Study	Reason for exclusion
Aszmann 2000	Prospective study but not a randomized controlled study. Used comparison to the opposite non‐operative side to assess improvement.
Aszmann 2004	Retrospective study with no control arm.
Baravarian 2006	Discussion of a paper.
Dellon 1992	Prospective study but not a randomized controlled study.
Ducic 2006	Prospective study but not a randomized controlled study.
Maloney 2006	Retrospective study with no control arm.
Rader 2005	Prospective study but not a randomized controlled study. Used comparison to the opposite non‐operative side to assess improvement.
Seckel 1992	Personal opinion.