Arthrocentesis: hip

Overview

Indications

General arthrocentesis indications

  • Suspicion of septic arthritis
  • Suspicion of crystal induced arthritis
  • Evaluation of therapeutic response for septic arthritis
  • Unexplained arthritis with synovial effusion
  • Evaluation of joint capsule integrity if overlying laceration
  • Relative: therapeutic (decrease intra-articular pressure, injection of anesthetics/steroids)

Contraindications

General arthrocentesis contraindications

  • No absolute contraindications for diagnostic arthrocentesis
  • Do not inject steroids into a joint that you suspect is already infected
  • Relative Contraindications:

Equipment Needed

General arthrocentesis equipment

  • Betadine or Chlorhexadine
  • Sterile gloves/drape
  • Sterile gauze
  • Lidocaine
  • Syringes
    • Small syringe (6-12cc) for injection of local anesthetic
    • Large syringe (one 60cc or two 30cc) for aspiration
  • Needles
    • 18 gauge: knee
    • 20 gauge: most other joints
    • 25 gauge: MTP joints
    • 27 gauge for anesthetic injection
  • Collection tubes (red top and purple for crystal analysis)
  • Culture bottles
  • Consider utilizing U/S to assess for effusion

Procedure

General Setup

  • Prep area with betadine or chlorhexadine using circular motion moving away from joint x 3
  • Drape joint in sterile fashion
  • Inject lidocaine with 25-30ga needle superficially and then into deeper tissues
  • Insert 18ga needle (for larger joints) into joint space while pulling back on syringe
  • Stop once you aspirate fluid; aspirate as much fluid as possible
    • Send: cell count, culture, Gram Stain, crystal analysis

Specific Approach[1]

  • Should only be done under ultrasound guidance
  • Orient your probe along the axis of the femoral neck (indicator towards abdomen)
  • Identify Landmarks (Femoral V/A/N, Acetabular Labrum, Femoral Head/Neck)
  • Effusion will be seen between femoral head/neck and the iliopsoas muscle
  • Insert needle under probe, making sure that you know where patient's femoral V/A/N are

Evaluation

Arthrocentesis of synoval fluid

Synovium Normal Noninflammatory Inflammatory Septic
Clarity Transparent Transparent Cloudy Cloudy
Color Clear Yellow Yellow Yellow
WBC <200 <200-2000 200-50,000

>1,100 (prosthetic joint)

>25,000; LR=2.9

>50,000; LR=7.7

>100,000; LR=28

PMN <25% <25% >50%

>64% (prosthetic joint)

>90%

Culture Neg Neg Neg >50% positive
Lactate <5.6 mmol/L <5.6 mmol/L <5.6 mmol/L >5.6 mmol/L
LDH <250 <250 <250 >250
Crystals None None Multiple or none None
  • Viscosity of synovial fluid may actually be decreased in inflammatory or infectious etiologies, as hyaluronic acid concentrations decrease
  • The presence of crystals does not rule out septic arthritis; however, the diagnosis is highly unlikely with synovial WBC < 50,000[2]

Complications

General arthrocentesis complications

  • Pain
  • Infection
  • Re-accumulation of effusion
  • Damage to tendons, nerves, or blood vessels

See Also

External Links

References

  1. *Freeman, K., A. Dewitz, et al. (2007). "Ultrasound-guided hip arthrocentesis in the ED." Am J Emerg Med 25(1): 80-86.
  2. Shah K, Spear J, Nathanson LA, Mccauley J, Edlow JA. Does the presence of crystal arthritis rule out septic arthritis?. J Emerg Med. 2007;32(1):23-6.