Ultrasound-guided arthrocentesis and intra-articular injections of the radiocarpal and tarsocrural joints in the dog.

Abstract

OBJECTIVE: To provide a video tutorial on ultrasound-guided arthrocentesis and injection of the canine radiocarpal and tarsocrural joints. ANIMALS: Dogs undergoing arthrocentesis or intra-articular injections for diagnostic or therapeutic purposes. METHODS: The radiocarpal joint is visualized in long axis and the tarsocrural joint in short axis with a 70% isopropyl alcohol medium and linear array probe with a frequency range of 3 to 22 MHz and footprint of 25.5 mm after clipping a window and preparing the region sterilely. The needle is inserted, bevel up, in long axis with the probe angled at the appropriate trajectory to enter the visible joint space. The needle is advanced until the tip is visualized entering the joint. Aspiration to obtain synovial fluid can further confirm needle placement or provide diagnostic sampling prior to injection. The aspirate syringe is exchanged for that containing the therapeutic agent, and injectate can then be visualized entering and/or expanding the joint upon injection. RESULTS: Ultrasound-guided arthrocentesis will help to avoid surrounding vasculature and soft tissue structures, confirm needle placement, and target fluid pocketing. Needle guidance into a joint can reduce iatrogenic tissue damage from inappropriate needle placement and/or by minimizing attempts. CLINICAL RELEVANCE: For arthrocentesis, ultrasound guidance can maximize joint fluid volume acquisition for diagnostic purposes while avoiding blood contamination. For joint injections, ultrasound will help ensure intra-articular delivery of the injectate, particularly when synovial fluid aspirate feedback is inhibited (dry joint or obstructive synovial proliferation). Imaging guidance can help reduce iatrogenic tissue damage and procedure time.