摘要:

Study Design.An anatomic study of the peripheral nerves innervating the occipital region.Objectives.To study the topography of the extracranial occipital nerves, to define optimal locations for anesthetic nerve blockades, to provide guidelines to use with the suboccipital surgical approach, and to search for structures with putative pathogenetic implications in cases of unilateral headache.Summary of Background Data.There is little consensus in the literature concerning the sensory innervation of the scalp. Previous clinical and morphologic studies have not proven the existence of an entrapment mechanism in cases of unilateral head pain. Specific sites for anesthetic blockades have been defined only partly with reference to topographic landmarks.Methods.The topography of the greater occipital (n = 20), the minor occipital (n = 19), and the greater auricular nerves (n = 17) was studied by dissection of 10 embalmed cadavers. Measurements of internerve distances and distances to defined landmarks were supplemented by drawings and photographs.Results.A great variability in nerve topography was seen interindividually and intraindividually. The greater occipital nerve ascended between 5 mm and 28 mm from the midline along the intermastoid line. The minor occipital nerve was found between 32 mm and 90 mm from the midline along the same landmark. In most cases, both the greater occipital nerve and the minor occipital nerve pierced the aponeurosis after branching. Thirteen greater occipital nerves and eight minor occipital nerves also were embedded in this tissue. Twelve of the 20 greater occipital nerves formed a rich network around the occipital artery. However, anatomic structures with an imminent risk of causing entrapment were not observed.Conclusion.The results of this study suggest that optimal locations for blockade techniques should be reconsidered. The acquired knowledge concerning greater auricular and minor occipital nerves behind the sternocleidomastoid muscle may aid in preventing intraoperative injuries.

ISSN:0362-2436    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Study Design.Anterior shearing force was applied to immature calf lumbar functional spinal units until failure.Objectives.To clarify the mechanism of slippage in immature calf lumbar spines with pars defects as a first step to understand the mechanism of spondylolisthesis in pediatric human lumbar spines.Summary of Background Data.Progression from lysis to olisthesis occurs during the adolescent growth spurt. However, the mechanism of slippage in the immature lumbar spine has not yet been understood clearly.Methods.Bilateral pars defects were created at the rostral vertebra. The specimens then were assigned to one of the two groups: functional spinal units with intact disc (n = 5) and with disc dissected (n = 5). In the former group, the disc was left intact, whereas in the disc dissected group, the anterior longitudinal ligament and 75% of the anterior-to-posterior depth of the disc were incised along the mid-disc plane. Using a uniaxial MTS machine (MTS System, Minneapolis, MN), anteroposterior shearing force was applied to each specimen. Failure load and displacement at failure were calculated from the load-displacement curve. Failure sites also were assessed radiographically and histologically.Results.The five functional spinal units in the intact disc group failed at 973.8 ± 78.1 N, whereas specimens in the disc dissected group failed at 986.4 ± 124.2 N. The data showed no significant differences between the two groups. All the specimens showed displacement through the growth plates on radiographs. Histologically, failure was observed to occur between the superior growth plate and osseous endplate of caudal vertebra, indicating that this site is the weakest link.Conclusions.The results suggest that in the pediatric immature lumbar spine with pars defects, slippage may occur between the growth plate and osseous endplate.

ISSN:0362-2436    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:0362-2436    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Study Design.A retrospective case-control study was performed using the radiographs taken at the first hospital visit in two groups; in one group, spondylolisthesis developed after the first hospital visit, and, in the other, spondylolisthesis had not developed over 10 years.Objectives.To determine possible radiographic differences between these two groups to clarify the pathoanatomic mechanisms of anterior slipping.Summary of Background Data.The etiology of degenerative spondylolisthesis, for example, underlying pathoanatomic mechanisms such as dysfunction of the disc or horizontalization of the lamina and the facets, has been difficult to resolve, because radiographs taken before the occurrence of the slip have not been available in previous investigations.Methods.Sixty-nine patients with spondylolisthesis in whom degenerative spondylolisthesis developed after the first hospital visit and for whom radiographs taken before the slip were available were studied retrospectively. In 63 patients slipping did not develop over 10 years, with or without intervertebral instability; these patients were studied as a control group. The radiographs taken before and after the occurrence of the slip in the patients with spondylolisthesis were examined and compared with those without spondylolisthesis. Dysfunction of the disc, horizontalization of the lamina and the facets, and the sagittal alignment of the facet joints were assessed in each group.Results.Patients in whom anterior slipping developed had signs indicating that horizontalization of the lamina and the facets had occurred before the slip. However, the patients in whom spondylolishesis did not develop had no horizontalization of the lamina and the facets at the first hospital visit or during the follow-up period. There was no significant difference in dysfunction of the disc between the cases with and without spondylolisthesis. Sagittal alignment of the facet joints was seen more frequently in the patients in whom slipping occurred than in patients with no spondylolisthesis, but approximately 40% of the patients in whom slipping occurred did not demonstrate sagittal alignment.Conclusion.Horizontalization of the lamina and the facets is a pathoanatomic risk factor that can predispose for the development of degenerative spondylolisthesis. If dysfunction of the disc occurs in addition to these conditions, spondylolisthesis may develop.

ISSN:0362-2436    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Study Design.Sequential study of magnetic resonance images of the lumbar spine.Objectives.To determine the variation in position of the conus medullaris in a living adult population without spinal deformity.Summary of Background Data.Cadaveric studies have shown that the position of the conus medullaris in the adult most commonly is located at L1-L2. There have been several studies documenting the changing level of the conus throughout infancy and childhood, but there is no detailed study that documents the range of conus positions in a living adult population without spinal deformity.Methods.The T1-weighted, midline, sagittal, spin-echo magnetic resonance imaging studies of 504 patients were assessed to identify the tip of the conus medullaris. This location was recorded in relation to the upper, middle, or lower third of the adjacent vertebral body or the adjacent intervertebral disc.Results.The study group consisted of 231 men and 273 women with a mean age 46 years (range, 16-85 years). Most patients were being examined for low back pain. Patients with spinal deformity were excluded. The mean conus position was the lower third of L1 (range, middle third of T12 to upper third of L3). The variation in conus positions followed a normal distribution. No significant difference in conus position was seen between male and female patients or with increasing age.Conclusions.The distribution of conus location in a large adult population was shown to range from the middle third of T12 to the upper third of L3.

ISSN:0362-2436    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Study Design.A questionnaire was mailed to 3000 randomly selected 35-45-year-old individuals in three communities in central Sweden.Objectives.To study the 1-year prevalence of spinal pain and its ramifications in the form of pain, function, sick leave, and health care use.Summary of Background Data.Previous researchers have used a variety of definitions and populations, but primarily have investigated the occurrence of pain. Comprehensive data are needed concerning health care use, the degree of the pain problem, functional disturbances, and sick leave.Method.Participants in the study completed a questionnaire regarding spinal pain during the past year including the degree of their experienced pain, functional impairment, lost work days, and health care use.Results.A total of 2305 people (78.5%) responded to the questionnaire. Nonrespondents had similar characteristics but a slightly lower 1-year prevalence rate than did respondents. For respondents, the prevalence of spinal pain during the past year was 66.3%, with women having a slightly higher prevalence than men. Approximately 25% of the respondents indicated that they had a substantial problem based on ratings of pain, functional impairment, and sick leave. Work absenteeism reported to the Public Social Insurance Office involved 19% of those with pain, but an additional 15% indicated unreported absenteeism. On average, those with pain visited health care providers three times during the past year, but a small number of those who experienced pain consumed large amounts of health care and illness benefits. An important gender difference was shown, such that when pain was at its worst, men took sick leave, whereas women sought health care.Conclusions.Taken together, these data indicate that spinal pain is common among 35-45-year-old men and- women, and that it is related to marked problems for approximately one fourth of those who experience pain. Gender differences exist in the pattern of sick leave and health care use, and a small proportion of those with pain consume very large amounts of the resources. Consequently, there is a need for early, effective, preventive treatments.

ISSN:0362-2436    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Study Design.Prospective cohort study.Objectives.To assess the amount of scar tissue by viewing magnetic resonance images, and to evaluate the correlation between the amount of scar tissue and clinical outcome, surgical technique, and fibrinolytic factors.Summary of Background Data.The influence of fibrinolytic factors on magnetic resonance images has not been investigated previously. The relation between clinical outcome and findings on magnetic resonance imaging remains uncertain.Methods.Magnetic resonance imaging at 0.5 Tesla was performed to produce sagittal and axial spin-echo T1-weighted images before and after contrast enhancement on 78 patients 7 years after traditional lumbar discectomy with partial or full laminectomy. Before surgery all patients had been tested for fibrinolytic factors.Results.The overall clinical success rate of the surgery was 73%. No evidence of scar formation was seen in 19 patients, a small amount was seen in 36 patients, a moderate amount in 17 patients, and a large amount was observed in 6 patients. Ten patients who had undergone surgery at two disc levels and 18 who had been treated with full laminectomy exhibited more scar tissue than those patients who had undergone surgery on a single level (P= 0.033) and those who had undergone a partial laminectomy, respectively (P= 0.017). The amount of scar formation also was associated with a poor outcome (P= 0.017) and with low preoperative values of tissue plasminogen activator antigen (P= 0.003) and tissue plasminogen activity (P= 0.048) in samples collected after venous occlusion. The intensity of contrast enhancement, however, was not influenced by these or any other parameters.Conclusion.The amount of scar formation after lumbar discectomy seems to be related to the clinical outcome, the size of the surgical exposure, and some fibrinolytic factors.

ISSN:0362-2436    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Study Design.An analysis of the outcome and effectiveness of instrumented arthrodesis of the lumbosacral spine in elderly patients conducted using a review of records, assessment of fusion via plain radiographs, and a two-part questionnaire.Objective.To ascertain the outcome and efficacy of instrumented arthrodesis of the lumbosacral spine in patients 60 years of age and older.Background Data.From 1987 to 1991, 38 patients of at least 60 years of age underwent instrumented arthrodesis of the lumbosacral spine using the Wiltse or Selby pedicle screw fixation system (Advanced Spine Fixation Systems, Inc., Irvine, CA). Patients were considered for surgery only after attempts at conservative management, including physical therapy, medication, injection blocks, and home exercises, had proven unsuccessful.Methods.Follow-up examinations were performed 3 months, 6 months, 1 year, and 2 years after surgery. Fusion was assessed using plain radiographs, including flexion-extension films. Inpatient and outpatient records were reviewed, and a two-part questionnaire was used to establish the effect of surgery on function and lifestyle. Thirty patients responded to the questionnaire. Follow-up observation of the patients ranged from 25 to 56 months. The mean age was 73.8 years (range, 60-90 years).Results.The mean co-morbidity was 1.7. Based on the authors' method of evaluation of fusion, the fusion rate was 92%. Fifty-seven percent of the patients reported excellent or good results, 26% reported fair results, and 17% reported poor results. Functional gains of 50% or more were reported by 71% of the respondents. Female patients had significantly more complications than male patients, but reported comparable outcomes.Conclusion.Despite the increase in age, co-morbidity, and associated risk of perioperative complications inherent in this population, an outcome comparable with that of younger patients is reported.

ISSN:0362-2436    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Study Design.Eighteen patients with lumbar instability from fractures, postlaminectomy syndrome, or infection were treated prospectively with minimally invasive retroperitoneal lumbar fusions.Objectives.To determine if interbody Bagby and Kuslich fusion cages and femoral allograft bone dowels can be inserted in a transverse direction via a lateral endoscopic retroperitoneal approach to achieve spinal stability.Summary of Background Data.Endoscopic spinal approaches have been used to achieve lower lumbar fusion when instrumentation is placed through a laparoscopic, transperitoneal route. However, complications of using this approach include postoperative intra-abdominal adhesions, retrograde ejaculation, great vessel injury, and implant migration. This study is the first clinical series investigating the use of the lateral retroperitoneal minimally invasive approach for lumbar fusions from L1 to L5.Methods.Eighteen patients underwent anterior interbody decompression and/or stabilization via endoscopic retroperitoneal approaches. In most cases, three 12-mm portals were used. Two parallel transverse interbody cages restored the neuroforaminal height and the desired amount of lumbar lordosis was achieved by inserting a larger anterior cage, distraction plug, or bone dowel.Results.The overall morbidity of the procedure was lower than that associated with traditional "open" retroperitoneal or laparotomy techniques, with a mean length of hospital stay of 2.9 days (range, outpatient procedure to 5 days). The mean estimated intraoperative blood loss was 205 cc (range, 25-1000 cc). There were no cases of implant migration, significant subsidence, or pseudoarthrosis at mean follow-up examination of 24.3 months (range, 12-40 months) after surgery.Conclusions.This preliminary study of 18 patients illustrates that endoscopic techniques can be applied effectively through a retroperitoneal approach with the patient in the lateral position. Unlike the patients who had undergone transperitoneal procedures described in previous reports, in these preliminary 18 patients, there were no cases of retrograde ejaculation, injury to the great vessels, or implant migration.

ISSN:0362-2436    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Study Design.A case of a late infantile atlantoaxial rotatory fixation is reported for which transoral anterior release was performed.Objectives.To report a patient who underwent transoral anterior release of the dislocated atlantoaxial joint for a case of late infantile atlantoaxial rotatory fixation and quadriparesis.Summary of Background Data.Infantile atlantoaxial rotatory fixation is diagnosed easily by using recently developed imaging techniques such as computed tomography, magnetic resonance imaging, and three-dimensional computed tomography. Nevertheless, patients in whom the condition has been overlooked still are encountered, and the reduction in these patients becomes impossible by traction or by simple posterior open reduction. Few reports on the management of type II-IV chronic atlantoaxial rotatory fixation in which an anterior surgery was performed exist in the literature, and no report exists in which atlantoaxial joint release on the both sides was attained.Methods.A 9-year-old girl had a type III atlantoaxial rotatory fixation and quadriparesis. She received direct skull traction and repeated manual reduction while she was awake or under general anesthesia. Neither reduction nor movement was obtained, according to the radiographs. Therefore, it was necessary to perform open reduction posteriorly and transorally to release the fixed and contracted joints between C1 and C2.Results.After the anterior release of the joints, there was an inherent force preventing a complete rotational reduction. However, after a successful posterior reduction and fusion, and for more than 4 years after surgery, neither rotatory displacement nor neurologic deterioration was noted.Conclusions.The authors suggest that careful transoral anterior release of the atlantoaxial joint permits successful reduction in a case of chronic fixed atlantoaxial rotatory fixation combined with cord compression.

ISSN:0362-2436    

出版商:OVID    

年代:1998

数据来源: OVID