Clinical trial NCT04772625: Failure Analysis of Patellofemoral Arthroplasty
Official title: Failure Analysis of Patellofemoral Arthroplasty
Study type: OBSERVATIONAL
Overall status: ACTIVE_NOT_RECRUITING
Conditions: Patellofemoral Osteoarthritis
Arthroplasty Complications
Knee Osteoarthritis
Keywords: Patellofemoral arthroplasty
Knee revision surgery
Indication
Lead sponsor: Rigshospitalet, Denmark
Sponsor class: OTHER
Collaborators: name: Stryker Orthopaedics
First posted: 2021-02-26
Enrollment: 550
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Patients operated with patellofemoral arthroplasty for patellofemoral osteoarthritis.

Brief summary: The purpose of the retrospective cohort study is 1) to determine preoperative risk factors for revision af patellofemoral arthroplasty, and 2) to provide a detailed description of indications for revision after patellofemoral arthroplasty. All patients operated with patellofemoral arthroplasty in Denmark from January 1, 2008 to December 31, 2015, will be included in the cohort.

Detailed description: Approx. 11,000 operations with the insertion of a knee arthroplasty (knee prosthesis) are performed annually DK. The durability and quality of the treatment are assessed with prosthesis survival, that expresses the proportion of prostheses that are still functional after a given number of years (eg the 10-year prosthesis survival for all types of knee prostheses in DK is approximately 94%).

Unicompartmental implants are increasingly used, so that only the worn part of the knee is replaced. Especially for osteoarthritis between the patella and the femur, a patellofemoral prosthesis (PFA - patellofemoral alloplasty) can be inserted, which is much smaller than the traditional full prosthesis (TKA - total knee arthroplasty).

PFA operations are controversial. A recently published Danish study (double-blind RCT) comparing TKA and PFA has shown that PFA patients achieve greater satisfaction, better knee function and greater quality of life than TKA patients. A recent study has also demonstrated that the cost of a PFA procedure is less than that of a TKA. As a paradox to this clear RCT finding, all national implant registers (Sweden, England, New Zealand, Denmark, etc.) show a significantly poorer prosthesis survival for PFA compared with TKA.

It is important for the future treatment of patients with severe osteoarthritis between the patella and femur to understand the cause of the discrepancy between RCT and registry results. The discrepancy gives rise to a number of questions regarding. indications, techniques, competences, postoperative regimens etc.

The divergence between the RCT and registry studies can only be clarified by a study that 1) examines the influence of preperative factors (patient history, physical findings, radiology etc.) on outcome, and that 2) attempts a causal analysis for each reoperation. The investigators intend to do this though a cohort study including all cases of patellofemoral arthroplasty performed in Denmark from January 1, 2008 until December 31, 2015.

The purpose is to determine preoperative risk factors for revision after PFA and to provide a detailed description of indications for revision after PFA.

Eligibility criteria: Inclusion Criteria:

* Patellofemoral arthroplasty
* Primary procedure performed between Jan 1 2008 and Dec 31 2015
* Primary procedure performed in Denmark

Exclusion Criteria:

* Patella-nail syndrome
* Dislocating tendon following patellectomy.

Primary outcomes:
measure: Implant revision and reoperation rates
timeFrame: 10-year
Secondary outcomes:
measure: The 6-year cumulative revision rate
timeFrame: 6 years
Other outcomes:
Locations:
city: Copenhagen
country: Denmark
facility: Rigshospitalet
Study officials:
affiliation: Rigshospitalet, Denmark
name: Anders Odgaard, MD, DMSc
role: PRINCIPAL_INVESTIGATOR
References:
citation: Odgaard A, Madsen F, Kristensen PW, Kappel A, Fabrin J. The Mark Coventry Award: Patellofemoral Arthroplasty Results in Better Range of Movement and Early Patient-reported Outcomes Than TKA. Clin Orthop Relat Res. 2018 Jan;476(1):87-100. doi: 10.1007/s11999.0000000000000017.
citation: Bendixen NB, Eskelund PW, Odgaard A. Failure modes of patellofemoral arthroplasty-registries vs. clinical studies: a systematic review. Acta Orthop. 2019 Oct;90(5):473-478. doi: 10.1080/17453674.2019.1634865. Epub 2019 Jul 1.
citation: Odgaard A, Eldridge J, Madsen F. Patellofemoral Arthroplasty. JBJS Essent Surg Tech. 2019 Apr 24;9(2):e15. doi: 10.2106/JBJS.ST.18.00094. eCollection 2019 Jun 26.
citation: Fredborg C, Odgaard A, Sorensen J. Patellofemoral arthroplasty is cheaper and more effective in the short term than total knee arthroplasty for isolated patellofemoral osteoarthritis: cost-effectiveness analysis based on a randomized trial. Bone Joint J. 2020 Apr;102-B(4):449-457. doi: 10.1302/0301-620X.102B4.BJJ-2018-1580.R3.