Role of preoperative pain, muscle function, and activity level in discharge readiness after fast-track hip and knee arthroplasty

Figures & data

Table 1. Patient characteristics before surgery. Values are mean (SD)

Variable	THA(n = 75)	TKA(n = 75)
Age, years	67 (9.1)	65 (9.6)
BMI, kg/m^2	29 (5.0)	31 (5.2)
Gender, (F/M)	44/31	51/24
Leg-press power, W/kg	1.9 (0.9)	1.2 (0.7)
Timed up and go, s	7.9 (0.9)	9.3 (2.3)
HOOS-pain, points	46 (18)	–
HOOS-symptoms, points	43 (19)	–
HOOS-ADL, points	48(18)	–
HOOS-sport/rec, points	29 (21)	–
HOOS-QOL, points	32 (17)	–
KOOS-pain	–	46 (16)
KOOS-symptoms, points	–	56 (20)
KOOS-ADL, points	–	52 (17)
KOOS-sport/rec, points	–	17 (20)
KOOS-QOL, points	–	30 (17)
METtotal, METs	45 (12)	43 (12)

THA: total hip arthroplasty;

TKA: total knee arthroplasty;

BMI: body mass index;

HOOS: hip dysfunction and osteoarthritis outcome score;

KOOS: knee injury and osteoarthritis outcome score; MET: metabolic equivalent of task.

Plots of the initial univariate linear regressions for predictor variables with p-values less than 0.2 for THA (A and B) and TKA (C–F). These predictor variables were subsequently used in the multiple linear regression models.

Table 2. Multiple regression analyses of discharge readiness, with age, HOOS-pain, and METtotal as predictor variables (THA), and age, Timed up and go, KOOSqol, and METtotal as predictor variables (TKA)

Variable	β	T-value	p-value
THA: Age	0.03	3.2	0.002
TKA: Age	0.02	2.3	0.03

For abbreviations, see Table 1