Shear wave elastography in the diagnosis of the ulnar tunnel syndrome.

Publication date: Available online 4 September 2018

Source: Journal of Plastic, Reconstructive & Aesthetic Surgery

Author(s): Ł Paluch, BH Noszczyk, J Walecki, K Osiak, M Kiciński, P Pietruski

Summary

An interesting alternative to traditional diagnostic techniques of the upper extremity nerve entrapments might be provided by an ultrasound elastography that started to gain attention in recent research. The aim of this preliminary study was to verify if quantitative analysis of ulnar nerve stiffness with shear-wave elastography can be used to diagnose the ulnar tunnel syndrome, an ulnar nerve neuropathy at the Guyon's canal. The study included 46 patients (39 women) and 39 healthy controls (34 women). All diagnoses in patients and controls were confirmed with nerve conduction studies. Measurements of nerve stiffness were taken at three levels: in Guyon's canal (G) and at distal (DF) and mid-forearm (MF). Additionally, ulnar nerve cross-sectional area at the canal's level was determined by means of ultrasonography. Patients with the ulnar tunnel syndrome presented with significantly greater nerve stiffness than the controls (mean, 99.41 kPa vs. 49.08 kPa, P <0.001). No significant intergroup differences were found in the nerve elasticity at DF and MF (P <0.836 and P < 0.881, respectively). Ulnar nerve stiffness value of 80 kPa, and G:DF and G:MF ratios equal to 1.5 provided 100% sensitivity, specificity, positive and negative predictive value in the detection of the syndrome. Mean nerve cross-sectional area in the Guyon's canal was significantly greater in patients than in the controls (4.63 mm², range, 2-7 mm² vs. 3.23 mm², range, 2-5 mm², P <0.001). In conclusion, we believe that shear-wave elastography has a potential to become a useful adjunct diagnostic test for the ulnar tunnel syndrome.