Carpal tunnel syndrome: usefulness of sonography

Abstract

The aim of this study was to evaluate sonographic signs described for carpal tunnel syndrome (CTS). Sixty-four wrists from 40 patients with CTS confirmed by electromyography, and 42 wrists from 24 healthy individuals, were examined using sonography. Cross-sectional area, flattening ratio in proximal, middle and distal segments of the carpal median nerve and bowing of the flexor retinaculum were measured. The accuracies of the sonographic diagnostic criteria for CTS were assessed using receiver-operating-characteristic (ROC) analytical techniques. A significant swelling of the median nerve was observed at the proximal (p < 0.001), middle (p < 0.0001) and distal (p< 0.0001) segments and a significant bowing of the flexor retinaculum in CTS patients with respect to healthy subjects. No significant differences were found in the mean value of flattening ratio between the groups. The sensitivity, specificity, positive predictive value, and the negative predictive value were 73.4, 57.1, 72.3 and 58.5%, respectively, in the proximal and middle segments; 75, 57.1, 72.7 and 60% in the distal segment for areas greater than 11 mm2: and 81.3, 64.3, 77.6 and 69.2% for the bowing of the flexor retinaculum greater than 2.5 mm. All sonographic criteria were found in 34 CTS patients (53.1%) and none in 3 patients. Sonography may be useful in the diagnosis of CTS. The most reliable sign was increased bowing of the flexor retinaculum and cross-sectional area of median nerve with specificity close to 60%.

High‐resolution ultrasound analysis of subsynovial connective tissue in human cadaver carpal tunnel

“…Analysis of CTS by ultrasound has focused so far on cross-sectional area or flattening of the medial nerve in relation to CTS, 1,2,5,6,19,23,27 but a universally standardized method for diagnosis of CTS with ultrasound has not been established. Erel and colleagues 15 used ultrasound to examine longitudinal median nerve sliding in patients with CTS and compared the results to controls.…”

“…The usefulness of ultrasonography in monitoring carpal tunnel syndrome has also been investigated by many authors. [1][2][3][4][5][6][7] Carpal tunnel syndrome (CTS) is the most common form of peripheral nerve entrapment neuropathy and is caused by compression of the median nerve in the carpal tunnel. Within the tunnel are the flexor digitorum profundus (FDP) and superficialis (FDS) tendons to each finger; the flexor pollicis longus (FPL) tendon, the tenosynovium of these tendons, two bursae, and the median nerve.…”

The Sensitivity and Specificity of Ultrasound for the Diagnosis of Carpal Tunnel Syndrome: A Meta-analysis

“…EDX traditionally has been used as the confirmatory test for the diagnosis of CTS; however, ultrasound has garnered interest as an alternative diagnostic test for CTS [2, 5, 12-14, 17, 22, 24, 27]. Studies have used either EDX [4,15,25,28,32] or clinical diagnosis [4,12,14,15,30] as the reference standard when determining the sensitivity and specificity of ultrasound in the diagnosis of CTS. The cutoff point used for determining abnormality in the measurement of nerve conduction is highly variable, making comparison between studies difficult [14].…”

Use of Sonography in Carpal Tunnel Syndrome Surgery-A Prospective Study-

“…Recently, sonography has been evaluated for the evaluation of patients with CTS, 3,11,[16][17][18][19]21,25,28,31,32,34,35,37) and may be a useful alternative to the nerve conduction study, 7,11,20,21,23,31,34,38) with high sensitivity and specificity. 3,11,25,31,32,34,37) Most studies used nerve conduction as the gold standard.…”

“…3,11,25,31,32,34,37) Most studies used nerve conduction as the gold standard. A few surgical studies also utilized sonography to identify CTS.…”