Aims: Ulnar nerve compression at the elbow known as cubital tunnel syndrome is the second most common compression neuropathy of the upper limb. There is currently no consensus on the optimal operative treatment approach. The objective of this meta-analysis of randomized controlled trials was to evaluate the efficacy of simple decompression versus anterior transposition of the nerve in the treatment of cubital tunnel syndrome.

Methods: Multiple databases (Medline, Embase, Cochrane Library, Cinahl and several meeting archives) were searched for randomized controlled trials (RCTs) reporting on the outcome of operative treatment of cubital tunnel syndrome in patients with no trauma or previous surgeries. Two reviewers abstracted baseline characteristics, clinical scores and motor nerve conduction velocities independently. Data were pooled across studies, standard mean differences in effect sizes (SMD) weighted by study sample size were calculated and heterogeneity across studies was assessed.

Results: We identified four RCTs comparing simple decompression to anterior ulnar nerve transposition (two submuscular and two subcutaneous). Three studies used a clinical scoring system as the primary clinical outcome (n=261). There were no significant differences between simple decompression and anterior transposition. (SMD= − 0.04, 95%CI: −0.36 to 0.28, p=0.81). We did not find significant heterogeneity across studies (I2=34.2%; p=0.22). Two studies presented postoperative motor nerve conduction velocities (n=100) with no significant differences (SMD=0.24 in favor of simple decompression, 95%CI: −0.22 to 0.57, p=0.23; I2=0%; p=0.9).

Conclusions: The results of this meta-analysis suggests that there is no difference in motor nerve conduction velocities and clinical outcome scores between simple decompression and ulnar nerve transposition for the treatment of moderate to severe ulnar nerve compression at the elbow in patients with no prior trauma or previous surgeries to the affected elbow. Confidence intervals around the points of estimate are narrow probably excluding clinically meaningful differences. Since ulnar nerve transposition is the more invasive of the two procedures, this data supports the use of simple decompression of the ulnar nerve unless a plausible indication for ulnar nerve transposition exists.