Rapid Versus Standard Recovery Protocol Is Associated With Improved Recovery of Range of Motion 12 Weeks After Total Knee Arthroplasty.

INTRODUCTION: With the increasing demand for total knee arthroplasty (TKA), rapid recovery protocols (RRPs) have been introduced to reduce costs and the length of stay (LOS). Little is known about the effects of RRPs on postoperative knee range of motion (ROM). METHODS: We reviewed the medical charts of 323 patients who underwent primary TKA performed by a single orthopaedic surgeon at a university-based orthopaedic tertiary care safety net practice. Of the 323 patients, 129 were treated with a standard recovery protocol (SRP) between January 1, 2012, and December 10, 2013, and 194 with a RRP beginning December 11, 2013. Knee ROM was assessed at the preoperative visit and at scheduled postoperative visits for up to 1 year. Differences in mean LOS between the groups were compared using a Poisson regression with and without adjustment for covariates. Repeated measures analysis of covariance was used to evaluate the effects of recovery protocol, time, and the interaction of recovery protocol by time on flexion and flexion contracture. The probability of achieving flexion ≥120° and having a flexion contracture ≥10° was estimated using the SAS/STAT GLIMMIX procedure with a binary distribution and a logit link. RESULTS: The mean LOS for the RRP and SRP groups was 0.8 and 2.5 days, respectively. RRP was associated with greater flexion at 2, 6, and 12 weeks and a higher probability of attaining flexion ≥120° at 6 and 12 weeks. Patients receiving a RRP had less severe flexion contracture and a lower probability of flexion contracture ≥10° at 2, 6, and 12 weeks. DISCUSSION: During the first 12 weeks after TKA, patients who received a RRP had a markedly greater ROM than patients who received a SRP, suggesting that RRP may allow patients to do a greater variety of activities of daily living during the first 3 postoperative months while reducing health care costs. LEVEL OF EVIDENCE: Level III.