Accuracy and safety of two landmark‐guided techniques for arthrocentesis and intra‐articular injection of the shoulder in dogs

Abstract Objective To determine the accuracy and safety of two landmark‐guided techniques for shoulder arthrocentesis and injection. Study design Ex vivo prospective study. Animals A total of 36 paired canine cadaver forelimbs. Methods An electronic survey was used to assess the prevalence of injection technique amongst surgeons in clinical practice. Thoracic limbs were randomized to technique for shoulder arthrocentesis and injection (subacromial [SA], n = 18, or supratubercular [ST], n = 18). Repositions, attempts, and the acquisition of synovial fluid was recorded. After the needle was placed, contrast was injected into the joint to determine accuracy of position. The radiographic presence of intra‐articular contrast was judged as an accurate injection. Shoulders were disarticulated and India ink assay performed to assess for iatrogenic articular cartilage injury (IACI). Results Both SA and ST techniques were not accurate. Completely accurate injection was identified in 50% SA and 44% ST ( p = .80). IACI was identified in 50% SA versus 11% ST ( p = .027). There were no significant differences in repositions, attempts, presence of synovial fluid ( p = .5, p = .6, p = .7). Conclusion Landmark‐guided shoulder injections performed via SA and ST approaches in cadaveric dog shoulders are overall inaccurate. If performing landmark‐guided shoulder injection, ST technique carries a lower risk of IACI than SA in cadaveric shoulders. Clinical significance Landmark‐guided shoulder injections are inaccurate in dogs and may result in treatment failure. A ST approach may be considered preferable due to the lower risk of cartilage damage. Future studies should assess ultrasound‐guided techniques to improve accuracy and safety.