HSS Research Shows “Quiet Knee” Protocol Could Redefine Knee Replacement Recovery

Hospital for Special Surgery (HSS), the world's leading academic medical center focused on musculoskeletal health, today announced the results of a retrospective study analyzing the results of the "Quiet Knee" protocol after total knee arthroplasty (TKA), also known as knee replacement surgery. The study results were shared at the American Association of Hip and Knee Surgeons (AAHKS) annual meeting.

The Quiet Knee protocol, which some HSS surgeons began implementing several years ago, takes a more conservative approach to knee replacement recovery than traditional clinical protocols. This new technique focuses on controlling inflammation and swelling postoperatively through restricted mobility and passive range of motion (ROM) and aggressive cryotherapy (icing) for the first 10 days immediately following surgery. This contrasts with standard protocols, which often emphasize early and aggressive movement that can cause inflammation in surgical tissue that is healing.

All HSS total knee replacement patients from 2020 to 2024 were retrospectively reviewed as part of the study. A Quiet Knee group consisting of 271 patients received structured postoperative care and monitored telerehabilitation. One comparison group was given Quiet Knee guidance verbally, while a second cohort followed traditional early motion postoperative therapy.

"Patients are told they have to work really hard to get motion back after surgery-the no pain, no gain type of mentality," said Brian P. Chalmers, MD, a hip and knee surgeon at HSS and one of the authors of the study. "The problem with that is that the more patients do in the early period of recovery-the more they bend, the more they are up and walking-the more the knee will swell."

Every person undergoing TKA experiences pain and swelling after surgery, but the intensity differs, making the patient's recovery process more challenging and often more painful than most other surgeries.

"It's not uncommon to see a counterproductive early physical therapy program that is too aggressive," Dr. Chalmers said. "In these cases, the knee becomes very swollen, which causes patients to have more pain. As the knee becomes more inflamed and patients are able to bend it less, it just becomes a cycle."

Under the Quiet Knee protocol, patients avoid intensive physical therapy immediately after surgery, allowing the body time to heal before progressing to motion and other strength work. Early results suggest this approach helps set the stage for a smoother long-term recovery. The study also showed that the protocol significantly reduced 90-day opioid exposure by more than 25%.

"This isn't a surgeon-driven protocol or a research-driven protocol. It's a physiology-driven protocol," said Michael P. Ast, MD, Chief of the Knee Service and Chief Medical Innovation Officer at HSS and co-author of the study. "It is a recognition of what the human body goes through in recovery from surgery. It is a very logical way of respecting the body's inflammatory response to trauma. Early on after surgery, less really is more. That is really the guiding principle of this protocol."

Study Details

A Retrospective Cohort-Based Analysis of the "Quiet Knee" Protocol After Primary Total Knee Arthroplasty

Pravjit Bhatti, Lauren Moeller, Michael P Ast, Tony Sicheng Shen, Peter Keyes Sculco, David Jacob Mayman, Brian Chalmers