AdhFix promises to repair difficult fractures

Difficult and unstable fractures could soon be repaired with a AdhFix, new biocompatible polymer-based composite material that is claimed to be as strong as dental composites.

AdhFix
The newly developed material and method were used to fixate a variety of fractures on a pig skull (Image: KTH)

Developed at KTH Royal Institute of Technology in Stockholm, the newly developed material and a surgical method will be used in clinical studies in 2023 and 2024, with a focus on hand fractures. The advance is detailed in Advanced Functional Materials.

Michael Malkoch, professor of fibre and polymer technology at KTH, said that AdhFix will enable customised plating for fixation of fractures with a more comfortable, less complicated recovery. Collarbone and rib fractures in particular are said to be ideally suited for the proposed treatment, since such injuries are not easy to stabilise.

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Metal plates cannot be easily customised in shape, and they tend to adhere to soft tissue, resulting in debilitating complications, Malkoch said. Researchers in the US have found that nearly 64 per cent of finger fractures treated with metal plates result in mobility complications.

AdhFix combines screws with a build-up of the polymer/hydroxyapatite composite instead. The composite is shaped in situ before being rapidly cured on demand via high-energy visible-light-induced thiol-ene coupling.

Evaluations on human cadaver hands with proximal phalanx fractures show that AdhFix withstands the forces from finger flexing exercises. In models of in vivo femur fractures in rats, the methodology supported bone healing without degradation, adverse effects or soft-tissue adhesions.

“No fracture is the same as the other, this is one of the absolute advantages of the material,” Malkoch said in a statement. “A surgeon can tailor the fixation plate according to the patient’s bone shape and the structure of the fracture. The hospital also does not have to store metal plates.”

Malkoch added that the material and method also may be applied to veterinary care. Animals with metal plates are known to avoid going outdoors in cool temperatures because the metal conducts the cold differently than the KTH researchers’ composite.

The work was carried out with RISE in Gothenburg and hand surgeons working at Karolinska Institutet and Södersjukhuset. Daniel Hutchinson, a researcher in polymer and fibre technology at KTH, led the study.