The correlation between pre-operative ultrasonographic median nerve evaluation and the operative procedure in CTS

Background: Ultrasonography is a convenient non-invasive diagnostic tool with wide availability and cost effectiveness. Musculoskeletal ultrasonography is a growing field used for diagnosis of many musculoskeletal disorders; carpal tunnel syndrome (CTS) could be one of these disorders. The purpose of this study was to assess the impact of median nerve ultrasonography in carpal tunnel syndrome on surgical management, and its added value in operative techniques selection, and in tailoring the surgical steps. Thirty patients with CTS and thirty normal subjects underwent superficial ultrasonography. The cross-sectional area at different levels and flattening ratios were measured on both groups. The patients who had failed conservative treatment had surgical carpal tunnel release. Results: There was significant positive correlation between the need for external neurolysis with increased flattening ratio with cutoff values > 4, and between the need for approach extension with increased cross-sectional area difference between pisiform level and pronator quadratus level with cutoff values of cross-sectional area difference > 7. Conclusions: Ultrasonographic measurements of median nerve in CTS could be helpful in selection and modification of operative procedure including the surgical approach and need for neurolysis.