Anomalous Flexor Carpi Radialis Tendons Giving Rise to a Novel Surgical Technique in the Treatment of Thumb Carpometacarpal Joint Arthritis: A Case Report.

Introduction: Incidental discovery of anomalous muscles and anatomical variants within the forearm and wrist through surgical exposure and advanced imaging techniques is relatively common.

Case Report: The patient presented with pain and swelling in her hand that was refractory to rest and anti-inflammatory medications. Here, we describe the intraoperative discovery of an anatomical variant of the flexor carpi radialis (FCR), as well as an anomalous flexor carpi radialis brevis (FCRB) in a 58-year-old patient being treated for thumb carpometacarpal joint (CMCJ) arthritis.

Conclusion: To the best of our knowledge, this is the first description of both anomalies within a single patient and the first use of the surgical technique, described here, in treating the patient's thumb CMCJ arthritis. This report reinforces the importance of meticulous dissection and identification of individual anatomy to optimize patient outcomes.