Xie et al reported a nomogram for predicting complications within the 90 days after a total knee arthroplasty (TKA). This can help to identify a patient who may require more aggressive management. The authors are from Zhujiang Hospital and Southern Medical University in Guangzhou, China
Patient selection: total knee arthroplasty (TKA)
Parameters:
(1) age-adjusted Charlson Comorbidity Index (ACCI; adding 1 to CCI if age >= 50)
(2) ASA status
(3) tourniquet time in minutes
(4) estimated intraoperative blood loss (EIBL) in mL
points for age-adjusted CCI =
= 4 * (ACCI)
points for EIBL =
= (0.1818 * (EIBL)) - 9.0909
|
Parameter
|
Finding
|
Points
|
|
ASA status
|
1 or 2
|
0
|
|
|
3, 4 or 5
|
40.3
|
|
tourniquet time
|
<= 120 minutes
|
0
|
|
|
121 to 180 minutes
|
30.5
|
|
|
>= 181 minutes
|
61.5
|
total score =
= SUM(points for all of the parameters)
Interpretation:
• minimum score: 0
• maximum score: 225.8
• The higher the score the greater the risk of complications within the next 90 days.
value of X =
= (0.04518 * (score)) - 5.315
probability of complications within 90 days =
= 1 / (1 + EXP((-1) * X))
Performance:
• The area under the ROC curve is 0.73.
