Self-reported functional outcome after primary total hip replacement treated with two different periopera-tive regimes: A follow-up study involving 61 patients

Figures & data

Figure 1. Flow chart showing progress through the different phases of the study.

Figure 2. Daily time out of bed (in min) during the first 6 postoperative days after admission in the two groups (mean and SEM). a = p ≤ 0.05; b = p ≤0.01.

Table 1.  Overall comparison of demographics and perioperative data for the study population

Variables	Intervention (n = 28)	Control (n = 33)
Sex (F/M)	17/11	17/16
Age in years: median (range)	56 (28–84)	58(26–81)
ASA classification^a (n)
I (normal healthy)	16	18
II (mild systemic disease)	12	11
III (severe systemic disease)	0	4
Harris hip score preoperatively ^b	53.7 (48.6–58.8)	57.0(51.4–62.7)
Type of prosthesis (n)
Uncemented	19	19
Hybrid	6	4
Cemented	3	10
Surgical time in min.^b	77 (69–85)	92 (79–106)
Preoperative hemoglobin (mmol/L)^b	8.4 (8.1–8.6)	8.8(8.5–9.1)
Postoperative hemoglobin (mmol/L)^b	6.7(6.4–7.0)	6.7 (6.5–7.0)
Blood transfusion	3	2
Nausea (n)	11	14
Pain at rest^b	1.3(1.0–1.6)	1.5(1.1–2.0)
Pain during mobilization^b	3.1 (2.3–3.8)	3.2(2.4–4.1)
Wound infection (n)	1	1
Urinary tract infection (n)	7	4

^a American Society of Anaesthesiology classification.

^b Mean (95% CI)

Table 2.  Changes in WOMAC and SF 36 scores between baseline and follow-up 3 and 6 months postoperatively. Differences in changes over time baseline and 3 months; baseline and 6 months between groups were analyzed and tested for statistically significant differences by a repeated measurements model

Outcome variables	Intervention group (n = 28)			Control group (n = 33)			P-value
	A	B	C	A	B	C	D
WOMAC
Pain, mean	194	144	149	226	187	194	0.1
95% CI	142–245	98–191	100–199	184–269	145–229	153–235
Stiffness, mean	90	64	62	103	77	80	0.4
95% CI	69–111	43–85	42–82	85–121	60–94	61–99
Function, mean	658	374	456	795	575	620	0.03
95% CI	516–798	25–5886	325–588	666–924	440–711	497–743
Total WOMAC, mean	941	582	668	1126	839	894	0.03
95% CI	737–1146	389–776	476–859	944–1308	661–1017	728–1061
SF-3
Physical functioning, mean	44	25	31	42	27	32	1.0
95% CI	36–52	15–35	22–40	34–50	17–36	24–41
Role physical, mean	38	17	30	24	30	39	0.6
95% CI	22–53	–2–36	12–49	11–36	13–46	23–56
Bodily pain, mean	42	38	43	38	39	48	0.6
95% CI	33–50	29–47	35–52	31–45	28–49	39–56
General health, mean	61	11	11	70	6	7	0.6
95% CI	54–69	4–17	4–18	64–77	2–13	–1–15
Vitality, mean	55	11	18	53	16	19	0.5
95% CI	47–62	3–19	9–26	45–62	7–25	10–28
Social functioning, mean	80	4	12	71	12	17	0.5
95% CI	70–90	–6–13	5–19	61–81	2–22	8–27
Role emotional, mean	61	18	23	52	8	27	0.2
95% CI	44–78	1–35	6–40	35–68	14–30	9–45
Mental health, mean	74	7	10	74	7	8	0.8
95% CI	67–80	0.3	3–17	67–80	–0.5–15	–0.3–17
Physical component
summary scale, mean	33	11	14	33	13	15	0.9
95% CI	30–37	7–16	10–18	30–36	9–16	11–19
Mental component
summary scale, mean	53	1	–3	51	1	3	0.9
95% CI	49–57	3–64	–0.3–6	47–55	–4–5	–1–4
A Baseline score
B Change in score after 3 m	months
C Change in score after 6 months
D Equal changes between groups

Table 3.  Psychometric properties of WOMAC and SF-36 at baseline and at follow-up 3 and 6 months postopera-tively, showing the number of patients with the lowest score (floor effect) and the number of patients with the highest score (ceiling effect). Study population was 61 patients

Variables	Baseline		3 months postop.		6 months postop.
	A	B	A	B	A	B
WOMAC
Pain	0	0	0	5	0	9
Stiffness	0	0	0	6	0	9
Function	0	0	0	3	0	4
SF-36
Physical functioning	1	0	0	2	0	4
Role physical	32	9	20	24	13	30
Bodily pain	2	0	0	20	0	20
General health	0	1	0	8	0	11
Vitality	0	2	0	6	0	6
Social functioning	2	25	0	37	0	44
Role emotional	21	28	15	37	6	44
Mental health	0	2	0	10	0	11

^A Number of patients with lowest score

^B Number of patients with highest score

Figure 3. Scores of THR patients and healthy controls in the SF-36 subscales physical functioning (PF), role physical (RP), and physical component summary scale (PCS) broken down according to patient age (age groups according to Bjorner et al. (1997)). Scores are presented as mean an SEM. Statistically significant differences in mean scores between patients and controls are shown as follows: a = PF: p < 0.05; b = RP: p < 0.05; c = PCS: p < 0.05.

Bjorner J B, Damsgaard M T, Watt T, Bech P, Rasmussen N K, Kristensen T S, et al. Danish Manual for the SF-36. Læmiddelindustriforeningen. LIF, Copenhagen 1997

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