Relative contraindications Severe bleeding diathesis, which may need to be corrected before arthrocentesis; routine therapeutic anticoagulation is not a contraindication, particularly if infection is suspected Prosthetic joint, which is susceptible to iatrogenic infection; prosthetic joint arthrocentesis should generally be done by an orthopedic surgeon Complications of Elbow Arthrocentesis Complications are uncommon and include Infection Damage to tendon, nerve, or blood vessels (traumatic tap) Equipment for Elbow Arthrocentesis Antiseptic solution (eg, chlorhexidine, povidone iodine, isopropyl alcohol), sterile gauze, and gloves Nonsterile underpads Local anesthetic (eg, 1% lidocaine, 25 - to 30-gauge needle, 3 - to 5-mL syringe) For joint aspiration, a 25 - to 38-mm (1 - to 1.5-inch) 20 - or 22-gauge needle and a 10 - to 20-mL syringe Appropriate containers for collection of fluid for laboratory tests (eg, cell count, crystals, cultures) For intra-articular therapeutic injection, a syringe containing a corticosteroid (eg, triamcinolone acetonide 20 to 30 mg or methylprednisolone acetate 40 mg) and / or a long-acting anesthetic (eg, 0.25% bupivacaine), a 23 - to 25-gauge needle, and a hemostat to help switch syringes, if needed Additional Considerations for Elbow Arthrocentesis Sterile technique is necessary to prevent microbial contamination of both the joint space and the aspirated synovial fluid.