Arthrocentesis is a procedure performed to aspirate synovial fluid from a joint cavity. It has both diagnostic and therapeutic uses. While arthrocentesis is deemed to be a minor surgical procedure, there is always the potential to injure blood vessels, nerves, and tendons. Thus, the procedure should only be performed by clinicians with extensive knowledge of the anatomy of joints. To minimize the risk of injury, the joint's extensor surface should be in extension with minimal flexion.
Anatomical considerations include:
Therapeutic: Large and painful joint effusions can be aspirated for pain relief. Also, it can be used for intra-articular injection of certain medications (primarily steroids). Evaluate response to treatment.
Diagnostic: Synovial fluid analysis can provide physicians with an unequivocal etiology of acute arthritis, specifically to differentiate between septic arthritis and an inflammatory cause of bloody mono-arthritis.
The procedure can be done in the clinic or the minor operating room.
No absolute contraindications. Relative contraindications include overlying cellulitis (potential intra-articular seeding of bacteria), coagulopathy/bleeding disorders, a joint prosthesis (preferably performed by orthopedic surgery in theatre ), acute fracture, adjacent osteomyelitis, and uncooperative patient.
Skin cleansing solution (betadine, chlorhexidine, etc.), skin marking pen, sterile gloves, sterile gauze, 1% lidocaine, 10 cc syringe, 30 cc to 60 cc syringe, 18 g and 27 g needle, specimen tubes (cell count, gram stain, culture and sensitivity in addition to crystal analysis for gout and pseudogout).
A skilled clinician can usually perform the procedure without an assistant. If the patient is anxious or exceptional circumstances apply, an assistant will make it much easier to perform the procedure.
Anxious patients in pain or unable to cooperate with the procedure might require assistance and procedural sedation. It is a strong recommendation to utilize some type of local anesthesia. For most surgeons, lidocaine 1% will work to numb the skin. It is important to avoid deep injections with the local anesthetic because there is a risk that it may alter the synovial fluid analysis.
The clinician or medical care professional must obtain informed consent. A timeout should take place to confirm the patient and correct joint. The most crucial step is having the patient lay in a comfortable position with the affected knee fully extended or flexed at 15 to 20 degrees with a towel roll under the knee. This position helps to facilitate procedure success by ensuring quadriceps muscle relaxation. The clinician should then locate the patella. The clinician may mark it with a marking pen.
The knee is the largest synovial cavity in the body and is easily accessible from either the medial or lateral aspect, and superior, inferior at the midpoint of the patella.
Sterilize area and drape in a typical sterile fashion.
Choose the approach, then use a small syringe and small-bore needle, draw up lidocaine and anesthetize superficial skin and then deeper tissue in the projected trajectory of joint aspiration to anesthetize the track.
“Milking” or compressing the joint can help facilitate the aspiration of fluid.
Transfer fluid to specimen tubes. Remove the needle from the joint and place bandage over the insertion site.
If the needle placement is poor or the synovium is thickened, it may result in a dry tap.
Hemarthrosis can occur if a large needle damages a blood vessel when performing multiple attempts. In most cases, the hemarthrosis presents within a few hours after the procedure. It is often associated with pain, stiffness, and swelling of the joint. The majority of hemarthrosis is self-limited and resolves within a few weeks. If the patient has a coagulopathy, it may need to be corrected, and consultation with a hematologist may help.
If arthrocentesis is performed through an infected area of skin to look for a septic joint, the patient must receive antibiotics promptly. If the fluid is frankly purulent, admission is recommended.
Arthrocentesis is performed to identify the etiology or pain relief, injection of medications, or effusion drainage. To avoid complications, the clinician should be familiar with the anatomy. The risk of complications can be minimized by using an appropriate technique.
Crystal analysis is usually an important result of a successful knee aspiration. The clinician commonly differentiates gout (negatively birefringent urate crystals), pseudogout (weakly positive birefringent crystals), and an infectious process.
Synovial fluid associated with septic or infectious joint effusion is as follows:
Knee joint aspiration is often an outpatient procedure. However, in most cases, the primary care provider or nurse practitioner should always consult with the orthopedic surgeon on management because there are many causes of a swollen knee. To avoid complications, the knee should only be aspirated by clinicians familiar with the anatomy.
|||Situ-LaCasse E,Grieger RW,Crabbe S,Waterbrook AL,Friedman L,Adhikari S, Utility of point-of-care musculoskeletal ultrasound in the evaluation of emergency department musculoskeletal pathology. World journal of emergency medicine. 2018 [PubMed PMID: 30181793]|
|||Partridge DG,Winnard C,Townsend R,Cooper R,Stockley I, Joint aspiration, including culture of reaspirated saline after a 'dry tap', is sensitive and specific for the diagnosis of hip and knee prosthetic joint infection. The bone [PubMed PMID: 29855250]|
|||Jennings JM,Dennis DA,Kim RH,Miner TM,Yang CC,McNabb DC, False-positive Cultures After Native Knee Aspiration: True or False. Clinical orthopaedics and related research. 2017 Jul [PubMed PMID: 27942968]|
|||Bhavsar TB,Sibbitt WL Jr,Band PA,Cabacungan RJ,Moore TS,Salayandia LC,Fields RA,Kettwich SK,Roldan LP,Suzanne Emil N,Fangtham M,Bankhurst AD, Improvement in diagnostic and therapeutic arthrocentesis via constant compression. Clinical rheumatology. 2018 Aug [PubMed PMID: 28913649]|
|||Battistone MJ,Barker AM,Grotzke MP,Beck JP,Berdan JT,Butler JM,Milne CK,Huhtala T,Cannon GW, Effectiveness of an Interprofessional and Multidisciplinary Musculoskeletal Training Program. Journal of graduate medical education. 2016 Jul [PubMed PMID: 27413444]|
|||Kontovazenitis PI,Starantzis KA,Soucacos PN, Major complication following minor outpatient procedure: osteonecrosis of the knee after intraarticular injection of cortisone for treatment of knee arthritis. Journal of surgical orthopaedic advances. 2009 Spring [PubMed PMID: 19327266]|
|||Guyver PM,Arthur CH,Hand CJ, The acutely swollen knee. Part 1: Management of atraumatic pathology. Journal of the Royal Naval Medical Service. 2014 [PubMed PMID: 24881423]|