ORIGINAL ARTICLE Short-term outcome after Onstep versus Lichtenstein technique for inguinal hernia repair: results from a randomized clinical trial K. Andresen 1 • J. Burcharth 1 • S. Fonnes 1 • L. Hupfeld 1 • J. P. Rothman 1 • S. Deigaard 1 • D. Winther 1 • M. B. Errebo 2 • R. Therkildsen 2 • D. Hauge 3 • F. S. Sørensen 4 • J. Bjerg 5 • J. Rosenberg 1 Received: 20 March 2015 / Accepted: 18 September 2015 Ó Springer-Verlag France 2015 Abstract Purpose Because of the high number of patients with chronic pain following inguinal hernia repair, a new, sim- ple and safe method of repair is needed. Onstep is a new type of inguinal hernia repair that might be able to reduce postoperative acute and chronic pain. The aim of this study was to investigate if there were differences in early post- operative pain during the first 10 days between the Onstep and the Lichtenstein technique. Methods This was a double-blinded, randomized clinical trial conducted in five surgical departments in Denmark, from April 2013 to June 2014. Eligible participants for this study were male patients, [ 18 years, with a primary inguinal hernia. Experimental treatment in this study was the Onstep technique, which was compared with the Lichtenstein repair. Primary outcome was postoperative pain during the first 10 days following surgery. Secondary outcomes included duration of surgery, period for return to normal daily activities (days), and recurrence. Random- ization was done in blocks and stratified on centers. Participants and study personnel handling questionnaires and analysis were blinded to the allocation. Results In total, 290 participants were randomized. We found no significant differences between the groups regarding early postoperative pain or minor postoperative complications. Four patients had a recurrence within the first 10 days of follow-up, one patient in the Lichtenstein group and three patients in the Onstep group, p = 0.30. Conclusion The Onstep technique for inguinal hernia repair was safe and had comparable results to the Licht- enstein repair regarding short-term pain and postoperative complications. Trial registration Clinicaltrials.gov (NCT01753219). Keywords Inguinal hernia Á Lichtenstein Á Onstep Á Randomized clinical trial Introduction National and international guidelines recommend that inguinal hernia repair should be performed using a mesh either by open (Lichtenstein repair) or laparoscopic surgery [1, 2]. Inguinal hernia repair can result in long-term com- plications such as chronic pain in 11–17 % of patients [3– 5], impairment of sexual function [6], and recurrence [7]. Because of the high frequency of chronic pain a new, simple and safe method of repair is needed. Onstep is a new type of groin hernia repair that might be able to reduce the number of complications since the first report docu- mented 0 % pain at one-year follow-up in 693 patients operated by the inventors of the technique [8]. A mesh is placed without using sutures between two muscle layers (internal and external oblique) laterally and in the preperitoneal space medially. The mesh is held in place by & K. Andresen kristofferandresen@gmail.com 1 Department of Surgery, Center for Perioperative Optimization, Herlev Hospital, University of Copenhagen, Herlev Ringvej 75, 2730 Herlev, Copenhagen, Denmark 2 Department of Surgery, Horsens Hospital, Horsens, Denmark 3 Department of Surgery, Bispebjerg Hospital, Copenhagen, Denmark 4 University Hospital Aalborg, Dagkirurgisk Center Hobro, Aalborg, Denmark 5 Department of Surgery, Sygehus Lillebælt, Kolding Hospital, Kolding, Denmark 123 Hernia DOI 10.1007/s10029-015-1428-8