Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Sep;33(9):3218-3227.
doi: 10.1002/ksa.12675. Epub 2025 Apr 13.

Wearable health technology finds improvements in daily physical activity levels following total knee arthroplasty: A prospective study

Kevin A Wu  1 , David N Kugelman  1 , Rahul K Goel  1 , Eric S Dilbone  1 , Devika Shenoy  1 , Sean P Ryan  1 , Samuel S Wellman  1 , Michael P Bolognesi  1 , Thorsten M Seyler  1
Affiliations

Wearable health technology finds improvements in daily physical activity levels following total knee arthroplasty: A prospective study

Kevin A Wu et al. Knee Surg Sports Traumatol Arthrosc. 2025 Sep.

Abstract

Purpose: Wearable technologies, like the Apple Watch, offer new possibilities for collecting objective data on physical activity post-operatively following total knee arthroplasty (TKA). This study aims to describe changes in daily physical activity levels using objective metrics over different time points following TKA.

Methods: This study analyzed data from a prospective cohort of 152 patients undergoing a unilateral TKA. Patients wore an Apple Watch and used a digital care management application for data collection. Step count, steadiness, standing duration, gait speed and performance on a 6-min walk test were collected from Apple HealthKit at multiple time points: pre-operative, 6 weeks post-operatively, 6 months post-operatively and 12 months post-operatively. Statistical analyses were performed using R software, including descriptive statistics and paired t tests to compare outcomes at different time points post-operatively.

Results: Participants demonstrated significant improvements in daily physical activity levels over the course of 12 months post-operative. At 6 months post-operative, participants showed the highest average daily step count (mean ± SD: 5293 ± 236 steps; p < 0.001), with improvements persisting at 12 months post-operative (5180 ± 260 steps; p < 0.001) compared to preoperative values. Gait speed increased from 0.88 ± 0.01 m/s preoperatively to 1.01 ± 0.01 m/s (p = 0.006) at 12 months post-operative. Standing hours increased from 9.99 ± 0.30 to 11.47 ± 0.31 h at 6 months post-operative and persisted. Steadiness and the estimated 6-minute walk test showed recovery trends, though variability remained at 12 months post-operative, suggesting the need for additional longitudinal assessment CONCLUSION: This study provides one of the first longitudinal analyses of post-operative functional recovery using Apple HealthKit, offering continuous real-world gait and activity tracking beyond traditional patient-reported measures. These findings highlight the value of wearable technology in monitoring post-operative activity and offering insights into TKA recovery patterns. The study suggests a critical recovery window at 6 months post-operative and emphasizes the need for ongoing support to maintain improvements. The integration of wearable technology in post-operative monitoring offers a promising approach to tracking patient progress and optimizing functional outcomes following TKA.

Level of evidence: Level II.

Keywords: patient‐reported outcome measures; recovery of function; rehabilitation; total knee arthroplasty; wearable electronic devices.

PubMed Disclaimer

References

REFERENCES

    1. Adriani M, Becker R, Milano G, Lachowski K, Prill R. High variation among clinical studies in the assessment of physical function after knee replacement: a systematic review. Knee Surg Sports Traumatol Arthrosc. 2023;31:3854–3860.
    1. Bolam SM, Batinica B, Yeung TC, Weaver S, Cantamessa A, Vanderboor TC, et al. Remote patient monitoring with wearable sensors following knee arthroplasty. Sensors. 2021;21:5143.
    1. Christensen JC, Blackburn BE, Anderson LA, Gililland JM, Peters CL, Archibeck MJ, et al. Recovery curve for patient reported outcomes and objective physical activity after primary total knee arthroplasty—a multicenter study using wearable technology. J Arthroplasty. 2023;38:94–102.
    1. Deckey DG, Stein MK, Atkins LM, Richards AE, Wu KA, Wyles CC, et al. Fitting the knee to the patient, not the other way around: a three‐dimensional analysis of total knee arthroplasty implant fit. J Arthroplasty. 2025;40:S333–S342. https://www.arthroplastyjournal.org/article/S0883-5403(25)00158-5/abstract
    1. Ditton E, Johnson S, Hodyl N, Flynn T, Pollack M, Ribbons K, et al. Improving patient outcomes following total knee arthroplasty: identifying rehabilitation pathways based on modifiable psychological risk and resilience factors. Front Psychol. 2020;11:1061.