Wearable-Device Data Challenge Assumptions About Recovery After Total Knee Arthroplasty

Wearable-device data are challenging common assumptions about recovery after total knee arthroplasty (TKA) and may offer a more objective way to monitor postoperative mobility.

Although TKA is highly effective for advanced osteoarthritis, objective data on real-world recovery remain limited, says Nicolas S. Piuzzi, MD, Vice Chair of Research for Orthopaedics and Rehabilitation at Cleveland Clinic. Patients undergo TKA to improve pain, function and quality of life, yet physicians have relied primarily on subjective feedback rather than empirical activity data to assess outcomes.

“While data exists on patient-reported outcomes and survivorship rates, we lack broad, objective, real-world TKA recovery metrics,” he says.

To better characterize recovery trajectories after TKA, Cleveland Clinic investigators analyzed step-count data from the National Institutes of Health All of Us Research Program database. Dr. Piuzzi presented key findings from the study at the American Academy of Orthopaedic Surgeons (AAOS) 2026 meeting.

Recovery varies by age, sex and BMI

The research team studied records from 46 patients having primary TKA who used a Fitbit® device to track daily step counts from six months before to six months after surgery.

Average daily step counts declined substantially at 30 days after TKA, falling from nearly 5,500 steps preoperatively to 3,700. This early decline is consistent with expected postoperative healing and activity restrictions.

By three to six months after surgery, step counts had rebounded to approximately 5,300, approaching the presurgical baseline (although this did not indicate universal improvement beyond baseline activity).

While this recovery pattern was predictable, it varied by patient demographics and phenotypes. Age, sex, and body mass index (BMI) all influenced recovery patterns:

• Patients with obesity or who were overweight had lower step counts before and after surgery than patients with normal BMI.
• Patients with obesity and those older than 75 showed persistently low activity levels before and after surgery. Patients with obesity tracked an average of 3,762 daily steps before TKA and 3,590 after. Patients over 75 tracked an average of 2,023 daily steps before TKA and 1,083 after.
• Men increased daily step counts after surgery, whereas women decreased step counts. Men’s daily steps increased from an average of 4,970 preoperatively to 6,185 postoperatively. Women’s daily steps decreased from an average of 5,532 preoperatively to 4,652 postoperatively.

“While recovery after total knee arthroplasty generally follows an expected trajectory, wearable-device data provide a far more nuanced and objective understanding of how patients regain mobility in real life,” says Dr. Piuzzi. “These technologies allow us to move beyond snapshots in clinic and begin characterizing personalized recovery patterns.”

Collecting personalized data may ultimately help orthopaedic surgeons optimize rehabilitation, set more accurate expectations, and identify patients who may benefit from earlier intervention or additional support, he adds.

Clinical implications

Dr. Piuzzi says the findings challenge several assumptions about TKA recovery. The data indicate that:

• Recovery patterns are highly variable and individualized. The assumption that all patients recover similarly is not true.
• Surgery does not provide immediate functional improvement. There’s a significant early decline requiring time for recovery, and this timeline varies by patient.

For Dr. Piuzzi, the findings also underscore that postoperative recovery cannot be inferred from patient-reported pain and function scores alone. Wearable data offers a supplement to patient-reported outcomes, which may not correlate with actual activity levels.

“We should be getting an assessment of patient mobility and tracking their activity even before we indicate joint replacement,” he says. “Tracking data from wearables could provide a truer understanding of activity levels early on as osteoarthritis is diagnosed and perhaps help inform timing of surgical intervention.”

Dr. Piuzzi says he now routinely asks patients about walking patterns, activity limitation and whether they track steps, particularly when surgery is not yet under consideration.

“It’s extremely important to assess activity patterns, intensity and performance along with pain and subjective quality of life,” he says.

Moving toward precision recovery

Understanding activity patterns may help physicians provide more accurate expectations for recovery and identify patients who may need additional support after TKA.

“I am hopeful that our findings will lead to more personalized care pathways,” Dr. Piuzzi says. “Integrating this data into wearables-driven orthopaedics could be a step forward in precision recovery and true value-based care. If we can get the field to acknowledge the value and utility of wearable data, I think we will deliver better care for our patients.”