Utilization of Femoral Nerve Blocks for Total Knee Arthroplasty

Little information exists on national trends in the utilization of femoral nerve blocks (FNBs) in total knee arthroplasties (TKAs). We sought to describe the variations in anesthetic practice for FNB using the National Anesthesia Clinical Outcomes Registry.

We used the National Anesthesia Clinical Outcomes Registry to obtain patient, procedural, and provider information from January 2010 to June 2015. Case characteristics and clinical outcomes were compared using chi-square or t tests. We used logistic regression to identify associations between patient and case characteristics with anesthetic technique.

Overall, 219,327 cases met the inclusion criteria, in which 72.7% and 27.3% did not or did receive a FNB, respectively. Patients less than 18 years old and those with higher American Society of Anesthesiologists physical status class (≥III) were less likely to receive a FNB. Surgeries performed after 5:00 PM also were less likely to receive the block. Cases with urban zip code had approximately 20% increased odds of receiving a FNB. General or neuraxial anesthesia types were not associated with utilization of FNB. FNB was associated with decreased percentage of extended recovery room stays and postoperative nausea and/or vomiting.

There is considerable practice variation in the use of FNB for TKA, which is associated with various factors such as geographic location, time of day, and patient-specific comorbidities. Approximately one fourth of TKA cases include FNB. Overall, our study supports the clinical utility of FNB in TKA. As more data are compiled, it will be important to examine how national trends shift in the future.