Predictors for Failure of Nonsurgical Treatment in Mild to Moderate Cubital Tunnel Syndrome

Background: Activity modification to reduce mechanical stress on the ulnar nerve is an effective treatment for mild to moderate cubital tunnel syndrome (CuTS). However, some patients do not improve with nonsurgical management and ultimately require surgical intervention. This study aimed to identify predictors associated with nonsurgical treatment failure in CuTS.

Methods: We retrospectively reviewed data from patients with CuTS classified as McGowan grades 1 and 2. Non-surgical management primarily consisted of activity modification, with adjunctive treatments including vitamin B12, nonsteroidal anti-inflammatory drugs, pregabalin or mirogabalin and corticosteroid injections. Treatment failure was defined as the need for subsequent surgical intervention (transition-to-surgery group). The success group included 37 patients, and the transition-to-surgery group included 26 patients. Univariate and multivariate regression analyses were performed to evaluate predictors of nonsurgical treatment failure, including age, sex, body mass index, disease duration, comorbidities (diabetes mellitus, thyroid disease and radiographic cervical spondylosis) and concomitant elbow disorders (osteoarthritis, ganglion cysts and cubitus varus or valgus deformity). Elbow osteoarthritis was assessed radiographically using the Broberg and Morrey classification system.

Results: Univariate analysis showed that corticosteroid injections, current smoking, radiographic cervical spondylosis and elbow osteoarthritis were more common in the transition-to-surgery group than in the success group. Multivariate analysis identified corticosteroid injections, radiographic cervical spondylosis and elbow osteoarthritis as independent predictors of nonsurgical treatment failure.

Conclusions: Patients who received corticosteroid injections and those with radiographic cervical spondylosis or elbow osteoarthritis were more likely to experience nonsurgical treatment failure for mild to moderate CuTS and subsequently require surgical intervention. Early recognition of these risk factors may help clinicians identify patients who are less likely to respond to conservative management and consider earlier surgical treatment to prevent persistent symptoms and disease progression.

Level of Evidence: Level IV (Therapeutic)