Quiet Knee Rehabilitation Protocol After Primary Total Knee Arthroplasty Is Associated with Lower Opioid Exposure and No Added Risks: A Retrospective Cohort Study.

Abstract

Conventional early rehabilitation after total knee arthroplasty (TKA) that emphasizes immediate, aggressive range of motion and ambulation may heighten early inflammation and pain. We implemented a supervised 10-day "quiet knee" protocol prioritizing edema control, limited passive range of motion, rest, and telerehabilitation oversight. We retrospectively reviewed 15,646 primary TKAs (quiet knee, n = 841; conventional, n = 14,805) performed from February 1, 2020, to January 15, 2025. We included patients under a strict, quiet knee protocol with telerehabilitation oversight and compared them to a conventional therapy cohort. Primary outcomes were inpatient postoperative morphine milligram equivalents (MME) and 90-day post-discharge MMEs prescribed. Cohorts were compared for the primary outcomes using multivariable linear regression adjusting for age, sex, body mass index, and Charlson Comorbidity Index. The mean lengths of stay (LOS) was shorter in the quiet knee cohort (1.2 versus 1.8 days; P < 0.001). Unadjusted opioid exposure was lower with the quiet knee group: inpatient 52.5 versus 67.5 MME and 90-day post-discharge 265.5 versus 332.1 MME. In adjusted models, conventional rehabilitation used more opioids: +15 MME inpatient (P < 0.001) and +58 MME post-discharge (P = 0.001). Patient-reported outcomes improved similarly in both cohorts at two years (Knee Injury and Osteoarthritis Outcome Score for Joint Replacement 79.4 versus 80.2; visual analog scale 19.1 versus 13.2). Complications were low and similar in each group (manipulation under anesthesia: 1.9 versus 0.1%; venous thromboembolism: 0.1 versus 0.3%; two-year revision: 0.1 versus 0%; quiet knee versus conventional). Compared with conventional hands-on, aggressive post-TKA rehabilitation, the quiet knee protocol was associated with lower inpatient and 90-day post-discharge opioid exposure and shorter LOS, without detriment to pain, function, or major complications. This study can serve as a basis for designing a prospective trial to further investigate this alternative therapy protocol post-TKA.