Short-term functional outcome after fast-track primary total knee arthroplasty: analysis of 623 patients

Figures & data

Table 1. Patient demographics (N = 623). Values are count (%) unless otherwise specified

Demographics	623 TKA
Age, median [IQR] (range)	70 [64–77] (32–93)
Female sex	420 (67)
Smoking yes	64 (10)
ASA score
I	100 (16)
II	437 (70)
III	86 (14)
BMI
Normal weight (< 25)	100 (16)
Overweight (25–30)	267 (43)
Obesity (> 30)	256 (41)
LOS, median [IQR] (range)	2 [2–3] (0–9)

LOS = length of stay by hospital nights.

Table 2. Median function scores at the 3 time points. Values are median [IQR] (range)

Item	Preoperative	6 weeks	3 months
OKS	23 [17–28] (2–45)	30 [25–36] (4–48)^a	35 [29–41] (9–48)^b
KOOS-PS	51 [42–62] (15–100)	40 [34–46] (0–100)^a	35 [28–44] (0–100)^b
EQ-5D VAS	71 [60–81] (3–100)	75 [60–86] (0–100)^a	79 [65–88] (6–100)^b

a Significant improvement between preoperative and 6 weeks, Wilks’ λ < 0.001.

b Significant improvement between 6 weeks and 3 months, Wilks’ λ < 0.001.

Figure 1. Median KOOS-PS course in 3 months.

Figure 2. Median OKS course in 3 months.

Figure 3. Median EQ-5D VAS health course in 3 months.

Table 3. Responder analysis. Values are count (%) unless otherwise specified

Factor		Group 1	Group 2	Group 3	Group 4
Total number		218 (41)	119 (23)	177 (33)	14 (3)
Age	≤ 75 years	142 (65)	90 (76)	121 (68)	10 (71)	0.3^a
	> 75 years	76 (35)	29 (24)	56 (32)	4 (29)
BMI	< 25	26 (12)	16 (13)	42 (24)	1 (7)	0.02^b
	25–30	101 (46)	55 (46)	71 (40)	3 (21)
	> 30	91 (42)	48 (40)	64 (36)	10 (71)
Smoking	Yes	21 (10)	11 (9)	19 (11)	1 (7)	1.0^a
	No	197 (90)	108 (91)	158 (89)	13 (93)
ASA	I–II	197 (90)	102 (86)	155 (88)	11 (79)	0.4^b
	III–IV	21 (10)	17 (14)	22 (12)	3 (21)
Preoperative EQ-5D
Mobility
No problems		8 (4)	2 (2)	18 (10)	0 (0)	0.004^b
Some problems in walking or confined to bed		210 (96)	117 (98)	159 (90)	14 (100)
Self-care
No problems		165 (76)	101 (84)	151 (85)	7 (50)	0.001^b
Some problems or unable to wash or dress		53 (24)	18 (15)	26 (15)	7 (50)
Usual activities
No problems		32 (15)	18 (15)	50 (28)	0 (0)	0.001^b
Some problems or unable to perform usual activities		186 (85)	101 (85)	127 (72)	14 (100)
Pain/discomfort
No pain or discomfort		16 (7)	10 (8)	25 (14)	1 (7)	0.1^b
Moderate or extreme pain or discomfort		202 (93)	109 (92)	152 (86)	13 (93)
Anxiety/depression
Not anxious or depressed		173 (79)	91 (76)	137 (77)	4 (29)	< 0.001^b
Moderate or extremely anxious or depressed		45 (21)	28 (24)	40 (23)	10 (71)
VAS health, median		70	74	73	67	0.3^c
IQR		60–81	60–82	60–82	50–79
range		11–100	25–100	13–100	3–100

Group 1: responders at 6 weeks, responders at 3 months.

Group 2: non-responders at 6 weeks, responders at 3 months.

Group 3: non-responders at 6 weeks, non-responders at 3 months.

Group 4: responders at 6 weeks, non-responders at 3 months.

a Chi-square

b Kruskall–Wallis

c ANOVA

Table 4. Post-hoc pairwise analysis

Item	Group 1 vs. 2	Group 1 vs. 3	Group 1 vs. 4	Group 2 vs. 3	Group 2 vs. 4	Group 3 vs. 4
BMI	1.0	0.2	0.4	0.8	0.3	0.05
EQ-5D
Mobility	1.0	0.03	1.0	0.008	1.0	0.6
Self-care	0.3	0.1	0.1	1.0	0.01	0.008
Usual activities	1.0	0.004	1.0	0.03	1.0	0.06
Anxiety/depression1.0	1.0	< 0.001	1.0	< 0.001	< 0.001

Group 1–4: See Table 3.

Table 5. OKS per group for each time-point. Values are median [IQR] (range)

Group	Preoperative	6 weeks	3 months
1	19 [14–24] (3–36)	35 [30–40] (12–48)	40 [34–44] (21–48)
2	23 [19–27] (3–37)	26 [22–31] (11–42)	37 [34–42] (16–48)
3	27 [22–31] (5–45)	26 [21–31] (5–46)	29 [24–34] (9–47)
4	19 [16–25] (9–28)	32 [27–36] 19–39)	25 [20–28] (15–33)

Group 1–4: See Table 3.