45 and older, any sex, with Physical Activity. Patients with the condition only — healthy volunteers not accepted.
Results — posted to ClinicalTrials.gov
Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.
Physical Activity Measured by an Actigraph GT3X MonitorPrimary· Baseline, discharge from PT, and 6 months after PT discharge
Time spent in Moderate to Vigorous Physical Activity (MVPA) average minutes/week
Baseline MVPA
Group
Value
95% CI
Intervention
9.8
4.2 – 15.4
Control
23.8
11.2 – 36.4
Discharge MVPA
Group
Value
95% CI
Intervention
63
35 – 91
Control
86.8
48.3 – 125.3
6 Months MVPA
Group
Value
95% CI
Intervention
55.3
15.4 – 95.2
Control
89.6
31.5 – 147.74
Adverse events — posted to ClinicalTrials.gov
Time frame: Adverse Events were collected from enrollment until the last follow up, i.e., at 12 months after discharge from outpatient physical therapy, up to 16 months..
Reporting threshold: 5%.
Adverse-event reports describe events observed during the trial — not all are caused by the drug.
Control Group
Serious: 9/58 (16%)
Deaths: 0/58
Intervention Group
Serious: 5/62 (8%)
Deaths: 0/62
Serious adverse events (5 terms)
Reaction
System
Control Group
Intervention Group
Pain
Musculoskeletal and connective tissue disorders
—
—
Knee Replacement Revision
Surgical and medical procedures
—
—
Surgical Complication
Surgical and medical procedures
—
—
Shortness of Breath
Respiratory, thoracic and mediastinal disorders
—
—
Cancer Diagnosis
Neoplasms benign, malignant and unspecified (incl cysts and polyps)
Background: The definitive treatment for knee osteoarthritis is Total Knee Replacement (TKR), which results in clinically meaningful improvements in pain and physical function. However, evidence suggests that physical activity remains unchanged after TKR. This randomized clinical trial is investigating the efficacy, fidelity, and safety of a physical therapist administered physical activity intervention for people after TKR.
Methods/Design: One hundred and twenty individuals, over the age of 45, who seek outpatient Physical Therapy (PT) following a unilateral TKR will be randomized into a control and intervention group. The intervention group will receive a weekly physical activity intervention during PT, which includes a FitbitTM monitor, individualized step goals, and face-to-face feedback provided by the physical therapist. Efficacy of the intervention will be measured by minutes/week spent in Moderate-to-Vigorous Physical Activity (MPVA) using an Actigraph GT3X monitor from enrollment to discharge, 6 months and 12 months from discharge from PT. The association of self-efficacy for exercise and kinesiophobia with physical activity will also be measured at the same time points. Fidelity and safety of the intervention will be assessed during outpatient PT.
Discussion: This study is designed to fill a critical clinical need to increase physical activity after TKR. The primary objective of the study is to evaluate the efficacy of a physical therapist administered physical activity intervention for people after TKR. The secondary objectives are to evaluate the fidelity and safety of a physical therapist administered physical activity intervention for people after TKR and to investigate changes in self-reported and performance-based physical function after a physical therapist administered physical activity intervention for people after TKR. The tertiary objective is to explore the association of psychosocial factors with physical activity 6 and 12 months after discharge from a physical therapist administered physical activity intervention for people after TKR. The findings will be used to support a large multi-site clinical trial to test the effectiveness, implementation, and cost of this intervention.
Publications & conference data
2 peer-reviewed publications reference this trial (live from Europe PMC):
Publications: Europe PMC API search by NCT ID, retrieved 10 June 2026
Drug + disease cross-links: matched in real time against Drug Landscape's normalised drug + company + condition tables
Sponsor: as reported to ClinicalTrials.gov by University of Delaware
Last refreshed: 11 May 2025
Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT03228719.