Table 1.

Study and patient characteristics

	Study	Treatment	Parallel treatment	Learning cases	Mean follow-up,months		Sample sizeb		Mean age,years		Female, %		Mean BMI
Study	designa	period	period	included	A	P	A	P	A	P	A	P	A	P
Comparative studies:
Balasubramaniam et al. 2016	RN	2006–2011	No	Yes	12	12	50	42	63	57	50	67	31	30
Barrett et al. 2013	RCT	2010–2011	Yes	No	12	12	43	44	61	63	33	57	31	29
Batailler et al. 2017	RN	2013–2015	Yes	Yes	14	14	201	101	72	74	65	65	26	28
Fransen et al. 2016	RN	2012	Yes	Yes	12	12	45	38	64	63	67	63	25	28
Luo et al. 2016	RCT	2014	Yes	No	14	14	52	52	62	64	67	58	23	24
Malek et al. 2016	RN	2010–2014	Yes	No	18	18	265	183	71	70	56	53	29	29
Newman et al. 2016	RN	–	NR	NR	24	24	235	120	63	59	54	57	29	34
Rathod et al. 2014	RN	2007–2011	No	No	16	30	286	293	62	61	55	57	26	26
Rodriguez et al. 2014	PN	2010	Yes	No	12	12	60	60	60	59	53	57	27	28
Sugano et al. 2009	RN	2005–2007	No	NR	24	24	33	39	56	57	88	92	23	23
Taunton et al. 2014	RCT	2012	Yes	No	12	12	27	27	62	66	56	52	28	29
Tripuraneni et al. 2016	RN	2012–2015	Yes	Yes	14	13	66	66	60	60	61	61	28	28
Tsukada and Wakui 2015	RN	2000–2009	No	NR	64	110	139	177	67	62	90	83	23	24
Watts et al. 2015	RN	2010–2014	NR	NR	12	12	716	3,040	64	62	51	51	29	30
Zhang et al. 2006	RCT	2002–2004	Yes	NR	20	20	60	60	61	63	58	53	–	–c
Registries
Amlie et al. 2014	RN	2008–2010	Yes	No	24	30	421	421	67	66	69	64	–	–
Mjaaland et al. 2017	RN	2008–2013	Yes	Yes	52	52	2,017	5,961	67	65	67	65	–	–
Sheth et al. 2015	RN	2001–2011	No	Yes	36	36	1,851	31,747	65	66	60	58	28	29
Zijlstra et al. 2017	RN	2007–2015	No	Yes	40	40	14,446	100,823	–	–	68	68	–	–

A = anterior approach; P = posterior approach; NR = not reported

^aStudy design: PN = prospective nonrandomized; RCT = randomized controlled trial; RN = retrospective nonrandomized.

^bReported as number of patients or hips.

^cAll patients with BMI ≤27 kg/m².