NCT07067060

Brief Summary

SUMMARY Background: After knee arthroplasty (KA), rehabilitation is widely recommended, yet its clinical effectiveness-especially the need for supervision-has been challenged. While some argue that supervised rehabilitation may prevent serious adverse events (SAEs), previous trials show no superiority of rehabilitation, supervised or not, over no rehabilitation in terms of function. However, these trials were underpowered for safety outcomes. A large-scale evaluation is needed to determine if supervision impacts SAE risk, thereby informing rational use of health care resources. Rationale for the proposed study. A conventional randomized trial to assess the safety of supervised versus unsupervised rehabilitation after KA would require an ethically and logistically infeasible sample size. By emulating such a trial using routinely collected registry data, the investigators can estimate the causal effect of supervision on the risk of serious adverse events-while accounting for confounding and preserving real-world relevance. Actionable objective and hypothesis: To test whether unsupervised rehabilitation after knee arthroplasty increases the risk of serious adverse events over a 2-year period compared with supervised rehabilitation. The investigators hypothesize that unsupervised rehabilitation is non-inferior, defined as a hazard ratio for SAE risk below 1.4. Design: Target trial emulation (TTE) using nationwide registry data to replicate the design and intent of a pragmatic randomized trial. Setting: Danish hospitals and municipalities. Patients: Adults undergoing primary total or unicompartmental knee arthroplasty for osteoarthritis, identified from Danish registries. The target trial assumes consecutive recruitment at hospital discharge to mirror real-world referral practices. Interventions: Referral to unsupervised home-based exercise or supervised municipal physiotherapy, defined by referral to rehabilitation pathways initiated at hospital discharge. Methods: Primary outcome is serious adverse events; secondary is number of hospital contacts. Propensity score-based weighting will adjust for confounding using patient and administrative covariates (e.g. age, BMI, comorbidities, surgery year), enabling causal inference from observational data. Results: Findings will inform clinical practice by estimating the comparative safety of unsupervised versus supervised rehabilitation after knee arthroplasty, based on real-world data from over 40,000 patients. Limitations: As with all non-randomized studies, residual confounding is possible. Despite adjustment strategies, causal interpretations should be made with caution due to reliance on observational data. Conclusion: While TTE can provide valuable insight, the causal inferences made with TTE should be interpreted with caution, when not supported with an RCT. Funding: Section for Biostatistics and Evidence-Based Research, the Parker Institute, Bispebjerg and Frederiksberg Hospital is supported by a core grant from the Oak Foundation (OFIL-24-074). External funding: in process. Registration: TBD (registration on ClinicalTrials.Gov)

Trial Health

65
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Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
40,000

participants targeted

Target at P75+ for all trials

Timeline
20mo left

Started Jan 2026

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress17%
Jan 2026Dec 2027

First Submitted

Initial submission to the registry

July 4, 2025

Completed
11 days until next milestone

First Posted

Study publicly available on registry

July 15, 2025

Completed
6 months until next milestone

Study Start

First participant enrolled

January 1, 2026

Completed
12 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 31, 2026

Expected
1 year until next milestone

Study Completion

Last participant's last visit for all outcomes

December 31, 2027

Last Updated

July 31, 2025

Status Verified

July 1, 2025

Enrollment Period

12 months

First QC Date

July 4, 2025

Last Update Submit

July 29, 2025

Conditions

Keywords

emulated target trialtotal knee replacementarthroplastyserious adverse eventssupervised rehabilitationunsupervised rehabilitation

Outcome Measures

Primary Outcomes (2)

  • Serious adverse events (SAE)

    The term "serious adverse events" (SAE) is defined by the ICH framework as any untoward medical occurrence that, at any dose, results in: 1) death, 2) life-threatening conditions, 3) inpatient hospitalization or prolonged existing hospitalization, 4) persistent or significant disability/incapacity, or 5) congenital anomalies/birth defects.

    2 years

  • Serious adverse events (SAE)

    The term "serious adverse events" (SAE) is defined by the ICH framework as any untoward medical occurrence that, at any dose, results in: 1) death, 2) life-threatening conditions, 3) inpatient hospitalization or prolonged existing hospitalization, 4) persistent or significant disability/incapacity, or 5) congenital anomalies/birth defects

    2 years

Secondary Outcomes (1)

  • Hospital contact

    2 years

Eligibility Criteria

Sexall
Healthy VolunteersNo
Age GroupsChild (0-17), Adult (18-64), Older Adult (65+)
Sampling MethodNon-Probability Sample
Study Population

Each year, approximately 14,000-15,000 patients undergo knee arthroplasty in Denmark. These procedures take place in both public and private hospitals, all following fast-track surgery protocols with standardized pre-, peri-, and post-operative routines. Hospitals are legally required to report specific hospital-related data to the National Patient Register and the Danish Knee Arthroplasty Register, ensuring high data completeness.

You may qualify if:

  • Adults undergoing primary total or unicompartmental knee arthroplasty (KA) for osteoarthritis in Denmark

You may not qualify if:

  • None

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Design

Study Type
observational
Observational Model
COHORT
Time Perspective
OTHER
Target Duration
2 Years
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
PhD

Study Record Dates

First Submitted

July 4, 2025

First Posted

July 15, 2025

Study Start

January 1, 2026

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

December 31, 2027

Last Updated

July 31, 2025

Record last verified: 2025-07