Pua et al reported a prediction model for walking limitation after a total knee arthroplasty. The authors are from Singapore General Hospital and the Australian Catholic University.
Patient selection: unilateral TKA
Parameters:
(1) age in years
(2) body mass index in kilograms per square meter
(3) hypertension
(4) falls history
(5) preoperative walking aids
(6) contralateral knee pain
(7) adult reconstruction specialist (vs general orthopedic surgeon)
(8) preoperative walking ability
(9) week 4 fast gait speed in meters per second
(10) week 4 knee pain on a Likert scale from 0 to 10
|
Age in Years |
Points |
|
45 to 65 |
(0.013937 * ((age)^2)) - (2.716 * (age)) + 117.38 |
|
65 to 89 |
(0.02831 * ((age)^2)) - (2.9403 * (age)) + 70.662 |
points for body mass index =
= (1.7 * (BMI)) - 25.5
points for week 4 gait speed from 0 to 1.8 meters per second =
= (-22.31 * ((speed)^2)) - (15.88 * (speed)) + 99.24
points for week 4 pain =
= (2.0771 * (scale)) + 0.07325
|
Parameter |
Finding |
Points |
|
hypertension |
no |
0 |
|
|
yes |
12.3 |
|
falls history |
none |
0 |
|
|
once |
14.6 |
|
|
recurrent |
3.0 |
|
walking aid |
none |
0 |
|
|
stick |
8.1 |
|
|
frame or 2 canes or crutches |
16.5 |
|
|
quadstick |
45.1 |
|
contralateral knee pain |
no |
0 |
|
|
yes |
22.6 |
|
adult reconstruction specialist |
no |
11.3 |
|
|
yes |
0 |
|
preop walking ability |
> 30 minutes |
0 |
|
|
15 to 30 minutes |
23.2 |
|
|
5 to 15 minutes |
30.2 |
|
|
around the house |
53 |
total score =
= SUM(points for all 10 parameters)
Interpretation:
• minimum score: 0
• maximum score: 373.9
|
Score |
Risk of walking <= 15 minutes |
|
< 73.2 |
< 1% |
|
73.2 to 202.1 |
(0.000011489 *((score)^3)) - (0.00239898 * ((score)^2)) + (0.21223 * (score)) - 5.6458 |
|
202.1 to 278 |
(-0.0011777 * ((score)^2)) + (1.2329 * (score)) - 171.44 |
|
> 278 |
> 80% |
|
Score |
Risk of walking <= 30 minutes |
|
< 79.6 |
< 5% |
|
79.6 to 180.4 |
(0.00352 * ((score)^2)) - (0.4706 * (score)) + 20.28 |
|
180.4 to 281.7 |
(-0.0023432 * ((score)^2)) + (1.5647 * (score)) - 155.51 |
|
> 281.7 |
> 95% |
Specialty: Surgery, orthopedic
