Doubtful effect of continuous intraarticular analgesia after total knee arthroplasty

Figures & data

Figure 1. Flow-chart of the study.

Table 1. Patient characteristics

	Therapy group (n = 100)	Control group (n = 100)
Age, years^a	69 (9)	69 (8)
Sex (female/male)	65/35	62/38
BMI^a	29 (5)	30 (5)
ASA classification
ASA 1	21	22
ASA 2	69	66
ASA 3	10	12
Charnley classification
A	35	30
B	23	32
C	42	38
Side TKA (right/left)	52/48	60/40
Anesthesia (spinal/general)	83/17	92/8

^a mean (SD).

Figure 2. Difference in VAS pain between groups.

Table 2. Results. Data are mean (SD) or number of patients

			No. of missing observations
Variables	Therapy group (n = 97)	Control group (n = 95)	therapy group	control group	p-value	95% CI
VAS preop. (0–100)	60 (16)	61 (15)			0.9	−3.5 to 5.4
VAS on op. day, 8 p.m.	14 (20)	21 (25)	1		0.05	−0.3 to 13
VAS on day 1, 12 noon	33 (24)	40 (22)			0.02	1 to 14
VAS on day 1, 8 p.m.	36 (24)	43 (21)	1	4	0.03	0.8 to 14
VAS on day 2, 12 noon	34 (24)	33 (25)			0.8	−8.3 to 5.8
VAS on day 2, 8 p.m.	27 (20)	30 (22)	3	5	0.5	−3.8 to 8.5
VAS on day 3, 12 noon	26 (19)	23 (20)	11	10	0.3	−8.9 to 2.9
VAS 2 weeks postop.	34 (24)	29 (19)	3	1	0.8	−12 to 0.7
VAS 3 months postop.	19 (21)	17 (19)	6	5	0.4	−8.6 to 3.2
ROM preop., degrees	112 (16)	109 (23)			0.2	−8.2 to 3
ROM on day 3 postop.	82 (16)	84 (12)			0.6	−3.6 to 4
ROM 3 months postop.	113 (12)	110 (13)	2	3	0.1	−6.3 to 0.7
Dressing change	0.5 (0.9)	0.7 (1.1)			0.2	−0.5 to 0.1
Postop. stay, days	4.1 (0.9)	4.1 (1.0)			0.8	−0.2 to 0.3
Nausea/vomiting	0.8 (1.4)	1.1 (2.0)			0.2	−0.8 to 0.2
Leg-raising ability preop. ^a	96	93			0.6
Leg-raising ability on day 3 ^a	93	92			1.0
Wound infection ^a	11	2			0.02
Total additional oxycodone, 5 mg	4 (5)	5 (6)			0.06	−0.1 to 3.2

^a number of patients