Danoff JR, et al. - The efficacy of two commonly used periarticular injection (PAI) formulations; liposomal bupivacaine and bupivacaine (EXP) and ropivacaine, epinephrine, ketorolac, and clonidine (ROP) was compared by the experts in cases that underwent bilateral total knee arthroplasty (TKA) or unicompartmental knee arthroplasty (UKA). After knee arthroplasty, periarticular injections of EXP and ROP were noted to be equally efficacious and patients did not appreciate differences between the knees as determined by pain score or perceived functional recovery during the first 2 days following bilateral knee arthroplasty. Findings demonstrated that compared to a less expensive injection formulation, a liposomal bupivacaine injection did not add an incremental benefit for pain control.