Surface structural damage study in cortical bone due to medical drilling

Abstract

A bone's fracture could be produced by an excessive, repetitive, or sudden load. A regular medical practice to heal it is to fix it in two possible ways: external immobilization, using a ferule, or an internal fixation, using a prosthetic device commonly attached to the bone by means of surgical screws. The bone's volume loss due to this drilling modifies its structure either in the presence or absence of a fracture. To observe the bone's surface behavior caused by the drilling effects, a digital holographic interferometer is used to analyze the displacement surface's variations in nonfractured post-mortem porcine femoral bones. Several nondrilled post-mortem bones are compressed and compared to a set of post-mortem bones with a different number of cortical drillings. During each compression test, a series of digital interferometric holograms were recorded using a high-speed CMOS camera. The results are presented as pseudo 3D mesh displacement maps for comparisons in the physiological range of load (30 and 50 lbs) and beyond (100, 200, and 400 lbs). The high resolution of the optical phase gives a better understanding about the bone's microstructural modifications. Finally, a relationship between compression load and bone volume loss due to the drilling was observed. The results prove that digital holographic interferometry is a viable technique to study the conditions that avoid the surgical screw from loosening in medical procedures of this kind.

Cortical bone quality affectations and their strength impact analysis using holographic interferometry

“…7 it is possible to notice that well hydrated and mineralized bone samples (m + H2O) have a decreasing magnitude as the compression load increases. This behavior is in good agreement with that reported in reference [21]. This surface response is replicated in the hydrated bone samples with a demineralization process of 4 hours.…”

“…DHI is a non-contact, remote and non-invasive optical technique [55][56][57][58][59], capable of recording fast and non-repeatable dynamic events such as the bone compression [21]. The deformation of the sample is recorded from the overlapping, at the camera's sensor, of the backscattered light that illuminates its surface and a reference beam (an undisturbed beam coming from the illumination light source, e.g., a laser, that contains the undisturbed spatial coherence of the source), forming an image hologram [60].…”

“…This configuration has the advantage to record the surface deformation information during the entire test (dynamic test) without the need to remove the samples to analyze them (static test). In addition, the interferometer registers full-field information over the entire object's surface, a feature required due the bone's anisotropy which results in non-repeatable or scalable tests which depend on the load value and its applied speed [21]. A precise characterization of the affectation procedures was carried out before each compression test is performed.…”

Macro to nano specimen measurements using photons and electrons with digital holographic interferometry: a review

“…Bone analyzes using DHI are focused on its mechanical strength and how external factors could modify this. Reference [65] presents a study where the mechanical response of a porcine femoral bone is analyzed when it suffers a compression. In this study the bones are affected by means of cortical hole drillings which simulate the condition when a prosthetic plaque needs to be fixed in order to heal a fractured bone.…”

A Strain Distribution Sensing System for Bone-Implant Interfaces Based on Digital Speckle Pattern Interferometry

“…In bio-material strain detection area, the DSPI technology has already achieved a wide application in dry bio-material, such as femurs, bird beaks, skulls, trabecular, cortical bones, mandibles, meniscus, teeth structures, etc. [35,36,37,38,39]. Nevertheless, this technology is used very limited and restricted in fresh bio-material.…”