Drill Tip Research Articles

The Effect of Drill Trajectory on Proximity to the Posterior Interosseous Nerve During Cortical Button Distal Biceps Repair

The aim of this study was to evaluate the effect that different drill trajectories across the radius have on the proximity of the drill tip to the posterior interosseous nerve (PIN). In 10 cadaveric specimens, we drilled from the bicipital tuberosity across the radius using 4 different trajectories: (1) aiming across the radius at 90° to the longitudinal axis of the radius, (2) distally at 45°, (3) ulnarly, and (4) radially. We measured the distance between the tip of the drill as it exited the dorsal cortex of the radius and the PIN. Aiming 90° across the radius and aiming ulnarly across the radius resulted in a distance of 11.2 ± 3.2 mm (95% confidence interval [CI], 8.9 to 13.5 mm) and 16.0 ± 3.8 mm (95% CI, 13.3 to 18.7 mm), respectively, between the drill tip and the PIN. Aiming the drill 45° distally and aiming radially resulted in a distance of only 2.0 ± 2.2 mm (95% CI, 0.5 to 3.6 mm) and 4.2 ± 2.2 mm (95% CI, 2.6 to 5.8 mm), respectively. The differences were found to be statistically significant. On the basis of the results of this anatomic study, when using the cortical button distal biceps repair technique, we recommend drilling across the radius at 90° to its longitudinal axis and aiming from 0° to 30° ulnarly, with the patient's forearm in full supination. This provides an increased margin of safety to prevent injury to the PIN compared with drilling radially or distally. By avoiding distal and radial drilling, the risks of PIN injury should be minimized during distal biceps tendon repair.

Influence of orthopaedic drilling parameters on temperature and histopathology of bovine tibia: An in vitro study

Orthopaedic drilling operations without optimum operating parameters by surgeons may cause bone defects such as bone fracture, cracks, osteolysis and tissue loss around the drilling zone. For the sake of optimum drilling parameters, an in vitro study was performed by considering the bone mineral density, bone sex, drill tip angle, drill speed, drill force and feed-rate. The specimens were taken from the drilled sites of fresh male and female calf tibias. The temperature changes at the drill site were investigated throughout the statistical and histopathological analysis. It was observed that the temperature increased with an increasing drill speed and decreased with high feed-rates and applied drill forces. The drilling temperatures of the female bovine tibias were found to be higher than that of the male tibias and the drill speed was found to be a significant parameter on the maximum temperature. Moreover, the maximum temperature increased with an increasing drill tip angle and bone mineral density. Therefore the bone quality around the drill site was found to be worse than the bone samples exposed to low temperatures.

Influence Axial Vibration on Lateral Bending Deformation of Twist Drill in Machining Small Hole

According to material mechanics theory and drilling practice, the equation of lateral bending deformation (LBD) of drill was built and the inclined angle of drill tip was solved when drilling small hole. And then the drilling test was done and the character of drilling force was analyzed. Based on this, the LBD of drill was studied. The result shows that, the rise of lateral force and thrust force will increase the inclined angle of drill tip in drilling process, and lateral force is the main factor of generating LBD. By choosing suitable axial vibration parameter, axial vibration drilling can reduce the LBD of drill and improve the dimensional accuracy of hole evidently.

Arthroscopic-Controlled Navigation for Retrograde Drilling of Osteochondral Lesions of the Talus

Retrograde drilling of symptomatic osteochondral lesions (OCL) is usually controlled by fluoroscopy. Due to the limited visualization of the OCLs in the acquired images and the narrow access to the talar dome, this approach can be demanding. Several navigation procedures have been reported (2D- or 3D- fluoroscopy or intraoperative CT-based) to increase the accuracy and reduce the radiation exposure. We developed a new arthroscopic-controlled navigation procedure which is free of radiation exposure and free of a reference base rigidly fixed to the bone. We hypothesized that this procedure (Fluoro-Free) is at least as precise as the standard 2D-Fluoro navigation (2D-Fluoro). Furthermore, our first clinical experiences are described and discussed. Sixteen drillings per group (standard 2D-Fluoro vs. Fluoro-Free) were performed in artificial sawbones. Times for the different steps of each drilling procedure were recorded and the precision evaluated by measuring the deviation and depth of drilling. The accuracy of the Fluoro-Free navigation was as precise as the standard 2D-Fluoro based navigation (axis deviation of drill tip to the target point: 1.07 ± 0.11 versus 1.14 ± 0.15 mm). Due to the simplified workflow without radiation exposure and fixation of a reference base, the Fluoro-Free procedure was significantly faster (mean procedure time per drilling: 23.7 ± 11.6 versus 165 ± 9 seconds) and easy to use. Its clinical usefulness was demonstrated during three retrograde drillings of a talar OCL in a 16-year-old patient. The Fluoro-Free navigation procedure is a simplified approach for retrograde drilling of OCL in the talus under arthroscopic control without radiation exposure and without the need for fixation of a dynamic reference base to the bone.

Fracture phenomena of microdrills in static and dynamic conditions

The mechanical drilling of microholes with diameters below 0.5 mm is executed using miniature drills, which are exposed to loads of relatively large cutting forces, frequently causing the failure of the fragile tools. This paper describes the experimental investigations into the deformation, strength, and fracture of the cutting parts of microdrills in static and dynamic conditions. Firstly, microdrill behaviour owing to bending, compression, and torsion was investigated separately in static tests. In addition, torsion was applied together with compression. The values of deflections, forces, and torque were measured and the formation of microcracks and their propagation observed. The tests indicated the characteristic forms of the fracture sections for the kinds of microdrills and loads investigated. In dynamic conditions, the start of the drilling plays an important part. The surface irregularities on the work part cause the drill tip to be pushed aside and changes of its axial position. A typical reason for tool destruction during drilling is excessive stress from cutting forces. The cases of microdrill failure in dynamic conditions collated with various drilling trials. The results show distinctions in the behaviour of microdrills in both circumstances as well as the similarities and differences in the forms of fracture sections.

Retrieval of a fractured drill tip during osteoid osteoma treatment

Osteoid osteomas are relatively common accounting for approximately 10% of all biopsied benign bone tumours. They typically present with pain and arise predominantly in the cortex of long bones in children and young adults.1 Traditional treatments include surgical resection and curettage; however, localization of the central nidus intraoperatively can be problematic. This may lead to incomplete removal and subsequent increased risk of recurrence. Furthermore, removal of a section of the cortex to access the nidus canweaken the bone potentially resulting in fracture. A number of percutaneous treatments have been described including radiofrequency ablation, drilling, trepanation, laser photocoagulation, and chemical destruction of the nidus.2 The most widely used of these techniques is radiofrequency ablation and it has become the method of choice in the treatment of osteoid osteoma.3 Complications are rare and include infection, thermal injury to skin, soft tissues, and articular cartilage, and equipment malfunction. Needle fracture is a recognized

A sensory-guided surgical micro-drill

This article describes a surgical robotic device that is able to discriminate tissue interfaces and other controlling parameters ahead of the drill tip. The advantage in such a surgery is that the tissues at the interfaces can be preserved. A smart tool detects ahead of the tool point and is able to control the interaction with respect to the flexing tissue, to avoid penetration or to control the extent of protrusion with respect to the position of the tissue. For surgical procedures, where precision is required, the tool offers significant benefit. To interpret the drilling conditions and the conditions leading up to breakthrough at a tissue interface, a sensing scheme is used that discriminates between the variety of conditions posed in the drilling environment. The result is a fully autonomous system, which is able to respond to the tissue type, behaviour, and deflection in real-time. The system is also robust in terms of disturbances encountered in the operating theatre. The device is pragmatic. It is intuitive to use, efficient to set up, and uses standard drill bits. The micro-drill, which has been used to prepare cochleostomies in the theatre, was used to remove the bone tissue leaving the endosteal membrane intact. This has enabled the preservation of sterility and the drilling debris to be removed prior to the insertion of the electrode. It is expected that this technique will promote the preservation of hearing and reduce the possibility of complications. The article describes the device (including simulated drill progress and hardware set-up) and the stages leading up to its use in the theatre.

810 マイクロ波ドリル先端部の電磁界数値シミュレーションと基礎的考察(生産加工・工作機械I)

810 マイクロ波ドリル先端部の電磁界数値シミュレーションと基礎的考察(生産加工・工作機械I)

Potential risk of thermal damage to cervical nerve roots by a high-speed drill

Using the transverse processes of fresh porcine lumbar spines as an experimental model we evaluated the heat generated by a rotating burr of a high-speed drill in cutting the bone. The temperature at the drilled site reached 174 degrees C with a diamond burr and 77 degrees C with a steel burr. With water irrigation at a flow rate of 540 ml/hr an effective reduction in the temperature was achieved whereas irrigation with water at 180 ml/hr was much less effective. There was a significant negative correlation between the thickness of the residual bone and the temperature measured at its undersurface adjacent to the drilling site (p < 0.001). Our data suggest that tissues neighbouring the drilled bone, especially nerve roots, can be damaged by the heat generated from the tip of a high-speed drill. Nerve-root palsy, one of the most common complications of cervical spinal surgery, may be caused by thermal damage to nerve roots arising in this manner.

Drilling tool geometry evaluation for reinforced composite laminates

In this work, a comparative study on different drill point geometries and feed rate for composite laminates drilling is presented. For this goal, thrust force monitoring during drilling, hole wall roughness measurement and delamination extension assessment after drilling is accomplished. Delamination is evaluated using enhanced radiography combined with a dedicated computational platform that integrates algorithms of image processing and analysis. An experimental procedure was planned and consequences were evaluated. Results show that a cautious combination of the factors involved, like drill tip geometry or feed rate, can promote the reduction of delamination damage.

El Greco’s Jesus

El Greco’s Jesus Richard Schiffman (bio) El Greco’s Jesus, lit theatrically from behind by a single shaft of sunlight pouring like water through a chink in the gathering storm, his thin, artistic fingers cradling the cross which rests as easy as balsa upon his willing shoulder, gazing here beyond the picture frame, beyond life itself, almost tender with transcendence. And in the dark pupils of those eyes two stars of light— all that we shall ever see of God—two small stars, the dim reflection in the flesh of the world he has already fled to. Two stars, but that’s enough, and more than enough, because it shows how God enters upon the slimmest thread of feeling—not much in the vastness of the night— but enough to refute the darkness, that’s the point. Enough to prove that the night is not all. [End Page 242] The tip of a diamond drill, invisible to the eye, bores through steel plate. The love that made the world, invisible to the world. But focus those slender rays within the soul and they will burn through everything even death. That is what El Greco’s Jesus knows. Once on a beach in San Francisco an urban shaman rocked a boulder back and forth—whispering to it as tenderly as Jesus stroked his cross— until the great stone hung like a ballerina striking an impossible pose, defying the law of gravity. How can so much rest upon so small a fulcrum? Like the weight of God poised tremulous upon the mind, and faith—that thinnest strand, absurd on the face of it, bearing that which is greater than the world. How is it possible for so much to rest upon so little? [End Page 243] But faith doesn’t need much. A sparrow perches upon a twig, a grassy stem. Faith too—poised upon the thinnest stalk of evidence— flies to the Shoreless Sky without denying the pain— that’s the point— without denying the weight of the world pressing like a boulder, without rejecting the bloody lumber of human cruelty, which Jesus bore throughout his short and stormy life. The very same Jesus who said: “My burden is light.” [End Page 244] Richard Schiffman Richard Schiffman is the author of two spiritual Biographies: “Mother of All,” and “Sri Ramakrishna, A Prophet For the New Age.” His poetry has appeared or is upcoming in Sojourners, Poetry East, The Southern Poetry Review, the Potomac Review and many other print and internet journals. Copyright © 2009 The Johns Hopkins University Press

Evaluation of the activity of intraarticular hyaluronic acid in the repair of experimentally induced osteochondral defects of the stifle joint in dogs

The present study examined the results of using hyaluronic acid with autogenetic cancellous grafts in the treatment of experimentally induced osteochondral defects in the stifle joints of dogs. In this study, 10 mature dogs of different breeds, weights and of both sexes were used. General anesthesia and usual operation procedures were followed. A 10 mm deep defect was created on the femoral sulcus of the trochlea with a drill tip of 8 mm in diameter. The defects in the right and left legs were filled with autogenic cancellous grafts taken from the metaphysial region of the tibia. The left legs constituted the experimental group while the right legs served as control group. In the experimental group, 2 mg/kg intraarticular hyaluronic acid was twice administered into the stifle joint, i.e., immediately subsequent to the operation and 1 month afterwards. Parenteral antibiotics were prescribed postoperatively for ten days. Five animals were sacrificed at the third and sixth month after surgery. Macroscopic and microscopic findings obtained from each case were evaluated. On macroscopical examination, trochlear defects were determined to be incompletely filled at the third month in both control and experimental groups. On histopathologic examination, a loose fibrovascular formation in the area where the graft was applied was observed to be present in both control and experimental groups. However, in the experimental group this formation was more superficial, ossification activity was greater and trabeculous bone formation had been initiated. Macroscopical examination carried out in the sixth month determined that in the control group the defect surface did not fill up to the trochlear sulcus level. In the histopathologic examination, in control groups it was found that fibrocartilageous structures were developing in the fibrovascular space even though ossification was incomplete. The macroscopic examination showed that in the experimental group, the defect surface reached the trochlear sulcus level of defects in this month. The histopatologic examination revealed that fibrous tissue comprised a thin layer, under which ossification processes were complete and bone trabeculates fully formed. It was concluded that the usage of autogenic cancellous graft along with hyaluronic acid may be useful in the repair of large osteochondral defects.

Analysis of ultrasonic-assisted drilling of Ti6Al4V

In this study ultrasonic vibration was applied on the drilling of Ti6Al4V workpiece samples. Several parameters of ultrasonic-assisted drilling were monitored, including feed force, chip formation by means of high-speed imaging, and temperature measurement on the drill tip by means of infrared radiation thermometry. Ultrasonic assistance offered lower feed force and higher process temperatures as compared to conventional drilling. It has also shown higher force reductions and higher temperature increments when vibration amplitude was increased.

Technical Notes and Tips: A Simple Technique for Easy Removal of Titanium Elastic Nails

Titanium elastic nails are becoming increasingly popular in the treatment of paediatric long bone fractures. Once inserted, the nails are buried under the skin to reduce the risk of infection. In order to avoid tenting the skin and causing irritation, they are often cut off close to the bone before the stab incision is closed over the top. However, this may cause problems as the tip of the nail is difficult to grip when trying to remove the nail. This is facilitated by the use of a free-hand hollow reamer, from the damaged screw set. These can be matched to the size of the nail. The drill tip is inserted over the tip of the nail to clear any bony growth and to clear the tip of the nail. The hollow reamer can also be used to add a slight bend to the tip of the nail to enable easier grasping. Figure 1 Intra-operative radiographs of a paediatric radius and ulna titanium elastic nails. (A) Prior to removal of nail. (B) The hollow reamer being inserted over the tip of the nail. (C) The increase in bend on the tip can clearly be seen. (D) Easy grasping ...

Micro-Hole Drilling on Silicon Nitride Ceramics in Ethanol

Micro-hole drilling of engineering ceramics has potential for application to fuel injection nozzles and fiber spinning nozzles, etc. To date among engineering ceramics, less study has been reported on the micro-hole drilling of silicon nitride. We therefore conducted micro-hole drilling of hot-pressed silicon nitride using a chemical vapor deposition (CVD) diamond-coated tool with ethanol as the cutting fluid. As a result, the successful drilling of silicon nitride was achieved with a smooth drilled surface and sufficient accuracy of the hole size. Wear damage of the CVD coated diamond tool and drilling debris of silicon nitride were investigated using scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX). As a result, it is suggested that tribochemical reaction of silicon nitride effectively contributed to the micro-hole drilling characteristics; that is, smoother hole surface was obtained due to the polishing action of wear debris and tribochemical reaction products. The hole inlet size, varied during successive drilling process, could be explained in relation to the wear damage of the diamond-coated drill tip.

Bayonet Tip versus Drill Tip Wires: Are they Deflected Similarly by Bone?

Bayonet Tip versus Drill Tip Wires: Are they Deflected Similarly by Bone?

Technical Notes and Tips: Bayonet Tip versus Drill Tip Wires: Are they Deflected Similarly by Bone?

Technical Notes and Tips: Bayonet Tip versus Drill Tip Wires: Are they Deflected Similarly by Bone?

The wear of single flute gun drill and tool life tests

In the machining industry, the demand for higher productivity can be gained with higher cutting parameters and also by developing new tools and work materials. Drill condition monitoring assists in choosing suitable cutting parameters for specific applications, e.g. for new work material. In addition, tool wear can be measured quite eas-ily in laboratory conditions.The object of this study was to ascertain the wear-ing of the gun drill and the measured wear types that the best indicate the tool condition. In the present study, dif-ferent tool wear types were found in the gun drill. To test these wear types, gundrilling tests were carried out by us-ing two different kinds of drill geometries. The best wear types for predicting the condition of a gun drill seem to be flank wear in the drill tip (CT), the average flank wear (VB) and the mean and maximum flank wear (VB, V´B) on the outside edge.

Fluoroscopically based drilling of the femoral head in a model of adiposis

Objective: Exact drilling into the ischemic areas of necrotic lesions of the femoral head remains a challenging procedure, particularly in obese patients. This study was conducted to evaluate the precision of fluoroscopically based drilling and the associated radiation exposure in an in-vitro model of adiposis.Materials and Methods: In an in-vitro model of necrotic lesions in adiposis, 20 sawbones were drilled under the guidance of an intraoperative navigation system (VectorVision®, BrainLAB, Munich, Germany) and 20 more were drilled conventionally under fluoroscopic control only.Results: A statistically significant difference was found with respect to the distance from the drill tip to the desired mid-point of the lesion, with a mean distance of 0.56 mm for the navigated group and 1.15 mm for the control group. Furthermore, a significant difference was found in the number of drilling corrections required, as well as the radiation exposure time: The navigated group required a mean of 0.35 second drillings or corrections of the drilling direction, compared to 2.45 for the control group, and the duration of radiation exposure was less than 1 second for the navigated group and 3.85 seconds for the control group.Conclusions: Drilling guided by the VectorVision® navigation system shows high precision, even under difficult circumstances such as those encountered in adiposis, with a marked reduction in the duration of radiation exposure.

A309 医療用ドリル先端の形状最適化(軟・硬組織のバイオメカニクス)

A309 医療用ドリル先端の形状最適化(軟・硬組織のバイオメカニクス)