Journal of Yeungnam Medical Science

Myun Whan Ahn

14 Articles

Natural Course of Lumbar Spinal Stenosis: Myun Whan Ahn; Yeungnam Univ J Med. 2007;24(2 Suppl):S49-56. Published online December 31, 2007; DOI: https://doi.org/10.12701/yujm.2007.24.2S.S49

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Abstract PDF: The purpose of this paper is to review the natural course of spinal stenosis in order to establish an optimal therapeutic plan. As the population becomes older, this condition is encountered more frequently. The numbers of detected cases were increased internationally with the diagnositc tools improved. Good knowledge of natural evolution and of the predictive factors influencing the course of the disease is crucial for the selection of methods of treatment. Unfortunately, in contrast with numerous reports of the results of surgical series, few studies have been reported on the natural evolution. However, results of the studies analyzed in this review suggest that a substantial proportion of patients do not automatically deteriorate and will remain unchanged or even improved by medical means. They also suggest that patients with severe baseline symptoms, block stenosis and degenerative spondylolisthesis tend to require surgical decompression.

An Epidemiologic Study of Low Back Pain of Women Working at a General Hospital.: Dong Gu Park, Myun Whan Ahn, Jong Chul Ahn, Sae Dong Kim, Jae Sung Seo; Yeungnam Univ J Med. 2007;24(2):186-196. Published online December 31, 2007; DOI: https://doi.org/10.12701/yujm.2007.24.2.186

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BACKGROUND
The aim of this study was to confirm the risk factors for low back pain and injury to improve the prevention and treatment of lower back pain. MATERIALS AND METHODS: An epidemiologic study of low back pain and injury was performed with questionnaires distributed to 471 women working at Yeungnam university hospital. The differences in low back pain and injuries among various hospital departments were analyzed by a one-way analysis of variance (ANOVA), and the relevant factors included in the questionnaire were determined by a factor analysis. RESULTS: The frequency of low back pain in women in the department of diet and in the maintenance department was higher than among the other departments. The frequency of low back pain was mainly related to the frequency of psychosomatic symptoms. In addition, the low back pain was partially related to the frequency of psychosomatic symptoms and partially related to the frequency of pushing during the workday. The degree of disability from low back pain was increased by lifting and hard physical work and was related to the frequency of psychosomatic symptoms and the degree of work dissatisfaction. The frequency of low back injury was increased by increased standing time during work and hard physical work. The frequency of low back injury was related to advancing age and in part to psychosomatic symptoms. CONCLUSION: Lower back pain and its associated complications are related to psychosomatic factors and type of work. Lower back injury is related to physiological factors such as age. For the prevention and treatment of lower back pain, a multidisciplinary approach is required.

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Effects of the Hand Acupressure and Lumbar Strengthening Exercise on Women with Lower Back Pain
Eun Young Jeon
journal of east-west nursing research.2013; 19(2): 63. CrossRef

Analysis of Compression Behavior on Intervertebral Disc L4-5 in Pedicle Screw System Instrumented Lumbar Spine under Follower Load.: Myun whan Ahn, Jong chul Ahn, Su ho Lee, Il sub Chung, Choon yeol Lee, Jang woo Lee; Yeungnam Univ J Med. 2003;20(2):160-168. Published online December 31, 2003; DOI: https://doi.org/10.12701/yujm.2003.20.2.160

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Abstract PDF

BACKGROUND
Confirm the stability of intervertebral disc sustaining each fused lumbar spine cases, comparing vertical compression, A-P shear force and rotational moment on intervertebral disc of instrumented lumbar spine with simple vertical compression load and follower load using finite element analysis. MATERIALS AND METHODS: We analyze the stability of intervertebral disc L4-5 supporting fused lumbar spine segments. After performing finite element modelling about L1-L5 lumbar vertebral column and L1-L4 each fusion level pedicle screw system for fused lumbar spine fine element model. Intervertebral discs with complex structure and mechanical properties was modeled using spring element that compensate stiffness and tube-to-tube contact element was employed to give follower load. Performing geometrical non-linear analysis. RESULTS: The differences of intervertebral disc L4-5 behavior under the follower compression load in comparision with vertical compression load are as follows. CONCLUSION: As a result of finite element interpretation of instrumented lumbar spine, the stability of L4-5 sustaining fused lumbar segment, the long level fused lumbar spine observed hing stability under follower load. This research method can be the basis tool of effects prediction for instrumentation, a invention of a more precious finite element interpretation model which consider the role of muscle around the spine is loaded.

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Spinal Stability Evaluation According to the Change in the Spinal Fixation Segment Based on Finite Element Analysis
Cheol-Jeong Kim, Seung Min Son, Jin-Young Heo, Chi-Seung Lee
Journal of the Computational Structural Engineering Institute of Korea.2020; 33(3): 145. CrossRef

Thoracolumbar Spine Injury.: Myun Whan Ahn; Yeungnam Univ J Med. 2002;19(2):73-91. Published online December 31, 2002; DOI: https://doi.org/10.12701/yujm.2002.19.2.73

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Abstract PDF: Method of management of the spine injury should be determined, based on the status of neurological injury as well as on the presence of traumatic instability. At the thoracic and lumbar spine, patterns of neurological injury are different from the cervical spine due to their neuro-anatomical characteristics. Especially, at the thoracolumbar junction, neurological injury patterns with their respective prognosis vary from the complete cord injury or conus medullaris syndrome to the cauda equina syndrome according to the injury level. The concept of Holdsworth's instability based on the posterior ligament complex theory has evolved into the current 3-column theory of Denis. Flexion-rotation injury and fracture-dislocation are well known to be unstable that surgical fixation is frequently needed for these injuries. However, there have been some controversies for the stability of burst fractures and their treatment, such as indirect or direct decompression and anterior or posterior approach. In this article, current concepts and management of traumatic instabilities at the thoracic and lumbar spine have been reviewed and summarized.

Anterior Cervical interbody Fusion with Cervical Spine Locking Plate.: Joo Tae Park, Gil Young Ahn, Young Tae Lee, Myun Whan Ahn; Yeungnam Univ J Med. 1997;14(1):209-219. Published online June 30, 1997; DOI: https://doi.org/10.12701/yujm.1997.14.1.209

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Abstract PDF: OBJECTIVES
Anterior approach to achieve arthrodesis of the cervical spine has become a widely accepted and often-used approach since its earliest reports by Bailey and Badgley, Smith and Robinson and Cloward. However, anterior interbody fusion in the presence of the presence of the posterior instability may be complicated by the bone graft dislodgement, kyphotic defomity or nonunion. As an attemp to prevent this undesirable complication, additional methods such as skeletal traction, halo appratus or even posterior fusion has been utilized. Therefore, The cervical spine locking plate(CSLP) with the anterior intervertebral body bone grafting provide immediate cervical stabilization and widely successful in achieving fusion. MATERIAL AND METHODS: This study analysed 14 patients who underwent a single anterior procedure and application of CSLP for the treatment of the cervical spinal disorder. Eleven patients were disc herniations and three patients were traumatic lesion. The average ago of the patient was 47 years and the mean follow up periods was 20 months ranging from 13 to 27 months. RESULTS: Ambulation was started 2nd day after the operation with the aid of the Philadelpia orthoses. Bone union was observed 13 cases on average 12 weeks after operation. The one case was nonunion with plate breakage without clinical symptom. CONCLUSION: Anterior fusion with CSLP are thought to be a safe and valuable method for treating cervical spine disorder.

Histological Observation of Bone Reaction with Relation to Surface Treatment of Titanium.: Myun Whan Ahn, Yong Sug Choi, Jong Chul Ahn, Jae Sung Seo, Dong Chul Lee, Jae Hyuk Jang; Yeungnam Univ J Med. 1996;13(1):116-133. Published online June 30, 1996; DOI: https://doi.org/10.12701/yujm.1996.13.1.116

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Abstract PDF: The biocompatibility of the titanium has been estabilished through various experimental studies such as cell culture toxicity test, pyrogen test, mutagen test and others. In order to confirm biocompatibility after fabrication of titanium and to clarify the difference between the bone reaction after insertion of the lathed titanium rods and the bone reaction after insertion of the finished and polished rods, both rods were implanted into the proximal femur of a rabbit. Histologic reactions in the bone were observed according to the ASTM standards at the intervals of 6 weeks, 12 weeks and 26 weeks after implantation. The result were as follows In 6 weeks after implantation of lathed titanium rods, inflammatory reactions, such as minimal degree infiltration of polymorphonuclear leukocytes and lymphocytes were observed in all cases. This was thought to be caused by surgical trauma. However, inflammatory cell infiltration was not seen after implantation of polished and finished rods in all cases. The cellular infiltration and the histologic reaction of the bone after implantation of lathed group were significantly more pronounced than those after implantation of the finished group. In 12 weekt after implantation of lathed rods, two of four cases revealed a minimal degree of cellular infiliration and histologic reaction seemed to be more pronounced in the lathed group, but they were not significant statistically.

Treatment of the tibia shaft fractures with ender nails.: In Ki Kim, Dong Chul Lee, Jae Sung Seo, Myun Whan Ahn, Se Dong Kim, Jong Chul Ahn; Yeungnam Univ J Med. 1992;9(1):130-136. Published online June 30, 1992; DOI: https://doi.org/10.12701/yujm.1992.9.1.130

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Abstract PDF: Fractures of the tibial shaft are the most common among the long bone fractures, and have much difficulty in treatment due to their numerous complications. Thirty patients with fractures of the tibial shaft were treated with Ender nails under the image intensifier at the Department of Orthopedic Surgery, Yeungnam University Hospital from December 1986 to November 1991. The following results were observed. 1. The average age was 37.3 years and the number of male was three times of the female. The most common cause was traffic accident. 2. Twenty cases out of thirty one were closed fracture and the remaining 11 were open. The comminuted and segmental fractures were 18 (57.7%) in number and the most common fracture site was the middle one third (53%). 3. Average interval from injury to operation was 7.6 days and 19 cases showed associated injuries. 4. The mean duration of the bone union was 18.9 weeks and 2 cases showed the delayed union. 5. Twelve complications were noted such as shortening, varus deformity, delayed union, ankle motion limitation, nail irritation, and soft tissue infection.

Two cases of disc internal disruption syndrome.: Jong Hyeung Lee, Myun Whan Ahn, Jong Chul Ahn; Yeungnam Univ J Med. 1991;8(1):238-245. Published online June 30, 1991; DOI: https://doi.org/10.12701/yujm.1991.8.1.238

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Abstract PDF: The disc internal disruption syndrome is not well known to us, but the following hypothesis is widely accepted in clinical practice. The disc internal disruption syndrome may develop intractable back pain with aggravated of pain, loss of spinal motion with any physical exercise, leg pain, loss of energy, marked weight loss, and profound depression. The patient with this syndrome will be found to have normal plain roentgenograms, myelograms, CT scans, results of blood examination and neurologic findings. For these reasons, this syndrome was frequently diagnosed by abnormal discographic findings. We had experience with two cases of disc internal disruption syndrome with clinical, roentgenographic and discographic evaluations. Thus we present these case with a brief review of the concerned literature.

Three Cases of Unusual patterns of Pyogenic Spondylitis.: Myun Whan Ahn, Dae Jin Suh, Jong Chul Ahn, Joo Chul Ihn; Yeungnam Univ J Med. 1990;7(2):189-195. Published online December 31, 1990; DOI: https://doi.org/10.12701/yujm.1990.7.2.189

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Abstract PDF: Pyogenic vertebral osteomyelitis is rare. It most commonly occurs at the lumbar area and in the fifth to seventh decades of life. Most individuals present with back pain, abdominal pain, hip pain and meningeal syndrome. We experienced three cases of unusual patterns of pyogenic osteomyelitis. The first case developed after sepsis. The second case developed after open fracture and infection of other site. The third case was misdiagnosed as metastatic cancer. We present these cases with a brief review of literatures.

A study of the cause of metal failure in treatment of femur shaft fracture: Fractographical and clinical analysis of metal failure.: Chun Bae Jeon, Jae Sung Seo, Jong Chul Ahn, Myun Whan Ahn, Joo Chyl Ihn; Yeungnam Univ J Med. 1990;7(1):81-93. Published online June 30, 1990; DOI: https://doi.org/10.12701/yujm.1990.7.1.81

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Abstract PDF: The author fractographically analyzed the cause of metal failure (the first time this procedure has been used for this metal failure) and also analyzed in clinically. In this study, I selected eight cases which have been analyzed fractographically. In all these cases, the analysis was done after treatment of metal failure of implants internally fixed to femur shaft fractures at the Department of Orthopedic Surgery, Yeung-Nam University Hospital during the six year period from May 1983 to September 1989. 1. Metal failure occurred in five dynamic-compression plates, one Jewett nail, one screw in Rowe plate, and one interlocking nail. 2. The clinical cause of metal failure was deficiency of medial buttes in five cases, incorrect position of implant in one case, and incorrect selection of implant in two cases. 3. The time interval between internal fixation and metal failure was four months in one case, between five months to twelve months in six cases, three years in one case. 4. The fractographically analytical cause of metal failure was ; first, impact failure, one case, second, fatigue failure, six cases, machining mark (stress riser), four case type: low consistent cyclic fatigue failure irregular cyclic fatigue failure third, stress corrosion crack, one case. 5. 316 L Stainless Steel has good resistance to corrosion. However, when its peculiar surface film is destroyed by fretting, it shows pitting corrosion. This is, perhaps, the main cause of metal failure. 6. It is possible that mechanical injury occurred in implants during the manufacturing of implants or that making a screw hole in the main cause of metal failure.

A Clinical Study of Femur Neck Fractures.: Hwan Mo Koo, Myun Whan Ahn, Joo Choul Ihin; Yeungnam Univ J Med. 1990;7(1):69-80. Published online June 30, 1990; DOI: https://doi.org/10.12701/yujm.1990.7.1.69

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Abstract PDF: A clinical analysis was done on 23 patients (24 hips) with fracture of the femoral neck, who had been admitted and treated at our Orthopedic department during the period of 4 years, from Jan. 1984 to May 1988. The results were as follows 1. 23 patients were comprised of 4 males and 19 females, and 11 patients were over 65 years old. 2. 18 cases of 24 cases were due to minor traumas such as slipping down, and for over 65 years old, all cases were due to simple minor traumas, 8 cases were showed a severe osteoporosis, below grade 3 of the Singh's index. 3. 14 cases of 24 cases were displaced subcapital fractures, and 6 cases displaced transcervical fractures. Only 4 cases were the undisplaced transcervical fractures. 4. In treatment of fractures internal fixations after manipulation were performed in 14 cases and primary arthroplasties in 10 cases. Secondary arthroplasties were done in complicated 4 cases of 14 cases treated with internal fixations. 5. Complications after internal fixation were developed in 7 cases out of 14 cases, avascular necrosis in 6, nonunions in 2, pin migrations in 3, and metal failure in 1 case. 6. In 14 arthroplasty immediate surgical fitness of femoral stem were related to late loosening of femoral stem (correlation coefficient γ=–0.68, p<0.01).

Photoelastic analysis of the Stress distribution on an intervertebral disc.: Hyun Kug Shin, Jae Chang Lee, Myun Whan Ahn, Jong Chul Ahn, Joo Chul Ihn; Yeungnam Univ J Med. 1989;6(2):223-239. Published online December 31, 1989; DOI: https://doi.org/10.12701/yujm.1989.6.2.223

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Abstract PDF: To observe the change in the status of stresses according to three different postural angulation of an intervertebral disc with or without nucleus pulposus, 6 specimens of a 3-dimensional photoelastic model of the spine were made of epoxy. The nucleus pulposus portion was replaced with silicon in three models, and the three were made without silicon. Through axial application of a vertical compressive load of 8 kg, the peculiar patterns of the isochromatic fringes were observed. Stresses on the intervertebral disc were analyzed according to three different postural angulations of the intervertebral disc with the nucleus pulposus and without the nucleus pulposus. The results of these study are as follow: 1. In an erect neutral posture with the nucleus pulposus, the stress concentration was much increased at the posterior portion rather than at the anterior portion. Also, the high stress was concentrated at the medial and central portion. In an erect neutral posture without the nucleus pulposus, the stress concentration was much increased at the anterior portion rather than at the posterior portion and the stress distribution seemed to be locally concentrated. 2. In a maximal flexed posture, the stress concentration was much increased at the posterior portion rather than at the anterior portion. Comparing the presence of the nucleus pulposus with the absence of the nucleus pulposus, the stress concentration was lower at the anterior portion in the presence of the nucleus pulposus than in the absence of the nucleus pulposus. However, the stress distribution at the posterior portion was nearly same in the two groups. According to the analysis of the stress distribution diagram, as a whole, the stress pattern around the disc was evenly distributed. 3. In a maximal extended posture, the higher concentration of the stress distribution at the anterior and medial portion rather than in the posterior and lateral portion was observed. The stress concentration was higher in the presence of the nucleus pulposus than in the absence of the nucleus pulposus. 4. Comparing the maximal flexed posture with the erect neutral posture, the stress concentration in the flexed posture was much decreased in the posterior portion rather than in the erect neutral posture, and an even distribution of the stress pattern in the flexed posture was observed. 5. In the presence of the nucleus pulposus, at the anterior and posterior portion, the stress concentration in the flexed posture was much decreased compared with the extended posture. In the absence of the nucleus pulposus, at the anterior and posterior portion, the stress concentration in the extended posture was much decreased compared with the flexed posture.

The Effect of Tension Band Wiring in the Treatment of the Olecranon Fracture.: Joo Chul Ihn, Jong Chul Ahn, Sae Dong Kim, Myun Whan Ahn, Jae Sung Seo; Yeungnam Univ J Med. 1985;2(1):59-63. Published online December 31, 1985; DOI: https://doi.org/10.12701/yujm.1985.2.1.59

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Abstract PDF: Treatment of the olecranon fractures by prolonged immobilization often results in limited elbow motion. With the use of tension band wiring, anatomical reduction was obtainable, and only a short period of immobilization was needed. We reviewed the cases of 17 patients who underwent surgical treatment of the olecranon fracture. All patients were treated by tension band wiring. In the overall series, we were able to obtain 53 percent excellent, 30 percent good, and 18 percent fair results.

A Case of the Solitary Neurofibroma at the Median Nerve.: Joo Chul Ihn, Jong Chul Ahn, Sae Dong Kim, Myun Whan Ahn; Yeungnam Univ J Med. 1984;1(1):199-206. Published online December 31, 1984; DOI: https://doi.org/10.12701/yujm.1984.1.1.199

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Abstract PDF: With respect to the histogenesis of the neurofibroma, there are many controversies, since von Recklinghausen postulated that neurofibromas are mainly fibrous tumors arising from the connective tissue of the nerve sheaths. According to the recent studies through the electron microscope, the neoplastic perineurial cells are regarded as the main components of the tumor. So, the neurofibroma enucleated from the median nerve at the level of proximal arm without resulting neurologic sequale was examine through the light-and electron microscope. Ultrastructurally, this tumor is composed of the perineurial cells, fibroblasts, and collagen fibers. The predominant perineurial cells show distinct basal lamina, and contain abundant microfilaments.

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