than joint pain
o Irritable
o Refusal to feed
o Fever
o Rapid pulse
o Joint warm, tender and resistant to movement
o a/w umbilical cord inflammation, IV site
inflammation

18. • Baby’s chest, spine and abdomen should be
examined for any infection
• Look for concomitant osteomyelitis in an
adjacent bone end

19. In children
• Acute pain in a single large joint (commonly
the hip or the knee)
• Reluctance to move the limb
(pseudoparesis)
• Fever
• Rapid pulse
• Joint swelling and redness
• Joint tenderness
• All movements are restricted and often
completely abolished by pain and spasm
• Look for source of infection

20. In adults
• Often involve a superficial joint (knee,
wrist, finger, ankle or toe)
• Joint painful, swollen and inflamed
• Unable to bear weight
• Warm and tender
• Evidence of gonococcal infection or drug
abuse
• Patients with RA and on corticosteroids
may develop silent joint infection

21. Differential diagnosis
1. Acute osteomyelitis
2. Other infections such as psoas abscess
3. Traumatic synovitis or hemarthrosis
4. Transient synovitis
5. Hemophilic bleed
6. Rheumatic fever
7. Juvenile rheumatoid arthritis
8. Sickle cell disease
9. Gaucher’s disease
10. Crystal induced arthritis (gout, pseudogout)
11. Periarticular syndrome (bursitis, tendinitis)

22. Investigations
Blood investigations
• WBC raised
• ESR raised
• C-Reactive Protein raised
• Blood culture may be positive

23. Aspiration of joint fluid and analysis
• May be frankly purulent or in early cases clear
• White cell count and Gram stain
• Fluid culture and sensitivity

25. Imaging –
May help confirm the suspicion but not diagnostic
Radiographs
• Usually normal- in first few days of infection
• Soft tissue swelling, displacement of fat pad
or joint space widening from localized edema
• As infection progresses, joint space narrowing
from destruction of cartilage

26. Ultrasonography
• Used to detect even small collections of fluid
deep in the large joints such as hip
• Widening of space between capsule and bone
of more than 2 mm is indicative of an effusion
• Echogenic fluid- likely septic
• Echo-free fluid- likely synovitis
• Used to guide joint aspiration and drainage

27. MRI and Radionuclide bone scans
o Helpful in diagnosing infections that are
difficult to assess
o In obscure sites such as sacro-iliac and
sternoclavicular joints

29. Score Likelihood of septic arthritis
1 3%
2 40%
3 93%
4 99%

30. Treatment
• Principles
1. Adequate drainage of the joint and resection
of infected tissue
2. Antibiotics to diminish the systemic effects of
sepsis
3. Resting of the joint in a stable position

31. • Suspected arthritis suspected
• Blood and synovial fluid sample
• Empiric parenteral antibiotics based on Gram stain
• Joint drainage
• Adjust antibiotics based on culture and sensitivity result

32. • Empirical antibiotic treatment is based on the
patient’s age and risk factors
• Empirical antibiotic therapy should be given until
culture and sensitivity results are available, at
which time definitive treatment is initiated
• If no organism is isolated, empirical therapy
should be continued

33. Empirical Antimicrobial Therapy
Pathogen Empirical antimicrobial
Gram positive cocci in clusters with MRSA
risk factor or Beta lactam allergy
Vancomycin 15 mg/kg IV q12h
Gram positive cocci in clusters, no MRSA risk
factors
Nafcillin or oxacillin 2 g IV q4h
Gram positive cocci, no MRSA risk factors Cefazolin 2 g IV q8h
Gram positive cocci in chains (Streptococci
presumed)
Penicillin G 12-18 MU/d or ampicillin 2 g IV
q4h
Gram negative cocci ( Neisseria presumed) Ceftriaxone 1-2 g IV/ IM q12-24h or
cefotaxime 2 g IV q8h
Gram negative rods Ceftazidime 2 g IV q8h or cefepime 2 g IV q8h

34. Negative Gram stain, previously healthy,
no MRSA risk factors
Cefazolin 2 g IV q8h
Negative Gram stain, health care
associated or other MRSA risk factors
Vancomycin 15 mg/kg IV q12h plus
ceftazidime 2 g IV q8h, cefepime 2 g IV
q8h or piperacillin/tazobactam 4.5 g IV
q6h
Human, dog or cat bite Ampicillin sulbactam 1.5-3 g IV q4h

35. Pathogen directed Anti-microbial
Therapy
Pathogen Anti-microbial therapy
S. aureus( methicillin sensitive) Nafcillin or oxacillin 2 g IV q4h x 3 weeks
Cefazolin 2 g IV q8h x 3 wk
S. aureus (methicillin resistant or type I
penicillin allergy)
Vancomycin 15 mg/kg IV q12h x 3 wks
Streptococci including penicillin-sensitive
S.pneumonia
Penicillin G 12-18 MU IV qd divided dose
or ampicillin 2 g IV q4h
S. Pneumonia(penicillin resistant) Ceftriaxone 1-2 g IV q12h or
Cefotaxime 2 g IV q8h if susceptible or
vancomycin 15 mg/kg IV q12h x 2 wk
Enteric gram negative
bacilli
Ceftriaxone 1-2 g IV q12h or
cefotaxime 2 g IV q8h × 3 wk
Gram-negative bacilli
(P. aeruginosa)
Ceftazidime 2 g IV q8h or cefepime
2 g IV q8h, plus gentamicin or
tobramycin 5 mg/kg IV q24h ×
3 wk

36. Gram-negative bacilli Ciprofloxacin 400 mg IV q8-12h or
750 mg PO q12h or levofloxacin
750 mg IV or 750 mg PO qd × 3 wk
Polymicrobial Ampicillin/sulbactam 1.5-3 g IV q4h
× 3 wk
Clindamycin 600 mg IV q6-8h ×
3 wk plus ciprofloxacin 400 mg IV
or 750 mg PO q12h or levofloxacin
750 mg IV or 750 mg PO qd × 3 wk
Gram-positive
etiology and type I
penicillin allergy
Vancomycin 15 mg/kg IV q12h ×
3 wk

37. • If the diagnosis is made early and the involved
joint is superficial, such as the elbow or ankle,
aspiration should be performed and repeated
if necessary
• Appropriate antibiotics should be
administered, and the joint should be splinted
in a position of function.

38. • If the response is not favorable and repeat
aspiration does not show a decrease in the
synovial leukocyte count within 24 to 48
hours, open surgical drainage is necessary.
• If purulent material is deeply situated in a
joint, such as the shoulder or hip, open
surgical drainage should be done

39. • Arthroscopic drainage is a good alternative to
open drainage in many instances, especially
for infections involving the knee, elbow,
shoulder, or ankle

40. • Except for gonococcal arthritis, which usually
can be treated effectively with antibiotics,
drainage should be performed for all other
infectious arthritis.

41. Aspiration and Drainage approaches

42. Aspiration of ankle
needle is
inserted 2.5 cm proximal and 1.3 cm anterior
to the tip of the
lateral malleolus.

43. Ankle Drainage
1. Anterolateral
2. Anteromedial
3. Posterolateral- safer and more effective
4. Posteromedial

44. POSTEROLATERAL DRAINAGE
OF THE ANKLE
• Hold the foot in dorsiflexion
• Begin the incision 5 cm proximal to the tip of the
lateral malleolus and just lateral to the Achilles
tendon. Extend the incision distally to the
calcaneus and curve it along the superior border
of that bone for 2.5 cm.
• Retract the sural nerve and small saphenous vein
laterally.
• Retract the peroneal tendons laterally
• Incise the posterior capsule under direct vision

45. Aspiration of knee
needle is inserted on the lateral side at the
level of the superior pole of the patella. It is
advanced through the lateral retinaculum and
into the joint.

46. Knee - Drainage
1. Anteromedial- most common
2. Anterolateral
3. Posteromedial
4. Posterolateral

47. ANTERIOR DRAINAGE OF THE KNEE
• Make parallel anterior incisions 7.5 to 10 cm long
on each side of the patella and sufficiently medial
or lateral to the sides of the patellar tendon.
• Incise the capsule and synovium, carefully
evacuate the purulent material, and disrupt any
loculations or adhesions. Use copious saline
irrigation.
• Leave the synovium open, but loosely close the
capsule and skin over drains. Use absorbable
monofilament sutures for closing the capsule.

48. • If the posterior compartment of the knee is
distended and a popliteal abscess is well
established, parallel anterior incisions
combined with posterolateral and
posteromedial (Henderson) incisions usually
are best.

49. POSTEROMEDIAL AND
POSTEROLATERAL DRAINAGE
OF THE KNEE• (KELIKIAN)
• Make a posterior longitudinal incision 7.5 to 10 cm long centered over the joint and the
semimembranosus tendon.
• Develop the interval between this tendon and the medial head of the gastrocnemius
muscle.
• Divide the semimembranosus and suture its proximal end to the deep fascia
• Make a generous window in the joint capsule and excise the posterior horn of the
medial meniscus.
• If the posterior compartment is divided by a median septum and complete drainage is
impossible through the posteromedial incision, or if drainage of only the lateral
compartment is desired, make a longitudinal incision 7.5 to 10 cm long over the biceps
femoris tendon.

50. • Incise the deep fascia lateral and anterior to this tendon
and free the tendon from the head of the fibula. Also free
the popliteus tendon from its insertion on the lateral
femoral condyle.
• Suture the free ends of both tendons to the deep fascia
• Window the joint capsule and remove a wedge of the
lateral meniscus.
• Kelikian advises that drains not be used but rather that
skeletal traction be applied to separate the joint surfaces.

52. Aspiration of Hip
• Insert the needle 2.5 cm
lateral and 2.5 cm distal
to the point joining
inguinal ligament and
femoral artery at a 45-
degree angle to the skin
surface.
• Advance the needle 5 to
7.5 cm medially and
proximally into the joint.

53. Insert the needle at a 45-degree angle with the
surface of the thigh just inferior and anterior to
the greater trochanter

54. Hip- Drainage
• Anterior – in children
• Posterior- in adults
• Medial
• Lateral

55. POSTERIOR DRAINAGE OF THE HIP
• Make an oblique incision in the line of the femoral neck
extending from the greater trochanter toward the
posterior superior iliac spine
• Split the gluteus maximus muscle in line with its fibers,
ligating branches of the inferior gluteal vessels as they
are encountered.
• Identify and protect the sciatic nerve in the medial
angle of the incision.
• Divide the external rotators of the hip at their
insertions on the greater trochanter.
• Incise the capsule
• Irrigate the joint profusely with saline

56. ANTERIOR DRAINAGE OF THE HIP
• Make a vertical incision beginning about 1 cm below the anterior
superior iliac spine inferiorly.
• Expose the sartorius muscle on the medial side and the tensor
fasciae latae and vastus lateralis muscles on the lateral side. Use
blunt dissection to separate these muscles.
• Identify the lateral border of the rectus femoris and retract this
muscle medially ; this exposes the hip joint capsule.
• Incise the capsule, evacuate the pus, and irrigate the joint with
saline.
• Leave the capsule open, but close the skin loosely over drains.

58. Aspiration of Shoulder
The aspiration site is located half the distance
between the coracoid process and the anterolateral
edge of the acromion. The needle is directed
posteriorly through the joint capsule, and the joint
is aspirated.

59. Shoulder- Drainage
• The shoulder may be drained through an
anterior incision or a posterior incision, but
the anterior incision is preferable.

60. ANTERIOR DRAINAGE OF
THE SHOULDER
■• Begin an anterior longitudinal incision at the anterior
border of the acromion and extend it 5 to 7.5 cm over the
center of the humeral head.
• Split the fibers of the deltoid muscle 5 cm from the
acromion, divide the subscapularis tendon, and open the
capsule under direct vision.
• Open the synovial sheath of the long head of the biceps
tendon. Evacuate the pus and irrigate the joint copiously
with saline.
• In children, drill the proximal humeral metaphysis to
decompress any abscess but take care not to injure the
physis.
• Close the wound loosely over drains.

61. Elbow- Aspiration
Flex the elbow and insert the needle on its
posterior aspect just lateral to the
olecranon

62. Elbow
DRAINAGE
• The elbow is best drained through a medial or
lateral approach or both.

63. MEDIAL DRAINAGE OF THE ELBOW
• Make an incision over the medial humeral
epicondyle and extend it 5 cm proximally and 2.5
cm distally.
• Develop the interval between the triceps
posteriorly and the brachialis anteriorly, taking
care not to injure the ulnar nerve.
• Elevate the periosteum laterally and distally until
the capsule is exposed.
• Incise the capsule and evacuate the pus.
• Irrigate the joint with saline and close the skin
loosely over drains.

64. LATERAL DRAINAGE OF THE ELBOW
• Make an incision over the lateral humeral epicondyle and
extend it 5 cm proximally and 2.5 cm distally.
• Separate the triceps muscle posteriorly from the extensor
carpi radialis longus anteriorly and expose the joint capsule.
Dissect close to the bone to avoid injuring the radial nerve.
• Incise the capsule, evacuate the pus, and irrigate the joint
with saline.
• Close the skin loosely over drains.
• The posterior compartment of the joint also may be
drained through this incision by dissecting posteriorly on
the humerus and elevating the attachment of the triceps
from the lateral surface of the bone.

65. Complications
1. Epiphyseal damage and altered bone growth
2. Pathological dislocation
3. Pathological fracture
4. Metastatic infection
5. Chronic osteomyelitis
6. Pelvic abscess
7. Septicemia

66. References
• Apley’s System of Orthopedics
• Campbell Operative techniques
• www.orthobullets.com