Electrodiagnostic Testing Predicts Postdecompression Outcomes in Patients With Cubital Tunnel Syndrome.

Purpose: Electrodiagnostic (EDX) testing is commonly used in conjunction with symptoms and physical examination findings to diagnose cubital tunnel syndrome (CuTS). The purpose of this study was to investigate the relationship between preoperative EDX diagnosis and the degree of Disabilities of the Arm, Shoulder, and Hand (DASH) improvement after surgery within the CuTS patient population.

Methods: A retrospective review was designed to analyze patients from a single institution who underwent a cubital tunnel release. Patients who had preoperative EDX testing, as well as preoperative and 3-month postoperative DASH scores were eligible for inclusion. These patients were divided into two groups, EDX-positive or EDX-negative, based on the findings of their EDX testing for CuTS. Demographics, preoperative DASH, postoperative DASH, and changes in DASH were compared between the two groups.

Results: Fifty-seven patients were included-34 EDX-positive and 23 EDX-negative. The EDX-negative cohort had higher preoperative DASH scores, which approached but did not reach significance ( = .06). Both groups had significant improvement in DASH following cubital tunnel release ( = .021, < .01). Patients with EDX-negative testing had a significantly greater improvement in DASH from before surgery to 3 months after surgery (25 points vs 11, < .01).

Conclusions: Patients who underwent cubital tunnel release had a significant short-term improvement in their DASH scores, regardless of EDX diagnosis. However, negative preoperative EDX studies in the setting of strong clinical suspicion of CuTS do not exclude diagnosis and may in fact be a positive, rather than a negative, predictive factor for short-term postoperative functional improvement.

Type Of Study/level Of Evidence: Prognostic IV.