Anti-bacterial gel fights infection in knee and hip replacements EU-funded project develops special coating for bone implants that cuts the risk of infection and minimises the need for further surgery, potentially benefitting thousands of patients across Europe.
Picture of a doctor examining a patient

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Every year a fast-growing number of patients in Europe receive knee and hip replacements. While most operations are successful, implants carry a significant risk of infection, with 1-2% of all hip and knee replacements getting infected after surgery.

In Italy alone, the cost of such infections is estimated to be €90-100 million (2011 figures) per year due to the cost of prolonged hospital stays — in particular for Methicillin-Resistant Staphylococcus Aureus (MRSA) infections — and the higher costs of secondary surgery.

Aiming to cut implant infection rates, EU-funded project IDAC has developed a special coating for implanted biomaterial. It is capable of both being absorbed by the body and preventing bacteria from colonising the implant.

“Periprosthetic joint infection is a serious and challenging issue for the patient and health care systems. It can result in severe functional limitation of the joint replacement, pain and disability,” says project coordinator Daniele Pressato of Novagenit in Italy.

Special antibacterial coating

IDAC researchers developed a resorbable hydrogel that carries antibiofilm and antibacterial compounds. The gel — called an implant defensive antibacterial coating, or IDAC — is highly effective and easy to use as it is available in a single-use, sterile kit.

The hydrogel works as a barrier against biofilm formation. Surgeons mix it with different active antibacterial drugs during surgery, allowing the correct dosage for each individual patient. It is spread over the orthopaedic implants, effectively winning the 'race to the surface' against bacteria which can be unintentionally introduced during surgery.

IDAC has no drug-resistance risks, and can be stored for up to two years in a refrigerator as a powder in a prefilled syringe. It can be delivered in a few minutes and doesn’t require any specific training of a surgeon or nurse.

Successful clinical trials

The gel was tested in two randomised, controlled, single-blind clinical trials carried out in four European Centres of excellence for orthopaedic surgery. In the first trial, hip or knee replacement patients were randomly assigned to receive either IDAC gel-coated or uncoated implants.

“The clinical outcomes after 12 months show a high safety profile for the gel and a significant reduction in the incidence of infection compared to the untreated group,” says Pressato. Patients treated with IDAC did not develop any infection, while 7.5% of patients not treated with IDAC developed an infection.

In a second trial, patients receiving treatment for fractures in long bones had gel-coated implants of plates, nails and screws, while another group had uncoated implants. “Even in this trial the results showed a significant reduction of infection in the gel-treated groups,” says Pressato.

The project also successfully demonstrated the ability of the hydrogel to be resorbed by the body within 72 hours, helping to avoid the risk of side effects or interfering with the osteointegration of the implant.

Unique position on the global market

IDAC was awarded a patent in 2013 in the EU and US, and it is currently available on the European market (with a CE mark). It has no direct competitors in a market which is growing as the demand for orthopaedic implants increases by about 2.5-4 % a year.

Pressato expects demand to continue to rise, and he hopes that it will soon be available on markets in the Far East and the United States. In the future, the gel could also be adapted to other sectors including plastic surgery, chronic wound management, dental surgery and oncological orthopaedics.

Project details