Ultrasound‐versus landmark‐guided medium‐sized joint arthrocentesis: A randomized clinical trial

Objectives Arthrocentesis is commonly performed in the emergency department, but success rates vary based on location. Presently, there is a paucity of data assessing the utility of ultrasound‐guided (USG) medium‐sized joint arthrocentesis. The objective of this study was to compare the success of USG and landmark‐guided (LMG) medium‐sized joint arthrocentesis. Methods This was a single‐center, prospective, randomized clinical trial (NCT03327584) of a convenience sample of adult patients who presented to an urban, university hospital with > 105,000 visits annually. Patients with a suspected medium‐sized joint effusion (defined as elbow, wrist, or ankle) undergoing arthrocentesis were randomized into LMG or USG using the GE Logiq e linear transducer (4–10 MHz). The following patients were excluded: on anticoagulation, with soft tissue infection overlying the joint, or involving an artificial joint. Statistical analysis included the Fisher exact, Mann‐Whitney U‐test, and t‐test. Results Overall, 44 patients were enrolled with 23 patients randomized into the LMG group and 21 patients into the USG arm. USG was significantly better than LMG with an overall success of 94.1% versus 60% for LMG (difference = 34.1%, 95% confidence interval [CI] = 4.90 to 58.83). USG first‐pass success was 82.4% versus 46.7% for LMG (difference = 35.7%, 95% CI = 2.76 to 60.37) and a mean of 1.35 attempts versus 2.00 for LMG (difference = 0.65, 95% CI = 0.005 to 1.296). Of the 14 LMG failures, eight had no effusion present on USG crossover. Four patients in the USG group had no effusion present. Conclusions Ultrasound guidance improved first‐pass and overall successful arthrocentesis of medium‐sized joint effusions.