Bone Breakthrough Research Articles

Parametric Power Spectral Density Estimation-Based Breakthrough Detection for Orthopedic Bone Drilling with Acoustic Emission Signal Analysis

Manual bone drilling in orthopedic surgical operations may cause injury to patient tissues if the drill bit continues to progress after exiting the bone. In this study, a new bone breakthrough detection algorithm based on acoustic emission (AE) signal analysis has been developed to minimize temporary and permanent injuries that can be caused by surgeon-controlled surgical drills. Three parametric estimation methods, Burg, Yule–Walker and Modified Covariance were used to estimate Power Spectral Density (PSD) of the AE signal during the drilling operation. Four frequency features, Mean Frequency, Median Frequency, Mean–Median and Power Bandwidth were calculated for each PSD estimate. An artificial neural network-based breakthrough detection classification was constructed from the extracted features. The highest breakthrough detection performance was obtained with the features extracted by the Burg method with an accuracy rate of 90.95 ± 0.97% in the training phase and 92.37 ± 1.09% in the test phase. In the detection of Not-Breakthrough situations, the highest accuracy was obtained with features extracted with the Covariance method as 99.04 ± 0.03% in the training phase and 99.05 ± 0.08% in the testing phase. This new approach which could be integrated into conventional drills with minimum configuration changes and without any major cost has the potential to increase the performance and safety of bone drilling procedures.

Experimental Study of Thrust Force and Torque for Drilling Cortical Bone.

Excessive drilling forces can result in drill breakage, bone breakthrough, and thermal necrosis during bone drilling process. However, the effect of drilling process parameters, drill geometry parameters, and bone material type on drilling forces have not been fully investigated. Three designs of experiments are introduced separately to study single factor's effect on drilling forces, identify significant geometry parameters and possible interactions for drilling forces, and formulate direct relationship between drilling forces and process parameters. The results show that thrust force and torque are increased with feed rate, drill diameter or web thickness. The effect of spindle speed, point angle, helix angle, and chisel edge angle on drilling forces is complex. The results also show that the drilling forces are affected by bone type significantly, which are highest for bovine cortical bone, and lowest for Sawbones 3401. The levels of significance of geometry parameters are identified and different for thrust force and torque, which can assist new surgical drill development. Quadratic regression equations obtained by response surface methodology can predict thrust force and torque accurately in a wide range of process parameters, which can be used to control drilling conditions for robot assisted surgeries to realize safe drilling.

A Novel Measurement for Monitoring Mechanical Impedance Applied to Breakthrough Detection of Bone-Drill System

Based on a Chain Scattering Description and the Hilbert Huang Transform, this paper proposes a new measurement for monitoring dynamic changes of mechanical impedance without applying conventionally mechanical sensors. The proposed method is applied to the bone drilling system to detect the moment of bone breakthrough. The single frequency mechanical impedance of bone can be computed from the electrical signal of a DC motor in accordance with the proposed method. The experimental results demonstrate that the moment of bone breakthrough can accurately be detected by monitoring changes of mechanical impedance.

Design and experimental force analysis of a novel elliptical vibration assisted orthopedic oscillating saw

Orthopedic oscillating saws (OOSs) are widely used for plane processing in orthopedic surgery such as knee and hip replacement. However, sawing has been associated with bone breakthrough and necrosis problems. In this paper, a novel elliptical vibration assisted OOS was designed to achieve a low cutting force under the condition of deepening cut depth and reducing cutting speed, based on the analysis of brittle fractures of the bone and elliptical vibration assisted cutting kinematics. The elliptical vibration was generated using two parallel stacked piezoelectric actuators assembled with the fixture. In order to reduce the large cutting forces due to the large cutting depth, a series of experiments was also conducted to investigate the influence of processing parameters on cutting forces. It was demonstrated that cutting forces are significantly reduced by increasing the vibration frequency and vibration amplitude, and decreasing the sawing speed in the current design. The new design could minimize the cutting forces during sawing and allow surgeons to have better control over the sawing process.

Smart bioimpedance-controlled craniotomy: Concept and first experiments.

Craniotomy is part of many neurosurgical interventions to create surgical access to intracranial structures. The procedure conventionally bears a high risk of unintended dural tears or damage of the soft tissue underneath the bone. A new synergistically controlled instrument has recently been introduced to address this problem by combining a soft tissue preserving saw with an automatic cutting depth control. Many approaches are known to obtain the information required on the local bone thickness. However, they suffer from unsatisfactory robustness against disturbances occurring during surgery and many approaches require additional intra- or preoperative steps in the workflow. This article presents first concepts for real-time cutting depth control based on in-process bioimpedance measurements. Furthermore, sensor integration into a synergistic surgical device incorporating a bidirectional oscillating saw is demonstrated and evaluated in first feasibility tests on a fresh bovine bone specimen. Results of bipolar measurements show that the transition of different layers of bicortical bone and bone breakthrough lead to characteristic impedance patterns that can be used for process control.

Novel surgical machining via an impact cutting method based on fracture analysis with a discontinuum bone model

Cutting (including sawing and drilling) is a common procedure in orthopedics. Although it is widely used, cutting is associated with surgical problems, such as bone breakthrough and necrosis. In this study, the phenomenon of large fractures was analyzed with a discontinuum model of a bone by initially predicting crack propagation. A cutting method utilizing impacts by vibration was then proposed, and experiments were performed. The results indicated that the principal cutting force decreased by more than 80% in each cutting direction. The findings suggest that the method can realize low load, high efficiency, and high accuracy of bone machining.

Applied anatomic study of narrow pedicle in thoracolumbar spine of adults

Objective To explore the demographic factors and the risk of the pedicle screw insertion of the narrow pedicles. Methods Thoracolumbar spine thin-section CT image data of 312 adults from September 2014 to September 2015 were analyzed. The pedicle width, medial and lateral cortical thickness, spongy bone thickness, spongy bone thickness/cortical thickness, e angle and screw path length of each pedicle were measured. The incidence and the distribution characteristics of the narrow pedicle were analyzed. Anatomic parameters and age, gender and stature were compared between the narrow pedicle group and non-narrow pedicle. The risk of the pedicle screw insertion of the narrow pedicle was assessed. Results Among the 3 081 pedicles, 74 narrow pedicles were determined as their pedicles width were less than 5 mm, and the proportion of narrow pedicle was 2.40%. Among the 312 subjects, 26 subjects were found having narrow pedicles, and the proportion of individuals with narrow pedicles in the population was 8.33% (26/312). The incidences of narrow pedicle in thoracolumbar spine were T10 0.32%, T11 0.32%, T12 0.98%, L1 7.54%, L2 2.92%. The spongy bone thickness, spongy bone thickness/cortical thickness of narrow pedicle were lower than non-narrow pedicle. However, there were no significant differences of medial and lateral cortical thickness, e angle and screw path length between the narrow pedicle and non-narrow pedicle. Difference of the mean age between the two subjects groups had no statistical significance. The percentage of female in narrow pedicle subjects group was 84.6% (22/26), which was higher than that in non-narrow pedicle subjects group (49.7%, 142/286). The mean stature of the male and female of stenosis pedicle group subjects were 163.8±1.3 cm and 152.5±4.3 cm, which were shorter than those of non-narrow subjects pedicle group (169.5±5.6 cm, 160.1±6.6 cm). The percentage of the cortical bone breakthrough by the pedicle screws of narrow pedicle group was (84.6%, 27/32), which was higher than that of non-narrow pedicle group (14.7%, 33/224). Conclusion L1 is the most common segment of thoracolumbar spine that narrow pedicle exist, which is the result of reduction of the spongy bone thickness. Narrow pedicle mostly appears in short stature female. There is high risk of cortical bone breakthrough by insertion of the posterior pedicle screws in the narrow pedicle. Key words: Thoracic vertebrae; Lumbar vertebrae; Tomography, X-ray computed; Anatomy

A Design Concept of an Orthopedic Bone Drilling Mechatronics System

Bone drilling manipulationstake placevery ofteninthe orthopedic surgery. The successful execution of bone drilling requires a high level of dexterity and experience. The patient’s recovering depends on the operation performance. This paper presents a design concept of a bone drilling hand-hold mechatronic system. It is based on the modified structure of the previous our robot ODRO. It isable to detect the bone breakthrough and the stops. It is intended to perform drilling a preliminary set depth. Resistantforce is measured and experimental results are shown.

Control and breakthrough detection of a three-axis robotic bone drilling system

This paper describes a robotic bone drilling system for applications in orthopedic surgery. The goal is to realize a three-axis robotic drilling system which can automatically stop drilling at the moment a drill breaks through bone. The proposed robotic bone drilling system consists of an inner loop fuzzy controller for robot position control, and an outer loop PD controller for feed unit force control. Moreover, breakthrough detection is a function of thrust force threshold information and trends in drill torque and feed rate. The proposed technique has been verified by drilling pig bones, the results for both the bone drilling and bone breakthrough processes are in accord with theoretical model.

Analgesic Efficacy of Bradykinin B 1 Antagonists in a Murine Bone Cancer Pain Model

Cancer pain is a significant clinical problem because it is the first symptom of disease in 20% to 50% of all cancer patients, and 75% to 90% of patients with advanced or terminal cancer must cope with chronic pain syndromes related to failed treatment and/or tumor progression. One of the most difficult to treat cancer pains is metastatic invasion of the skeleton that can generate ongoing and bone breakthrough pain, which represents one of the most debilitating cancer-related events. Because bradykinin has been shown to be released in response to tissue injury and plays a significant role in driving acute and chronic inflammatory pain, we focused on bradykinin antagonists in a model of bone cancer pain. In our model of bone cancer, which involves the injection and confinement of 2472 sarcoma cells to the mouse femur, pharmacologic blockade of the bradykinin B 1 receptor is effective in reducing pain-related behaviors at both early and advanced stages of bone cancer. Perspective Bone cancer pain can be severe and difficult to control fully. With a mouse model of bone cancer pain we demonstrate that pharmacologic blockade of the bradykinin B 1 receptor is effective in reducing bone cancer pain–related behaviors, suggesting that B 1 antagonists might be useful in attenuating bone cancer pain in humans.

Electrical thresholds for biomechanical response in the ankle to direct stimulation of spinal roots L4, L5, and S1. Implications for intraoperative pedicle screw testing.

A comparison of electrical thresholds for biomechanical response in the ankle and for evoked electromyographic signals from specific leg muscles during intraoperative extradural direct stimulation of roots L4, L5, and S1. To determine whether a biomechanical response in the ankle to direct root stimulation occurs before evoked electromyographic signals and to determine differences in electrical excitability of the roots circumferentially. Stimulus intensities of 1.2-5.7 mA are reported to evoke electromyographic response in corresponding muscles to direct stimulation of normal roots. Stimulus intensities of 6-8 mA were suggested to detect bony pedicular compromise by stimulation of a hole or a screw during pedicle instrumentation. Electrical thresholds of three-dimensional torque response in the ankle to direct root stimulation have not yet been evaluated and compared with thresholds of evoked electromyogram. Direct monopolar stimulation of the surgically exposed roots L4, L5, and S1 was performed from different sites around the root by a cuff multielectrode. Biomechanical response was measured as an isometric torque in the ankle at each of three orthogonal axes. Compound muscle action potentials (CMAPs) from root-specific muscles were detected by a pair of surface or wire electrodes. Mean threshold for biomechanical response in the ankle to stimulation of roots L4, L5, and S1 was 0.72 +/- 0.39 mA and for CMAP response was 1.09 mA +/- 0.36 (N = 13). Thresholds for biomechanical responses were significantly lower than for CMAP responses (P = 0.0004; paired t test). Nerve roots were electrically most excitable on their ventral aspects. The biomechanical response in the joint to root stimulation can be used to test all root-related muscles crossing that joint at their individual innervation pattern and their residual innervation and to detect electrical excitation of the root at electric thresholds lower than those for detecting CMAP from single standard root-specific muscle. However, this method does not provide sufficient root specificity. It will be valuable in conjunction with multimodality neurophysiologic monitoring of the roots for earlier and more reliable detection of pedicle bone breakthrough or integrity. Further clinical investigations are suggested.