Selective Spinal Nerve Block for the Treatment of Lumbar Spinal Stenosis that indicated Operation / 대한정형외과학회잡지

PURPOSE: This study evaluated the effectiveness of a selective nerve root block (SNRB) for a lumbar spinal stenosis (LSS) that indicated surgery. MATERIALS AND METHODS: Twenty-one LSS patients, who were indicated for surgery but could not be operated on due to a high anesthetic risk, were evaluated retrospectively an evaluated on average of 19.5 months (range, 12 to 60 months) following the SNRB from April 1998 to October 2002. There were 9 males and 12 females with a mean age of 66.4 years (range, 59 to 78 years). The medical records and radiologic studies were reviewed, and a telephone interview was carried out where needed. The anesthetic risk was evaluated by the American Society of Anesthesiologists (ASA) physical status classification. The Kirkaldy-Willis criteria (at 9 months after SNRB and last FU) and the recurrence of symptoms (at 2 weeks, 1 month, 3 months, 5 months, 9 months after the SNRB, and the last FU) were analyzed. RESULTS: Among the 21 patients, 8 patients were in the ASA class 3, 13 in class 4. The major physical conditions that indicated a high anesthetic risk was cardiac problems in 17 patients, renal problems in 2, and endocrine problem in 2. The interval between the onset of symptom and the SNRB ranged from one month to 30 years (average, 41.6 months). All but 3 patients had a recurrence of their symptoms at an average 1.9 months (range, 1 day to 9 months) after the SNRB. According to the Kirkardy-Wills criteria, 9 months after SNRB, the results were good in 1 patient, fair in 2, and poor in 18. At the last follow-up, all but 4 patients did not show a chang in their status according to the Kirkardy-Wills criteria, and 4 patients improved (poor to good in 2, poor to fair in 2) without treatment. CONCLUSION: The symptoms of LSS improved for a very short period (average, 1.9 month) by SNRB. These results suggest that SNRB suitable for the LSS patients who require need surgery.

Normal Predictive Values of Spirometry in Korean Population / 결핵및호흡기질환

BACKGROUND: Spirometry should be compared with the normal predictive values obtained from the same population using the same procedures, because different ethnicity and different procedures are known to influence the spirometry results. This study was performed to obtain the normal predictive values of the Forced Vital Capacity(FVC), Forced Expiratory Volume in 1 Second(FEV1), Forced Expiratory Volume in 6 Seconds(FEV6), and FEV1/FVC for a representative Korean population. METHODS: Based on the 2000 Population Census of the National Statistical Office of Korea, stratified random sampling was carried out to obtain representative samples of the Korean population. This study was performed as a part of the National Health and Nutrition Survey of Korea in 2001. The lung function was measured using the standardized methods and protocols recommended by the American Thoracic Society. Among those 4,816 subjects who had performed spirometry performed, there was a total of 1,212 nonsmokers (206 males and 1,006 females) with no significant history of respiratory diseases and symptoms, with clear chest X?rays, and with no significant exposure to respiratory hazards subjects. Their residence and age distribution was representative of the whole nation. Mixed effect models were examined based on the Akaike's information criteria in statistical analysis, and those variables common to both genders were analyzed by regression analysis to obtain the final equations. RESULTS: The variables affecting the normal predicted values of the FVC and FEV6 for males and females were age2, height, and weight. The variables affecting the normal predicted values of the FEV1 for males and females were age2, and height. The variables affecting the normal predicted values of the FEV1/FVC for male and female were age and height. CONCLUSION: The predicted values of the FVC and FEV1 was higher in this study than in other Korean or foreign studies, even though the difference was < 10%. When compared with those predicted values for Caucasian populations, the study results were actually comparable or higher, which might be due to the stricter criteria of the normal population and the systemic quality controls applied to the whole study procedures together with the rapid physical growth of the younger generations in Korea.

Treatment of the Intertrochanteric Fractures of the Femur in Elderly Patients: Comparision of Wayne-County Reduction and Anatomical Reduction

PURPOSE: To compare the radiological and clinical results of Wayne-County reduction with anatomical reduction in treatment of the intertrochanteric fractures of the femur in elderly patients. MATERIALS AND METHODS: Among one hundred-three of intertrochanteric fractures treated with 135- degree angled compression hip scresw, eighty three cases treated by Wayne-County reduction (Group 1, 42 cases) and anatomical reduction (Group 2, 41 cases) with at least 1 year follow-up were reviewed. The average pateint ages were 72.4 (65~92) in group 1, 71.6 (65~89) in group 2, respectively. 33 cases (75.2%) in group 1 and 31 cases (77.5%) displayed unstable fractures by Jensen classification. The radiological observation was included neck-shaft angle, penetrating length of lag screw into head, sliding length of lag screw and time of bony union. The clinical results were evaluated by Koval criteria, Kyle's functional evaluation, leg length inequality and complications. RESULTS: There were no significant changes between group 1 and group 2 in stable fractures in the radiological and clinical results. In unstable fractures, the neck-shaft angle averaged 132.2 degree in group 1 and 129.4 degree in group 2 in the final follow-up films. The penetrating length of lag screw into head were 2.2 mm in group 1 and 3.1 mm in group 2 (p<005). But there were little differences in the sliding length of lag screw, the time of bony union and complication rates between groups. In post- operative evaluation of walking abilility by Koval, 31 patients (73.8%) in group 1 and 28 (68.3%) recovered the activity level before injury by the postoperative 1 year follow-up. Leg length discrepancy at final follow-up was 4.1+/-6 mm shortening in group 1 and 6.5+/-8 mm in group 2, respectively. CONCLUSION: Both Wayne-County reduction and anatomical reduction had a favorable results after treatment of stable intertrochanteric fractures of the femur, but Wayne-County reduction may be a better method in treatment of unstable fractures, especially in elderly patients, in which it is difficult to obtain anatomical reduction.

Morphological and Biochemical Changes in Bone-to-tendon Insertion Site after Achilles Tendon-Bone Graft in Rabbits / 대한정형외과연구학회지

Allografts or autografts of bone-tendon unit has been used widely for ligament or tendon reconstruction of ligament injuries or ligament deficiencies after limb salvage operation to treat malignant bone tumors around joints. While the remodeling process of the ligament or tendon itself after allograft or autograft and the microscopic and biomechanical changes of tendon- bone graft interface have been widely investigated, little is known about the ultrastructural and biochemical changes of the transitional zone in tendon-bone junction. This study was performed to analyze the morphological changes by microscopic (part I), and ultrastructural, and biochemical remodeling of the transitional zone after tendon-bone auto- and allo-grafting (part II). Preliminary, a microscopic studies at bone to tendon insertion site was done as control (part I). And as an experimental work (part II), a total of twenty four rabbits were divided into two group. In 12 animals (allograft group), an Achilles tendon-bone unit was taken with tenotomy 3 cm proximal to calcaneal attachment and osteotomy 5mm distal to the attachment site. This unit was preserved below -70degrees C for 2 weeks and then it was transplanted to another rabbit. In the other 12 animals (autograft group), the Achilles tendon-bone unit was harvested with the same maneuver from one side and transplanted to the other side of the rabbit. After operation, their legs were immobilized with short leg cast for 4 weeks, and then mobilized freely. Four animals in each group were sacrificed at four, eight and sixteen-weeks after transplantation, and their grafted Achilles tendon-bone interfaces were used for analysis of the ultrastrucural and biochemical changes. The following results were obtained. Part I: We conducted an experiment (part I) to investigate the histologic chronologic changes of tendon to bone fixation using the Cole's method and the role of periosteum to the tenodesis. The periosteum around the tenodesis was excised in group I, but it was incised longitudinally and sutured to tendon in group II. As a result, the tendons in the marrow cavity of tibia were firmly fixed by fibrosseous metaplasia in group I at 8 weeks after experiment, but not formed the fibrocartilagenous layer in both groups as a transitional zone of internal stress transmission from tendon to bone in normal tendon, and the group II show the firm connection between sutured periosteum and transferred tendon by external calluses after 3 weeks. These mean the periosteum should be sutured over the inserted tendon to get the early rigid fixation by the induction of external callus around the edges of the tendon to bone insertion. Part II: Histologically in part II experiment, new cartilage cells were observed at postoperative 16 weeks with locally presence of faint tidemark in the autograft group but not in the allograft group. Complete histological remodeling of the transitional zone had not restored both groups.. Ultrastructural analysis revealed no definite differences, but showed time-related restoration of fibers and fibroblasts between both groups except the slightly rapid appearance of parallelism and cross-striation of microfibrils in the autograft group. From biochemical analysis, type I collagen was increased in its concentration, and an early rapid increase of type III collagen and glycosaminoglycan was also observed. In conclusion, these data suggested that type III collagen and glycosaminoglyan are important in stabilization of grafted tendon-bone unit, especially in the transitional zone. The histological and biochemical changes in allograft group were relatively similar to that of autograft group although the allograft group showed the delayed pattern of remodeling. And so the tendon-bone allograft could be used as a good but second substitute followed by autograft.

Lung Cancer Occurring in a Worker Exposed to Coke Oven Emissions / 대한산업의학회지

OBJECTIVES: We report a case of lung cancer (small cell carcinoma) occurring in a worker exposed to coke oven emissions. METHODS: We examined the chest CT and pathologic findings of the patient. We reviewed previous environmental measurements for coke oven emissions at the workers place of employment. Also we measured the airborne concentrations for coke oven emissions and total polycyclic aromatic hydrocarbons in the work area. Finally, we analyzed the 1-hydroxypyrene and 2-naphthol concentrations in the subjects urine and compared this with student controls. RESULTS: This case was a 56-year-old male who had worked in a coke oven plant within a steel manufacturing factory for 21 years (1977-1998). The airborne concentrations of coke oven emissions at the worksite were above the permissible exposure level (0.2 mg/m3) in 45 cases (33.1%) among 136 workers. The concentrations of 1-hydroxypyrene and 2-naphthol in the subjects urine were statistically significantly elevated as compared with those of controls (P<0.01). CONCLUSIONS: We confirmed that the lung cancer occurring in this patient was as an occupational disease due to exposure to coke oven emissions. To prevent occupational cancer in coke oven plant workers, we must remodel the engineering procedure, begin comprehensive medical surveillance, educate workers on risks and the benefits of smoking cessation, and increase awareness of safety regulations in the workplace.

A Case of Chronic Methyl Bromide Poisoning Associated with Cerebellar Ataxia, Polyneuropathy and Optic Neuropathy

Methyl bromide is a commonly used fumigant to disinfect soil, grains, and warehouses. The accumulation of danger-ous concentrations can produce various neurotoxic effects in humans. A 45-year-old man, who had worked in the fumi-gation business, presented with polyneuropathy, optic neuropathy, and cerebellar sign, and serially sampled blood, urine and cerebrospinal fluid showed significant elevation of methyl bromide concentration. Regular education to workers and strict adherence to the safety precautions are needed to avoid the risk of toxicity associated with methyl bromide fumigation.

Analysis of Claimed Cases as an Occupational Disease at Korea Occupational Safety and Health Agency from 1992 to 1999 / 대한산업의학회지

OBJECTIVES: Pneumoconisis and noise-induced hearing loss(NIHL) have been reported as main occupational diseases by the Special Health Examination. The Industrial Accident Compensation Insurance has reported various work-related diseases, however, these two diseases occupied almost a half of compensated cases. Therefore, it was not well known about the status of occupational diseases other than pneumoconiosis, NIHL, and cardiocerebrovascular accident(CVA). This study was conducted to analyze claimed cases as an occupational disease, that was requested to the Korea Industrial Safety and Health Agency (KOSHA). METHODS: The local office of the Korea Labor Welfare Corporation(KLWC) has asked the KOSHA for confirmation of claimed cases as an occupational disease. We analyzed 379 cases requested from KLWC, the Ministry of Labor, employers, unions and occupational health agencies from 1992 to 1999. RESULTS: Male was 80. 7 % of the requested cases. Their mean age was 42 years old and 75. 5 % of them were more than 35 years old. The requested cases were increased rapidly from 25 cases in 1992 to 108 cases in 1999 and the accept rate was 50. 7 %. The majority of requested cases were respiratory diseases(22.4 %), cancers(18.5 %), Neuropsychiatric problems (14. 5 %), and musculoskeletal problems (13. 5 %). The accept rate was high in reproductive, respiratory, musculoskeletal and digestive disorders and low in neuropsychiatric, renal and otologic problems and occupational cancers. 73. 6 % of them were caused by chemical agents, especially 28. 5 % were by organic solvents. 67 % of them were clinically confirmed at university hospitals. A half of the cases were from KyongIn area, even the request came from the whole country. CONCLUSIONS: A claim was common in workers whose age was over 35 years old and exposure history was over 10 years. The respiratory diseases and neuropsychiatric disorders were still main problems in occupational health and occupational cancers was increasing even though its accept rate was not high yet.

Evaluation of Puretone Threshold Using Periodic Health Examination Data on Noise-exposed Workers in Korea / 예방의학회지

OBJECTIVES: This study was carried out to evaluate hearing impairment judgement and to investigate the differences in various diagnostic criteria for noise-induced hearing loss (NIHL) among workers who required for close observation (C). METHODS: Out of 731,029 workers who had taken the specific periodic health examination in 1994, we used the audiometric data on 37,999 workers (C) eliminating the employees who had previous otologic problems. Many investigators have being using different criteria for the evaluation of hearing impairment. In this study, we used the criteria of early (1989-1994), current, compensation for NIHL in Korea, 2-, 3-, 4-divided classification and hearing loss at 4,000 Hz and compared the evaluation results. RESULTS: The prevalences of C and workers who had occupational disease (D1) diagnosed for NIHL were 11.1 % and 0.44 %. There were significant difference in the prevalences of C and D1 depending on different province of Korea. Pure tone averages (PTAs) were not appropriately applied in their evaluation. 97% of workers whom we studied on were below the level of mild hearing loss judged by ISO standard. However, there were wide variations in the prevalence rate of mild hearing loss by diagnostic criteria. Thus, there were different judgements in determining the degree of NIHL depending on which diagnostic criteria were utilized. PTAs were found 20.54 (Rt) and 20.74 (Lt) when the method of 3-divided classification was applied for audiometric data. The degree of hearing impairment of the left ear was more severe than that of right ear. The prevalence of normal hearing threshold below 20 dB was 75.4% and the range of difference in both ear was below 10 dB. Right sided hearing threshold levels were 21.08 dB (500 Hz), 18.44 dB (1,000 Hz), 22.09 (2,000 Hz) and 52.36 dB (4,000 Hz). There was typical high frequency loss (C5-dip at 4,000 Hz) above 30 - 40 dB in normal hearing level. The increasing trend in hearing threshold level was gradually decreased by the increase of PTAs. The difference between PTAs and threshold at 4,000 Hz was about 10 dB. CONCLUSIONS: We could found that PTAs in the previous examination were not appropriately evaluated. This study revealed that they did not use unique criteria for managing the workers of NIHL. For the prevention of NIHL, it was found that the quality control on diagnosis and comprehensive management program were required, especially for those of hearing loss (C).

Arthroscopic Treatment of the Localized Pigmented Villonodular Synovitis of the Knee

Pigmented villonodular synovitis (PVNS) is a relatively rare condition. The disorder almost always involves a single joint and the knee is most commonly affected. We report on three cases of localized PVNS that involved the patella fat pad and synovium. Diagnostic and therapeutic arthroscopies were performed, and typical findings of localized PVNS were found. Complete resection of the lesions were performed arthroscopically. Arthroscopy can be used as an effective diagnostic and therapeutic tool for identification and resection of intraarticular localized PVNS of the knee.

Medical Surveillance of Glass Fiber Workers in Korea / 예방의학회지

The industrial use of MMMF(man-made mineral fibers), has been increasing, particularly since the banning of most asbestos products. Fibrous minerals can cause health abnormalities currently associated with occupational exposure to glass fiber. This study was conducted to evaluate health risks of glass fiber manufactory workers within the country. we examined questionaries, physical examination including auscultation, chest x-ray, pulmonary function test for 488 male workers, to go through their dermal itching symptoms and respiratory evaluation. we had the results as follows. 1. In 45% of the workers itching had been expressed at their entrance. At that time we was investigating, 18.5% had itching, and most of them complained it when they fall asleep and night. The frequent itching site is waist and groin, upper and lower extremity in order, and it had been expressed mainly during summer and winter. 2. As the results of ventilatory functions test, 6.0% were obstructive type, 1.0% were restrictive type. so, glass fiber exposures should be controlled or elimination by protective devices in the workplace. 3. The means of FVC, FFV1, FFV1% were in normal range. As the comparison of ventilatory functions by age groups, MMF was decreased significantly for the group, 50 years old and more than other groups. And the comparison by the serving periods at glass fiber producing factory, MMF was decreased for the workers had worked for 11-15 years. Therefore, MMF be more sensitive index in the evaluation of ventilatory impairments caused by glass fiber workers.

Carpal Tunnel Syndrome among workers in a condom industry / 예방의학회지

The objectives of this study are to investigate the prevalence of occupation related carpal tunnel syndrome(CTS) among workers in a condom industry; to analyse the sensitivity and specificity of clinical signs or symptoms such as hand diagram, Tinel's sign and Phalen's sign in carpal tunnel syndrome; and to test vibration threshold test using audiometry as a technically easy and noninvasive method in the diagnosis of carpal tunnel syndrome in stead of nerve conduction velocity(NCV). The study group was divided into exposed group(39 cases)and non-exposed group(48 cases) based on whether or not excessive use of wrist movements exist. 1. There are statistically significant differences in symptoms and signs of carpal tunnel syndrome such as hand diagram, Tinel's sign and Phalen's sign between exposed and non-exposed group(p<0.05). 2. Six cases(9 hands) were confirmed as carpal tunnel syndrome by NCV. Five cases(7 hands) belonged to exposed group, 1 case(2 hands) to nonexposed group. As there are significant differences in prevalence of carpal tunnel syndrome between two groups(p<0.05), excessive use of wrist in occupation is a risk factor of carpal tunnel syndrome. 3. When we use NCV as a gold standard in the diagnosis of carpal tunnel syndrome, sensitivity and specificity of hand diagram, Tinel's sign and Phalen's sign is as followed; hand diagram; sensitivity 88.9%, specificity 84.2%. Tinel's sign; sensitivity 55.6%, specificity 72.8%. Phalen's sign; sensitivity 14.3%, specificity 88.4%. Among above clinical signs and symptoms, hand diagram is the best clinical screening test. 4. The differences of vibration threshold between median and ulnar nerve at the same time are useful in the diagnosis of carpal tunnel syndrome but the time change of vibration threshold of median nerve over time are not sensitive enough. It is concluded that vibration threshold between median and ulnar nerve at the same time can be used as a supplementary or alternative criterion to indicate that the nerve dysfunction is located in the carpal tunnel.

Bronchial Hyperresponsiveness in Workers Exposed to Isocyanates / 예방의학회지

We studied the association of nonspecific bronchial hyperresponsiveness with general characteristics, exposure concentration, respiratory symptoms, chest x-ray findings, past histories and pulmonary function. We determined bronchial hyperresponsiveness by methacholine challenge test. And we conducted a respiratory symptom questionnaire and performed spirometry on 111 workers occupationally exposed to isocyanates in various industries. About 21.6% of subjects had bronchial hyperresponsiveness. No significant differences were observed between the hyperresponsive and non-responsive group with respect to age, sex, employment period, height, and smoking histories cough and breathlessness were significantly associated with the bronchial hyperresponsiveness. The hyperresponsive group had more experience of bronchitis and asthma in the past than the non-responsive group. The lower FEV1 and FEV1 % were closely related with bronchial hyperresponsiveness. Bronchial hyperrespoosiveness seems to be associated with some of respiratory symptoms, past histories and pulmonary function parameters in workers exposed to isocyanates.

Respiratory Health of Foundry Workers Exposed to Binding Resin / 예방의학회지

The effects of resin on the respiratory health have been investigated in 309 workers from four iron and steel foundries and the results compared with those from 122 workers who were not significantly exposed to resin gas and silica dust at the same industries. Phenol-formaldehyde resin was used in the core making and molding processes and workers were exposed to their decomposition products as well as to silica dist containing particulates The subjects were grouped according to formaldehyde, dust and other gas exposures, and smoking habits were considered also in the analysis. Standardized respiratory symptom questionnaire was administered by trained interviewers. Chest radiograph, pulmonary function tests, and methacholine challenge tests were done. Environmental measurements at the breathing zone were carried out to determine levels of formaldehyde, respirable dust and total dust. Foundry workers had a higher prevalence of symptoms of chronic bronchitis with chronic phlegm and chronic cough when exposed to dust. Exposure to gas was significantly associated with lowered FEV1 and obstructive pulmonary function changes. Exposure to formaldehyde and phenol gas was associated with wheezing symptom among workers, but FEV1 changes after methacholine challenge were not significantly different among different exposure groups. When asthma was defined as the presence of bronchial hyperreactivity with more than 20% decrease in FEV1 after methacholine challenge, 17 workers out of 222 tested had asthma. Fewer asthmatic workers were found among groups exposed to for maldehyde, gas and dust, which indicates a healthy worker effects in a cross-sectional study. The concentration of formaldehyde gas ranged from 0.24 to 0.43 ppm among studied foundries. The authors conclude that fornaldehyde and phenol gas from combust resin is probably the cause of asthmatic symptoms and also a selection force of those with higher bronchial reactivity away from exposures.

Normal Predictive Values of FVC and FEV1 for Healthy Korean Male Workers / 대한산업의학회지

Lung Function test results can be influenced by race, socioeconomic status, and physical fitness. The choice of the most appropriate predictive equations should be based upon these considerations as well as age, sex, and body size. About 70% of Korean males smoke, and non-smokers can be a selective group in Korea. In this study, lung function test results of 683 healthy Korean male workers were analyzed to get the predictive equations of Forced Vital Capacity(FVC), Forced Expiratory Volume in 1 second(FEV(1)), and FEV(1)/FVC (FEV(1)%). The age of studied workers ranged from 18to 60, and most of those finished high school or less. Healthy smokers without any respiratory symptoms or disease history were included in the study, while the effect of smoking on the test results were examined in the analysis. FVC, FEV(1), and FEV(1)% were regressed against age, height, weight and smoking status or smoking amount. Age and height explained FVC and FVC(1) most efficiently and the contribution of other variables were not significant. Whereas, smoking was significantly associated with a decrease in FEV(1)% even among healthy un-symptomatic workers. For FEV(1)%, age, height, and smoking amount were significant variables, constituting the most efficient prediction model. The lower limit of normal for percent predicted values was calculated from lower 95 percentile as well as 95% confidence interval. When the results of this study was compared to those from studies of white Caucasians, the predicted FVC and FEV(1) were lower for the given age and height but the differences were less than 10%. The slopes of regression equation for height and age were, however, not significantly different when the social backgrounds of the studied subjects were similar.

Lung Function Test for Workers and its Quality Control Program / 대한산업의학회지

Lung function test can be influenced by technical as well as biological variables, and the quality control of test has been stressed as an important part of lung function test program. This study was done to survey the current status of lung function test program in workers' health examination, and examine the variablity of test results when quality control is not achieved. Forty nine Workers' Health Examination Institutes and 7 Pneumoconiosis Referal Centers were surveyed for their current lung function tests, types of spirometers, and performance of technicians. To examine the effect of quality control program of lung function tests on the variablity of test results, 118 miners were tested under a quality control guideline and the results were compared to those obtained ignoring 4 major areas of the guideline-spirometer calibration, minimum number of tests per session, suitable prediction equations, and selection process of final results for each tested subjects. Among surveyed Institutes and Centers, only 38%(20/53) are performing any calibration of spirometers, and most of those calibrations are done automatically by the machine. All the surveyed Institutes and Centers obtain acceptable test no more than 2 times. The background of technicians include office workers and nurse aids without an adequate training in pulmonary physiology, and the testing posture and formats vary among Institutes and Centers. When the types of pulmonary dysfunction under the definition of the Ministry of Labor were compared between those obtained with and without quality control guidelines, spirometer calibration affected the test results in 6(5.1%) out of 118 subjects. The change in the minimum number of adequate tests from 1 to 3 and more brought changes in 19(16.1%) subjects. The test results of 9(7.6%) subjects differed between two different prediction equations, and the results of 7(5.9%) subjects differed between two different selection process of final results. The current practice of lung function tests of workers needs quality control programs, and the results of this study indicate that the first remedy should be to bring the minimum number of acceptable test to more than 3.

A Comparative Study on Evaluation Methods of Permanent Impairment in Korea / 예방의학회지

In this study, literature review was done to examine and compare the current status and problems of different evaluation approaches toward permanent impairment in Korea. Alternatives and improvements in the current approaches in Korea were suggested. Series of cases were also examined to compare different approaches applied to the real cases, using 105 cases from a hospital data and another 207 cases from insurance company data. The main findings of the literature review are as follows; 1. The current evaluation methods of permanent impairment in Korea are grouped into two categories, grading and rating. Grading of impairments are expressly specified in 17 various statutes. 2. In Grading methods, the rigid system of 14 different grades has been adopted uniformally for the convenience of administration, which may not be, appropriate or valid from medical and scientifical aspect. 3. The advantage of McBride method is assessment of occupational disability rate. However the classified compensable occupations are only 280 and limited to manufacturing industries in 1960s' of U.S.A., which is not appropriate to current Korean circumstances. Especially, the job list does not include managerial officers or mental workers. 4. AMA Guides is the scientific and reasonable method for the assessment of physical impairment rate. However compensation and reparation of impairment case is difficult because this method cannot assess the disability rate according to occupation, age, etc. The results of cases comparative study are as follows: 5. The physical impairment could be compared in 167 out of total 312 cases and for the cases of complex impairment, McBride method underestimate physical impairment rate compared with AMA method. 6. When disability rate was assessed, occupation was considered the compensation of only 85 cases, and age was used in only 21 cases. This was because occupation and age compensation in McBride method are unreasonable. 7. The most ideal alternative is to assess physical impairment according to AMA method and then to develop a compensation method appropriate for the circumstances of Korea society.