IntroductionCubital tunnel syndrome (CuTS) is the second most common compressive neuropathy of the upper extremity. Several surgical approaches are available for a definitive treatment. This systematic review and meta-analysis aimed to comprehensively assess and compare the efficacy and safety of endoscopic in situ decompression (EISD) and open in situ decompression for CuTS.MethodsA systematic search was conducted using online databases (PubMed/MEDLINE, Embase, and Cochrane) on the 14th of April 2024. All human RCTs and observational studies in English were included in this review.ResultsEleven studies, involving 686 patients, met the inclusion criteria. Pairwise meta-analyses showed that EISD had significantly increased surgery time [MD = 9.32 minutes, 95% confidence interval (CI) (3.54, 15.11), P = 0.002], higher risk of postoperative hematoma [RR = 4.44, 95% CI (1.30, 15.20), P = 0.02], higher risk of postoperative surgical-site pain [RR = 1.50, 95% CI (1.09, 2.05), P = 0.01], lower risk of postoperative elbow numbness [RR = 0.06, 95% CI (0.01, 0.48), P = 0.007], and better postoperative grip and pinch strength [MD = 6.29, 95% CI (1.35, 11.24), P = 0.01]. In addition, it trended insignificantly toward lower rates of chronic painful scarring recurrence rates. Other measured variables did not show significant differences between the 2 surgical techniques, including the functional outcomes assessed by Bishop's score, disabilities of the arm, shoulder, and hand score, and neurophysiologic data, in addition to the postoperative infection rate, subluxation of the ulnar nerve, and reoperation rates.ConclusionsThis meta-analysis demonstrated that both surgical techniques were effective in treating CuTS. Although it was inferior in some of the measured short-term outcomes, EISD showed better results in some of the long-term measured outcomes with questionable clinical significance. The choice of the surgical approach should be tailored for each case to optimize the quality of care and overall outcomes.