A Smart, Fully Subcutaneous Distraction System to Improve Outcomes in Patients with Congenital or Acquired Craniofacial Differences

SUMMARY / ABSTRACT Each year, ~200,000 newborns worldwide, 80-85% of whom require surgical intervention, are afflicted with congenital conditions that cause impaired growth of the skull or mandible, leading to abnormalities that affect breathing, hearing, speech, visual function, neurologic development, and mastication. Unfortunately, current surgical treatments, including endoscopic surgery, open reconstruction, and distraction osteogenesis (DO), suffer inherent drawbacks, impacting outcomes. A better solution is needed for this vulnerable patient population. DO is a widely recognized treatment modality that harnesses the body’s natural ability to regenerate bone in order to correct skeletal deficiencies and defects. While still emerging for craniomaxillofacial (CMF) applications, surgeons have shown the utility of DO for restoring functional discrepancies in patients with craniofacial differences. The technique of DO involves surgical placement of one or more distractors, which are devices used to slowly separate two opposing bony fragments at an osteotomy site, to gradually lengthen and reshape the affected bone and stimulate new bone growth. However, DO is not without shortcomings. First, all current distractors have an external component for manual expansion. The external component significantly increases patient risk for complications such as infection (35%), device dislodgement (3.0%), increased analgesic use, and scarring (15.6%). Second, since the burdensome responsibility for manual expansion lies with the caregiver, treatment noncompliance (4.7%) is a serious issue, introducing vulnerabilities ranging from inconsistent device expansion to complete treatment failure. Therefore, DO necessitates extensive physician clinic time and patient radiation exposure to monitor therapeutic progress and thus has not been widely adopted in the CMF skeleton despite recognition of potential advantages over endoscopic surgery (narrower indication for use) and open reconstruction (more invasive, longer anesthesia time, higher blood transfusion rate, longer hospital stay). The Ostiio distraction (OD) system addresses many of the issues associated with DO treatment as the first fully subcutaneous, contactless DO system for the CMF skeleton. At a high level, the OD system leverages magnetic coupling to transfer torque from the hand-held driver (HHD) to the implant, thereby expanding the implant in a contactless fashion. This novel approach will markedly reduce infection, scarring, and manipulation noncompliance. In addition, because the design uniquely permits wireless communication between the implant and HHD, it will enable physicians to better control and monitor treatment progress. This proposal aims to validate a key performance spec of the OD system by demonstrating it can rigorously meet distraction force performance parameters similar to those achieved by the current standard of care. Successful demonstration of this outcome will support Phase II in which we will further development of the OD system by validating function and performance in an in vivo model and formative human factors study. This work will speed to market a novel approach to CMF surgery that can significantly improve DO patient outcomes and experience.