Arthrocentesis: A bedside procedure in which a sterile needle and syringe are used to drain fluid from the joint, and in some conditions, medication is injected into the joint after fluid removal.

1. Prepared by:Prepared by:
Dr. Abdulla KamalDr. Abdulla Kamal
knee jointknee joint
ArthrocentesisArthrocentesis

2. ArthrocentesisArthrocentesis
A bedside procedure in which a sterile
needle and syringe are used to drain fluid
from the joint, and in some conditions,
medication is injected into the joint after
fluid removal.

3. Knee joint anatomyKnee joint anatomy
It is a synovial hinge joint formed between
three bones: the femur, tibia, and patella.
It has strongest capsule
MCL , LCL, ACL, PCL
med. and lat. menisci

4. Knee joint anatomyKnee joint anatomy
Largest synovial membrane
Surrounded by strong
muscles
ROM =flexion 0-130

5. IndicationsIndications
 DiagnosticDiagnostic knee arthrocentesis:knee arthrocentesis:
Evaluation of monoarticular arthritisEvaluation of monoarticular arthritis
Evaluation of suspectedEvaluation of suspected septic arthritisseptic arthritis
Evaluation of joint effusionEvaluation of joint effusion
Identification of HemarthrosisIdentification of Hemarthrosis
Identification of crystal arthropathyIdentification of crystal arthropathy

6. IndicationsIndications
 TherapeuticTherapeutic knee arthrocentesis:knee arthrocentesis:
Relief of pain by aspirating effusion or bloodRelief of pain by aspirating effusion or blood
Injection of medications (corticosteroids,Injection of medications (corticosteroids,
antibiotics, chemotherapy or anesthetics)antibiotics, chemotherapy or anesthetics)
Drainage of septic effusionDrainage of septic effusion

7. ContraindicationsContraindications
 There areThere are no absoluteno absolute contraindicationscontraindications
for knee arthrocentesis.for knee arthrocentesis.
 RelativeRelative contraindicationscontraindications;;
Cellulitis overlying the joint .Cellulitis overlying the joint .
Skin lesion or dermatitis overlying the jointSkin lesion or dermatitis overlying the joint
Known bacteremiaKnown bacteremia
Adjacent osteomyelitisAdjacent osteomyelitis
Uncontrolled coagulopathyUncontrolled coagulopathy
Joint prosthesisJoint prosthesis

8. EquipmentsEquipments
The materials required for knee arthrocentesisThe materials required for knee arthrocentesis
include the following:include the following:
Sterile gloves and drapesSterile gloves and drapes
5 gauze pads, 4 × 4 in.5 gauze pads, 4 × 4 in.
Skin preparatory solutionSkin preparatory solution
Lidocaine 1%Lidocaine 1%
Syringes, 5 mL, 20 mL, 30 mL, 60 mLSyringes, 5 mL, 20 mL, 30 mL, 60 mL
Needles, 18 or 20 gauge and 25 or 27 gauge, obeseNeedles, 18 or 20 gauge and 25 or 27 gauge, obese
patients might require a 21-gauge spinal Hemostatpatients might require a 21-gauge spinal Hemostat
Specimen tubesSpecimen tubes
BandageBandage

9. Approach ConsiderationsApproach Considerations
 parapatellar approachparapatellar approach (which is generally(which is generally
preferred) ( med. & lat.)preferred) ( med. & lat.)
 suprapatellarsuprapatellar approachapproach
( med. & lat.)( med. & lat.)
 infrapatellarinfrapatellar approachapproach
( med. & lat.)( med. & lat.)

10. Patient PreparationPatient Preparation
 informed consent.informed consent.
 identification of theidentification of the
needle insertion siteneedle insertion site
and marking it.and marking it.

11. Patient PreparationPatient Preparation
 skin preparation andskin preparation and
draping the joint.draping the joint.
 Local anesthesia;Local anesthesia;
• lidocaine 1%lidocaine 1%

12. procedureprocedure
 Parapatellar approachParapatellar approach midpoint of eithermidpoint of either
the medial or the lateral border of thethe medial or the lateral border of the
patella. Insert a needle 3-4 mm below thepatella. Insert a needle 3-4 mm below the
point.point.
 useful when there isuseful when there is
a small effusiona small effusion

13. procedureprocedure
 Suprapatellar approachSuprapatellar approach, midpoint of either the, midpoint of either the
superomedial or the superolateral border of thesuperomedial or the superolateral border of the
patella.patella.
 Insert a needle through the midpoint of either setInsert a needle through the midpoint of either set
of superior borders.of superior borders.
 useful for large effusionsuseful for large effusions

14. procedureprocedure
Infrapatellar approach, position the patient
sitting with knee bent at 90°
 Identify inferior border of the
patella and the patellar tendon.
 Insert a needle 5 mm below
the inferior border of the patella
and just lateral to the edge of the
patellar tendon.

15. Ultrasound-guidedUltrasound-guided
arthrocentesisarthrocentesis
1. less procedural pain1. less procedural pain
2. improved arthrocentesis success2. improved arthrocentesis success
3. greater synovial fluid yield3. greater synovial fluid yield
4.more complete joint decompression4.more complete joint decompression
5. improved clinical outcomes.5. improved clinical outcomes.

16. Analysis of Synovial Fluid
 AppearanceAppearance
 Cytological investigationsCytological investigations
 Histological investigationHistological investigation
 Biochemical investigationsBiochemical investigations
 Culture and sensitivityCulture and sensitivity

17. Analysis of Synovial Fluid
Normal Noninflammatory inflammatory septic
Clarity Transparent Transparent Cloudy Cloudy
Color Clear Yellow Yellow Yellow
WBC/L <200 <200–2000 200–50,000 >50,000
PMN % <25 <25 >50 >50
Culture Negative Negative Negative >50% positive
Crystals None None Multiple or none None
Glucose Normal Normal < 25 < 25
Protein 1.3-1.8 2-3.5 > 4 > 4
Associated
conditions
Osteoarthritis,
trauma, rheumatic
fever
Gout, pseudogout,
spondyloarthropath
ies, RA, Lyme
disease, SLE
Non-
gonococcal or
gonococcal septic
arthritis

18. Complications
1.1. InfectionInfection; with proper; with proper aseptic technique 1;10,0001;10,000
• on infected skin IV-ABon infected skin IV-AB should be administered
2. Hemarthroses are small and self-limited
• coagulopathic patients requires correction
3. damage to articular cartilage
4. Damage to adjacent neurovascular organs