To compare early ambulation and ability to participate in rehabilitation in patients undergoing total knee replacement using two different nerve block techniques for pain control. The 2 methods are 1) Adductor canal block with posterior capsular injection 2) femoral nerve block with tibial nerve block

Early mobilization in the postoperative period is important to the success of surgery following total knee replacement. However, severe post-operative pain is an impediment to early implementation of rehabilitaion program. The use of femoral nerve block combined with tibial nerve block as part of a multimodal analgesic program provides effective pain control but causes weakness of the operative extremity preventing patients from bearing weight, exercising the leg and increasing the risk of falls thereby delaying early participation in rehabilitation. Adductor canal block is a new technique that has been described to provide pain control after total knee arthroplasty (1). The advantages of this block is that it could potentially minimize lower extremity weakness because the target nerve (saphenous nerve) blocked in this technique is a purely sensory nerve and does not provide any motor innervation to any muscle groups. Adductor canal block lends itself easily to providing prolonged analgesia because a perineural catheter can be inserted and the block maintained by a continuous infusion of dilute local anesthetic solution for days. A disadvantage of this method is that it may not provide adequate analgesia for posterior knee pain in the early postoperative period. By combining adductor canal block with ultrasound guided posterior and antero-medial knee injection, the posterior knee pain can be controlled effectively. Posterior and antero-medial knee injection of local anesthetic solution has been used as a method of controlling posterior knee pain after total knee arthroplasty (2).

Inclusion Criteria:

• Patients having primary, unilateral total knee arthroplasty
• ages 18 - 80

Exclusion Criteria:

• history of neurological disease
• neuropathy
• diabetes
• major systemic illness
• pregnancy
• chronic narcotic use
• allergy to local anesthetic solution or NSAIDS
• inability to give consent or cooperate with the study protocol
• BMI> 40