An observational study in Arthritis Knee, Bariatric Surgery Candidate and Prosthesis Failure, sponsored by Bispebjerg Hospital. Completed at 1 site in Denmark. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-02-27.
Sponsored by Bispebjerg Hospital · Observational
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.
119 studies on the registry are indexed under Prosthesis Failure; 35 are open to participants now.
This study's enrollment of 99,965 is above the median of 119 across 49 observational studies indexed under Prosthesis Failure.
Browse Prosthesis Failure studies →Bispebjerg Hospital is the lead sponsor of 289 studies on the registry; 29 are open to participants now.
Counted across the registry records on this site, refreshed daily.
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.
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Exclusion Criteria:
Patients who received bariatric surgery prior to their knee arthroplasty
Other: BAS
Patients who did not receive bariatric surgery prior to their knee arthroplasty
Other: Non-BAS
NOMESCO (Nordic Medico-Statistical Committee) Classification of Surgical Procedures (KJDF10 \& KJDF11 \[gastric bypass\]; KJDF20 \& KJDF21 \[gastric banding\]; KJDF40, KJDF41, KJDF96 \& KJDF97 \[gastric sleeve\]).
Patients without BAS codes
Hazard rate of Revision due to any cause
Revision surgery is defined as surgery with debridement and/or exchange of at least one component
Time frame: within 90 days and within 2 years
Hazard rate of Revision due to infection
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.
Time frame: within 90 days and within 2 years
Hazard rate of Knee related antibiotic use 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
Time frame: within 30- and 90-days following KA
Hazard rate of Antibiotic use due to other causes
the use of one of oral antibiotics other than those that were mentioned in outcome 3.
Time frame: within 30- and 90-days following KA
Mortality
Mortality registered in the Danish Civil Registration System (DCRS) by date
Time frame: 2 years postoperatively
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: No
This study is completed, as verified in Feb 2026. You cannot join it, but the record below documents what was studied.
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