Moderate evidence supports that rehabilitation started on day of total knee arthroplasty (TKA) compared to rehabilitation started on postop day 1 reduces pain and improves function.

Rationale
Two high quality studies (Labraca 2011; Larsen 2008) investigated the effects of starting rehabilitation on the day of surgery compared to delayed rehabilitation (start on the day after surgery or later). Labraca compared a group who initiated rehabilitation within the first 24 hours post-surgery to a control group who remained at rest during the first 24 hours and started rehabilitation after that. They found that the group who started rehabilitation within 24 hours had fewer days of hospital stay, reduced pain, and improved physical function (balance, muscle strength and range of knee motion). Larsen compared an intervention group who received a new accelerated peri-operative protocol compared to a control group who received conventional perioperative procedure. The accelerated protocol aimed to mobilize the patient in bed and out of bed in the day of surgery and progressed to four hours out of bed (combination of physical and occupational therapy) on the first postoperative day, and eight hours of mobilization for the rest of the hospital stay. The control group started mobilization in and out of bed on the day after surgery and increased mobilization according to patient’s state. The accelerated protocol also included education, pain relief, nausea control, nutrition, and elimination. The study found that the accelerated group had less length of stay as compared to the control group. Quality of life was not different between the groups. 
  1. Labraca,N.S., Castro-Sanchez,A.M., Mataran-Penarrocha,G.A., Arroyo-Morales,M., Sanchez-Joya,Mdel M., Moreno-Lorenzo,C. Benefits of starting rehabilitation within 24 hours of primary total knee arthroplasty: randomized clinical trial. Clin Rehabil. 2011/6; 6: 557-566
  2. Larsen,K., Sorensen,O.G., Hansen,T.B., Thomsen,P.B., Soballe,K. Accelerated perioperative care and rehabilitation intervention for hip and knee replacement is effective: a randomized clinical trial involving 87 patients with 3 months of follow-up. Acta Orthop 2008/4; 2: 149-159