Point of care ultrasound combined with CTS-6 to diagnose idiopathic carpal tunnel syndrome

Hiroo Kimura; Ryogo Furuhata; Tomoki Matsuo; Taku Suzuki; Noboru Matsumura; Kazuki Sato; Takuji Iwamoto

doi:10.1016/j.jos.2024.01.007

Point of care ultrasound combined with CTS-6 to diagnose idiopathic carpal tunnel syndrome

J Orthop Sci. 2024 Jan 31:S0949-2658(24)00008-3. doi: 10.1016/j.jos.2024.01.007. Online ahead of print.

Authors

Hiroo Kimura¹, Ryogo Furuhata², Tomoki Matsuo³, Taku Suzuki⁴, Noboru Matsumura⁵, Kazuki Sato⁶, Takuji Iwamoto⁷

Affiliations

¹ Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan; Department of Orthopaedic Surgery, Kitasato Institute Hospital, Tokyo, Japan. Electronic address: kimura.hiroo@kitasato-u.ac.jp.
² Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan. Electronic address: ryogo4kenbisha@gmail.com.
³ Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan. Electronic address: matt.10mk.hi341@gmail.com.
⁴ Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan. Electronic address: sutaku49@gmail.com.
⁵ Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan. Electronic address: noboru18@gmail.com.
⁶ Institute for Integrated Sports Medicine, Keio University School of Medicine, Tokyo, Japan. Electronic address: kazuki3005@gmail.com.
⁷ Department of Orthopaedic Surgery, Keio University School of Medicine, Tokyo, Japan. Electronic address: iwatakuji@gmail.com.

PMID: 38302310
DOI: 10.1016/j.jos.2024.01.007

Abstract

Background: This study aimed to demonstrate the effectiveness of our new diagnostic chart using point of care ultrasound combined with CTS-6 for diagnosing idiopathic carpal tunnel syndrome.

Methods: We conducted a retrospective analysis of the data of patients who visited our department and received point of care ultrasound combined with CTS-6 from 2020 to 2023. Data regarding age, sex, initial and final diagnosis, cross-sectional area of the median nerve, CTS-6 score, and electrodiagnostic severity were obtained and statistically analyzed.

Results: Of the 177 wrists included in our study, 138 (78 %) were diagnosed with carpal tunnel syndrome, while 39 (22 %) were not (non-carpal tunnel syndrome). With our diagnostic method, 127 wrists (72 %) were diagnosed initially with carpal tunnel syndrome, 23 wrists (13 %) with non-carpal tunnel syndrome, and the rest 27 wrists (15 %) as borderline. Our initial diagnoses of carpal tunnel syndrome and non-carpal tunnel syndrome were maintained in all cases except for two. Cross-sectional area, CTS-6 score, and electrodiagnostic severity showed a positive correlation. A post hoc analysis showed that the new scoring system (CTS-6 score + 2 × cross-sectional area) with a cutoff value of 31.25 points showed a sensitivity as high as 95 % and a specificity of 100 %.

Conclusions: Our findings suggest that most suspected idiopathic carpal tunnel syndrome cases can be diagnosed correctly using the diagnostic chart. Although additional tools, including electrodiagnostic studies, may be needed for borderline cases, the use of point of care ultrasound combined with CTS-6 may be a recommendable first-line confirmatory test because point of care ultrasound and CTS-6 could be complementary tools, and this chart may be especially beneficial for atypical or outlier cases.

Level of evidence: Diagnostic III.

Keywords: CTS-6; Carpal tunnel syndrome; Electrodiagnostic study; Reference standard; Ultrasound.