Comparison 1. Posterior vs Direct Lateral approach for THA.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Dislocation	2	149	Risk Ratio (M‐H, Fixed, 95% CI)	0.35 [0.04, 3.22]
2 Trendelenburg gait	3	166	Risk Ratio (M‐H, Fixed, 95% CI)	0.52 [0.21, 1.27]
3 Nerve palsy or injury	2	92	Risk Ratio (M‐H, Fixed, 95% CI)	0.16 [0.03, 0.83]
4 Pain	1	50	Risk Ratio (M‐H, Fixed, 95% CI)	0.59 [0.17, 2.03]
4.1 Trochanteric pain (>3/10)	1	50	Risk Ratio (M‐H, Fixed, 95% CI)	0.59 [0.17, 2.03]
5 Trendelenburg score [0‐2]	1	49	Mean Difference (IV, Fixed, 95% CI)	0.03 [‐0.25, 0.31]
6 Limp score [0‐4]	1	49	Mean Difference (IV, Fixed, 95% CI)	‐0.14 [‐0.61, 0.33]
7 Abductor power score [0‐5]	1	49	Mean Difference (IV, Fixed, 95% CI)	0.20 [‐0.24, 0.64]
8 Sciatic nerve palsy	1	42	Risk Ratio (M‐H, Fixed, 95% CI)	0.18 [0.01, 3.59]
9 Sup. gluteal nerve palsy	1	50	Risk Ratio (M‐H, Fixed, 95% CI)	0.28 [0.03, 2.19]
10 Obturator nerve palsy	1	42	Risk Ratio (M‐H, Fixed, 95% CI)	0.18 [0.01, 3.59]
11 Femoral nerve palsy	1	42	Risk Ratio (M‐H, Fixed, 95% CI)	0.30 [0.01, 7.07]
12 Harris hip score	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
12.1 Pre‐operative	1	49	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
12.2 Postoperative	1	49	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
12.3 Change post‐preop at folllow‐up	1	49	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
13 WOMAC score	0	0	Mean Difference (IV, Fixed, 95% CI)	0.0 [0.0, 0.0]
14 Range of motion	1		Mean Difference (IV, Fixed, 95% CI)	Subtotals only
14.1 Internal rotation	1	49	Mean Difference (IV, Fixed, 95% CI)	16.0 [8.64, 23.36]
15 Limb‐length discrepancy	1	42	Risk Ratio (M‐H, Fixed, 95% CI)	0.61 [0.20, 1.84]
15.1 LLD > 1cm	1	42	Risk Ratio (M‐H, Fixed, 95% CI)	0.61 [0.20, 1.84]
16 Stem loosening	1	49	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
17 Cup loosening	1	49	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
18 Reoperation	1	49	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
19 Periprosthetic fracture	0	0	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
20 Heterotopic ossification [Brooker 1‐4]	1	245	Risk Ratio (M‐H, Fixed, 95% CI)	0.57 [0.30, 1.09]
20.1 Brooker I	1	49	Risk Ratio (M‐H, Fixed, 95% CI)	0.5 [0.16, 1.55]
20.2 Brooker II	1	49	Risk Ratio (M‐H, Fixed, 95% CI)	1.5 [0.15, 15.46]
20.3 Brooker III	1	49	Risk Ratio (M‐H, Fixed, 95% CI)	0.25 [0.01, 5.91]
20.4 Brooker IV	1	49	Risk Ratio (M‐H, Fixed, 95% CI)	0.0 [0.0, 0.0]
20.5 Total	1	49	Risk Ratio (M‐H, Fixed, 95% CI)	0.56 [0.23, 1.38]