A Novel Ultrasound Window for Simultaneous Botulinum Neurotoxin Injection Into Three Deep Leg Muscles in Ankle and Foot Spasticity Patterns

Ankle and foot conditions with muscle overactivity often require botulinum neurotoxin (BoNT) injections into the flexor digitorum longus (FDL), tibialis posterior (TP), and flexor hallucis longus (FHL) muscles. This manuscript introduces a novel ultrasound (US) window for simultaneous BoNT injections into these muscles to improve efficiency and patient comfort in treating ankle and foot spasticity. A novel posterior approach using a transverse US probe placement on the distal leg was developed in patients requiring BoNT injections for lower limb muscle overactivity. This technique modifies traditional probe handling to achieve a horizontal alignment of TP, FDL, and FHL within the US window, facilitating simultaneous visualization and a single skin puncture three-muscle in-plane injection. This single US window allows concurrent visualization of the TP, FDL, and FHL. It may facilitate more precise needle and injectate placement. The approach reduces the number of skin punctures. It may also improve procedural efficiency and patient comfort. This technique offers a practical option for BoNT injections into deep posterior leg muscles. It could be considered for routine clinical use in managing ankle and foot muscle overactivity.