Prepared by:Prepared by:Dr. Abdulla KamalDr. Abdulla Kamal

knee joint knee joint ArthrocentesisArthrocentesis

ArthrocentesisArthrocentesisA 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.

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

Knee joint anatomyKnee joint anatomyLargest synovial membrane

Surrounded by strongmuscles

ROM =flexion 0-130

IndicationsIndications

DiagnosticDiagnostic knee arthrocentesis: knee arthrocentesis:

Evaluation of monoarticular arthritisEvaluation of monoarticular arthritisEvaluation of suspected Evaluation of suspected septic arthritisseptic arthritisEvaluation of joint effusionEvaluation of joint effusion Identification of Hemarthrosis Identification of Hemarthrosis Identification of crystal arthropathyIdentification of crystal arthropathy

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

ContraindicationsContraindications

There are There are no absolute no absolute contraindications contraindications for knee arthrocentesis.for knee arthrocentesis.

RelativeRelative contraindications contraindications; ; Cellulitis overlying the joint .Cellulitis overlying the joint .Skin lesion or dermatitis overlying the jointSkin lesion or dermatitis overlying the jointKnown bacteremiaKnown bacteremiaAdjacent osteomyelitisAdjacent osteomyelitisUncontrolled coagulopathyUncontrolled coagulopathyJoint prosthesisJoint prosthesis

EquipmentsEquipmentsThe materials required for knee arthrocentesis include the The materials required for knee arthrocentesis include the following:following:

Sterile gloves and drapesSterile gloves and drapes5 gauze pads, 4 × 4 in.5 gauze pads, 4 × 4 in.Skin preparatory solutionSkin preparatory solutionLidocaine 1%Lidocaine 1%Syringes, 5 mL, 20 mL, 30 mL, 60 mLSyringes, 5 mL, 20 mL, 30 mL, 60 mLNeedles, 18 or 20 gauge and 25 or 27 gauge, obese patients might Needles, 18 or 20 gauge and 25 or 27 gauge, obese patients might require a 21-gauge spinal Hemostatrequire a 21-gauge spinal HemostatSpecimen tubesSpecimen tubesBandageBandage

Approach ConsiderationsApproach Considerationsparapatellar approach parapatellar approach (which is generally (which is generally

preferred) ( med. & lat.)preferred) ( med. & lat.)suprapatellarsuprapatellar approach approach ( med. & lat.)( med. & lat.) infrapatellarinfrapatellar approach approach ( med. & lat.)( med. & lat.)

Patient PreparationPatient Preparation

informed consent.informed consent.

identification of theidentification of the needle insertion site needle insertion site and marking it.and marking it.

Patient PreparationPatient Preparationskin preparation and skin preparation and draping the joint.draping the joint.

Local anesthesia; Local anesthesia; • lidocaine 1%lidocaine 1%

procedureprocedureParapatellar approach Parapatellar approach midpoint of either midpoint of either

the medial or the lateral border of the the medial or the lateral border of the patella. Insert a needle 3-4 mm below the patella. Insert a needle 3-4 mm below the point.point.

useful when there isuseful when there is a small effusiona small effusion

procedureprocedure Suprapatellar approachSuprapatellar approach, midpoint of either the , midpoint of either the

superomedial or the superolateral border of the superomedial or the superolateral border of the patella.patella.

Insert a needle through the midpoint of either set Insert a needle through the midpoint of either set of superior borders. of superior borders.

useful for large effusionsuseful for large effusions

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.

Ultrasound-guided Ultrasound-guided arthrocentesisarthrocentesis

1. less procedural pain1. less procedural pain2. improved arthrocentesis success2. improved arthrocentesis success3. greater synovial fluid yield3. greater synovial fluid yield4.more complete joint decompression4.more complete joint decompression5. improved clinical outcomes.5. improved clinical outcomes.

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

Analysis of Synovial FluidNormal Noninflamma

toryinflammatory

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, spondyloarthropathies, RA, Lyme disease, SLE

Non-gonococcal or gonococcal septic arthritis

Complications

1. 1. InfectionInfection; with proper ; with proper aseptic technique 1;10,0001;10,000• on infected skin IV-AB on 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