Air Drill Research Articles

Reconstruction of the Laminar Roof With Miniplates for a Posterior Approach in Intraspinal Surgery: Technical Considerations and Critical Evaluation of Follow-up Results

A retrospective clinical follow-up study of patients who underwent intraspinal surgery with reconstruction of the laminar roof using titanium miniplates. To evaluate the surgical technique of laminar roof reconstruction and to analyze follow-up results with regard to bony healing of the laminae and the development of spinal deformities. The reconstruction of the laminar roof was initially proposed to overcome adverse effects associated with extensive cervical laminectomy in children. Because technical evolutions such as the use of an air drill and miniplates have facilitated the procedure, it has gained more widespread use as a posterior approach for intraspinal surgery. Thus, with a sufficient number of patients treated and a longer period of follow up, it seems reasonable to critically evaluate the technique and its suitability as a standard approach for intraspinal surgery. The surgical procedures of 79 patient who underwent intraspinal surgery with osteotomy and reconstruction of a total of 323 spinal laminae using an air drill and miniplates were analyzed. In 59 patients, data of a complete clinical and radiologic follow-up examination were evaluated. Plain radiographs and computed tomography scans were analyzed for bony healing of the laminae and spinal alignment. Minor complications such as cerebrospinal fluid collections and disturbed wound healing occurred within normal ranges. The was no case of dural, nerve root, or spinal cord injury attributable to laminotomy or laminar reconstruction. Eight (14.3%) patients complained of moderate to severe local pain at the time of follow-up examination and 8 patients stated impaired mobility of their spine at the surgical site. Bony healing was confirmed radiologically in 86.1% of the laminae. In 12 patients, a preexisting spinal deformity worsened after surgery and five patients demonstrated a new spinal malalignment. No patient required additional surgery because of progressive spinal deformity. Intramedullary location of the lesion and cervical location of surgery were significantly associated with the development of spinal malalignment, whereas incomplete bony healing of the laminae was not. The reconstruction of the laminar roof using the technique described is safe, well suitable to serve as a standard posterior approach to intraspinal pathologies, and offers distinct advantages over laminectomy. However, some patients, particularly those with intramedullary cervical lesions, could develop spinal malalignment after surgery despite reconstruction of the laminar roof and sufficient bony healing of the laminae.

“Air Drill” for Submerged Massive Coral Drilling

The handy and inexpensive drilling method using SCUBA tanks was developed specifically for submerged massive coral drilling, which is an effective technique for its annual bands research. All required equipment for 10 m drilling can be packed up into two suitcases, except for the SCUBA tank. This carries the advantage that researchers can bring full equipment in carry-on luggage and can obtain samples quickly at inconvenient or inaccessible locations. A field experiment was successfully operated to obtain 1 m coral cores within 1 hour at a depth of 17 m below sea level.

Compressed-air power tools in orthopaedic surgery: exhaust air is a potential source of contamination.

To determine if the exhaust from surgical compressed-air power tools contains bacteria and if the exhaust leads to contamination of sterile surfaces. Bacteriologic study of orthopaedic power tools. Level I trauma center operative theater. None. Part I. Exhaust from two sterile compact air drills was sampled directly at the exhaust port. Part II. Exhaust from the drills was directed at sterile agar plates from varying distances. The agar plates represented sterile surfaces within the operative field. Part III. Control cultures. A battery-powered drill was operated over open agar plates in similar fashion as the compressed-air drills. Agar plates left open in the operative theater served as controls to rule out atmospheric contamination. Random cultures were taken from agar plates, gloves, drills, and hoses. Incidence of positive cultures. In Part I, all filters from both compressed-air drill exhausts were culture negative ( = 0.008). In Part II, the incidence of positive cultures for air drills number one and number two was 73% and 82%, respectively. The most commonly encountered organisms were, coagulase-negative Staphylococcus, and Micrococcus species. All control cultures from agar plates, battery-powered drill, gloves, and hoses were negative ( < 0.01). Exhaust from compressed-air power tools in orthopaedic surgery may contribute to the dissemination of bacteria onto the surgical field. We do not recommend the use of compressed-air power tools that do not have a contained exhaust.

Penetrating injury of the brain by the burr of a high-speed air drill during craniotomy: case report

The most critical complications of craniotomy are caused by the plunging of a skull drill, and there have been no reports of penetrating brain injury caused by the broken burr of a high-speed air drill during craniotomy. Left orbitofrontal craniotomy was performed to clip two aneurysms in a 44 year old man. Wh ile cutting the lateral orbital rim with the burr of an Ultra Power™ surgical drill system, the burr broke off and penetrated the frontal lobe down to the falx cerebri. There were no discernible contusion or haemorrhage in the brain. The accident occurre d because a long burr for the angled attachment of a Surgairtome™ was erroneously attached to the angled attachment of an UltraPower™ surgical drill. The mismatch between the steel strength and torque of the two burrs designed for different drill systems seemed responsible for breakage of the burr. We learned a valuable lesson from this failure: that all new instruments, including high-speed air drills, must be studied carefully so that staff become thoroughly familiar with their handling.

Management and outcome of choanal atresia correction

Objectives: Outcome analyses of factors that may either maximize success or predict a better outcome following choanal atresia correction. Methods: A retrospective review of children undergoing choanal atresia correction at Great Ormond Street Hospital for Children, London between January 1990 and April 1998. Children with unilateral or bilateral choanal atresia were studied. In all cases, correction was by a transnasal approach under endoscopic control. A 120° Hopkins rod telescope was used to visualize the atretic plate from the nasopharynx. Straight urethral sounds were used to perforate the plate followed by use of an air drill to remove the bony component. Portex endotracheal tubes were subsequently inserted as nasal stents. Results: Sixty-five children (19 M, 46 F: age range 1 day to 17 years) presented with choanal atresia and the outcomes for 46 were included in the study. Twenty-six patients (40%) had other major anomalies. In children with unilateral atresia neither duration of stenting nor presence of facial anomalies had an impact on outcome. Of those children with bilateral choanal atresia and associated facial anomalies ( n=9), 56% were asymptomatic following correction. In children with isolated bilateral choanal atresia ( n=19), 74% were asymptomatic following correction; 29% ( n=7) of infants who weighed ≤2.3 kg were asymptomatic as compared to 81% of infants that weighed >2.3 kg ( n=21). Patients with a stent size of >3.5 mm ( n=6) had an 83% chance of a good outcome. Those patients stented with a tube ≤3.5 mm ( n=22) had only a 64% success rate. None of the patients who were stented for at least 12 weeks remained symptomatic. Conclusions: Neonates with bilateral choanal atresia who were stented for at least 12 weeks with the largest Portex tube that comfortably passed through the anterior nares had the best outcome. If they had either associated anomalies or low weight at surgery, they were less likely to become asymptomatic. For patients with unilateral choanal atresia, neither the presence of facial anomalies nor stent duration had an impact on outcome.

New nerve root holders during spinal decompression

New nerve root holders have been developed to protect nerve roots and dural sac during spinal bony decompression, especially if it takes place in the region of the lateral recess by means of a high speed air drill. Their design derives from the adaptation of common brain spatulas to the anatomy of the lumbar nerve roots. Their use, together with the contralateral approach (the operative microscopical visualization of the lesion from the side of the patient opposite to it), represents an available method to protect nervous structures from operative injuries without superfluous retraction of them. The contralateral approach permits the visualization of the deepest angles of the lateral recess without withdrawal of lateral parts of the articular facets, important for vertebral stability. In order to achieve satisfactory results without vertebral instrumental stabilization, the holder assists in the drilling procedure to enlarge the periradicular space covering the nerve root and helps avoid undue dural tearing or radicular damage. [Neurol Res 1999; 21: 79–83]

Fixation of fractures of the midshaft of the clavicle with Kirschner wires. Results in 108 patients.

We treated 110 fractures of the middle third of the clavicle in 108 patients aged between 14 and 66 years, by fixation with 2 mm Kirschner wires. The wire was introduced, using an air drill and a telescoping guide, from the medial into the lateral fragment. The medial end of the wire which perforated the anterior cortex of the medial fragment was bent backwards to prevent migration into the lung or mediastinum. In cases of nonunion and acute fracture in which a bone gap was present, bone graft was laid around the fracture site after internal fixation. All the fractures united. No wires broke but in three patients one migrated before union was achieved. Twenty-one patients failed to return for removal of the wire; nine of them had radiological evidence of union before they were lost to follow-up.

Fixation of fractures of the midshaft of the clavicle with Kirschner wires

We treated 110 fractures of the middle third of the clavicle in 108 patients aged between 14 and 66 years, by fixation with 2 mm Kirschner wires. The wire was introduced, using an air drill and a telescoping guide, from the medial into the lateral fragment. The medial end of the wire which perforated the anterior cortex of the medial fragment was bent backwards to prevent migration into the lung or mediastinum. In cases of nonunion and acute fracture in which a bone gap was present, bone graft was laid around the fracture site after internal fixation. All the fractures united. No wires broke but in three patients one migrated before union was achieved. Twenty-one patients failed to return for removal of the wire; nine of them had radiological evidence of union before they were lost to follow-up.

Irrigation system equipped on a high-speed air drill--technical note.

An irrigation system which can easily be applied to the conventional high-speed air drill was developed to allow simultaneous irrigation during micro-drilling. The irrigation system is constructed with a tube of 0.8 mm outer diameter and supporting rings. Irrigation is entirely coordinated with drilling by a single foot switch. The tube of the system ejects normal saline intermittently toward the cutter bar tip. Use of this system in skull base surgery showed that effective irrigation and a clean operative field was achieved even in a narrow space under the operating microscope, saline is ejected exactly on the point of drilling and over-heating does not occur so that heat-related damage to the local nerves and blood vessels is avoided. The system can easily be applied to any type of high-speed air drill by using supporting rings of the correct size. This irrigation system is particularly useful in microneurosurgery using the high-speed air drill.

Transoral resection of the odontoid

The odontoid process is located in a critical area of the spine and is part of a complex structure, the atlanto-axial junction. This C1-2 junction allows for a great deal of cervical mobility in planes of rotation, flexion, and extension. Lesions of the odontoid process and associated ligaments can result in compression of the brainstem, cervicomedullary junction, and spinal cord. Resultant symptoms include weakness, spasticity, lower cranial nerve palsies, including difficulty in swallowing, phonation disorders, Bell's cruciate paralysis, and breathing disorders. Patients with lesions in this area require a thorough neurological and otolaryngologic evaluation. The reducibility of the lesion needs to be determined as an operative prerequisite. Extensive multimodality radiographic imaging may be required pre-, intra-, and postoperatively. Transoral surgery of the odontoid is technically demanding and requires a thorough understanding of the relevant anatomy and pathology. Perioperative and intraoperative adjuncts such as the operating microscope, fluoroscopy, image guidance instruments, high-speed air drills, and somatosensory-evoked monitoring help to expedite the surgery and reduce the risk of complications. Postoperative instability must be assessed and treated. A team consisting of a spine surgeon, anesthesiologists, otolaryngologists, and critical care physicians skilled in managing patients with similar conditions may provide the best possible outcome for these patients. This article reviews the pertinent patient evaluation, imaging studies, surgical indications and techniques, and post-operative management.

Surgical removal of a cavernous sinus chondroma

Chondromas at the base of the skull are most commonly found in the parasellar and sellar regions, and present varying degrees of involvement of the cavernous sinus. However, those confined mainly to the cavernous sinus are rare, and only a few reports show detailed radiological and surgical findings. This 40-year-old woman experienced sudden right orbital pain followed by right third and sixth cranial nerve palsies. Computerized tomography scan and magnetic resonance image depicted a well-circumscribed mass in the right cavernous sinus. A frontotemporal craniotomy with orbito-zygomatic osteotomy was used to approach this lesion intradurally. We drilled away the anterior clinoid process using a high-speed air drill extradurally, exposed the intrapetrous carotid artery, and dissected the right sylvian fissure from the distal, fully exposing the surface of the right cavernous sinus. The soft and grayish tumor was easily removed using sucker and tumor forceps; the venous bleeding from the sinus itself was easily controlled. The tumor was successfully removed via a superior triangle. Intradural invasion of the tumor and heavy venous bleeding from the sinus were not observed. Histologically, the mass was diagnosed as a mature chondroma. The tumor was presumed to originate from the right posterior clinoid process. The lesion was totally removed, and postoperative right ophthalmoplegia had fully disappeared within 6 months after surgery. Successful surgical attack of lesions in the cavernous sinus requires comprehensive and precise knowledge of the microsurgical anatomy and neuroradiology.

Die Mechanisierung des Ruhrbergbaus, 1890–1930 by Uwe Burghardt

TECHNOLOGY AND CULTURE Book Reviews 519 straightforward assessment gains nothing by being wrapped in Lotman ’s semiotics, and the author would have been better served to avoid the theoretical musings entirely. Despite these difficulties, the book has some significant strengths. It is extremelywell researched, and the author has drawn his sources from a variety of archival materials in the Russian State Historical Archive, including the files for the Russian Technical Society and the State Council. In addition, the prose flows very smoothly and the chapter organization is both logical and effective. However, the emphasis falls on the bureaucratic politics of patent reform rather than on the history of technology, and the most receptive audience for the book will be those with an interest in Tsarist institutional history. As a result, the book’s appeal is limited. Jonathan Grant Dr. Grant is assistant professor of modern Russian history at Florida State Univer­ sity. He is completing a book manuscript that deals with Russian business history and technology transfer in late Imperial Russia. Die Mechanisierung des Ruhrbergbaus, 1890-1930. By Uwe Burghardt. Munich: C. H. Beck, 1995. Pp. 437; illustrations, tables, graphs, notes, bibliography, glossary, index. DM 34.00 (paper). Upon undertaking this major overview of the mechanization of the Ruhr mining industry from 1890 to 1930, Uwe Burghardt could perhaps have been given the traditional miner’s greeting (particu­ larly when descending into the pit) of Gluck auf! (good luck!). Yet Burghardt is quite successful in drawing from a large contemporary literature and archival sources to argue that the rationalization of Ruhr mining had its roots in the interplay of economic, technologi­ cal, and wartime factors in the two and a half decades before 1918. Rationalization, at least in the Ruhr mining area, was thus notjust a business response to the threats to profitability from a high-wage union state and to the financial opportunities opened up by infla­ tion in the early Weimar period, as many historians and economists have concluded. The study’s major contribution, therefore, is as a synthesis that relates political and social factors to the broad dynam­ ics of technoeconomic change. German mining companies changed their technological system in the very late 19th century after expanded production led to in­ creased factor costs in transportation, shaft construction, and venti­ lation and after the Rhenish-Westphalian Coal Syndicate stabilized prices. They focused on increasing production from each pit by abandoning pillar and wall as well as short side cut methods and by adopting longwall mining, which required above all an efficient conveyor system (shaking chute). The British and Americans had 520 Book Reviews TECHNOLOGY AND CULTURE used similar systems, which needed less labor and were suitable to the more level coal seams of the newly developed northern Ruhr region. Rather unanticipated were other advantages: the system de­ manded much larger, tight-knit teams that forced workers into task work, accelerated the work pace, decreased the number ofworksites and the need for ventilation, and reduced cave-in accidents because of less work space that was braced. After the companies increased conveyor and cable transportation in 1905-11, they began to focus on production efficiencies promised by the pneumatic drill. Burghardt’s analysis of mining in World War I is the most original aspect of this work. The war ended the first phase of mechanization with its increased demand for coal but shortages of labor and ma­ chinery. More important for the future was the war’s forced concen­ tration on richer seams, the abandonment of older mine areas and their subsequent loss to geologic forces, and the postwar necessity to develop deeper (and more expensive) shafts and seams. Building on these technological and economic precedents, the mine managers and owners launched a new mechanization drive in the very early 1920s by constructing power plants that served com­ pressed air (drills, locomotives) or electrical needs. With higher costs for new shafts and development, the companies focused their efforts on ever smaller, concentrated mined areas to reduce costs. Another legacy of the past was that two-thirds of the plant managers who replaced men killed in the war had obtained their mining train­ ing in the prewar mechanization phase and...

Cosmetic reconstruction after mastoidectomy for the transpetrosal-presigmoid approach: technical note.

We describe the technique of cosmetic reconstruction after mastoidectomy in the transpetrosal-presigmoid approach for petroclival lesions. This technique involves raising a single temporo-occipital bone flap and cosmetic mastoidectomy, removing the mastoid bone fragments (by means of a rongeur instead of an air drill) for later reconstruction. Replacement of the bone fragments mixed with fibrin glue enables tamponade against the dura to be achieved without a fat graft. Computed tomographic scans and plain cranial films taken a few years later showed successful reconstruction of the mastoid bone with a good appearance of the retromastoid area in seven patients who underwent this procedure. The only complication was infection in one patient from cerebrospinal fluid leakage from the wound. We have developed a simple and easy technique of cosmetic reconstruction after the transpetrosal-presigmoid approach.

Advances of geophysical prospecting for petroleum in marine carbonate areas of the upper Yangtze region, southern China

In the marine carbonate area of the upper Yangtze region, southern China, including parts of Guizhou and Sichuan Provinces, complex subsurface structures and undulating surface terrain exist because of multiple tectonic events. Various geophysical prospecting methods have been conducted in local areas in an attempt to map these structures. In the Guizhou Plateau, a carbonate‐exposed area, crooked seismic lines were acquired using vibrators as the main source, supplemented with dynamite. In Sichuan Province, a mountainous area, regional seismic profiles, wide‐line profiling, and 3-D seismic surveys were conducted. These were accomplished with portable air drills and human transport. Data processing techniques were designed to improve data quality in the presence of noise and to image complex structures. In central Sichuan Province, high‐resolution and converted‐wave seismic surveys were carried out for imaging complex structures and for collecting lithologic parameters. These methods have enabled us to get effective information from complex structural, mountainous, and carbonate‐exposed hilly areas in the upper Yangtze region of southern China. These collective efforts have produced a database appropriate for sedimentology, tectonic, and prospective area evaluation studies.

A technique for prevention of donor site pain associated with harvesting iliac bone grafts

Patients who have undergone anterior cervical spine fusion with an iliac bone graft frequently experience donor site pain after surgery. We found that an effective technique to avoid donor site pain is to round off the corners of the iliac crest with an air drill after harvesting the graft.

Vertebral artery injury during anterior decompression of the cervical spine. A retrospective review of ten patients

Ten patients who suffered iatrogenic injury to a vertebral artery during anterior cervical decompression were reviewed to assess the mechanisms of injury, their operative management, and the subsequent outcome. All had been undergoing a partial vertebral body resection for spondylitic radiculopathy or myelopathy (4), tumour (2), ossification of the posterior longitudinal ligament (1), nonunion of a fracture (2), or osteomyelitis (1). The use of an air drill had been responsible for most injuries. The final control of haemorrhage had been by tamponade (3), direct exposure and electrocoagulation (1), transosseous suture (2), open suture (1), or open placement of a haemostatic clip (3). Five patients had postoperative neurological deficits, but most of them resolved. We found direct arterial exposure and control to be safe, quick and reliable. Careful use of the air drill, particularly in pathologically weakened bone, as in infection or tumour, is essential. Arterial injury is best avoided by a thorough knowledge of the anatomical relationships of the artery, the spinal canal, and the vertebral body.

Posterior fossa craniotomy for lesions of the cerebellopontine angle

A safe technique is described for performing a lateral posterior fossa craniotomy to gain access to the cerebellopontine angle. The method makes use of currently available high-speed air drills. Thus, it is possible to replace the removed bone at the conclusion of the procedure and to re-establish normal tissue planes while providing rigid protection to the posterior fossa.

Clipping of an aneurysm 20 years after encasement with methyl methacrylate

A variety of agents have been used to coat aneurysms as an alternative to clipping. These agents were employed more frequently prior to the routine use of the operating microscope and the presently available variety of aneurysm clips. One such coating agent is methyl methacrylate. This report describes a patient with an anterior communicating aneurysm that rebled 20 years after being encased in methyl methacrylate. At operation, the pulsating aneurysm had eroded the adjacent layer of methyl methacrylate, creating a small intervening space. This space allowed removal under the microscope (with a high-speed air drill and a diamond bit) of the methyl methacrylate from the anterior cerebral arteries and aneurysm, exposing it for definitive clip placement. The feasibility of clipping encased aneurysms is discussed.

Inserting the distal screws in a locked femoral nail

We describe a simple method of inserting the distal screws in a locked femoral nail. The method requires no aiming device and no assistant. The only equipment needed is a 3 mm Kirschner wire and an air drill.

Continuous Electrical Stimulation as a Helpful Adjunct During Intraoperative Facial Nerve Monitoring

Routine intraoperative monitoring of facial function has been used since 1985. An adaptor has been developed for continuous stimulation (SACS) to be used with the new WR-S8, Monitor/Stimulation The SACS allows the microsurgical instruments and air drills to be electrified and to function as probe tips during surgical dissection. The new WR-S8 Monitor/Stimulator has an ultrasensitive strain gauge that detects facial movement before it is palpable. The remote probe allows an assistant to adjust the current easily. The routine use of facial nerve monitoring with SACS has decreased surgical time, has helped prevent iatrogenic injuries, and has improved our ability to save the facial nerve during otologic and neuro-otologic surgery.