Total knee arthroplasty (TKA) can be associated with a large amount of postoperative pain.
This pain can oftentimes be severe enough to limit participation in physical therapy and
ultimately delay discharge resulting in increased cost. Several strategies have been
developed in an effort to decrease postoperative pain following TKA while maintaining lower
extremity strength and maximizing participation in physical therapy. Recently, adductor canal
blockade has gained popularity as it is reported to provide analgesia to the anterior knee
without resulting in significant quadriceps muscle weakness. However, few studies have
carefully evaluated the impact of volume of injection of local anesthetic into the adductor
canal on motor weakness or pain control. The ability to achieve similar pain control with
decreased volumes of local anesthetic would allow the surgery team to apply more local
anesthetic to posterior knee structures. Decreased volumes of local anesthetic may also be
associated with a decreased risk of local anesthetic toxicity. This study aims to carefully
evaluate this relationship using a physical therapy evaluation method that relies on both
motor strength and pain control. In addition, the investigators hope to carefully evaluate
motor strength using a novel method of strength measurement in an effort to further evaluate
the impact of volume of injection of local anesthetic into the adductor canal on motor
strength.