TECHNICAL REPORT Role of ultrasound-guided perineural injection of the posterior antebrachial cutaneous nerve for diagnosis and potential treatment of chronic lateral elbow pain Sagar Wagle 1 & Katrina Glazebrook 1 & Michael Moynagh 1 & Jay Smith 2 & Jacob Sellon 2 & John Skinner 1 & Mark Morrey 3 Received: 13 July 2020 /Revised: 21 August 2020 /Accepted: 23 August 2020 # ISS 2020 Abstract Objective To examine diagnostic and therapeutic utility of novel ultrasound-guided perineural injection of posterior antebrachial cutaneous nerve in chronic lateral elbow pain. Materials and methods We performed a retrospective analysis of ultrasound-guided perineural injection of the posterior antebrachial cutaneous nerve with local anesthetic with or without corticosteroid in patients with chronic lateral elbow pain. Data variables collected included patient demographics, illness course, diagnostic ultrasound findings, immediate pre- and post- injection pain using numeric rating pain scale between 0 and 10, injection complications, and post-injection outcomes. Results Fifteen patients (9 females and 6 males) with average age 46.9 (range 16–69 years) underwent 20 perineural injections between 2009 and 2019. Patients had on average 84% reduction in pain immediately after the injection (median pre- and post- procedure numeric rating pain scale of 6 and 0, respectively, p < 0.001). Patients had pain relief for an average of 15 h (range 2– 48 h) when only local anesthetic was injected, compared with average pain relief of 26.5 days (range 2 h—43 days) when local anesthetic was combined with corticosteroid, p = 0.01. Conclusion Novel ultrasound-guided perineural anesthetic injections around the posterior antebrachial cutaneous nerve can be performed safely and have diagnostic and potentially therapeutic utility in select patients with chronic refractory lateral elbow pain. Keywords Posterior antebrachial cutaneous nerve . Posterior cutaneous nerve of forearm . Chronic lateral elbow pain . Cutaneous nerve block . Ultrasound guided nerve block Introduction Lateral epicondyle tendinopathy, or tennis elbow, is a common cause of chronic lateral elbow pain and is the most common overuse injury of the elbow [1–3]. The sheer number of treat- ment options for this disorder without a single gold standard provides evidence for the frustration the patients experience. Operative treatment for tennis elbow is typically reserved for non-operative treatment failure. While surgical techniques of- ten include some variation of the classic Nirschl lateral release, which includes debridement and release of the common exten- sor tendon, other pathologies contributing to chronic lateral elbow pain may be overlooked [4, 5]. In recalcitrant cases failing to improve with conservative measures or when symptoms persist beyond 2 years of onset, other diagnostic considerations should be entertained [6]. Additionally, approximately 10% of patients continue to have symptoms following surgery and are considered treatment failures [7]. For patients who have failed surgical treatment for lateral epicondyle tendinopathy and are suffering from chronic lateral elbow pain, it may represent one potential cause of recalcitrant pain. The posterior antebrachial cutaneous nerve (PABCN), also called the posterior cutaneous nerve of forearm (PCNF), is a sensory branch of the radial nerve that innervates the lateral humeral epicondyle and dorsal aspect of the forearm [8–10]. * Sagar Wagle wagle.sagar@mayo.edu 1 Department of Radiology, Mayo Clinic, Rochester, MN 55905, USA 2 Department of Physical Medicine and Rehabilitation, Mayo Clinic, Rochester, MN 55905, USA 3 Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN 55905, USA Skeletal Radiology https://doi.org/10.1007/s00256-020-03594-7