Symptomatic Bipartite Medial Cuneiform Treated with Fluoroscopic and Ultrasound-Guided Injections

Abstract

The bipartite medial cuneiform (BMC) is a rare congenital variant that was first described by Morel in the 18th century [2, 6]. Amongst the many causes of midfoot pain, BMC is primarily an imaging diagnosis that often depends on plain radiographs as the initial diagnostic test. Recognizing a BMC on radiographs can be difficult as the osseous segments are typically well corticated and blend with the remainder of the tarsal bones. Additionally, although there are many fracture patterns at the tarsometatarsal (TMT) joint level including Lisfranc injuries, the cleft between the osseous segments lies in the horizontal plane in contrast to the typical vertical orientation of isolated fractures through the medial cuneiform [9]. The cleft is formed by a pseudoarticulation between the osseous segments. Symptomatic patients typically present with chronic midfoot pain that is exacerbated with ambulation or acute injury typically due to the inherent instability of the pseudoarticulation resulting in stress response and/or degeneration. When a BMC is symptomatic, treatment has ranged from nonoperative to surgical interventions including fusion and excision, as well as a previously described computed tomography (CT)-guided corticosteroid injection [3]. We believe our case is unique in that the patient underwent imaging using plain radiographs, CT, and magnetic resonance imaging (MRI) as well as successful image-guided injections using fluoroscopy and ultrasound on a bipartite medial cuneiform with a fibrous pseudoarticulation. The procedures and outcomes of minimally invasive fluoroscopic and ultrasound-guided steroid and anesthetic injections have not been previously described.