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Undue heat production in surgical bone drilling leads to osteonecrosis and can be an important cause of failure of osteosynthesis, impaired healing, and loosening of implants following orthopedic surgery. The present work aims to minimize heat production below the critical temperature for thermal osteonecrosis (i.e., 47°C) and obviate thermal bone damage due to drilling. A total of 20 samples from the shaft of the human femur were obtained at autopsies and drilling was performed at room temperature by an operation theater (OT) compatible rotary ultrasonic bone drilling (RUBD) machine. K-type thermocouples were used to measure the temperature rise during drilling and the physical changes of the bone samples were observed by infrared gama camera. Light microscopic and transmission electron microscopic studies were performed to evaluate the bone cell damage. The maximum temperature recorded in RUBD (40.6 ± 1.3°C) was much below the critical temperature for thermal osteonecrosis (p

Aims During the COVID-19 pandemic, drilling has been classified as an aerosol-generating procedure. However, there is limited evidence on the effects of bone drilling on splatter generation. Our aim was to quantify the effect of drilling on splatter generation within the orthopaedic operative setting. Methods This study was performed using a Stryker System 7 dual rotating drill at full speed. Two fluid mediums (Videne (Solution 1) and Fluorescein (Solution 2)) were used to simulate drill splatter conditions. Drilling occurred at saw bone level (0 cm) and at different heights (20 cm, 50 cm, and 100 cm) above the target to simulate the surgeon ‘working arm length’, with and without using a drill guide. The furthest droplets were marked and the droplet displacement was measured in cm. A surgical microscope was used to detect microscopic droplets. Results Bone drilling produced 5 cm and 7 cm droplet displacement using Solutions 1 and 2, respectively. Drilling at 100 cm above the target produced the greatest splatter generation with a 95 cm macroscopic droplet displacement using Solution 2. Microscopic droplet generation was noticed at further distances than what can be macroscopically seen using Solution 1 (98 cm). Using the drill guide, there was negligible drill splatter generation. Conclusion Our study has shown lower than anticipated drill splatter generation. The use of a drill guide acted as a protective measure and significantly reduced drill splatter. We therefore recommend using a drill guide at all times to reduce the risk of viral transmission in the operative setting. Cite this article: Bone Jt Open 2021;2(9):752–756.

Bone drilling is a major stage in immobilization of the fracture site. During bone drilling operations, the temperature may exceed the allowable limit of 47 °C, causing irrecoverable damages of thermal necrosis and seriously threatening the fracture treatment. One of the parameters affecting the temperature rise of the drilling site is the frequency of applying the drill bit and its extent of wear. The present study attempted to mitigate the effect of drill bit wear on the bone temperature rise through the internal gas cooling method via CO2 and to reduce the risk of incidence of thermal necrosis. To this end, drilling tests were conducted at three rotational speeds 1000, 2000, and 3000 r·min-1 in two states of without cooling and with internal gas cooling by CO2 through an internal coolant carbide drill bit, along with six drill bit states (new, used 10, 20, 30, 40, and 50 times) on a bovine femur bone. The results indicated that in the internal gas cooling state, as the number of drill bit applications increased from the new state to more than 50 times, the temperature of the hole site increased on average by ΔT = 2-3 °C (n = 1000 r·min-1), ΔT = 5-8 °C (n = 2000 r·min-1), and ΔT = 5-7 °C (n = 3000 r·min-1). Furthermore, the internal gas cooling method was able to significantly reduce the effect of the drill bit wear on the temperature rise of the drilling site and to resolve the risk of incidence of thermal necrosis regardless of the process parameters for drilling operations.

Drilled hole quality is a significant parameter for successful orthopedic surgery. The present investigation is an effort to reduce the delamination produced drilling with state-of-the-art hybrid drilling i.e. ultrasonically-assisted drilling. A comparative analysis has carried out as per experimental design to assess the ultrasonic drilling with conventional drilling. The novelty of the work is the use of coordinate measuring machine (CMM) for characterization of the delamination during bone drilling. The results revealed that ultrasonically-assisted drilling caused lesser delamination than conventional drilling. The maximum percentage delamination during conventional drilling was found to be 9.153% and 8.541% during ultrasonically-assisted drilling.

Background: Mixed reality devices have made a bigimpact on the medical profession by creating a virtual world.Visual perception methods and 3D Touch can be used inteaching institutions to import knowledge and help performplastic surgery easily.Methods: This study has been done to evaluate the systematicscoping review and merits of Aumented RealityTechnology in Plastic Surgery for 3 years in the Departmentof Burn and Plastic Surgery in All India Institute of MedicalSciences, Rishikesh using PubMed Ovid and Google Scholar.This is a review to compare the advent and utility of mixedreality platforms in plastic surgery in the world by searchingthe PubMed database.Results: The records of 55 articles could be retrieved inplastic surgery from Pubmed and Ovid database. 26 werereview articles, 10 were on haptic devices, 13 on 3D printing,15 case reports, and one randomized controlled trial. Hapticdevices are a part of training skills such as bone drilling,burring, and cutting. Education is enhanced by virtual realityplatforms incorporating learning soft tissue skills with hapticdevices.Conclusion: Technological advancement in imaging modalitiesprovides a convenient way of teaching anatomy,mapping of perforators to design flaps, and perform virtualosteotomies. Virtual consoles can be designed to teach endoscopicplastic surgery with 3D scanning.

Thermal injuries inflicted during bone drilling significantly affect the success rate of surgery, hence, it is important to control thermal injury through temperature reduction. Low-frequency vibra...

The strength between the cortical screw and bone following an orthopaedic implant surgery is an important determinant for the success of osteosynthesis. An excessive axial cutting force during drilling produces microcracks in the bone surface, resulting in reduced strength between the screw and bone, resulting in loosening of implant. The present work, investigates the influence of drilling parameters on microcracks generated in the drilled surface and pull-out strength of screw fixed in cortical bone of human tibia. The holes were drilled by two different techniques: conventional surgical bone drilling (CSBD) and rotary ultrasonic bone drilling (RUBD), by a recently developed operation theatre (OT) compatible machine. Cutting force generated in drilling of human tibia using RUBD was 30-40% lesser than that of CSBD. Scanning electron microscopy (SEM) also revealed that RUBD produced significantly lesser and thinner microcracks than that of CSBD in human bones. Biomechanical pull-out test results showed that, the pull-out strength of screws inserted into drilled holes by RUBD was much higher (100-150%) than that of CSBD. A significant difference in pull-out strength (p < 0.05) between RUBD and CSBD was revealed by statistical analysis at 95% confidence interval.

Efficacy and outcomes of osteosynthesis depend on various factors including types of injury and repair, host factors, characteristics of implant materials and type of implantation. One of the most important host factors appears to be the extent of bone damage due to the mechanical force and thermal injury which are produced at cutting site during bone drilling. The temperature above the critical temperature (47 °C) produces thermal osteonecrosis in the bones. In the present work, experimental investigations were performed to determine the effect of drilling parameters (rotational speed, feed rate and drill diameter) and techniques (conventional surgical bone drilling and rotary ultrasonic bone drilling) on cutting force and temperature generated during bone drilling. The drilling experiments were performed by a newly developed bone drilling machine on different types of human bones (femur, tibia and fibula) having different biological structure and mechanical behaviour. The bone samples were procured from male cadavers with the age of second to fourth decades. The results revealed that there was a significant difference ( p

Objective: The aim of this study was to improve muscle flaps and to evaluate surgical outcomes with the use of a novel specialized retractor, which is a surgical instrument used to locate and shape a bony seat for minimally invasive cochlear implantation. Methods: 50 patients aged 1–75 years with sensorineural hearing loss who required cochlear implantation were recruited. A small incision (

Breakthrough detection is a crucial task to reduce the risks of damaging soft tissue bone drilling operations during orthopedic surgery. Conventional drills are not equipped with this function while the recent literature has offered this capability with high cost and complex modification needs. In this study, a new breakthrough detection approach based on closed-loop control characteristics of the drilling operation is proposed. A feature set containing closed-loop signals and force sensor data is created to train K-Nearest and Ensemble Classifier for breakthrough detection tasks with drilling the synthetic bone model and animal bone with a robot manipulator. The best accuracy of breakthrough detection with only closed-loop control signal attributes is achieved as 96.9 ± 0.8% for the synthetic bone model and 98.1 ± 0.2% for sheep femur bone. Breakthrough detection delay which included sampling and operation time of the method guarantees that the drill bit would stop with acceptable breakthrough range of 1.0413 mm. The proposed method can be used to detect breakthrough and also to estimate the state of the drill bit in robotic orthopedic bone drilling processes using only closed-loop signals so that it would be no need to use extra high-cost sensors.

INTRODUCTION: The performance of the drilling process depends on the characteristics of the drilling equipment and surgeon’s skill. To our knowledge, no research has focused on multi-parameter analysis of the dynamic behaviour of drills during the drilling process. This study aimed to characterise the physical changes and effects of different drills attached to a robotic arm during drilling of artificial bones in a standardised experimental setup. MATERIALS AND METHODS: Drilling processes using three brands of drills attached to a robotic arm were compared in terms of thrust force, vibration, noise level, speed deviation, and temperature. A standardised experimental setup was constructed, and measurement data were analysed statistically. Identical artificial bones were drilled 10 times with each drill. RESULTS: Thrust force measurements, which varied through the cortex and medulla, showed expressive differences for each drill for maximum and mean values (p

In order to feedback the cutting temperature in real time during the operation with the surgical robot, this study established a temperature prediction model to analyze the temperature distribution of the cortex. In this work, a three-dimensional governing equation for heat transfer of bone tissue during drilling is proposed, and the heat transfer of cortical bone is evaluated by a reverse heat transfer method. The prediction model was validated by experimental methods and the heat affected zone (HAZ) of cortical bone was analyzed. The results show that the prediction results are in good agreement with the relevant experimental results. HAZ increases with increasing rate of penetration; the closer the bone hole is, the earlier the temperature rises; and the temperature at which the cortical bone is difficult to measure (radial distance x

Background Bone drilling is a procedure that demands a high level of dexterity, fine motor skills and spatial awareness from the operating surgeon. An important consideration when drilling bone is minimising soft tissue damage. There are numerous causes of drilling associated soft tissue injury, of which most concerning is drilling into the tissue beyond the far cortex as unseen injury can occur. This is known as plunging. Objectives The objective of this study was to evaluate the impact of haptic feedback in virtual reality (VR) simulation-based training. The acquisition of drilling skill was assessed by changes to their drill plunge depth. Study Design & Methods The participants in the study were medical students, doctors and biomedical scientists. Participants were randomly allocated into two groups. One group had simulation with haptic feedback as part of their VR simulated learning, whereas the second group undertook the same VR simulation but did not receive haptic feedback during the simulation. Following completion of the simulated bone drilling protocol, a bone drilling exercise took place. Each participant was allowed to drill a synthetic tibia bone five times and then the plunge depth was measured. We quantified outcome in the form of plunge depth. Results There were four participants in each group. The average plunge distance in the group who were able to practice with haptic assisted VR simulation was 46mm (range: 37-56mm), the average plunge distance in the non-haptic group was 79mm (range: 44-136mm). Results showed an average reduction of 33mm in plunge depth from users in the haptic group compared to the non-haptic group. Conclusion Bone drilling simulation with haptic feedback may be an effective simulator of the motor skills that would be required to perform this action on a live patient. The study results suggest that there could be a reduction in soft tissue damage for users trained in VR simulations with haptic feedback.

The orthopedic manipulation “bone drilling” is the most executed one in the orthopedic surgery concerning the operative treatment of bone fractures. The drilling process is characterized by a number of input and output parameters. The most important input parameters are the feed rate [mm/s] and the drill speed [rpm]. They play significant role for the final result (the output parameters): thermal and mechanical damages of the bone tissue as well as hole quality. During the manual drilling these parameters are controlled by the surgeon on the base of his practical skills. But the optimal results of the manipulations can be assured only when the input parameters are under control during an automatic execution of the drilling process. This work presents the functional characteristics of the handheld robotized system ODRO (Orthopedic Drilling Robot) for automatic bone drilling. Some experimental results are also shown. A comparison is made between the similar systems which are known in the literature, some of which are available on the market. The application areas of ODRO in the orthopedic surgery practice are underlined.

Assessment techniques for orthopedics training are primarily subjective, and often based on qualitative metrics. In this paper, we propose an analytical approach for the quantitative assessment of orthopedic surgery training, specifically, bone drilling. Our goal in this paper is to help improve orthopedics training by providing a means to assess the resident training progress. To this end, we introduce a novel metric that assigns a unique signature to an individual’s drilling activity based on their drilling trajectory, and we compare it with the signatures of expert surgeons. We conduct a simple bone-drilling experiment with surgeons (experts) and novice users on a hybrid (physical - digital) setup consisting of 3D printed bone surrogates that emulate physical and perceptual properties of a human bone across the young and old age groups. We create expert models using our drilling signature metric to evaluate drilling performance for novice users with respect to expert orthopedic surgeons. Our preliminary analysis of drilling signatures across expert and novice users showcases a perceivable distinction across two different bone types highlighting some fundamental insights on the drilling setup, bone material, and user response to each bone type. Our results indicate that the drilling signature helps capture not only a novice user’s drilling behavior, but also their relative expertise as they progress with training.

Introduction: The aetiological factors of dental fear include negative information, witnessing or having a bad experience, and negative conditions related to periodontal treatment. Modified Dental Anxiety Scale Nepali version, is one of the tools used in epidemiological studies to measure dental anxiety in adults. The objective was to find out the prevalence of anxiety among dental patients visiting for periodontal therapy in a tertiary care hospital. Methods: This descriptive cross-sectional study was conducted among patients visiting for periodontal therapy from November 2020 to January 2021 at a tertiary care dental hospital. Ethical clearance from Institutional Review Committee (Reference no. 0311202001) was taken before the study. Convenient sampling was done. A standard questionnaire for dental anxiety was used for data collection after receiving informed consent from the participants. Data were entered and analyzed in Microsoft Excel Sheet. Descriptive data are presented as means, standard deviations, frequencies, and percentages. Results: Among a total of 311 participants visiting for periodontal therapy, 297 (95.49%) (92.57-97.42 at 95% Confidence Interval) were having anxiety. Among total patients, 113 (36.33%) were fairly anxious, 111 (35.69%) were slightly anxious, 62 (19.94%) very anxious and 11 (3.54%) were extremely anxious. Majority of males 54 (17.36%) were slightly anxious while most females 67 (21.54%) were fairly anxious. Mean Modified Dental Anxiety Scale-Nepali score of all the participants was 11.59±3.808. Extreme dental anxiety was observed in 11 (3.54%) participants 7 (2.25%) females; 4 (1.29%) males. Conclusions: The prevalence of anxiety among patients visiting for periodontal therapy in this study was found to be higher compared to other studies done in similar settings.

Background Bone drilling is a vital procedure in implant surgery and dental implant training systems based on virtual reality technology. Purpose Predict and update drilling force in real time based on a virtual dental implant training system and lay the foundation for realizing force feedback in dental implant training instruments. Materials and methods An experimental platform was established to measure the drilling force for human mandibles from donors of different ages. Response surface methodology was applied to analyze the drilling force. Results Force regression equations for different age groups were acquired. The order of the effects (from greatest to least) of the drilling parameters on the drilling force was the drill bit diameter, feed rate, and rotational speed. To obtain the minimum force, higher rotational speeds, lower feed rates, and smaller diameters were preferred within the range of commonly used medical reference parameters of bone drilling. Conclusion The experimental data were confirmed to be scientific for the predicted models of drilling force.

Retrograde Anbohrung des nekrotischen Areals im Huftkopf, um den intraossaren Druck zu senken und ein Einwachsen von neuen Blutgefasen zu ermoglichen. Atraumatische Huftkopfnekrose im ARCO-Stadium I (reversibel) und ARCO-Stadium II (potenziell reversibel) mit idealerweise einem medialen oder zentralen Nekroseareal 30 %, Infektionen. Ruckenlage. Darstellung des Nekroseareals mittels Bildwandler, Wahl des Zugangs durch aufgelegten Kirschner-Draht, laterodorsaler Hautschnitt auf Hohe des Drahtes, Tractusspaltung, Langsspaltung des M. vastus lateralis, Kirschner-Draht (2–3 mm) in die Nekrosezone vorbohren, evtl. durch weitere Drahte erganzen oder mithilfe einer Hohlfrase ausraumen, Wundverschluss. Teilbelastung (ca. 20 kg) fur 6 Wochen wegen der Gefahr einer Fraktur, anschliesend sollte fur weitere 6 Wochen Springen sowie Sprinten vermieden werden. Physiotherapeutische Beubung ab dem 1. postoperativen Tag, Thromboseprophylaxe bis zur Vollbelastung. Die Ergebnisse sind abhangig vom ARCO-Stadium und in den fruhen Stadien erfolgversprechend.

Heat reveals during the bone drilling operations in orthopedic surgery because of friction between bone and surgical drill bit. The heating causes extremely important damages in bone and soft tissues. The heating has a critical threshold and it is known as 47∘C. If bone temperature value exceeds 47∘C, osteonecrosis occurs in bones and soft tissues. Many factors such as surgical drill bit geometry and material, drilling parameters, coolant has important roles for the temperature rise. Many methods are used to decrease the temperature rise. The most effective method among them is to use the coolant internally. Numeric simulations of a new driller system to avoid the overheating during the orthopedic operating processes were performed in this study. The numerical simulation with/without coolant was also performed using the finite element based software. Computer aided simulation studies were used to measure the bone temperatures occurred during the bone drilling processes. The outcomes from the simulations were compared with the experimental results. A good temperature level agreement between the experimental results and FEA simulations was found during the bone drilling process.

Introduction: Many orthopaedic procedures require drilling of bone, especially fracture repair cases. Bone drilling results in heat generation due to the friction between the bone and the drill bit. A high-level of heat generation kills bone cells. Bone cell death results in resorption of bone around bone screws.Methods: We searched in the literature for data on parameters that influence drilling bone and could lead to thermal necrosis. The points of view of many orthopaedists and neurosurgeons based upon on previous practices and clinical experience are presented.Results: Several potential complications that lead to thermal necrosis are discussed and highlighted.Discussion: Even in the face of growing evidence as to the negative effects of heat induction during drilling, simple and effective methods for monitoring and cooling in real-time are not in widespread usage today. For that purpose, we propose some suggestions for the future of bone drilling, taking note of recent advances in autonomous robotics, intelligent systems and computer simulation techniques.Conclusions: These advances in prevention of thermal necrosis during bone drilling surgery are expected to reduce the risk of patient injury and costs for the health service.

Recently, the failure rate of fracture fixation to fractured bone has increased. Mechanical and thermal damage to the bone, which influences the contact area and cell growth between the bone and the screw, is the primary reason for fixation failure. However, research has mainly focused on force and temperature in bone drilling. In this study, the characteristics of hole edges, microcracks, empty lacunae, and osteon necrosis were investigated as viewed in the transverse and longitudinal sections after drilling. Drilling force and temperature were also recorded for comparing the relationship with mechanical and thermal damage. Experiments were conducted in vivo using five different drill geometries under the same drilling parameters. Characteristics of the hole wall were detected using computed tomography. Microcracks and necrosis were analyzed using the pathological sectioning method. The maximum microcrack was approximately 3000 and 1400 μm in the transverse section and longitudinal section, respectively, which were much larger than those observed in previous studies. Empty lacuna and osteon necrosis, starting from the Haversian canal, were also found. The drill bit geometry, chisel edge, flute number, edges, and steps had a strong effect on bone damage, particularly the chisel edge. The standard and classic surgical drill caused the greatest surface damage and necrosis of the five drill bit geometries studied. The microstructural features including osteons and matrix played an important role in numbers and length of microcracks and necrosis. More microcracks were generated in the transverse direction, while a greater length of the empty lacuna was generated in the longitudinal direction under the same drilling parameters. Microcracks mainly propagated in a straight manner in and parallel to the interstitial bone matrix and cement line. Drilling forces were not directly correlated with bone damage; thus, hole performance should be considered to evaluate the superiority and inferiority of drill bits rather than the drill force alone.

Ultrasonically assisted drilling as a new type of bone drilling technology has received increasing attention. However, the vibration energy of existing studies was limited. In this study, a robot-based ultrasonically assisted bone drilling experimental setup was designed, and high-energy ultrasonically assisted bone drilling (vibration frequency=24.1–41 kHz, and vibration amplitude=150–160 µm) was applied to bovine cortical bone to investigate the drilling temperature compared with conventional drilling. The effect of drilling speed on drilling temperature was also studied. The experiment results showed that, compared with the conventional bone drilling, high-energy ultrasonically assisted bone drilling had slightly higher drilling temperature (0.36–0.86 °C), which is in direct contrast to previous reports. We hypothesized that this finding was due to the thermal effect of ultrasonic vibration, which the present study confirmed. Moreover, the drilling temperature increased with higher drilling speed.

Purpose: Thermal injury to the optic nerve is a potential complication of bony decompression of the orbital apex. An animal model was used to compare and contrast temperature change while removing ...

Bone drilling and implantation are important in orthopaedic surgery, dentistry and also fracture treatment. In many cases, due to the rise in temperature during bone drilling (higher than 47 °C) and low conductivity of bone, thermal necrosis occurs. There is also risk of drill fracture due to the excessive thrust force. Despite many studies on the effect of different parameters on bone drilling temperature and force, there is still no clarity about the influence of the tool rotational speed and feed rate on the temperature and force responses. The aim of this study was to test and optimise the conditions in high-speed bone drilling, process force and temperature simultaneously. The results demonstrated that high-speed drilling is a suitable method for decreasing process temperature and force, and the rotational speed, feed rate and tool diameter were the most important factors in the high-speed bone drilling processes. Using a statistical method to model and optimise the process, a second-order model was developed to predict the behaviour of process temperature and thrust force in high-speed drilling. The optimised values were a rotational speed of 11778 rpm, feed rate of 50 mm/min and tool diameter of 2 mm, where the process force and temperature were 15.85 N and 33.4 °C, respectively. Therefore, in high-speed bone drilling, the process thrust force and temperature decline, and the low effect of feed rate on temperature enables an increase in the speed of operation in robotic surgery.

Implant stability is a prerequisite for successful implant osseointegration. Over the years, implant site preparation has been refined taking into consideration the fact that, the bone is a viable tissue. Even minor alterations in the steps of osteotomy like overheating, increased pressure etc. could lead to failure in osseointegration. This could be due to an alteration in the microvascular dynamics. Implant site osteotomies have been prepared using conventional drills since several decades. These drills are designed so as to excavate the native bone to create room for the implant to be placed. Contrary to that, a new technique is introduced which instead of excavating the bone tissue compacts and autografts the bone in an outwardly expanding directions from the osteotomy. This novel approach termed osseodensification, aids to preserve the bony bulk, increase primary stability through densification of the osteotomy walls, hastens the healing and facilitates ridge expansion. This narrative review focuses on the new bone drilling concept, namely osseodensification and its advantages over the standard subtractive drilling techniques.

Endoscopic middle ear surgery is a widely employed minimally invasive surgical technique to address middle ear and mastoid pathology. Bone drilling is the main technical challenge of endoscopic middle ear surgery. The accompanying video describes the detailed protocol of a constant-suction bone-drilling technique and the procedure of endaural exclusive endoscopic atticoantrotomy (retrograde mastoidectomy) using this technique. The main components of this bone-drilling technique include a soft and flexible suction tube, which is placed into the tympanic cavity to provide constant suction, and a soft sleeve, which is wrapped around the drill shaft to prevent the high-speed rotating shaft from damaging the lens of the endoscope. With these simple modifications, the traditional otological electrodrill can be used for drilling a tiny endaural incision in endoscopic middle ear surgery. Based on this bone-drilling technique, endaural endoscopic atticoantrotomy (retrograde mastoidectomy) can be successfully established for the removal of various amounts of bone, depending on the extent of the lesion. The short-term postoperative outcome seems promising.

STUDY DESIGN An experimental investigation of a robot-assisted ultrasonic osteotome applied to vertebral cancellous bone. OBJECTIVE The aim of this study was to investigate the effect of various ultrasonic parameter settings on temperature in the drilling site and penetration time and determine the most suitable parameters for efficient and safe robot-based ultrasonically assisted bone drilling in spinal surgery. SUMMARY OF BACKGROUND DATA A robot-assisted ultrasonic osteotome device may be safe and effective for spinal drilling. METHODS Sixty specimens of bovine vertebral cancellous were randomly assigned to one of six groups, which varied by mode of ultrasonic vibration (L-T and L) and feed rate (one percent [0.8 mm/s], two percent [1.6 mm/s], and three pecent [2.4 mm/s]). Maximum temperature in the drilling site and penetration time was recorded. RESULTS Maximum temperature in the drilling site decreased as output power increased for L-T and L modes, was significantly lower for L-T compared to L mode at each feed rate and power setting, was significantly different at feed rates of 1.6 mm/s versus 0.8 mm/s and 2.4 mm/s versus 0.8 mm/s for L-T mode at an output power of 60 W and 84 W, but was not influenced by feed rate for L mode. Penetration time did not significantly improve as output power increased for both L-T and L modes, was significantly decreased with increased feed rates, but was not significantly different between L-T and L modes. CONCLUSION The optimal parameters for applying a robot-assisted ultrasonic osteotome to vertebral cancellous bone are L-T mode, maximum output power of 120 W, and maximum feed rate of 2.4 mm/s.Level of Evidence: 4.

The paper seeks to address issues that arise during the drilling and fixation of bones in orthopedic, orthodontic and implant surgeries. Thermal necrosis is one of the widespread problems that occurs during bone/tooth drilling and which can lead to implant failures. The highest registered temperature during drilling is 86°C. However, when the temperature is increased beyond 47° C during the drilling process, it can often lead to osteonecrosis. The possibility of thermal necrosis can be minimized by controlling the drilling parameters. However, optimal parameter values identified by various researchers have not been complied so far, primarily because of the effects of multifactorial constraints. Overall, the drilling bore speed and the feed rate are found to be the most influential parameters in triggering thermal injuries in the course of time. The drilling speed is also more important to the feed rate. In addition, osteological location also increases the probability of necrosis by multiple means in terms of anatomy. A thermocouple is used to evaluate in vivo temperature conditions during the drilling process. However, given the uncertainty and the practical errors that occur during the experimental measurements, the finite-element analysis (FEA) is proposed in most studies. This paper explores the existing state of literature and summarizes various drilling methods and assess the related parameters using FEA. It also describes the impact of various constraints in detail to explore the optimum drilling parameters in order to minimize the danger of thermal necrosis.

The advanced tendency in development of robots oriented to orthopedic manipulations is maximally simplification of their mechanics. So called Handheld Robotized Systems appear. Here handheld bone drilling robotized system ODRO (Orthopedic Drilling Robot) is considered. The purpose is to compare its functional characteristics with the similar systems known in the literature. Experimental results are presented for porcine femur drilling by new drill module. The stop drilling decision is taken automatically. The information about experiments concerning the different modes is shown on the display after the drilling end. Handheld robotized systems can perform the accuracy and precise work like the stationary multifunctional robots. They do not need special software, pre-operative planning procedures, calibration, registration and systems for intraoperative navigation. In the same time they are much cheaper, accessible for usage, convenient for work and maintenance which will facilitate their mass application in the orthopedic surgery practice.

Deep-hole bone drilling is critical in many surgical implantation procedures. Unlike most common bone-drilling processes, deep-hole bone drilling is performed using a high drilling depth to drill-bit diameter ratio, which can lead to undesirable mechanical and thermal damage during surgical procedures. The objective of this study was to investigate the thrust force and torque generated in deep-hole bone drilling. Drilling tests were performed on bovine cortical bones at a drilling hole depth of 36 mm using a 2.5 mm diameter twist drill bit with a spindle speed of 3000 rpm and feed rates of 0.05, 0.075, and 0.1 mm/rev. Bone chips were collected at different depths and examined using a fiber-optic microscope. Not only are drilling forces a good indicator to assess drilling performances but also chip formation and morphology are important aspects for understanding bone-drilling behaviors. The force signals revealed two distinct states, which were referred to as normal and abnormal states in this study. In the normal state, the force signals remained constant once the drill tip became fully engaged in bone cutting, whereas after a certain drilling depth, the forces considerably increased in the abnormal state. The results of this study indicate that the rapid increase in the force in the abnormal state is mainly attributed to chip clogging inside the flutes as the drilling depth increases. This study also demonstrated that the chip morphology varies with respect to drilling depth, where fragmented chips are produced at shallow drilling depths and powdery chips are produced at deeper drilling depths.

Bone drilling is an important procedure in medical orthopedic surgery and it is inevitable that heat will be generated during the drilling process and higher temperatures can cause thermal damage to the bone tissue near the drilled hole. Therefore, the capability to obtain the cortical bone drilling temperature distribution area can have great significance for medical bone surgery. Based on the theory of heat transfer, a predictive model for cortical bone drilling temperature distribution was established. The energy distribution coefficient in cortical bone drilling was derived, based on conjugate gradient inversion. A cortical bone drilling experiment platform was built to verify the temperature distribution prediction model. The results show that the model of cortical bone drill temperature distribution could predict accurately the drilling temperature distribution, both for different depths and for different radial distances. Additionally, the effects of different drilling conditions (spindle speed, feed rate, drill diameter) on the temperature of drilling cortical bone were considered.

Currently, in the world of orthopedic surgeries, bone drilling is prevalent to hold broken bones and for bone implantation. Increase of bone temperature higher than 47 °C leads to a notorious phenomenon named thermal necrosis, which eventuates in cellular death of the bone tissue. Consequently, there is a chance for a loose implant after the operation. In this paper, for the first time, a 3D thermo-mechanical finite element (FE) model of a high-speed bone drilling process was introduced to study process force and temperature. Then comparing experimental results with numerical ones, the influence of the rotational speed and feed rate on both process force and the temperature was investigated. This study revealed that in high-speed drilling of the bone with a raise in rotational speed, due to different chip deformation and reduced chip thickness, both process force and temperature reduce remarkably. According to experimental and numerical findings, the optimum bone drilling setting was achieved with a tool diameter of 2 mm, the rotational speed of 12,000 rpm, and feed rate of 50 mm/min in which force and temperature were 14.11 N and 32.45 °C, respectively. The findings of this study can be an excellent help for robotic surgeries in order to decrease drilling force and temperature and ultimately squeezing of the recovery period.

Bone drilling processes are often carried out in numerous surgical areas in all operational theatre room in various hospitals across the world, these processes includes orthopedic surgeries, which is mending and fixing of broken bones. Bone drilling is classed as one of the most sensitive milling processes in biomedical engineering field. One of the most critical problems encountered during bone drilling is high cutting force which causes an increase in temperature rise more than the tolerable limit. Optimum concentration is also needed, in order to avoid extended cracks due to high vibration which could also cause more damage to the surrounding tissues, experimental results showed that it is better to keep bone external temperature below 50°C, if exceeded, the bone could be exposed to serious damage called thermal osteonecrosis which can result to loose of bone implant interface. Previous studies are only limited to investigate the relationship between the cutting force and temperature. However, the concept of this research work is an eye opener, which will also help us to predict the relationship between drilling vibration frequency and the temperature rise of the bone. Our discovery shows that vibrational drilling is good for surgical bone drilling, when applied moderately, a drastic reduction in bone temperature was observed, this could be used as a standard procedure to prevent necrosis during surgical bone drilling. Reduction in the cutting force and increase vibrational (frequency) is good for bone drilling, and this is to be investigated in this research work.

Background During drilling of bone, which is common in clinical surgeries, heat generation increases local temperature in the drilling site. Transmission of excessive heat to the surrounding bone tissue can cause thermal osteonecrosis. Consequently, it may lead to failure of implants and fixation screws or delay in healing process. Using cooling is a method for limiting temperature elevation. Materials and methods In this study, through comparing three conditions of drilling without cooling, external cooling with normal saline, and external cooling with OpSite spray, the efficiency of OpSite as coolant is studied. In this regard, 2 drill bit diameters, 3 drilling speeds, and 3 drilling feed-rates are considered as drilling variables in the experiments. Results For the whole experiments, while cooling with normal saline resulted in lower maximum temperatures than without cooling condition, OpSite had even better results and limited the temperature elevation during drilling of bone efficiently. Conclusion OpSite spray, which has lower infection risks than normal saline on one hand and lower maximum temperature rise with all combinations of drilling parameters on the other hand, can be considered in clinical surgeries for cooling applications.

In orthopedic and trauma surgical operations, drilling of bone is one of the commonly used procedures performed in hospitals and is a clinical practice for fixing the fractured parts of human bones. Force, torque and temperature play a significant role during the bone drilling and decide the stability of the medical implants. Therefore, it is necessary to minimize force, torque and temperature while drilling to avoid the thermal necrosis and osteosynthesis. This study focused on studying the influence of various types of bone drilling parameters (rotational speed, feed rate, drill diameter and ultrasonic amplitude), tools (solid tool, hollow tool and conventional twist drill bit) and techniques (conventional surgical drilling, rotary ultrasonic bone drilling and rotary bone drilling) on force, torque, temperature and microcracks produced in the drilled surface of the bone. The experimental investigations were conducted on porcine bone samples to perform the comparative study. Results revealed that increasing the diameter of drill tool and feed rate results in the increase in force, torque and temperature, while low rotational speed (500 r/min) generated a low temperature, high cutting force and torque for all types of drilling processes and tools evaluated in this study. Experimental results also revealed that rotary ultrasonic bone drilling with hollow tool generated the lowest cutting force, torque, temperature (

Bone drilling is an important step in orthopedic surgeries for the reconstruction and repair of fractured bones. The main concern in bone drilling is to create holes without causing minimum damage to the bone tissues. It is well reported that high temperature and high force in drilling cause bone thermal necrosis leading to the delayed bone healing and implant failure. In the past, a significant amount of research has been conducted to understand and mitigate the issues in bone drilling. However, the current practice in bone drilling is that medical surgeons still rely on their own experience and feeling, which often causes unwanted damage to the bone. The present paper aims to provide a comprehensive review of surgical bone drilling and impending factors affecting drilling and biological performance of the bone. Current protocols and practices in tackling issues around drilling are discussed and assessed in terms of results obtained in both experimental and computational domains. This pragmatic discussion will signify the importance and challenges ahead in empowering medical surgeons to enable improved surgical outcome. Furthermore, the findings of this extensive review are expected to drive further exploration of new opportunities for developing advanced bone drilling system integrated with intelligent sensors and control technology.

Osteotomy is a common step in oncological, reconstructive, and trauma surgery. Drilling and elevated temperature during osteotomy produce thermal osteonecrosis. Heat and associated mechanical damage during osteotomy can impair bone healing, with consequent failure of fracture fixation or dental implants. Several ex vivo studies on animal bone were recently focused on heating production during osteotomy with conventional drill and piezoelectric devices, particularly in endosseous dental implant sites. The current literature on bone drilling and osteotomic surface analysis is here reviewed and the dynamics of bone healing after osteotomy with traditional and piezoelectric devices are discussed. Moreover, the methodologies involved in the experimental osteotomy and clinical studies are compared, focusing on ex vivo and in vivo findings.

Bone drilling process is a prominent step of internal fixation in orthopedic surgeries. Process forces, leading to chip production, produce heat in the vicinity of the drilled bore and increase the probability of necrosis phenomenon. In this article, an analytical model to predict process temperature is presented based on Sui and Sugita model. This heat transfer model is the combination of a heat equilibrium equation for tool–chip system and a heat distribution equation for the bone itself where heat generation in tool’s tip is due to cutting frictional forces. In an analytical model, it is possible to use material properties of the bone and geometry of the tool; therefore, the calibration test is not necessary. In order to validate analytical model, experiments were done using bovine bone. Using response surface method, a second-order linear regression mathematical model is derived using experimental results. The effect of each individual parameter as well as their interactions on the output of the process was investigated. Within the range of the parameters studied in this article, with an increase in rotational speed, process temperature boosts up. Effect of feed rate is complicated due to the tool–bone contact time issue. While higher temperature is achieved in lower feed rates because of higher tool–bone contact time but higher temperature is observed with high feed rates due to an increase in force and friction. Optimized combination of the parameters to minimize temperature of 35.6 °C is tool diameter of 2.5 mm, rotational speed of 500 r/min and feed rate of 30 mm/min. Good correlation was observed between analytical and experimental results.

Objective To investigate drill wear and consequent intraosseous temperature elevation during freehand and guided bone drilling, with attention to the effect of metal-on-metal contact during guided drilling. Materials and methods Osteotomies were performed on bovine ribs, with 2.0 mm diameter stainless steel drill bits of the SMART Guide System, under 3 sterilization protocols, at 800, 1200, 1500, and 2000 rpm. Sterilization was performed after every 3 drilling. Temperature was measured after every 30 drilling. Results The studied contributing factors had a cumulative effect, and each contributed significantly to temperature elevation. Whether guide use led to a near-necrotic (47°C) temperature increment depended largely on the applied sterilization protocol. Conclusion The metal sleeve is a significant contributing factor to heat generation during guided osteotomy, but its effect can be offset by keeping the other studied factors under control.

Bone drilling is a crucial operation in orthopedic, maxillofacial, and trauma surgery. Delamination is a familiar defect in the drilling process and can seriously disrupt postoperative regeneration near the implant site in bone surgery. This research experimentally investigates the problem of delamination around drilled holes in vibration-assisted drilling of in cortical bone on the delamination around drill holes in cortical bone. Drilling speed and amplitude of vibration were found to have almost no influence on delamination, while higher feed rate was found to moderately increase delamination. Highest reduction in delamination was found to occur at higher frequencies of vibration imposed on the drill in the feed direction. Statistical analysis (ANOVA) also indicated that delamination is most significantly affected by frequency of drilling, only slightly by feed rate, and almost negligibly by drill speed. Overall, it can be concluded that ultrasonically assisted drilling, with an appropriately s...

Anterior clinoidectomy is a difficult yet essential technique in skull base surgery. Two main techniques (extradural and intradural) with multiple modifications have been proposed to increase efficiency and avoid complications. In this study, the authors sought to develop a hybrid technique based on localization of the optic strut (OS) to combine the advantages and avoid the disadvantages of both techniques.Ten cadaveric specimens were prepared for surgical simulation. After a standard pterional craniotomy, the anterior clinoid process (ACP) was resected in 2 steps. The segment anterior to the OS was resected extradurally, while the segment posterior to the OS was resected intradurally. The proposed technique was performed in 6 clinical cases to evaluate its safety and efficiency.Anterior clinoidectomy was successfully performed in all cadaveric specimens and all 6 patients by using the proposed technique. The extradural phase enabled early decompression of the optic nerve while avoiding the adjacent internal carotid artery. The OS was drilled intradurally under direct visualization of the adjacent neurovascular structures. The described landmarks were easily identifiable and applicable in the surgically treated patients. No operative complication was encountered.A proposed 2-step hybrid technique combines the advantages of the extradural and intradural techniques while avoiding their disadvantages. This technique allows reduced intradural drilling and subarachnoid bone dust deposition. Moreover, the most critical part of the clinoidectomy—that is, drilling of the OS and removal of the body of the ACP—is left for the intradural phase, when critical neurovascular structures can be directly viewed.

The current array of shoulder repair anchors, techniques, and constructs vary greatly and offer many choices to optimize soft-tissue healing to bone. The widely used all-suture anchor designs represent an innovative option that allows for versatile delivery and a low-profile anchor construct that minimizes bone drilling and preserves native bone. Various reports of tissue reactions to copolymer and biocomposite materials and now all-suture anchors have been published raising concerns in some cases over safety, adverse events, and clinical performance. Other studies have described reactions in which the clinical correlative significance remains unclear. Determination of what matters and what is significant will help to decide if radiographic tunnel enlargement does occur over time and if it changes our clinical decision-making and choice of which anchors to use.

Bone fracture occurs due to accident, aging, and disease. For the treatment of bone fractures, it is essential that the bones are kept fixed in the right place. In complex fractures, internal fixation or external methods are used to fix the fracture position. In order to immobilize the fracture position and connect the holder equipment to it, bone drilling is required. During the drilling of the bone, the required forces to chip formation could cause an increase in the temperature. If the resulting temperature increases to 47 °C, it causes thermal necrosis of the bone. Thermal necrosis decreases bone strength in the hole and, subsequently, due to incomplete immobilization of bone, fracture repair is not performed correctly. In this study, attempts have been made to compare local temperature increases in different processes of bone drilling. This comparison has been done between drilling without cooling, drilling with gas cooling, and liquid cooling on bovine femur. Drilling tests with gas coolant using direct injection of CO2 and N2 gases were carried out by internal coolant drill bit. The results showed that with the use of gas coolant, the elevation of temperature has limited to 6 °C and the thermal necrosis is prevented. Maximum temperature rise reached in drilling without cooling was 56 °C, using gas and liquid coolant, a maximum temperature elevation of 43 °C and 42 °C have been obtained, respectively. This resulted in decreased possibility of thermal necrosis of bone in drilling with gas and liquid cooling. However, the results showed that the values obtained with the drilling method with direct gas cooling are independent of the rotational speed of drill.

The Kirschner wire (K-wire) is a common bone drilling tool in orthopedic surgery to affix fractured bone. Significant heat is produced due to both the cutting and the friction between the K-wire and the bone debris during drilling. Such heat can result in high temperatures, leading to osteonecrosis and other secondary injuries. To reduce thermal injury and other high-temperature associated complications, a new K-wire design with three notches along the three-plane trocar tip fabricated using a thin micro-saw tool is studied. These notches evacuate bone debris and reduce the clogging and heat generation during bone drilling. A set of four K-wires, one without notches and three notched, with depths of 0.5, 0.75, and 1mm, are evaluated. Bone drilling experiments conducted on bovine cortical bone show that notched K-wires could effectively decrease the temperature, thrust force, and torque during bone drilling. K-wires with notches 1mm deep reduced the thrust force and torque by approximately 30%, reduced peak temperatures by 43%, and eliminated blackened burn marks in bone. This study demonstrates that a simple modification of the tip of K-wires can effectively reduce bone temperatures during drilling.