Direct anterior approach vs Hardinge in obese and nonobese osteoarthritic patients: A randomized controlled trial

Table 1 Demographic characteristics and clinical measurements of the study sample (n = 120)

Characteristics and Clinical Measurements	DAA–nonobese (n = 30)	DAA–obese (n = 30)	Hardinge–nonobese (n = 30)	Hardinge–obese (n = 30)	P value
Age (yr)1	66.40 ± 7.31	63.73 ± 6.96	69.00 ± 9.00	63.73 ± 6.96	0.102
Height (m)1	1.65 ± 0.09	1.64 ± 0.10	1.62 ± 0.08	1.64 ± 0.09	0.442
Weight (kg)1	73.10 ± 10.95	92.63 ± 14.14a,b	66.30 ± 8.10	93.93 ± 16.09a,b	< 0.001
Body mass index (kg/m2)1	26.61 ± 2.16	34.27 ± 4.12a,b	25.30 ± 2.03	34.73 ± 4.57a,b	< 0.001
Dominant lower limb, n (%)
Right	24 (80.0)	25 (83.3)	27 (90.0)	25 (83.3)	0.756
Left	6 (20.0)	5 (16.7)	3 (10.0)	5 (16.7)
Affected hip, n (%)
Right	15 (50.0)	18 (60.0)	14 (46.7)	18 (60.0)	0.442
Left	15 (50.0)	12 (40.0)	16 (53.3)	12 (40.0)
Walking aid, n (%)
No	25 (83.3)	22 (73.3)	24 (80)	19 (63.3)	0.292
Yes	5 (16.7)	8 (26.7)	6 (20.0)	11 (36.7)
Kellgren & Lawrence classification, n (%)
Grade 3	21 (70.0)	19 (63.3)	20 (66.7)	19 (63.3)	0.939
Grade 4	9 (30.0)	11 (36.7)	10 (33.3)	11 (36.7)
Face Pain Scale-Revised1 (10 = worst pain)	6.47 ± 1.55a	6.87 ± 1.80	7.13 ± 1.36	7.60 ± 1.52	0.045
Timed Up and Go test (s)1	16.09 ± 3.07a	16.07 ± 5.56a	17.12 ± 5.22	19.32 ± 4.99	0.033
Modified Harris Hip Score – Greek version1 (100 = max best score)	41.00 ± 6.55	33.94 ± 9.62b	38.53 ± 8.15	31.66 ± 11.14b	< 0.001
International Hip Outcome Tool (12 items) – Greek version1 (100 = max best score)	31.43 ± 9.04	31.52 ± 8.26	28.28 ± 9.24	26.39 ± 10.00	0.100

¹The values are expressed as mean ± SD.

^aP < 0.005 vs DAA-nonodese.

^bP < 0.005 vs Hardinge –nonobese. DAA: Direct anterior approach.

Table 2 Comparison of outcomes’ scores during the observation period per group

Groups	Preoperative measurement	6th postoperative week	12th postoperative week	P value
Face Pain Scale-Revised (min 0 - max 10)
DAA-nonobese	6.46 ± 1.55	1.97 ± 0.72	0.13 ± 0.35	F(2.58) = 563.8, P < 0.001
DAA-obese	6.87 ± 1.79	1.93 ± 0.69	0.30 ± 0.53	F(2.58) = 293.1, P < 0.001
Hardinge-nonobese	7.13 ± 1.36	3.20 ± 0.80	1.17 ± 0.70	F(2.58) = 830.9, P < 0.001
Hardinge-obese	7.60 ± 1.52	3.00 ± 0.69	1.00 ± 0.69	F(2.58) = 673.7, P < 0.001
Timed Up and Go Test (second)
DAA-nonobese	16.09 ± 3.07	11.22 ± 2.29	7.81 ± 1.74	F(2.58) = 399.81, P < 0.001
DAA-obese	16.07 ± 5.56	10.95 ± 2.52	8.02 ± 2.32	F(2.58) = 89.55, P < 0.001
Hardinge-nonobese	17.12 ± 5.21	14.17 ± 3.69	11.62 ± 3.00	F(2.58) = 122.04, P < 0.001
Hardinge-obese	19.32 ± 5.00	16.60 ± 4.14	14.33 ± 3.84	F(2.58) = 289.56, P < 0.001
Modified Harris Hip Score – Greek version (min 0 – max 100)
DAA-nonobese	41.00 ± 6.54	70.75 ± 8.20	92.41 ± 3.83	F(2.58) = 1148.1, P < 0.001
DAA-obese	33.94 ± 9.62	63.98 ± 10.86	87.83 ± 6.29	F(2.58) = 893.7, p<0.001
Hardinge-nonobese	38.53 ± 8.15	60.68 ± 10.68	82.17 ± 9.00	F(2.58) = 1291.8, P < 0.001
Hardinge-obese	32.07 ± 10.41	53.82 ± 15.00	74.38 ± 11.78	F(2.58) = 1066.6, P < 0.001
International Hip Outcome Tool (12 items) – Greek Version (min 0 – max 100)
DAA-nonobese	31.43 ± 9.04	67.00 ± 10.05	86.18 ± 10.00	F(2.58) = 703.53, P < 0.001
DAA-obese	31.52 ± 8.25	66.06 ± 12.95	88.43 ± 7.77	F(2.58) = 740.71, P < 0.001
Hardinge-nonobese	28.28 ± 9.24	50.39 ± 15.72	67.96 ± 14.77	F(2.58) = 411.82, P < 0.001
Hardinge-obese	26.39 ± 10.00	47.21 ± 16.88	63.46 ± 16.21	F(2.58) = 351.81, P < 0.001

All values are presented as mean ± SD; All time points are statistically significant different between them, P < 0.001. DAA: Direct anterior approach.

Table 3 Interaction between “body mass index” and “surgical approach” factors

Outcomes/Variables	6th postoperative week	12th postoperative week
Face Pain Scale-Revised	F(1.116) = 1.96, P = 0.164	F(1.116) = 4.11, P = 0.045
Timed Up and Go Test	F(1.116) = 0.97, P = 0.328	F(1.116) = 0.79, P = 0.376
Modified Harris Hip Score – Greek version	F(1.116) = 1.01, P = 0.316	F(1.116) = 0.93, P = 0.337
International Hip Outcome Tool (12 items) – Greek Version	F(1.116) = 0.80, P = 0.373	F(1.116) = 0.11, P = 0.917

Significant P < 0.05.

Table 4 The % percentage changes of outcome scores, between surgical approaches, according and regardless of body mass index, compared to corresponding baseline measurements

		Nonobese (ΒΜΙ < 30 kg/m2)			Obese (ΒΜΙ ≥ 30 kg/m2)			Comparison between surgical approaches regardless of BMI
Outcomes/variables	Postoperative measurements	DAA1	Hardinge1	P value3	DAA1	Hardinge1	P value3	DAA2	Hardinge2	P value3
Face Pain Scale - Revised (%)	6th week	-70.1 ± 6.7	-55.3 ± 7.3	< 0.001	-70.0 ± 15.8	-60.3 ± 6.9	0.002	-70.0 ± 1.3	-57.8 ± 1.3	< 0.001
	12th week	-98.4 ± 4.1	-84.4 ± 8.2	< 0.001	-93.3 ± 18.7	-87.5 ± 8.3	0.429	-95.8 ± 1.4	-86.0 ± 1.4	< 0.001
Timed Up and Go Test (%)	6th week	-30.1 ± 6.5	-16.5 ± 4.8	< 0.001	-29.9 ± 10.9	-13.9 ± 2.9	< 0.001	-30.0 ± 0.9	-15.2 ± 0.9	< 0.001
	12th week	-51.2 ± 6.4	-31.4 ± 5.9	< 0.001	-48.5 ± 14.4	-25.9 ± 3.9	< 0.001	-49.9 ± 1.1	-28.7 ± 1.1	< 0.001
Modified Harris Hip Score – Greek version (%)	6th week	76.2 ± 27.4	59.6 ± 13.9	0.026	97.9 ± 38.5	71.4 ± 23.6	0.012	87.0 ± 3.5	65.5 ± 3.5	< 0.001
	12th week	132.9 ± 50.4	121.4 ± 43.2	0.777	181.4 ± 89.6	147.8 ± 56.4	0.317	157.1 ± 8.1	134.6 ± 8.1	0.050
International Hip Outcome Tool (12 items) – Greek version (%)	6th week	124.4 ± 51.6	79.5 ± 22.9	< 0.001	115.7 ± 39.4	84.3 ± 46.0	0.031	120.1 ± 5.3	81.9 ± 5.3	< 0.001
	12th week	192.0 ± 76.1	150.3 ± 43.7	0.048	195.4 ± 64.2	156.1 ± 67.5	0.077	193.7 ± 8.3	153.2 ± 8.3	< 0.001

¹The values are presented as mean ± SD.

²The values are presented as mean ± SE (%).

³P value_{Bonferroni correction}. BMI: Body mass index; DAA: Direct anterior approach.

Table 5 The % percentage changes of outcome scores, between body mass index groups, according and regardless of surgical approach, compared to corresponding baseline measurements

Outcomes/variables	Postoperative measurements	DAA			Hardinge approach			Comparison between ΒΜΙ groups regardless of surgical approach
		Nonobese1	Obese1	P value3	Nonobese1	Obese1	P value	Nonobese2	Obese1	P value3
Face Pain Scale - Revised (%)	6th week	-70.1 ± 6.7	-70.0 ± 15.8	1.000	-55.3 ± 7.3	-60.3 ± 6.9	0.304	-62.7 ± 01.3	-65.1 ± 1.3	0.178
	12th week	-98.4 ± 4.1	-93.3 ± 18.7	0.468	-84.4 ± 8.2	-87.5 ± 8.3	0.451	-91.4 ± 1.4	-90.4 ± 1.4	0.631
Timed Up and Go Test (%)	6th week	-30.1 ± 6.5	-29.9 ± 10.9	1.000	-16.5 ± 4.8	-13.9 ± 2.9	0.102	-23.3 ± 0.9	-21.9 ± 0.9	0.278
	12th week	-51.2 ± 6.4	-48.5 ± 14.4	0.783	-31.4 ± 5.9	-25.9 ± 3.9	0.001	-41.3 ± 1.1	-37.2 ± 1.1	0.010
Modified Harris Hip Score – Greek version (%)	6th week	76.1 ± 27.4	97.9 ± 38.5	0.068	59.6 ± 13.9	71.4 ± 23.6	0.102	67.9 ± 3.5	84.6 ± 3.5	0.001
	12th week	132.9 ± 50.4	181.4 ± 89.6	0.061	121.4 ± 43.2	147.8 ± 56.4	0.186	127.1 ± 8.1	164.6 ± 8.1	0.001
International Hip Outcome Tool (12 items) – Greek version (%)	6th week	124.4 ± 51.6	115.7 ± 39.4	0.841	79.5 ± 22.9	84.3 ± 46.0	0.957	102.0 ± 5.3	100.0 ± 5.3	0.793
	12th week	192.0 ± 76.1	195.4 ± 64.2	1.000	150.3 ± 43.7	156.1 ± 67.5	1.000	171.1 ± 8.3	175.7 ± 8.3	0.697

¹The values are presented as mean ± SD.

²The values are presented as mean ± SE (%).

³P value_{Bonferroni correction}. BMI: Body mass index; DAA: Direct anterior approach.