Metal screws play a vital role in bone surgery, helping stabilise fractures and ensure proper alignment of bone fragments. However, these screws can sometimes loosen or break under everyday stress, leading to complications. A recent breakthrough study by researchers at Karl Landsteiner University of Health Sciences (KL Krems) offers a promising solution. By analysing bone structure in detail before implantation, the team can now accurately predict the likelihood of screw failure.
Advanced Imaging Unlocks Bone Secrets
The researchers used high-resolution micro-computed tomography (micro-CT) scans to assess bone quality at potential implant sites. Led by Assoc. Prof. DI Dr. Andreas Reisinger from the Division of Biomechanics at KL Krems, the team examined 100 pig bone samples – chosen for their similarity to human bones – under ten different loading conditions. These scenarios included axial, shear, and mixed forces to replicate real-life movements such as walking or lifting.
Volume and Density Drive Stability
After inserting the screws, the team subjected them to stress tests that mimicked daily activities. They found that two specific parameters – bone volume (BV) and bone volume fraction (BV/TV) – were highly predictive of screw stability. Regardless of the type of load applied, bones with greater volume and density provided significantly more support for the screws.
Powerful Prediction Models Developed
Building on these insights, the researchers created two statistical models to predict the failure force of screws. One model relied solely on bone volume, while the other incorporated multiple bone parameters in a stepwise analysis. Both models demonstrated remarkable accuracy, explaining 70–90% of the variation in screw stability across all samples.
Precision Enhances Surgical Planning
“Our goal was to determine whether we could predict screw failure before implantation,” says Dr. Reisinger. “And the answer is a resounding yes – with surprising precision.” With these models, surgeons can now identify the most stable positions in the bone, reducing the risk of screw loosening or breakage during recovery.
Towards Personalised Orthopaedic Care
This advancement holds significant potential for improving patient outcomes, especially among older adults or those with osteoporosis. By tailoring implant strategies to each individual’s bone structure, orthopaedic surgeons can achieve safer and more effective fracture fixation.
Engineering and Medicine Join Forces
As per the press release, the study at KL Krems showcases the power of interdisciplinary collaboration. By merging biomechanics, imaging technology, and statistical modelling, the team has set a new benchmark for personalised and predictive orthopaedic care.