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.