Adductor canal blocks: changing practice patterns and associated quality profile

Femoral nerve blocks have been the gold standard approach for post-operative analgesia following total knee arthroplasty; however, the adductor canal block has recently gained popularity due to less block-induced motor weakness. The primary aim of this time-series analysis was to identify whether regional anesthesia practice changes have occurred for total knee arthroplasty. Our secondary aim was to assess for possible associated changes in safety and quality.

Using a 20-member clinical registry, we examined the practice patterns and safety around the performance of adductor canal blocks for all total knee arthroplasties between 18 July 2011 to 9 October 2015. To obtain more information about changes in quality associated with this practice transition, we analyzed clinical outcomes data surrounding all primary total knee arthroplasties from the largest contributing institution.

A total of 6921 blocks were performed for 4822 primary and revision total knee arthroplasties (TKAs). Across the registry, adductor canal block utilization for TKA increased. This was not associated with any increase in immediate or recovery room-related complications. When analyzing unilateral primary TKAs from the largest surgical volume center (n = 766), there were no statistically significant changes in numeric rating scale scores (5.4 to 4.6, P value = 0.004), length of stay (3.0 to 2.8 days, P value = 0.3), or 30-day hospital re-evaluations for pain (2.8-4.9%, P value = 0.1).

There was a large increase in the utilization of adductor canal blockade for TKAs among participating registry members. This change in practice was not associated with significant changes in safety or quality.