Risk of Revision Following Knee Arthroplasty in Bariatric Surgery Patients

February 24, 2026 updated by: Saber Muthanna Saber, Bispebjerg Hospital

Risk of Revision and Other Complications Following Knee Arthroplasty in Patients Previously Exposed to Bariatric Surgeries: A Nationwide, Register-based Study

Previous studies have investigated the outcomes of Knee Arthroplasty (KA) following Bariatric Surgery (BAS), but with substantial limitations as not stratifying for Body Mass Index (BMI) at time of KA or not addressing the type of BAS (gastric bypass, banding or sleeve). Since BMI varies greatly in patients with previous BAS, it is likely that BMI affects outcomes after KA in BAS-operated patients.

The investigators believe that stratifying for BMI would explain the contradictions with the previous research in this patient group when it comes to the risk of revision after KA.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
99965

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Denmark
      • Copenhagen, Denmark
        • Orthopaedic department, Bispebjerg Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

The investigators will include patients with primary/idiopathic or secondary (due to meniscus or cruciate ligament lesion) osteoarthritis (OA) who received primary KA in the period from 2011 and 2 years earlier to data-extraction date. Patients will be identified from the DKR. Patients are followed for 2 years, until first revision, death or migration, whichever comes first.

Description

Inclusion Criteria:

  • Primary knee arthroplasty due to osteoarthritis

Exclusion Criteria:

  • Primary knee arthroplasty due to traumatic osteoarthritis.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
BAS group
Patients who received bariatric surgery prior to their knee arthroplasty
Other: BAS
NOMESCO (Nordic Medico-Statistical Committee) Classification of Surgical Procedures (KJDF10 & KJDF11 [gastric bypass]; KJDF20 & KJDF21 [gastric banding]; KJDF40, KJDF41, KJDF96 & KJDF97 [gastric sleeve]).
Non-BAS group
Patients who did not receive bariatric surgery prior to their knee arthroplasty
Other: Non-BAS
Patients without BAS codes

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Hazard rate of Revision due to any cause
Time Frame: within 90 days and within 2 years
Revision surgery is defined as surgery with debridement and/or exchange of at least one component
within 90 days and within 2 years
Hazard rate of Revision due to infection
Time Frame: within 90 days and within 2 years
Our definition of infection is adapted from the European Bone and Joint Infection Society (EBJIS) criteria as at least one of the following A. An indication of deep infection is reported to the Danish knee arthroplasty register (DKR) by the surgeon on revision surgery B. At least 2 deep-tissue samples of phenotypically indistinguishable bacteria isolated from at least 3 deep-tissue samples C. One or more positive intraoperative samples from a closed fluid aspirate AND a biopsy (fluid AND tissue) of phenotypically indistinguishable bacteria isolated.
within 90 days and within 2 years

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Hazard rate of Knee related antibiotic use within 30- and 90-days following KA
Time Frame: within 30- and 90-days following KA
the use of one of the following oral antibiotics: dicloxacillin, flucloxacillin, phenoxymethylpenicillin, amoxicillin, oral ciprofloxacin, roxithromycin, linezolid, cefuroxime and cefalexin
within 30- and 90-days following KA
Hazard rate of Antibiotic use due to other causes
Time Frame: within 30- and 90-days following KA
the use of one of oral antibiotics other than those that were mentioned in outcome 3.
within 30- and 90-days following KA
Mortality
Time Frame: 2 years postoperatively
Mortality registered in the Danish Civil Registration System (DCRS) by date
2 years postoperatively

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Bispebjerg Hospital

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Søren Overgaard, MD,DMSc,Prof, Department of orthopedic surgery, Bispebjerg University Hospital, Denmark

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 1, 2024

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 2, 2024

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
February 1, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
September 7, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 27, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
May 30, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 27, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 24, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • p-2023-14433

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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