Objectives:

Although ultrasonography is currently used in daily practice in the evaluation of soft tissue problems, its use in diagnosis of ulnar nerve entrapment at the elbow (UNE) is still limited. The purpose of this study is to demonstrate the feasibility of ultrasonograpy in UNE.

Methods:

This prospective study included 33 ulnar nerves of 33 consecutive patients ( 45,2 years, range: 23–69 years, 15 men and 18 women) with the diagnosis of unilateral UNE on clinical and electrodiagnostic studies and 32 ulnar nerves of 16 healthy volunteers ( mean age: 35,5 years, range: 26–62 years, 9 men and 7 women) as a control group were examined. The minimum and maximum diameters of the ulnar nerve and the cross sectional areas (CSA) at the level of the medial epicondyle, 4 cm proximal and 4 cm distal to the medial epicondyle. In statistical analysis, comparisons were made using student t tests. The Mann- Whitney U test was performed for the nonparametric variables, and all tests were considered significant at p<0.05 in 95% CIs.

Results:

The maximum diameter of the ulnar nerve at medial epicondyle (3,74±0,86 mm; 2,5–6,3 mm), proximal (2,68±0,31 mm; 2,1–3,3 mm) and distal to the medial epicondyle (2,37±0,30 mm; 1,9–2,9 mm) were significantly larger in patients when compared to the same parameters at the same levels in control subjects (2,75±0,37 mm; 2–3,5 mm; 2,16±0,26 mm; 1,6–2,7 mm; 2,16±0,27 mm; 1,7–2,6 mm, respectively, p<0,01). The CSA of the ulnar nerve at medial epicondyle (9,79±4,70 mm; 4-25 mm) and proximal (4,09±0,84 mm; 3-6 mm) to the medial epicondyle were also significantly larger in patients when compared to the same parameters at the same levels in control subjects (5,06±1,19 mm; 3-7 mm; 3,0±0,51 mm; 2-5 mm, respectively (p<0,01). The CSA distal to the medial epicondyle were larger in patients when compared to the CSA at the same level in control subjects, but this difference was not found statistically significant (p>0,05).

Conclusions:

Our ultrasonography findings are consistant with electrophysiologic and clinical findings in terms of identifying patients with UNE. Ultrasonography can become a screening imaging modality in patients with UNE.

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