ABOGRAFT: Antibiotic impregnated bone graft to reduce infections after hip replacement

Logo for the research project abograft with a hip prosthesis as an illustration.

ABOGRAFT stand for Antibiotic impregnated BOne GRAFT.

The ABOGRAFT trial is a multi-center randomized controlled double-blinded drug trial to investigate the effects of providing local antibiotics to prevent joint infection in patients who undergo hip replacement surgery using bone graft.

Overall aim

To reduce the number of patients that suffer from prosthetic joint infection after hip replacement.

Method

This is a multi-center international randomized and double-blinded study. Patients are randomized into two groups:

  • the treatment group will receive antibiotic impregnated bone graft
  • the control group will receive a placebo.

The study protocol will be submitted to BMJ Open. If, in the meantime you would like to have access to the full protocol, send us an email.

Contact

Contact us: jorg.schilcher@liu.se

About the study

FAQ about the study

Why is this study important?

In Sweden close to one in 12 people will have one or both of their hips partly replaced with a prosthesis. Undergoing a prosthetic hip replacement is considered the most successful treatment modern healthcare can offer to regain quality of life. However, the major cause for concern associated with the procedure is prosthetic joint infection (PJI). The number of hip replacement is projected to increase dramatically. Unfortunately, this means that more and more people will be at risk for PJI. As the effects of a prosthetic joint infection are serious and can be life threatening, efforts to reduce this risk are urgent.

Using bone allograft as a carrier for antibiotics?

The introduction of local antibiotics blended into bone cement has led to a 50% reduction in postoperative infection in primary hip replacement. Unfortunately, antibiotic impregnated bone cement cannot always be used and is not a very effective carrier for antibiotics.
Morselized bone allograft has been used as a carrier for local antibiotic treatment in multiple pilot studies and appears to be an attractive and effective treatment alternative. To date, a randomized clinical trial to support its use is lacking.

What is our aim?

The aim of this pragmatic randomized controlled double blinded drug trial is to investigate whether antibiotic impregnated bone graft can decrease the risk of infection after hip replacement surgery.

Which patients are eligible?

Patients over the age of 18 who are undergoing a hip arthroplasty requiring bone graft. Patient currently having a joint infection are excluded.

What is the antibiotic being used?

To account for both gram-positive and gram-negative organisms and to ensure no loose particles get airborne causing allergic reactions in the respiratory tract we dissolve 1 gram of vancomycin powder with 8 ml tobramycin. We add this liquid mixture to the morselized bone allograft. The placebo group will in turn receive 8 ml NaCl (0.9%) added to the bone graft.

How does the study affect the patient? 

Each participating patient receives care as usual, and no additional visits are required. Prior to surgery the patient is screened for inclusion, informed, and signs an informed consent (more information can be found here: ‘for the patient’). During surgery the patient will be randomized to either the treatment or the placebo group. Neither the patients nor the treatment team knows to which group the patient has been assigned. Adverse events are monitored at the day of the operation, at discharge and during the wound control visit.


What are the study outcomes?

Primary: Reoperation due to infection. The diagnosis of a prosthetic joint infection with bacteria that are sensitive to either vancomycin or tobramycin in the same hip joint and within two years after the hip arthroplasty procedure is required to fulfill the outcome.

Secondary:

  • Time and cause for reoperation for any reason within 2 and 5 years
  • Time and cause for implant revision due to any reason within 2 and 5 years
  • Type of microbe and antibiotic resistance pattern for cases complicated with postoperative infection

 

Safety outcomes:

  • Differences between the two experimental groups regarding the frequencies of adverse events
  • Differences between the two experimental groups regarding the rates of revision due to aseptic loosening

When is study data collected? 

Adverse events are monitored and registered at the day of the surgery, at discharge and during the wound control visit. Follow-up data 1, 2 and 5 years after surgery will be collected from the Swedish Joint Replacement Register or country equivalent. Data is validated using medical chart review performed at each individual participating treatment site.

Study organizational diagram

Read more about the persons involved in this study under ‘The ABOGRAFT consortium’.

Is the study registered and approved?

The study is registered at

 

Approval for this study was obtained by

  • Swedish medical ethical committee (Etikprovningsmyndigheten): 2021-02690
  • Swedish Drug Agency (Läkemedelsverket): Dnr. 5.1-2021-40666.

Can I read more information?

You can find a flyer with the study information here.

The study protocol will be submitted to BMJ Open. If, in the meantime you would like to have access to the full protocol, send us an email.

Contact us: jorg.schilcher@liu.se

For the patients

If you are scheduled to undergo a first time hip replacement, or an exchange operation of the old implant to a new one, your physician might have talked about the ABOGRAFT trial. You may have also been given a letter explaining what it means to participate in this research.

Here you can also find the information letter (in Swedish).

 

If you have any questions do not hesitate to contact your doctor or our research nurses.

Cornelia Klasson
Research nurse
cornelia.klasson@regionostergotland.se
010-1034024

Teréz Zara Hanqvist
Research nurse
terez.zara.hanqvist@regionostergotland.se
010-1034252

The ABOGRAFT consortium

Does your center want to join the ABOGRAFT consortium? Contact us!

Study sponsor
Jörg Schilcher (jorg.schilcher@liu.se)

Study coordinator
Daphne Wezenberg (Daphne.wezenberg@liu.se)

Study coordinating nurses
Cornelia Klasson (Cornelia.klasson@regionostergotland.se)

Teréz Zara Hanqvist (terez.zara.hanqvist@regionostergotland.se)

 

Microbiological study
Björn Berglund
Maud Nilsson
Lennart Nilsson
Bo Söderquist

Sites
We are currently running a feasibility study at the University Hospital of Linköping. We aim to include patients from other centers at the end of 2023. Interested? Contact us (jorg.schilcher@liu.se).

 

Steering committee
Olof Sköldenberg (chair)
Bo Söderquist (independent member)
Nils Hailer (independent member)
Nils ‘Johan’ Kärrholm (independent member)
Jörg Schilcher (sponsor)
Daphne Wezenberg (study coordinator)

Patient advisory committee
Maria Nylander (Spokesperson for the Reumatikförbundet in Sweden)

 

Data management committee
Mats Fredrikson
Hans Tropp

 

Monitoring agency
Forum Östergötland

News and updates

An image illustrating microbiology.

Microbiological efficacy

October 2023 - We have finalized our first results regarding the antibiotic efficacy of the bone graft impregnated with the antibiotic mixture. In this study we have investigated if the antibiotics used in the ABOGRAFT trial (vancomycin and tobramycin) mixed with the bone graft are effective against the most common types of bacteria found in infections of artificial joints. We have done this by adding the bone graft mixed with the antibiotics on a gel sprayed with bacteria from infected artificial joints. We found that the bone graft mixed with antibiotics was most effective when used fresh. The effect against bacteria decreased slightly when handled and exposed to irrigation but remained high enough to prevent bacterial growth.

Blood test tube.

Systemic antibiotic levels

April 2023 - We have analyzed whether the antibiotics given locally at the hip joint end up in the bloodstream. We have taken blood samples from the 20 patients treated with local antibiotics between 12-24 hours after the operation. There are only very minimal traces of the antibiotics detectable in the blood staying well below the minimal levels that we would normally aim for when giving the antibiotics through the blood stream. This means that the antibiotics remain at the hip joint where they are needed, and the risk for a toxic systemic reaction due to the antibiotics is very low.

A text saying

Progress...

January 2023 - The first 10 patients have been included! We congratulate all those involved. The process of inclusion, antibiotic preparation, data collection and follow-up run smoothly due to the great effort of the whole team. We will continue to optimize all steps and improve the protocol to ensure a smooth en easy roll-out to the other centers.
Now it is time for our data management committee to look at the first 10 patients to determine if the local administration of antibiotics leads to the increases of antibiotics in the blood circulation.

Starting line at a running track.

We have started! 

Spring 2022 - Our first patient is included. We will include the first 20 patients at the study coordinating center at the University Hospital in Linköping. After which we will start recruitment in the other participating centers.

News from LiU

The research group

Publications

Latest publications

2023

Mischa Woisetschläger, Ronald Booij, Erik Tesselaar, Edwin H. G. Oei, Jörg Schilcher (2023) Improved visualization of the bone-implant interface and osseointegration in ex vivo acetabular cup implants using photon-counting detector CT EUROPEAN RADIOLOGY EXPERIMENTAL, Vol. 7, Article 19 Continue to DOI
Jörg Schilcher, Alva Nilsson, Oliver Andlid, Anders Eklund (2023) Fusion of electronic health records and radiographic images for a multimodal deep learning prediction model of atypical femur fractures Computers in Biology and Medicine, Vol. 168, Article 107704 Continue to DOI
Mattias Rönnerfalk, Lotta Velin, Lars Palm, Andreas Meunier, Jörg Schilcher (2023) Autologous Bone Graft From the Ipsilateral Distal Femur in Tibial Condyle Fractures Journal of Orthopaedic Trauma, Vol. 37, p. E377-E381 Continue to DOI

2022

Abraham Nilsson, Anna Maria Nerhall, Ivan Vechetti, Lotta Fornander, Simon Wiklund, Björn Alkner, Jörg Schilcher, Ferdinand von Walden (2022) A prophylactic subcutaneous dose of the anticoagulant tinzaparin does not influence qPCR-based assessment of circulating levels of miRNA in humans PLOS ONE, Vol. 17, Article e0277008 Continue to DOI
Cornelia Bratengeier, Astrid D. Bakker, Aneta Liszka, Jörg Schilcher, Anna Fahlgren (2022) The release of osteoclast-stimulating factors on supraphysiological loading by osteoprogenitors coincides with expression of genes associated with inflammation and cytoskeletal arrangement Scientific Reports, Vol. 12, Article 21578 Continue to DOI

Funders

Logo Swedish research council.

 

Forss logotype

Contact

Jörg Schilcher

Professor
Lower extremity reconstruction unit
Department of orthopedic surgery and department of biomedical and clinical sciences
University Hospital Linköping and Linköping University
58185 Linköping
Phone: 0046101034291
Email: jorg.schilcher@liu.se