Functional and clinical outcome with modified lateral approach total hip arthroplasty in stiff hips with ankylosing spondylitis

Table 1 Comparison of preoperative and follow-up flexion, range of movement, and Harris hip score

Movement	Preoperative	Follow-up	Mean difference (95%CI)	P value
Flexion	29.35	102.17	65.76 ± 71.37	< 0.0001
ROM total	45.29	220.65	132.97 ± 171.86	< 0.0001
ROM score	1.71	4.95	3.33 ± 3.18	< 0.0001
MHHS	17.03	90.66	53.84 ± 72.16	< 0.0001

ROM: Range of movement; MHHS: Modified Harris hip score.

Table 2 Distribution of general health status and the 36-item short form health survey in 40 patients

SF-36 scores
Mental health	(n = 40)	84.10 ±11.58
Role limitations due to emotional problems	(n = 40)	94.17 ± 19.81
Social functioning	(n = 40)	86.25 ± 16.70
Energy fatigue/vitality	(n = 40)	71.87 ± 16.63
General health	(n = 40)	63.12 ± 24.22
Bodily pain	(n = 40)	80.00 ± 19.23
Physical functioning	(n = 40)	69.63 ± 18.58
Role limitations due to physical health	(n = 40)	85.00 ± 33.87

SF-36: 36-item short form health survey.

Table 3 The 36-item short form health survey scores compared to other series

SF-36 scores	Our series	Bahardoust etal[10], 2012	Dagfinrud etal[9], 2004	van Tubergen etal[19], 2002
Mental health	84.10 (11.58)	39.9 (28.2)	70 (19)	65.5 (18.1)
Role limitations due to emotional problems	94.17 (19.81)	79.1 (19.2)	66 (42)	68.5 (41.3)
Social functioning	86.25 (16.70)	28.5 (29.2)	70 (27)	64.6 (24.6)
Energy fatigue/vitality	71.87 (16.63)	56.2 (21.4)	43 (23)	42.6 (16.5)
General health	63.12 (24.22)	42.1 (26.3)	51 (24)	42.8 (20.2)
Bodily pain	80.00 (19.23)	48.2 (28.4)	44 (22)	48.3 (19.2)
Physical functioning	69.63 (18.58)	28.3 (11.1)	71 (23)	55.8 (23.4)
Role limitations due to physical health	85.00 (33.87)	31.2 (12.6)	44 (41)	35.6 (38.1)

SF-36: 36-item short form health survey.

Table 4 Comparison of parameters with other series

Ref.	Patients (hips)	Follow-up in mo	Pain relief, %	Final MHHS	ROM score/mean flexion	Approach	Complications, %
Bisla et al[20], 1976	23 (34)	42.5	91	NS	ROM-3	NS	5.88
Resnick et al[21], 1976	11 (21)	36	NS	NS	NS	NS	0
Williams et al[22], 1977	56 (99)	36	NS	NS	NS	NS	10
Baldursson et al[23], 1977	10 (18)	45.6	94	NS	Flexion-90	NS	0
Shanahan et al[24], 1982	12 (16)	89	94	NS	NS	NS	6.25
Finsterbush et al[25], 1988	23 (35)	90	NS	NS	Flexion-86	NS	14.28
Walker et al[26], 1991	19 (29)	58	97	NS	ROM-4	NS	0
Gualtieri et al[27], 1992	39 (73)	90	89	NS	NS	NS	0
Brinker et al[28], 1996	12 (20)	75	90	89.1	ROM-4	Posterior, lateral	0
Sochart et al[29], 1997	24 (43)	276	100	NS	ROM-4	NS	27.9
Lehtimäki et al[30], 2001	54 (76)	240	NS	NS	NS	NS	3.94
Joshi et al[31], 2002	103 (181)	120	96	NS	NS	Lateral, Hardinge	10.5
Kim et al[32], 2007	12 (24)	132	NS	82.3	NS	Lateral	12.5
Bhan et al[6], 2008	54 (92)	102	62	82.6	ROM-4	Posterior	14
Li et al[33], 2009	24 (39)	36	NS	91	ROM-4	Posterolateral	2.5
Tang et al[2], 2000	58 (95)	135.4	94	88.8	ROM-4.2	Posterior	20
Bangjian et al[34], 2012	12 (24)	50.4	100	86.25	Flexion-84	Posterolateral	0
Malhotra et al[35], 2012	23 (32)	42	NS	87.1	ROM-4	Posterior	4.7
Siavashi et al[36], 2014	77 (NA)	12	NS	88.22	ROM-5	Posterior, lateral	20.8
Xu et al[37], 2017	54 (81)	42	NS	86.1	Flexion-82.5	Posterolateral	0
Our series	40 (69)	38.33	92	90.67	Flexion-102.1739, ROM-4.9514	Modified Hardinge	1.4

ROM: Range of movement; MHHS: Modified Harris hip score; NS: Not specified; NA: Not available.