Date	Event	Description
2 March 2015	Amended	Amended text to clarify that no studies were identified that compared surgery to sham surgery or to non‐surgical interventions.
23 April 2014	New citation required but conclusions have not changed	We updated review, with no changes to the conclusions, and added a new review author.
14 October 2013	New search has been performed	We searched for new studies up to 08 August 2013 and included four new trials (Gangopadhyay 2012; Hansen 2013; Nilsson 2010; Salem 2012). We updated the Methods, Results and Discussion sections in accordance with current Cochrane Collaboration recommendations, and to align with the conduct and reporting standards recommended by the Cochrane Collaboration's Methodological Expectations of Cochrane Intervention Reviews (MECIR) project.
13 August 2009	New citation required but conclusions have not changed	Substantive amendment and addition of new author.
31 January 2009	New search has been performed	We searched for new studies to the end of 2008 and identified three new trials that met the inclusion criteria (Field 2007; Hart 2006; Nilsson 2005). We excluded one trial that was previously included (Belcher 2001) because the study was terminated early due to adverse events and data were not available at 12 months. The methods section was updated to reflect current Cochrane Collaboration guidelines to incorporate 'Risk of bias' and 'Summary of findings' tables.
2 April 2008	Amended	CMSG ID C084‐R
2 April 2008	Amended	Converted to new review format.