Multifunctional Smart Bone Implants: Fiction or Future?—A New Perspective

Abstract

Implantable medical devices have been developed to provide multifunctional ability to numerous bioapplications. In the scope of orthopaedics, four methodologies were already proposed to design implant technologies: non-instrumented passive implants, non-instrumented active implants, instrumented passive implants and instrumented active implants. Even though bone replacements are among the most performed surgeries worldwide, implant failure rates can still exceed 10%. Controversial positions multiply in the scientific community about the potential of each methodology to minimize the burden related to implant failures. In this perspective paper, we argue that the next technological revolution in the field of implantable bone devices will most likely emerge with instrumented active implants as multifunctional smart devices extracorporeally controlled by clinicians/surgeons. Moreover, we provide a new perspective about implant technology: the essence of instrumented implants is to enclose a hybrid architecture in which optimal implant performances require both smart instrumentation and smart coatings, although the implant controllability must be ensured by extracorporeal systems.

Best practice in digital orthopaedics

“…Moreover, major value is required for early noticing of implant failure or infections. This may be achieved through an interface bone–implant reaction that would be sent to a receiver after processing through a potential wireless communication ( 13 ). It may improve the diagnoses and reduce x-ray exposure by even potentially avoiding CT scans.…”

“…However, there are further challenges that need to be addressed by further research and development in this area. Apart from developing inexpensive, revision-free sensors, the patients’ daily activities must not be disturbed or influenced by the additional monitoring or clinician/surgeon–implant communication, either ( 13 ). Furthermore, the energy supply seems to be a serious problem to maintain function.…”

“…Furthermore, the energy supply seems to be a serious problem to maintain function. The sensor must be compact to avoid relevant changes in the original architecture of the implant, but it still must be able to harvest and store energy or to provide a self-powering system ( 13 ). Hall et al recently presented an in vitro trial to test an alternative for ultrasound-guided implant sensor that is able to detect loosening and temperature changes even though this technology does not expire ( 14 ).…”

“…This enables the early detection of inlay wear in case of decreasing thickness in relation to the femoral part ( 15 ). In addition, there are big concerns about smart implant failure and its possible cytotoxic, genotoxic, or pyrogenic effects directly in bone and soft tissue mostly in younger patients ( 13 ). At last, the collected data from sensors means an immense dimension of information.…”

Advancement of a High-Efficiency Wearable Antenna Enabling Wireless Body Area Networks

“…Hence, the emergence of wearable technology has significantly advanced healthcare, notably in implantable devices [4], [12]. These devices were developed for several medical applications, including neural stimulation [13], cochlear implants [14], pacemakers [15], [16], cardiac defibrillators [17], knee implants [18], [19], bone growth stimulators [20], [21], and foot drop implants [22]. Signals between the implanted device and the wearable network are received and sent by the wearable antenna, which is a key component of the wearable network [23], [24].…”