Table 1.

Demographic information of the studies (NA, not available)

Author	Journal	Year	Study period	Country	N of patients	Male/ Female	Mean age (range)
Lee et al.	Arch Orthop Trauma Surg	2010	July2004–Oct 2008	Korea	25	5/20	72.8 (65–85)
Omura et al.	Arch Orthop Trauma Surg	2000	Jan 1994–Nov 1997	Japan	8	3/5	79.2 (62–101)
Lalonde et al.	Iowa Orthop J.	2010	May 2001–May 2003	Canada	10	5/5	79 (53–90)
Craig et al.	Skeletal Radiol	2000	Mar 1995–Feb 1999	USA	13	10/3	56 (24–86)
Feldman et al.	AJR Am J Roentgenol	2004	1990–2003	USA	37	12/25	NA (50–95)
Kim et al.	J Orthop Trauma	2013	June 2005–Feb 2012	Korea	9	1/8	80.8 (65–91)
Suzuki	Arch Orthop Trauma Surg	2011	Jan 2009–Dec 2010	Japan	8	3/5	78 (58–92)