Xie and Li reported a nomogram for predicting early complications after a primary knee arthroplasty. This can help to identify a patient who may benefit from more aggressive management. The authors are from Zhujiang Hospital of Southern Medical University in Guangzhou, Shina.
Patient selection: status post primary knee arthroplasty
Outcome: early complications (within first 30-days)
Parameters:
(1) anemia (timing not mentioned)
(2) ASA class (ASA 5 unlikely candidate)
(3) anesthesia
(4) operative time in minutes
(5) tourniquet time in minutes
(6) estimated intraoperative blood loss in mL, >= 50
points for blood loss for 50 to 650 =
= (0.16667 * MIN(volume,650)) - 8.33333
|
Parameter
|
Finding
|
Points
|
|
anemia
|
no
|
0
|
|
|
yes
|
42
|
|
ASA class
|
1 or 2
|
0
|
|
|
>= 3
|
86.3
|
|
anesthesia
|
intraspinal
|
0
|
|
|
general
|
65.3
|
|
operative time
|
<= 150 minutes
|
0
|
|
|
> 150 minutes
|
63
|
|
tourniquet time
|
<= 120 minutes
|
0
|
|
|
121 to 180 minutes
|
32
|
|
|
> 180 minutes
|
100
|
total score =
= SUM(points for all of the parameters)
Interpretation:
• minimum score: 0
• maximum score: 456.6
• The higher the score the greater the risk of complications.
value of X =
= ( 0.0229* (score)) - 3.7
probability of complications within 30 days =
= 1 / (1 + EXP((-1) * X))
Performance:
• The area under the ROC curve is 0.82 in the derivation and 0.81 in the validation cohorts.
