Mechanical Engineering Assistant Research Professor, Dr. Kirk McGilvray of the Orthopaedic Bioengineering Research Laboratory (OBRL) received a $3.2M grant from the NIH to study fracture healing prediction.
Almost 800,000 patients face abnormal fracture healing each year in the United States alone, leading to chronic conditions associated with pain and disability. With the inability to detect or predict if a fracture is progressing towards a full recovery during the vitally important early treatment stages, it is nearly impossible to diagnose and then prevent abnormal, post-operative healing.
There is currently a high clinical demand for diagnosing early and abnormal fracture healing, and the absence of this strategy is a major obstacle in the orthopaedic field. With increased knowledge, measures like additional surgery or therapies could be taken, resulting in greater efficacy.
Fractures that involve a significant disturbance to the blood supply are the most prone to abnormal healing; specifically, diaphyseal and metaphyseal fractures caused by high-energy trauma incidents like car accidents, sports injuries, or falls from a height.
The two most popular surgical methods for treating diaphyseal fractures involves placement of either contoured plates or intramedullary nails; both offering safe and minimally invasive techniques. Metaphyseal fractures are commonly treated with plate fixation. Implant stiffness plays a significant role during healing, as currently there is no way to determine if the implant is loaded within the correct range; if the implant is too stiff or flexible, the underlying fracture is susceptible to incorrect healing.
Dr. McGilvray, and his mentor, ME Professor, Dr. Christian Puttlitz, have shed immense light on this issue and developed a biocompatible, microelectromechanical system, or bioMEMs sensor that can be attached to metal implants, and telemetrically reports data regarding the in vivo mechanical environment of the implant-bone construct, providing predictions of a fracture’s healing cascade. If the strain on the implant decreases, the bone is supporting more of the load and healing efficiently, however, if the strain borne by the implant plateaus or increases, the bone is most likely healing incorrectly. Consequently, this new technology provides higher quantitative diagnostic information as to the course of healing during the critically important initial post-operative period when adjunct therapies are the most effective.
This NIH grant seeks to extend the bioMEMs sensor technology by further enhancing this already impressive technology to resolve fracture cases with a higher incident of failure.
Dr. McGilvray, the principal investigator and Dr. Puttlitz, the co-investigator are researching effects of placing multiple sensors in close proximity to one another, allowing a deeper look into not just the fracture site, but adjacent healthy bone where implant failure is also possible. This data is crucial, not only to the patient on the table, but to future patients who may be able to utilize the next generation of implants that have a more strategic design, thanks to the results of this significant research.
In addition to that, Drs. McGilvray and Puttlitz are developing sensors that are flexible, as opposed to the ridged material used in their previous studies. This will allow a sensor to attachment to curved constructs, allowing for a larger range of implant placement, generating novel clinically relevant in vivo data.
We look forward to sharing Drs. McGilvray’s and Puttlitz’s contributions to the field of orthopaedics in on our website and in upcoming publications.