Utility of Ultrasound for Identifying Median Nerve Changes Indicative of Acute Carpal Tunnel Syndrome After Distal Radius Fracture.
Utility of Ultrasound for Identifying Median Nerve Changes Indicative of Acute Carpal Tunnel Syndrome After Distal Radius Fracture.
- 2023
Conclusions: ACTS should be suspected in patients with median nerves demonstrating increased CSA and adopting a more circular shape. Fracture positioning impacts median nerve CSA with wrist extension, causing the greatest change. Median nerve HWR may offer an easier ultrasonographic alternative to CSA. Methods: We used 10 upper-extremity specimens. We induced ACTS (carpal tunnel pressure >40 mm Hg) in a distraction-only model and then used a DRF model as a neutral position, under traction, or wrist extension. We measured the median nerve cross-sectional area (CSA), height, and width with ultrasound in each model. We used a novel calculation, height-width ratio (HWR), to describe nerve shape. A low HWR indicates an elliptical shape; as the HWR increases toward one, the shape becomes more circular. The CSA measurements and HWR at pressures >40 mm Hg were used to calculate a 95% confidence interval, which defined the threshold for ACTS. Purpose: Ultrasound offers a fast and inexpensive way to evaluate the median nerve. However, there is a paucity of data assessing ultrasound in acute trauma. Our study aimed to characterize median nerve changes indicative of acute carpal tunnel syndrome (ACTS) in a cadaveric distal radius fracture (DRF) model. Results: Wrist distraction created carpal tunnel pressures >40 mm Hg in all specimens. Distraction increased CSA compared with baseline (9.1 +/- 0.9 mm2 vs 6.3 +/- 1.2 mm2, P < .001). Under ACTS-level pressures, the thresholds for CSA and HWR were 8.5 mm2 and 0.41, respectively. HWR significantly increased with distraction compared with baseline (0.47 +/- 0.10 vs 0.28 +/- 0.09, P = .006). Most neutral DRF models (n = 8, 80%) met the CSA threshold for ACTS, whereas all specimens with a DRF extended or under traction had CSAs above the ACTS threshold. Compared to the baseline, the shape of the median nerve was more circular in all DRFs, including neutral (0.28 +/- 0.09 vs 0.39 +/- 0.13), under traction (0.43 +/- 0.09), and extended (0.45 +/- 0.09). Type of study/level of evidence: Diagnostic III. Copyright © 2023 The Authors.
English
2589-5141
10.1016/j.jhsg.2023.03.013 [doi] PMC10382869 [pmc] S2589-5141(23)00053-1 [pii]
Curtis National Hand Center
Journal Article
Conclusions: ACTS should be suspected in patients with median nerves demonstrating increased CSA and adopting a more circular shape. Fracture positioning impacts median nerve CSA with wrist extension, causing the greatest change. Median nerve HWR may offer an easier ultrasonographic alternative to CSA. Methods: We used 10 upper-extremity specimens. We induced ACTS (carpal tunnel pressure >40 mm Hg) in a distraction-only model and then used a DRF model as a neutral position, under traction, or wrist extension. We measured the median nerve cross-sectional area (CSA), height, and width with ultrasound in each model. We used a novel calculation, height-width ratio (HWR), to describe nerve shape. A low HWR indicates an elliptical shape; as the HWR increases toward one, the shape becomes more circular. The CSA measurements and HWR at pressures >40 mm Hg were used to calculate a 95% confidence interval, which defined the threshold for ACTS. Purpose: Ultrasound offers a fast and inexpensive way to evaluate the median nerve. However, there is a paucity of data assessing ultrasound in acute trauma. Our study aimed to characterize median nerve changes indicative of acute carpal tunnel syndrome (ACTS) in a cadaveric distal radius fracture (DRF) model. Results: Wrist distraction created carpal tunnel pressures >40 mm Hg in all specimens. Distraction increased CSA compared with baseline (9.1 +/- 0.9 mm2 vs 6.3 +/- 1.2 mm2, P < .001). Under ACTS-level pressures, the thresholds for CSA and HWR were 8.5 mm2 and 0.41, respectively. HWR significantly increased with distraction compared with baseline (0.47 +/- 0.10 vs 0.28 +/- 0.09, P = .006). Most neutral DRF models (n = 8, 80%) met the CSA threshold for ACTS, whereas all specimens with a DRF extended or under traction had CSAs above the ACTS threshold. Compared to the baseline, the shape of the median nerve was more circular in all DRFs, including neutral (0.28 +/- 0.09 vs 0.39 +/- 0.13), under traction (0.43 +/- 0.09), and extended (0.45 +/- 0.09). Type of study/level of evidence: Diagnostic III. Copyright © 2023 The Authors.
English
2589-5141
10.1016/j.jhsg.2023.03.013 [doi] PMC10382869 [pmc] S2589-5141(23)00053-1 [pii]
Curtis National Hand Center
Journal Article