High-speed Air Drill Research Articles

Usefulness of a high-speed surgical air drill in pubectomy during delayed anastomotic urethroplasty for pelvic fracture urethral injury.

Pubectomy is an ancillary technique used to increase exposure of the disrupted urethra and reduce anastomotic tension, which can be difficult for inexperienced surgeons. The objective of the present study was to illustrate the use of an air drill enabling delicate and precise bone resection in pubectomy for delayed anastomotic urethroplasty for pelvic fracture urethral injury. Between 2009 and 2019, 88 male patients underwent delayed anastomotic urethroplasty with pubectomy for pelvic fracture urethral injury. A total of 73 procedures used a high-speed surgical air drill (HiLAN HS; Aesculap, Tuttlingen, Germany) equipped with a short-hand piece. Operative time and blood loss in the air drill patient group (group1) were compared with that of patients who underwent pubectomy using a rongeur and/or gouge (group2, n=15). In 65 group1 patients, urethroplasty was carried out using the perineal approach, with partial inferior pubectomy. Eight group1 patients, whose proximal urethral end was displaced upward superior to the upper edge of pubis, underwent urethroplasty using the perineal and abdominal approach, with a superior partial pubectomy and supracrural urethral rerouting. No difficulty was encountered using the air drill in any of the cases. There was no significant difference in median operative time between the groups (group1 256min vs group2 228min; P=0.31). The median blood loss in group1 was significantly lower than group2 (149mL vs 453mL; P<0.0001). Surgical air drills might facilitate pubectomy in patients undergoing delayed anastomotic urethroplasty for pelvic fracture urethral injury. This tool offers the advantage of a delicate bone resection with reduced blood loss.

V06-09 USEFULNESS OF HIGH-SPEED SURGICAL AIR DRILL IN PARTIAL PUBECTOMY DURING DELAYED ANASTOMOTIC URETHROPLASTY FOR PELVIC FRACTURE URETHRAL INJURY

You have accessJournal of UrologyLower-Tract Reconstruction I: Sling/ Sphincter/ Penile & Urethral Reconstruction (V06)1 Apr 2020V06-09 USEFULNESS OF HIGH-SPEED SURGICAL AIR DRILL IN PARTIAL PUBECTOMY DURING DELAYED ANASTOMOTIC URETHROPLASTY FOR PELVIC FRACTURE URETHRAL INJURY Akio Horiguchi*, Kenichiro Ojima, Masayuki Shinchi, Yusuke Hirano, Koetsu Hamamoto, Keiichi Lto, Tomohiko Asano, and Ryuichi Azuma Akio Horiguchi*Akio Horiguchi* More articles by this author , Kenichiro OjimaKenichiro Ojima More articles by this author , Masayuki ShinchiMasayuki Shinchi More articles by this author , Yusuke HiranoYusuke Hirano More articles by this author , Koetsu HamamotoKoetsu Hamamoto More articles by this author , Keiichi LtoKeiichi Lto More articles by this author , Tomohiko AsanoTomohiko Asano More articles by this author , and Ryuichi AzumaRyuichi Azuma More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000885.09AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Partial pubectomy is an ancillary technique used in delayed anastomotic urethroplasty for pelvic fracture urethral injury (PFUI). This procedure widens the exposure of the disrupted urethra, and reduces anastomotic tension by shortening the urethral gap. Use of a less traumatic device for a pubectomy is optimal to avoid excessive bleeding from the venous plexus, located just behind the pubic symphysis. Surgical air drills enable delicate, precise bone resection and are widely used in spinal surgery. This video highlights our experience using an air drill in partial pubectomies for PFUI. METHODS: Between 2009 and 2019, 88 male patients underwent delayed anastomotic urethroplasty, with partial pubectomy for PFUI; performed by one surgeon (AH). Seventy-Three (83%) procedures used a high-speed surgical air drill (HiLAN HS®, Aesculap) equipped with a short, light hand piece. Operative time and blood loss in the air drill patient group (group 1) were compared with those patients who underwent pubectomy using rongeur and/or gouge in our early experience (group 2, n = 15, 17%). RESULTS: The median age was 37 years (IQR 23 to 55 years), the median urethral gap length on urethrogram was 25 mm (IQR 19 to 35 mm). In 65 of 73 (89%) patients, urethroplasty was performed via a perineal approach, with inferior partial pubectomy. After mobilizing the bulbar urethra and retracting split corporal bodies laterally, the inferior pubis was scraped by the drill using diamond burrs. In 8 (11%) patients whose proximal urethral end was displaced upward, superior to the upper border of pubic symphysis, urethroplasty was performed via a perineal and abdominal approach, with a superior partial pubectomy and supracrural urethral rerouting. After mobilizing the bulbar urethra via the perineal approach and making a lower abdominal incision extending over the pubic symphysis, a bony channel at the superior surface of the pubis was created by the drill. No difficulty was encountered in using the air drill in any of the cases. The surface of the pubic bone scraped by the air drill was flat; no sharp bony spikes remained. There was no significant difference in median operative time between the groups (256 minutes in group 1 vs. 228 minutes in group 2, p = 0.31). The median blood loss in group 1 (149 ml) was significantly smaller than that in group 2 (453 ml, p < 0.0001). CONCLUSIONS: Surgical air drills may be suitable for pubectomies even in amateur hands, and offer the advantage of delicate bone resection with reduced blood loss. Source of Funding: None © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e558-e558 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Akio Horiguchi* More articles by this author Kenichiro Ojima More articles by this author Masayuki Shinchi More articles by this author Yusuke Hirano More articles by this author Koetsu Hamamoto More articles by this author Keiichi Lto More articles by this author Tomohiko Asano More articles by this author Ryuichi Azuma More articles by this author Expand All Advertisement PDF downloadLoading ...

Simple New Screw Insertion Technique without Extraction for Broken Pedicle Screws.

Spinal transpedicular screw fixation is widely performed. Broken pedicle screw rates range from 3%-7.1%. Several techniques have been described for extraction of broken pedicle screws. However, most of these techniques require special instruments. We describe a simple, modified technique for management of broken pedicle screws without extraction. No special instruments or drilling in an adjacent pedicle are required. We used a high-speed air drill with a round burr. With C-arm fluoroscopy guidance, the distal fragment of a broken pedicle screw was palpated using free-hand technique through the screw entry hole. A high-speed air drill with a round burr (not a diamond burr) was inserted through the hole. Drilling began slowly and continued until enough space was obtained for new screw insertion. Using this space, we performed new pedicle screw fixation medially alongside the distal fragment of the broken pedicle screw. We performed the insertion with a previously used entry hole and pathway in the pedicle. The same size pedicle screw was used. Three patients were treated with this modified technique. New screw insertion was successful in all cases after partial drilling of the distal broken pedicle screw fragment. There were no complications, such as screw loosening, dural tears, or root injury. We describe a simple, modified technique for management of broken pedicle screws without extraction. This technique is recommended in patients who require insertion of a new screw.

Unilateral, multilevel, interlaminar fenestration in the removal of a multisegment cervical intramedullary ependymoma

Background contextLaminectomy is the traditional approach to intramedullary ependymomas and may lead to spinal instability and spinal deformities. Hemilaminectomy and laminoplasty have been developed to preserve the spinal stability and have been found to be effective. Unilateral, multilevel, interlaminar fenestration is another approach that may have more advantages in preserving the spinal stability; however, it has rarely been used by now. PurposeUnilateral, multilevel, interlaminar fenestration was often used in the surgical treatment of degenerative lumbar stenosis; however, it was rarely used for tumors. The aim of this study was to discuss the characteristics and advantages of its use for a multisegment intramedullary ependymoma. Study designCase report and literature review. MethodsThe 22-year-old man suffered from muscular atrophy of the left hand and the right hand for a period of 1.5 years and 3 months, respectively, and the cervical magnetic resonance imaging revealed an intramedullary mass of C4–C7. A right, unilateral, multilevel, interlaminar fenestration of the C3–C7 was performed with the help of high-speed air drills, and a midline myelotomy was made under microscope. The tumor was removed totally using piecemeal resection. ResultsThe magnetic resonance imaging, obtained 1 year after the operation, revealed that there were no residual mass lesion and no spinal instability, and the patient acquired an excellent functional outcome. So, this technique proved to be safe and easy in this case. ConclusionsUnilateral, multilevel, interlaminar fenestration allows good access to a long intraspinal segment, protects the structures essential to spinal stability as much as possible, preserves the spinal stability, and results in no additional injury to the spinal cord. It may be applicable to many other kinds of intraspinal tumors.

Cervicofacial emphysema and pneumomediastinum after a high-speed air drill endodontic treatment procedure

Cervicofacial subcutaneous emphysema is defined as the abnormal introduction of air in the subcutaneous tissues of the head and neck. It is mainly caused by trauma, head and neck surgery, general anesthesia, and coughing or habitual performance of Valsalva maneuver. The occurrence of subcutaneous emphysema after dental treatment is rare, and diffusion of gas into the mediastinum is much rarer, especially when the procedure is a nonsurgical treatment. The most common dental cause of pneumomediastinum is the introduction of air via the air turbine handpiece during surgical extraction of an impacted tooth. Only 6 cases of pneumomediastinum after endodontic treatment have been reported between 1960 and 2008. Pneumothorax is defined clinically as an “accumulation of air or gas between the parietal and visceral pleurae,” and although it is often not a medical emergency, it can result in respiratory distress, tension pneumothorax, shock, circulatory collapse, and even death. Although there are many possible causes of dyspnea during a dental procedure, 1 rare complication is pneumothorax. Although specific closed turbine systems are available for oral surgical procedures, these drills may be used in exodontia to section teeth and facilitate tooth extraction. We report a case of cervical subcutaneous emphysema and pneumomediastinum occurring after an endodontic treatment of right first molar using an air-tribune drill. We present here in a case of massive pneumomediastinum and cervicofacial subcutaneous emphysema that occurred after opening the access cavity for endodontic treatment. We describe its etiologies and guidelines for its prevention during nonsurgical endodontic treatment.

Endoscopy-assisted removal of periorbital inclusion cysts in children

Surgical treatment for periorbital inclusion cysts typically involves a brow, pterional, or partial bicoronal scalp incision for sufficient exposure. The authors have recently employed an endoscopy-assisted technique as an alternative approach intended to minimize the length of the skin incision and avoid scarring in the brow. Children having typical clinical findings of a dermoid cyst located on the hairless forehead were selected to undergo endoscopy-assisted cyst removal. For suspected intradiploic lesions, MR imaging was used to assess osseous involvement. After induction of general anesthesia, a 1-2-cm curvilinear incision was made posterior to the hairline. A 30°-angled endoscope (4 mm) was then used for dissection in the subgaleal compartment. Subgaleal dissection was followed by a circumferential periosteal incision in which the authors used an angled needle-tip unipolar cautery. For lesions within the diploe, a high-speed air drill was used to expose the lesion. Complete removal was accomplished with curettage of either the skull or dural surface. Eight patients (5-33 months of age) underwent outpatient endoscopic resection. Seven cysts were extracranial, and 1 cyst extended through the inner table. In all patients complete excision of the cyst was achieved. There was negligible blood loss, no dural violation, and no postoperative infection. There have been no recurrences at a mean follow-up of 15 months. Endoscopy-assisted resection of inclusion cysts of the scalp and calvaria is a safe and effective surgical approach. The technique results in negligible incisions with less apparent scarring compared with previously described incisions. This limited-access technique does not appear to be associated with a higher incidence of cyst recurrence.

Clinical outcomes of microendoscopic decompression surgery for cervical myelopathy

Retrospective study on the results of microendoscopic decompression surgery for the treatment of cervical myelopathy. The purpose of this study was to describe the microendoscopic laminoplasty (MEL) technique as the surgical method in the treatment of cervical myelopathy, and to document the clinical outcomes for MEL surgery. Endoscopic surgery poses several challenges for the aspiring endoscopic surgeons, the most critical of which is mastering hand-eye coordination. With training in live animal and cadaver surgery, the technical progress has reduced the problem of morbidity following surgery. The authors have performed microendoscopic decompression surgery on more than 2,000 patients for lumbar spinal canal stenosis. Fifty-one patients underwent the posterior decompression surgery using microendoscopy for cervical myelopathy at authors' institute. The average age was 62.9 years. The criteria for exclusion were cervical myelopathy with tumor, trauma, severe ossification of posterior longitudinal ligament, rheumatoid arthritis, pyogenic spondylitises, destructive spondylo-arthropathies, and other combined spinal lesions. The items evaluated were neurological evaluation, recovery rates; these were calculated following examination using the Hirabayashi's method with the criteria proposed by the Japanese Orthopaedic Association scoring system (JOA score). The mean follow-up period was 20.3 months. The average of JOA score was 10.1 points at the initial examination and 13.6 points at the final follow-up. The average recovery rate was 52.5%. The recovery rate according to surgical levels was, respectively, 56.5% in one level, 46.3% in two levels and 54.1% in more than three levels. The complications were as follows: one patient sustained a pin-hole-like dura mater injury inflicted by a high-speed air-drill during surgery, one patient developed an epidural hematoma 3 days after surgery, and two patients had the C5 nerve root palsy after surgery. The epidural hematoma was removed by the microendoscopy. All two C5 palsy improved with conservative therapy, such as a neck collar. These four patients on complications have returned to work at the final follow-up. This observation suggests that the clinical outcomes of microendoscopic surgery for cervical myelopathy were excellent or showed good results. This minimally invasive technique would be helpful in choosing a surgical method for cervical myelopathy.

Unilateral partial hemilaminectomy in the removal of a large spinal ependymoma

Background context Although the hemilaminectomy technique is known to neurosurgeons performing spinal surgery, laminectomy traditionally has been used during spinal canal surgery for extirpation of spinal cord tumors. Purpose Although the technique of unilateral partial hemilaminectomy is familiar in its various permutations to surgeons, its application in the spinal tumor surgery has been rarely reported. The aim of this study was to review the literature about the management of spinal cord ependymomas and to discuss the major controversies in treatment. Study design Case report. Patient sample A 52-year-old man. Methods The 52-year-old man complained of backache and leg pain bilaterally, dominant on the left side. Spinal magnetic resonance images revealed an intradural mass at the T12–L2 level. A left unilateral hemilaminectomy of the T12–L1 and L2 was performed with the help of high-speed air drills under microscopic magnification and a midline incision was made on the dura. The tumor was totally removed. Results By using microsurgical techniques and with the help of high-speed drills, a unilateral approach to the intramedullary tumors proved itself to be a safe and easy method in this case. It protected the posterior supporting elements and also permitted the surgeon to manipulate the intradural contralateral side easily. The only difficulty during the operation was the suturing of the dural sac. Conclusions This case report emphasizes the need to consider the hemilaminectomy technique in spinal tumor surgery.

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.

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]

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.

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.

Removal of a large asymptomatic calcified chronic subdural hematoma

An asymptomatic case of a large calcified chronic subdural hematoma was examined. The calcified mass was nearly totally removed at operation using a high-speed air drill. Immediately after the operation signs of brain compression seen in computed tomography scanning were somewhat relieved. However, at follow-up after 3 months, the shift was resumed and the calcification reap-peared 10 months after the operation.

Transorbital Intracranial Penetration by Chopstick

A 38-year-old female was struck in the eye with a wooden chopstick during a quarrel with her husband. The chopstick penetrated and lodged in her brain. Neurological examination revealed left hemiparesis and hemihypesthesia and right cranial nerve palsy of the 2nd, 3rd, 4th, and 6th nerves and the 1st branch of the 5th nerve. Computed tomography revealed a narrow, straight, low-density extending from the right orbit via the right parasellar region to the pons. A right carotid angiogram revealed a traumatic low flow/low pressure carotid-cavernous fistula. Magnetic resonance imaging yielded a low signal intensity image passing through the orbit and extending to the pons. A craniotomy was performed by the pterional approach. So that the pons and neighboring structures would not be damaged, the chopstick was first gently divided into two portions at the prepontine cistern by a high-speed airdrill and then resected piece by piece. The intraorbital portion of the chopstick was lodged firmly in the bony structure of the superior orbital fissure and could not be removed. The authors discuss the characteristics of transorbital intracranial foreign bodies, with particular emphasis on diagnostic procedures and the indications for and timing of their surgical removal.

Temporal bone resection. Review of 100 cases.

One hundred cases of temporal bone resection for cancer of the ear were reviewed retrospectively, allowing for a survival five-year follow-up period in all cases. Operative technique previously described varied from case to case but essentially involved subtotal resection of the mastoid, petrous pyramid and squamosa of the temporal bone, temporomandibular joint, base of zygoma, and attached adjacent soft tissues. The procedure sacrifices the facial nerve and hearing in the involved ear. Preoperative radiation or a sandwich technique of preoperative and postoperative radiation was used. Many complications were encountered, but with hypotensive agents, high-speed air drills, and adequate coverage of the defect, the death rate was reduced from 10% in 1954 to 5% in recent years. The overall five-year cure rate was 27%, with a 25% cure rate for squamous carcinoma.

Trephine lung biopsy with a high-speed air drill: Results of 50 biopsies in 47 patients

Trephine lung biopsy with a high-speed air drill: Results of 50 biopsies in 47 patients

Trephine biopsy of the lung and pleura.

During the last five years 140 biopsies of the lung or pleura have been performed with a high-speed air-drill. A specially designed trephine, 2·1 mm. in bore, proved effective in obtaining adequate specimens from patients with diffuse lung lesions. With this method 111 out of 119 (93%) consecutive lung biopsies were successful in producing specimens of lung tissue for histological examination and 101 (85%) of these biopsies were diagnostically significant. Conditions such as sarcoidosis, berylliosis, alveolar proteinosis, polyarteritis nodosa, asbestosis, and diffuse interstitial pulmonary fibrosis were conclusively diagnosed. Complications were not serious and the commonest, pneumothorax, which occurred in 26% of the lung biopsies, was usually asymptomatic. The procedure is rapid and painless and breath-holding is unnecessary. It is performed under local anaesthesia and can be repeated, if required, thus having many advantages over biopsy by open thoracotomy. However, full thoracic surgical cover should be available. Indications include diffuse and localized lesions of the lung or pleura where a definitive diagnosis is required for the purpose of treatment, prognosis, or a claim for industrial compensation.