Preservation of the Posterior Ligaments for Preventing Postoperative Spinal Instability in Posterior Decompression of Lumbar Spinal Stenosis: Comparative Study between Port-Hole Decompression and Subtotal Laminectomy / 대한정형외과학회잡지

PURPOSE@#To determine if sparing the interspinous and supraspinous ligaments during posterior decompression for lumbar spinal stenosis is significant in preventing postoperative spinal instability.@*MATERIALS AND METHODS@#A total of 83 patients who underwent posterior decompression for lumbar spinal stenosis between March 2014 and March 2017 with a minimum one-year follow-up period, were studied retrospectively. The subjects were divided into two groups according to the type of surgery. Fifty-six patients who underwent posterior decompression by the port-hole technique were grouped as A, while 27 patients who underwent posterior decompression by a subtotal laminectomy grouped as B. To evaluate the clinical results, the Oswestry disability index (ODI), visual analogue scale (VAS) for both back pain (VAS-B) and radiating pain (VAS-R), and the walking distance of neurogenic intermittent claudication (NIC) were checked pre- and postoperatively, while simple radiographs of the lateral and flexion-extension view in the standing position were taken preoperatively and then every six months after to measure anteroposterior slippage (slip percentage), the difference in anteroposterior slippage between flexion and extension (dynamic slip percentage), angular displacement, and the difference in angular displacement between flexion and extension (dynamic angular displacement) to evaluate the radiological results.@*RESULTS@#The ODI (from 28.1 to 12.8 in group A, from 27.3 to 12.3 in group B), VAS-B (from 7.0 to 2.6 in group A, from 7.7 to 3.2 in group B), VAS-R (from 8.5 to 2.8 in group A, from 8.7 to 2.9 in group B), and walking distance of NIC (from 118.4 m to 1,496.2 m in group A, from 127.6 m to 1,481.6 m in group B) were improved in both groups. On the other hand, while the other radiologic results showed no differences, the dynamic angular displacement between both groups showed a significant difference postoperatively (group A from 6.2° to 6.7°, group B from 6.5° to 8.4°, p-value=0.019).@*CONCLUSION@#Removal of the posterior ligaments, including the interspinous and supraspinous ligaments, during posterior decompression of lumbar spinal stenosis can cause a postoperative increase in dynamic angular displacement, which can be prevented by the port-hole technique, which spares these posterior ligaments.

Diagnosis of C2 Spondylotic Radiculopathy by Physical Examination and Imaging Studies and Treatment by Microscopic Posterior Foraminotomy: A Case Report / 대한척추외과학회지

STUDY DESIGN: Case report. OBJECTIVES: We report the case of a patient with C2 spondylotic radiculopathy who was treated by microscopic posterior foraminotomy. SUMMARY OF LITERATURE REVIEW: C2 spondylotic radiculopathy is rare, but it can occur due to spondylosis, compression by a venous plexus or vertebral artery, or hypertrophy of the atlantoepistrophic ligament. MATERIALS AND METHODS: A 64-year-old woman was hospitalized with severe occipital pain radiating toward the left cervical area and posterior to the left ear. It started 3 years previously, and became aggravated 3 months previously. Foraminal stenosis of C1-2 was observed on magnetic resonance imaging (MRI) and degenerative changes of the facet joint of C1-2 and osteophytes originating from the left atlantoaxial joint were shown on computed tomography (CT). Dynamic rotational CT showed narrowing of the left C1-2 neural foramen when it was rotated to the left. Selective C2 root block was done, but the pain was aggravated. Thus, we decompressed the C2 nerve root by microscopic posterior laminotomy of the C1 vertebra. After surgery, the patient's occipitocervical pain mostly resolved. By the 6-month follow up, pain had not recurred, and instability was not observed on plain radiographs. RESULTS: C2 Spondylotic radiculopathy was diagnosed by physical examination and imaging studies and it was treated by a surgical approach. CONCLUSIONS: C2 spondylotic radiculopathy should be considered when a patient complains of occipitocervical pain triggered by cervical rotation and C1-2 foraminal stenosis is observed on MRI and CT.

The Clinical Results after Posterior Ligaments Preserving Fenestration in Lumbar Spinal Stenosis: The Port-Hole Decompression / 대한정형외과학회잡지

PURPOSE: To describe the technical skills and to estimate the clinical outcomes of port-hole decompression preserving the posterior ligaments during lumbar spinal stenosis surgery. MATERIALS AND METHODS: Between March 2014 and March 2016, a total of 101 patients who underwent port-hole decompression were retrospectively analyzed. The mean age was 71.3 years (58–84 years) and there were 46 males and 55 females. The mean follow-up period was 18 months. Degenerative spondylolisthesis was observed in 24.8% of patients (25/101). Port-hole decompression was performed by removing the central portion of the distal part of the upper lamina with a burr. Then, the contralateral side of ligamentum flavum and hypertrophied facet joints were removed. We estimated the lumbar lordotic angle using radiographs, and measured the depth from skin to upper lamina central area using magnetic resonance imaging axial images. We estimated the mean slip angle and mean degree of slip in preoperative and postoperative radiography in standing flexion and extension. We also measured the operational time, length of skin incision, and blood loss. The clinical results were estimated by a walking distance caused by neurologic intermittent claudication, visual analogue scale, and Oswestry disability index. RESULTS: Most patients were generally older, and the mean lordotic angle was 25.3°, which is considered to be lower when compared with younger people. The mean depth from skin to lamina was mean 5.4 cm. With respect to the radiological results, there were no significant differences between the preoperative and postoperative groups. The operation time, length of skin incision, and bleeding were not increased proportionally to the operation level. The walking distance caused by neurologic intermittent claudication, visual analogue scale, and Oswestry disability index of the post-operative group were all improved compared with the pre-operative group. CONCLUSION: The port-hole decompression, which decompresses the contralateral side while preserving the posterior ligaments and facet joints may be a useful technique for elderly patients with multiple level stenosis, minimizing spinal segmental instability.

Diagnosis of C2 Spondylotic Radiculopathy by Physical Examination and Imaging Studies and Treatment by Microscopic Posterior Foraminotomy: A Case Report

OBJECTIVES@#We report the case of a patient with C2 spondylotic radiculopathy who was treated by microscopic posterior foraminotomy.SUMMARY OF LITERATURE REVIEW: C2 spondylotic radiculopathy is rare, but it can occur due to spondylosis, compression by a venous plexus or vertebral artery, or hypertrophy of the atlantoepistrophic ligament.@*MATERIALS AND METHODS@#A 64-year-old woman was hospitalized with severe occipital pain radiating toward the left cervical area and posterior to the left ear. It started 3 years previously, and became aggravated 3 months previously. Foraminal stenosis of C1-2 was observed on magnetic resonance imaging (MRI) and degenerative changes of the facet joint of C1-2 and osteophytes originating from the left atlantoaxial joint were shown on computed tomography (CT). Dynamic rotational CT showed narrowing of the left C1-2 neural foramen when it was rotated to the left. Selective C2 root block was done, but the pain was aggravated. Thus, we decompressed the C2 nerve root by microscopic posterior laminotomy of the C1 vertebra. After surgery, the patient's occipitocervical pain mostly resolved. By the 6-month follow up, pain had not recurred, and instability was not observed on plain radiographs.@*RESULTS@#C2 Spondylotic radiculopathy was diagnosed by physical examination and imaging studies and it was treated by a surgical approach.@*CONCLUSIONS@#C2 spondylotic radiculopathy should be considered when a patient complains of occipitocervical pain triggered by cervical rotation and C1-2 foraminal stenosis is observed on MRI and CT.

Wireless Energy and Data Transmission Using Inductive Coupling / 의학물리

Bio-implantable devices such as heart pacers, gastric pacers and drug-delivery systems require power for carrying out their intended functions. These devices are usually powered through a battery implanted with the system or are wired to an external power source. This paper describes an inductive power transmission link, which was developed for an implantable stimulator for direct stimulation of denervated muscles. The carrier frequency is around 1 MHz, the transmitter coil has a diameter of 46 mm, and the implant coil is 46 mm. Data transmission to the implant with amplitude shift keying (ASK) and back to the transmitter with passive telemetry can be added without major design changes. We chose the range of coil spacing (2 to 30 mm) to care for lateral misalignment, as it occurs in practical use. If the transmitter coil has a well defined and reliable position in respect to the implant, a smaller working range might be sufficient. Under these conditions the link can be operated in fixed frequency mode, and reaches even higher efficiencies of up to 37%. The link transmits a current of 50 mA over a distance range of 2-15 mm with an efficiency of more than 20% in tracking frequency. The efficiency of the link was optimized with different approaches. A class E transmitter was used to minimize losses of the power stage. The geometry and material of the transmitter coil was optimized for maximum coupling. Phase lock techniques were used to achieve frequency tracking, keeping the transmitter optimally tuned at different coupling conditions caused by coil distance variations.

Implantable Functional Electrical Stimulation with Inductive Power and Data Transmission System / 영남의대학술지

Functional electrical stimulation (FES) has developed over the last 35 years to become a scientifically, technologically and clinically recognized field of interest in clinical medicine. FES has been applied to locomotion, grasping, ventilation, incontinence, and decubitus healing. However, all of these achievements illustrate the initial applications of FES; its true potential has not yet been realized. Recently, FES systems, which are miniaturized stimulation devices, have been utilized in the clinical setting. However, because the stimulating electrodes of the current FES devices are percutaneous electrodes, which are susceptible to wire breakage, and skin infection an implantable FES stimulating electrode has been introduced in the U.S. and Japan. In the present study, an external power supply method using radio frequency (RF) coupling and data transmission was developed for the control of the implantable FES device. In addition, we review the current understanding of FES devices and their application in clinical medicine.

Development of Transcutaneous Energy Transmission System for Implantable Devices / 의학물리

As a part of implantable device in body, a transcutaneous energy transmission system has been developed. It would be desirable to tansfer electrical energy to implantable devices transcutaneously. The distance between transcutaneous transformer windings are approximately equal to the thickness of the human's skin, nominally between 10~20 mm. Class-E resonant amplifier is used to drive a primary coil for high efficiency. Maximum current is above 50 mA at any frequency. The developed system shows that the circuit operates correctly at each frequency; 500 kHz, 1 MHz and 4 MHz.

The Effects of Microwave Irradiated on Rabbit's ICP / 영남의대학술지

Damages on central nervous system induced by the exposure of microwave. However, the effects of microwave on ICP are not studied yet. The ICP affected by the condition of the condition of the brain has an significant effect on vital sign. So we investigated the changes of ICP of the rabbits after exposure. Twenty four rabbits were divided into 3 groups depending on the amount of exposure to microwave. One group was composed with 8 rabbits were exposed to microwave for 10 miniutes. Other were composed to microwave for 20 miniutes, 30 miniures, respectively. Intracranial pressure on each group were measured by subdural type ICP monitoring catheter immediately, first day, 3rd day, 5th day and 7th day after exposure of microwave. Results indicates that intracranial pressure of rabbits are not affected with statistical significance by exposure of microwave.

Development of Detachable IORT Table for Colorectal Cancer / 대한치료방사선과학회지

In spite of remarkable improvement of surgical skills and anesthesia, local failure still occurred in 36-45% of locally advanced colorectal cancer after curative resection with or without pre-or post-operative irradiation. Intraoperative radiation therapy (IORT) is the ideal modality which respectable lesions are removed surgically and the remaining cancer nests are sterilized by irradiation during a surgical procedure. Therefore, the excellent local control without the damage of the adjacent normal tissues can be achieved. In IORT, judicious set up of the treatment cone on the treatment surface of the patient is required for accurate and homogenous dose distribution within treatment field, especially on the slopping surface of sacrum and pelvic sidewall which are the common sites of the local recurrence in rectal cancer. For this purpose, adequate coordination of gantry rotation and table tilting are essential. Adjusting gantry rotation is not difficult but tilting of the table is impossible inconventional treatment couch. Department of Therapeutic Radiology in Yeungnam University Medical Center developed the IORT table for colorectal cancer which is easy to set up and detach on head-down is about 30 degree which is efficient and easy-to-use, not only for IORT but also for colorectal surgery. So far, authors performed IORT with newly developed treatment table in 2 patients with rectal cancer and we found that this newly developed table could contribute in improving the dose distribution of IORT and surgical procedure for colorectal cancer.

Assessment of Autonomic Nervous Dysfunction by Heart Rate Spectral Analysis (HRSA) in Patients with Angina Pectoris

BACKGROUND: The autonomic nervous control of the cardiovascular system has been thought to have a diurnal variation in its activity. This variation could be an important underlying mechanism for the circardian distribution of cardiac events such as angina pectoris attack, transient myocardial ischemia, and some arrhythmia. The vagal cardiac function is commonly impaired in patients with coronary artery disease. Recently, an assessment of parasympathetic and sympathetic activities is now possible using neart rate spectral analysis. The spectral density of R-R interval variability contains two major components, high frequency (HF) power spectral density (<0.25Hz) and low frequency (LF) power spectral density (<0.15Hz), which have magnitudes that are quantitative markers of cardiac vagal activity and sympathetic activity with vagal modulation, respectively. METHODS: We analyzed the spectral components of R-R interval variability from 24 hour ambulatory holter monitoring in 20 controls and 20 patients with angina pectoris. The patients had no clinical evidence of hypertension, acute myocardial infarction, heart failure, arrhythmia or diabetes mellitus. Recording continued for 24 hours while the subject undertook his normal work and leisure activities. For power spectral analysis, 1024 hours beats was sampled at early morning, afternoon, evening and during sleeping. RESULTS: The spectral component of R-R interval variability was unaffected by the time of day during the waking period, althought a significant decrease in LFCCV and HFCCV was observed during sleeping in controls(p<0.001). In comparison of two groups, patients with angina pectoris showed markedly diminished HFCCV values during waking period except during sleeping period. The R-R interval and LF/HFCCV and LF/HFCCV ratio at transient ischemic attack in patients with angina pectoris. CONCLUSION: Autonomic cardiac control during the waking period shows little variation with the time of day in both groups. We observed that vagal cardiac function was reduced in patients with coronary artery disease by heart rate spectral analysis. It is suggested that ischemic changes in patients with coronary artery disease underlying reduced vagal cardiac function is associated with increased sympathetic activity.

Fundamental Study for Rolling-Over Motion of the Body by Functional Electrical Stimulation (FES) / 영남의대학술지

A method to roll-over the paralyzed body by means of Functional Electrical Stimulation (FES) is considered. It is demonstrated that individual joint motions necessary for the rolling-over are realized by electrical stimulation. EMG measurements are also performed to analyze the cooperative activities of the muscles during rolling-over motion in a case where an upper extremity was used. These results of two experiments using normal subjects verifies the fundamental feasibility of body control by FES.

A Study on the Design of High-Frequency Jet Ventilator Using PLL system / 영남의대학술지

This paper describes to design and to examine the mechanical characteristics of high frequency jet ventilator. The device consists of Phase lock loop (PLL) system, solenoid valve driving control part and Air regulating system. This study is carried out by changing several factors such as endotracheal tube (E.T. tube) diameter, injector cannula diameter, 1%, and frequency (breaths/min.) having direct effects on the gas exchange as well as parameters of the entrained gas by venturi effect, so as to measure the tidal volume and minute volume. This system characteristics were as follows: 1) Frequency: 6-594 bpm 2) Inspiration time: 1-99% 3) Variance of input air pressure: 1-30 PSI

A Design of High-Frequency Oscillatory Ventilator Using Phase Lock Loop system / 영남의대학술지

In this study, high frequency oscillatory ventilator was designed and constructed. Using designed by phase-lock loop system, in order to accurately and easily treat both the outlet volume and rpm. A system has been designed and is being evaluated using CD4046A PLL IC. We use this PLL IC for the purpose of motor controls. The device consists of PLL system, pumping mechanism, piston, cylinder, and special crank shaft are required. This system characteristics were as follows: 1) Frequency: 20-1800 rpm 2) Outlet air volume: 1-50 cc

The Comparision of Histologic & Electrophysiologic Changing Area after Monopolar Coagulation in the Rabbit Brain

Lesions with controlled monopolar coagulation were generated in the cerebral cortex of 20 healthy rabbits. With 28 watts monopolar coagulation, average diameter of histologically changed area around lesion was aout 7.5mm with using Evans blue dye technique. At same time, EEGs in three points, which were 5mm, 10mm & 15mm distant from the coagulated lesion site, were cheched before and just after coagulation. In results, the frequency of EEG was slightly decreased after coagulation, but there were no relation with distance from lesion. But the amplitudes of EEG were decreased as 51.2 micro v(61.2%), 42.9 micro v(3.9) and 34.0 micro v(25.3%) after coagulation, which depended on the distance from site of coagulation. That means electrophysiologically changed area after coaguation was far beyond the histologically changed area.

The Comparision of Histologic & Electrophysiologic Changing Area after Monopolar Coagulation in the Rabbit Brain

Lesions with controlled monopolar coagulation were generated in the cerebral cortex of 20 healthy rabbits. With 28 watts monopolar coagulation, average diameter of histologically changed area around lesion was aout 7.5mm with using Evans blue dye technique. At same time, EEGs in three points, which were 5mm, 10mm & 15mm distant from the coagulated lesion site, were cheched before and just after coagulation. In results, the frequency of EEG was slightly decreased after coagulation, but there were no relation with distance from lesion. But the amplitudes of EEG were decreased as 51.2 micro v(61.2%), 42.9 micro v(3.9) and 34.0 micro v(25.3%) after coagulation, which depended on the distance from site of coagulation. That means electrophysiologically changed area after coaguation was far beyond the histologically changed area.

A Study on the Development of R-R Interval Analyzer using Microcomputer (1) / 영남의대학술지

The R-R interval analyzer was developed to measure the autonomic nervous system function using microcomputer. The system based on 8 bit microcomputer including bandpass filter, R-wave detector and clock generator in order to obtain the mean value, standard deviation, total time, CV value, maximum value and minimum value in the specific view point of R-R interval variation. The pattern of R-R interval change after resting, voluntary standing and deep breathing can be analyzed in normal subjects and diabetics with autonomic nervous dysfunction. The amplitude of the R-R interval variation showed sensitive pattern for normal subjects at resting, standing and deep breathing. On the contrary, the periodicities of amplitude for abnormal subjects with autonomic nervous dysfunction showed dull pattern. It was suggested that R-R interval analyzer is a good detection method for dysfunction of autonomic nervous system.