Bilateral Hip Arthroplasty: When Is It Safe to Operate the Second Hip? A Systematic Review

Table 3

Summary of selected articles including evidence quality assessment and results of the studies.

Study	Type of Study	Sample Size	Surgery definition	Mean age (years)		Quality of evidence	Findings (safety outcomes)
				Simultaneous	Staged
Eggli et al. 1996	Retrospective cohort	255	(i) Simultaneous; (ii) Staged less than 6 weeks; (iii) Stage 6 weeks and 6 months	54	61,3	Very low; (i) Low power; (ii) Selection bias	No difference between 3 groups
Alfaro- Adrián et al. 1999	Retrospective cohort	202	(i) Simultaneous; (ii) Staged 2 weeks and 2 months	65	63,9	Very low; (i) Low power	No difference between groups
Parvizi et al. 2006	Retrospective cohort	196	(i) Simultaneous; (ii) Staged 25 days and 10 months	53	65	Very low; (i) Low power; (ii) Selection bias	No difference between groups
Bhan 2006	Randomized clinical trial	168	(i) Simultaneous; (ii) Staged 3 and 7 months	46,5	43,8	Moderate; (i) Low power	More bleeding in staged surgery, more transfusion for simultaneous surgery; no difference in complications
Berend et al. 2007	Retrospective cohort	277	(i) Simultaneous; (ii) Staged 2 weeks and 2 years	52,7	57,3	Very low; (i) Poor definition for staged surgery	More complications in simultaneous surgery
Hooper et al. 2009	Register, nested cohort	2092	(i) Simultaneous; (ii) Staged without report of interval between surgeries	61	61	Very low; (i) Selection bias	No difference between groups
Aghayev et al. 2010	Register, nested cohort	1819	(i) Simultaneous; (ii) Staged less than 6 months; (iii) Staged 6 months and 5 years	59	62	Very low; (i) Poor outcome definition	No difference between groups
Saito et al. 2016	Retrospective cohort	89	(i) Simultaneous; (ii) Staged in the same hospitalization	59	61,9	Very low; (i) Low power	No difference between groups
Johnston et al. 2011	Retrospective cohort	594	(i) Simultaneous; (ii) Stage without report of interval between surgeries	61,5	66,5	Very low; (i) Selection bias	More adverse events in simultaneous surgery
Lindberg-Larsen et al. 2013	Register, nested cohort	680	(i) Simultaneous; (ii) Staged less than 6 months; (iii) Staged 6 months and 18 months	55,7	66,8	Low; (i) Selection bias	No difference between groups
Rasouli et al. 2014	Retrospective cohort	16330	(i) Simultaneous; (ii) Staged in the same hospitalization (1 to 35 days)	58,4	60,3	Moderate; (i) Selection process not clear	More complications in staged surgery during the same in-hospital stay
Garland et al. 2015	Register, nested cohort	42238	(i) Simultaneous; (ii) Staged less than 6 months; (iii) Staged 6 months and 1 year; (iv) Staged more than 1 year	<50 years = 18,3%	<50 years = 3%, 5,3%, 7,8%	Moderate; (i) Selection bias	Simultaneous surgery is safe in young and healthy patients
Quadri et al. 2015	Retrospective cohort	48	(i) Simultaneous; (ii) Staged without report of interval between surgeries	39	42	VERY LOW; (i) Low Power; (ii) Selection Bias	No difference between groups