Predicting the Exception—CRP and Primary Hip Arthroplasty

Abstract

Background: While primary hip arthroplasty is the most common operative procedure in orthopedic surgery, a periprosthetic joint infection is its most severe complication. Early detection and prediction are crucial. In this study, we aimed to determine the value of postoperative C-reactive protein (CRP) and develop a formula to predict this rare, but devastating complication. Methods: We retrospectively evaluated 708 patients with primary hip arthroplasty. CRP, white blood cell count (WBC), and several patient characteristics were assessed for 20 days following the operative procedure. Results: Eight patients suffered an early acute periprosthetic infection. The maximum CRP predicted an infection with a sensitivity and specificity of 75% and 56.9%, respectively, while a binary logistic regression reached values of 75% and 80%. A multinominal logistic regression, however, was able to predict an early infection with a sensitivity and specificity of 87.5% and 78.9%. With a one-phase decay, 71.6% of the postoperative CRP-variance could be predicted. Conclusion: To predict early acute periprosthetic joint infection after primary hip arthroplasty, a multinominal logistic regression is the most promising approach. Including five parameters, an early infection can be predicted on day 5 after the operative procedure with 87.5% sensitivity, while it can be excluded with 78.9% specificity.

A New Graphic Type Differentiation of Cell Account Determination for Distinguishing Acute Periprosthetic Joint Infection from Hemarthrosis

“…On the one hand, this may be due to it usually taking 2 to 4 weeks after surgery for the CRP value to normalize. In some cases, this might take up to 60 days and thus higher CRP values may be present during this time in the absence of infection [ 23 , 24 , 25 ]. On the other hand, the actual CRP level in the serum lags approximately 60 h behind the current situation in situ, so the onset of infection in the joint might already have occurred, while the CRP value in the serum is still below the defined threshold value ( Figure 2 and Figure 5 b) [ 22 , 23 , 24 ].…”