A Systematic Review of Retrospective Evidence on Patient and Surgical Factors in Recurrent Cubital Tunnel Syndrome

There is much debate regarding which patient-related risk factors and surgical techniques contribute to recurrent cubital tunnel syndrome (CuTS). This systematic review aimed to identify preoperative risk factors and surgical techniques associated with symptom recurrence or revision surgery following cubital tunnel release.

We searched PubMed, Scopus, Cochrane Library, and clinicaltrials.gov databases for potentially eligible articles published between January 2009 and November 2024. Using Covidence, four reviewers screened based on predefined inclusion criteria: studies examining recurrent CuTS following surgery, reporting patient characteristics and/or surgical techniques, and published in English. A standardized Excel sheet was utilized to extract patient demographics, recurrence rates, and revision outcomes. Risk of bias was assessed using the Newcastle-Ottawa Scale. Due to heterogeneity in outcomes, no formal metaanalysis was performed, and a narrative synthesis was done.

Fourteen studies were included, totaling 49,492 patients with idiopathic CuTS treated with ulnar nerve surgery. Revision rates ranged 1.2-23.8%. Younger age was described as a risk factor in ten studies, although one study identified older age as a predictive risk factor. In contrast, another study described it as a protective factor. Diabetes was associated with recurrence risk in two studies, while sex, BMI, and smoking showed inconsistent associations. Severe preoperative symptoms or higher McGowan scores were associated with poorer outcomes in two studies. Overall, recurrence and revision rates were low across all techniques.

The retrospective nature and limited power of included studies increase risk of selection and Type II errors. Regardless, there seems to be no significant difference in recurrence/revision rates based on surgical techniques. CuTR was often recommended as an initial procedure while ulnar nerve transposition (UNT) was reserved for revisions or patients with nerve subluxation.