The Utility of Preoperative Labs in Predicting Postoperative Complications Following Primary Total Hip and Knee Arthroplasty.

BACKGROUND

Preoperative testing costs billions of dollars despite little evidence supporting its utility. The purpose of this study was to determine the relationship between abnormal preoperative laboratory tests and postoperative complications following total joint arthroplasty.

METHODS

The NSQIP database was used to identify 45,936 primary total hip arthroplasty (THA) and 76,041 pri-mary total knee arthroplasty (TKA) cases performed between 2006 and 2013. Complications within 30 days of surgery were collected and multivariable regression modeling was performed incorporating all significant laboratory values as well as demographics and preoperative comorbidities.

RESULTS

For THA patients, abnormal sodium (p = 0.016, OR = 1.89), white count (p = 0.043, OR = 1.73), and partial thromboplastin time (p = 0.028, OR = 1.43) were significantly associated with complications. For TKA patients, abnormal alkaline phosphatase (p = 0.04, OR = 2.12), creatinine (p = 0.003, OR = 1.56), and INR (p = 0.008, OR = 1.99) were significantly predictive of complications.

CONCLUSION

Of the 13 laboratory values, only six were significantly associated with complications. These findings may have implications for risk stratification in the inpatient setting.