Adductor Canal Block for Total Knee Arthroplasty

Study Summary

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.

Primary Outcome

This will be evaluated by determining how quickly a patient is able to ambulate over 10 meters on POD 1 (10 meter walk test).

Interventions

• PROCEDURE Adductor Canal Block
• DRUG Adductor Canal Block