Research paper on Bonevolent® - AdhFix published in Veterinary and Comparative Orthopaedics and Traumatology
Robert Quinn at Vita Referrals, with the Swedish University of Agricultural Sciences (SLU), the AO Research Institute Davos (ARI), KTH Royal Institute of Technology and Biomedical Bonding AB, has published a study on the cyclic performance of Bonevolent® AdhFix. It compares AdhFix against a conventional locking plate for adjunctive fixation of the humeral epicondyle. Earlier work tested a single load to failure; this study addresses fatigue.
Twelve pairs of canine cadaver humeri were used, each receiving a 4.5 mm transcondylar cortical screw in lag fashion. One humerus then received an AdhFix construct with 2.7 mm cortical screws, the contralateral a 2.7 mm locking plate, screw spacing standardised in both groups. Testing both humeri from the same animal controls for bone quality and geometry. Constructs underwent 95,000 cycles of axial compression between 20 and 130 N, approximating six weeks of walking, then loading to failure.
All 24 constructs survived cyclic testing without mechanical failure. No significant differences were found in dynamic stiffness, crosshead movement or peak displacement, nor in yield load, where AdhFix recorded 640 ± 142 N against 692 ± 239 N for the plate (p = 0.54). The plate sustained a higher maximum load before catastrophic failure, 2,431 ± 530 N against 1,489 ± 304 N (p = 0.00002), though both lie far outside physiological loading and yield is the measure that matters in an articular fracture. AdhFix is also markedly less radiopaque than metal, leaving the fracture line visible on radiographs where a plate obscures it.
Michael Malkoch, Professor at KTH Royal Institute of Technology and Founder and CEO of Biomedical Bonding AB, stated:
Matching a locking plate is the result we wanted, not beating one. Steel and titanium are far stiffer than the bone they are attached to, and stiffness you do not need is not free.
The paper is open access and can be accessed via https://doi.org/10.1055/a-2926-9519.
(A) Image of sample 10R (AdhFix). (B) Radiograph of sample 10R. (C) Radiograph of the contralateral humerus 10L (plate). (D) Setup of 10R wrapped in gauze with saline during mechanical testing.
