摘要:

Study Design.The human leukocyte antigen (HLA) haplotypes in families of patients with known ossification of the posterior longitudinal ligament (OPLL) were reviewed.Objective.To clarify how genetic factors relate to the development of OPLL.Summary of Background Data.The association between genetic factors and the development of OPLL is still unknown.Materials and Methods.The association between HLA haplotypes and OPLL was studied in families of 24 patients with OPLL.Results.The prevalence of OPLL was higher in the siblings showing a higher share of identical HLA haplotypes: 10 (53%) of 19 with concurrence of two strands, and 5 (24%) of 21 with concurrence of one strand. Of 21 subjects who had no HLA haplotype identical with that in OPLL patients, only one showed evidence of OPLL.Conclusion.Genetic factors predispose toward the development of OPLL.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.Histologic examination was performed on the autologous intervertebral disc material that was removed from the intervertebral space at L1–L2 and then relocated to the L4 posterior epidural space after the addition of basic fibroblast growth factor (bFGF) in a rabbit.Objectives.To evaluate whether basic fibroblast growth factor influences the resorption process of the herniated intervertebral disc through the promotion of angiogenesis and chemotaxis.Summary of Background Data.It has been reported that newly formed vessels, inflammatory cells, and their products may play an important role in the spontaneous resorption process of herniated intervertebral discs. In a rabbit model that mimics the sequestration type of intervertebral disc herniation, it has been reported that the autologous intervertebral disc material that relocated into the epidural space was penetrated by newly formed vessels originating from the epidural fat tissue. Therefore, it is possible that promotion of angiogenesis may influence the resorption of herniated intervertebral discs. Basic fibroblast growth factor is well known as an angiogenesis stimulation factorin vivo.—Methods.Thirty-six adult rabbits were divided into three groups. The L1–L2 intervertebral disc was partially incised through a retroperitoneal approach in each rabbit. The harvested disc material, which contained nucleus pulposus and anulus fibrosus, was immersed in one of three kinds of solution before relocation into the posterior epidural space at L4. In the control group, the harvested intervertebral disc was immersed in physiologic saline for 2 hours before relocation. In the group receiving 5 &mgr;g bFGF, the disc was immersed in 5 &mgr;g/mL bFGF for 2 hours before the relocation. In the group receiving 20 &mgr;g bFGF, the disc was immersed in 20 &mgr;g/mL bFGF for 2 hours before the relocation. Rabbits of each group were killed for histologic examination 1, 2, 4, and 8 weeks after surgery.Results.In the bFGF-treated groups, newly formed vessels were observed to be in more numerous than those in the control group, 1 and 2 weeks after surgery. The number of inflammatory cells, including macrophages, lymphocytes, and fibroblasts, also increased in the bFGF-treated groups. The period from the surgery to the degradation of the intervertebral disc in the bFGF-treated groups was shorter than that in the control group, although the resorption process of the relocated discs was also observed in the control group. The size of relocated intervertebral discs in the bFGF-treated groups decreased at a higher rate than in the control group as time progressed. The rate of decrease in the size of discs in the group treated with 20 &mgr;g bFGF was more than that in the group treated with 5 &mgr;g.Conclusions.Epidural injection of bFGF facilitated the resorption of the intervertebral disc relocated to the epidural space.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.Thirteen spinal fixators with 26 stabilization bridges and 52 pedicle screws and a mean length of implantation of 10 months were prospectively examined for corrosion.Objectives.To determine the type of corrosion and the correlation between the construction of the spinal fixator and the type of corrosion.Summary of Background Data.Evidence of fretting and crevice corrosion is seen in many stainless steel implants in retrieval studies. Such reactions have not been described in the literature on spinal fixator systems.Methods.Macroscopic and microscopic alterations in the adjacent tissue were examined, and the corrosive alterations were documented photographically using stereoscopic optical light microscopy. The chemical composition of the implants was determined spectrographically. Microradiography and x-ray fluorescence analysis of the soft tissue were performed.Results.At surgery, tissue discoloration was found in four cases. Histologic examination showed extensive fibrosis, foreign body reaction and inflammation associated with a small number of metal particles, indicating metallosis in five cases. Corresponding particles were detected by microradiography. Corrosion was found on 13 telescopic rods and on two pedicle screws. The alterations on the telescopic rods could be interpreted as crevice corrosion and the alterations in the pedicle screws as fretting corrosion. The two monobloc fixator bridges did not show signs of corrosion. In these implants, the neighboring tissue was macroscopically inconspicuous, and histologic examination showed minimal fibrosis or presence of metal particles. Spectrographic examination of the spinal fixators showed no structural imperfection.Conclusions.The construction constraints of a spinal fixator make it prone to corrosion. New spinal implants should be examined not onlyin vitrobut alsoin vivoto ascertain whether corrosion and adjacent tissue reaction occur. Corrosion is one reason to explant the internal fixation system after fusion of the spinal fracture.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.A prospective, blind study was conducted to investigate the factors underlying the decisions of expert clinicians in diagnosis of acute, benign low back pain, compared with results obtained with an automated physical examination by machine. From the results, a strategy to significantly improve clinical diagnosis in cases of discordance was determined.Objectives.To identify factors in the clinical assessment of low back pain that indicate when independent diagnostic testing would be useful.Summary of Background Data.The clinical evaluation of low back pain is often dominated by subjective reports of pain. Published medical literature has underscored several inherent weaknesses of the clinical examination, and concerns have been raised about its effectiveness for assessing patients with low back pain. Thus, it has been proposed that objective measures to complement the clinician’s examination would be beneficial in the formulation of dependable diagnoses.Methods.Randomly designated subjects, who in describing their conditions were objective or role playing, were assessed by clinicians and a machine for diagnosis of low back pain assessmentversusnormal backs. Each subject’s pain assessment was compared with a gold standard that was established by experts in low back pain. Components of the clinical examination were analyzed to assess which were the most informative in making a reliable diagnosis. The information content of the machine assessment was also analyzed and a strategy to complement the clinical diagnosis with the machine diagnosis determined.Results.Discordance among the various components of the clinical examination was a strong indicator of when the efficacy of the clinical examination dropped below a random level of decision making. When there was discordance, incorporating the functional evaluation by machine into the clinical diagnosis improved the performance of the clinician. Notably, in nonobjective subjects, the accuracy of diagnosis was enhanced by as much as 69%.Conclusions.It is possible to improve the accuracy of clinical diagnosis by incorporating a functional evaluation by machine when there is discordance between physicalexamination findings and reported pain.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.A prospective observational study on the use of the Aberdeen Low Back Pain Disability Scale.Objective.To evaluate the reliability, validity, and responsiveness of the Chinese adaptation of the Aberdeen Low Back Pain Scale in Chinese patients in Hong Kong who have back pain.Summary of Background Data.Frontline clinicians, researchers, and health care managers in Hong Kong are urgently in need of a Chinese adaptation of a low back pain outcome measure that has been subjected to a rigorous process of psychometric and clinical testing.Methods.Four samples with 473 consecutive adult patients with low back pain from six physiotherapy outpatient departments in Hong Kong who completed the Aberdeen Low Back Pain Scale were observed and measured at time points including the beginning physiotherapy; 10 days, 3 weeks, and 6 weeks after physiotherapy; and when discharged from treatment.Results.The test–retest reliability coefficient was 0.94 (0.94 in the original English version; figures from the English version are reported in parentheses). The Cronbach &agr; coefficient was 0.85 (0.80). The Spearman correlation coefficient, when the Aberdeen score was correlated with that of a generic current 42-item questionnaire regarding the patient’s perceived health to establish cross-sectional construct validity, was 0.59 (0.36–0.66, with the Short Form 36 scale). The effect sizes (responsiveness) at weeks 3 and 6 after treatment began were 0.59 and 0.81, respectively (a high of 0.62 reported in the English version).Conclusions.The Chinese version of the Aberdeen Low Back Pain Disability Scale retained the high levels of reliability, validity, and responsiveness of the original English version when tested in Hong Kong in four samples of Chinese patients with low back pain.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.An analysis of consecutive adult patients treated surgically with anterior column structural allografts for sagittal plane abnormalities.Objectives.To evaluate the effectiveness of anterior structural allografts in maintaining long-term sagittal plane correction when combined with posterior spinal fusion and posterior segmental spinal instrumentation and to assess anterior allograft incorporation into adjacent vertebral bodies a minimum of 5 years after implantation.Summary of Background Data.There is no study in the literature in which incorporation and remodeling of anterior column structural allografts with minimum 5-year follow-up are assessed. Do they collapse or resorb or sustain stress fractures between a 2-year and 5-year follow-up?Methods.Twenty-three consecutive adult patients (mean age, 45 years; range, 25–63 years) had a combination of anterior structural fresh-frozen allograft plus posterior autogenous grafting and posterior segmental spinal instrumentation performed from June 1988 through August 1992. All patients had sagittal plane abnormalities, and all surgeries were performed by the same surgeon. Twenty of the 23 patients returned for follow-up examinations for at least 5 years (average, 7 ± 3 years; range, 5 ± 4–10 ± 3 years). Diagnoses included kyphoscoliosis (n = 8), spondylolisthesis (n = 3), degenerative disc disease (n = 3), and acute or chronic fracture (n = 6). The allografts spanned only disc spaces in 16 patients, and vertebral bodies and disc spaces in 4 patients. Forty disc spaces and four vertebral bodies were grafted, and 67 structural allografts were placed. Upright radiographs were analyzed before surgery, immediately after surgery, and at final follow-up examination to assess the degree of anterior allograft incorporation and maintenance of sagittal correction. A strict 4-point grading system was used. Two independent observers, not involved with surgical procedures, analyzed the radiographic results.Results.Of the 67 structural allografts, 66 (98.5%) showed incorporation. Both observers concluded that none of the 67 structural allografts showed evidence of collapse. In all grafted levels and in any patient, there was no difference in sagittal plane measurements obtained immediately after surgery and those obtained at follow-up examinations 2 years and 5 or more years after surgery.Conclusions.Anterior fresh-frozen structural allograft works effectively in the long term to maintain correction of sagittal plane abnormalities if combined with posterior fusion and instrumentation. A minimumof 5 years after surgery, there is a high rate of structural allograft incorporation into the adjacent vertebral bodies.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.Determination of the fusion level by direct observation and palpation of anatomic landmarks is compared with the finding obtained from a lateral intraoperative radiograph.Objectives.To assess the reliability of the use of intraoperative anatomic landmarks in determination of the fusion level.Summary of Background Data.Accurate determination of the level to be fused in noninstrumented posterolateral fusion is crucial. No studies are available in which the value of direct observation and palpation of the anatomic landmarks in determination of the fusion level has been assessed.Methods.Eighty patients who underwent posterolateral fusion without instrumentation in the lumbosacral spine were included in this study. During surgery, first, the cephalad transverse process at the desired level to be fused was determined by direct observation and palpation of the anatomic landmarks; second, a metal mark was placed beneath the cephalad transverse process at the level determined by anatomic landmarks. This was followed by a lateral radiograph. The consistency and discrepancy between the use of the anatomic landmarks and lateral radiography in determining the desired fusion level were recorded.Results.The fusion level determined by direct observation and palpation of the anatomic landmarks was accurate in 76 (95%) cases. In the remaining four cases, intraoperative x-rays determined that the selection of the cephalad transverse process for fusion was one level too high in three cases and one level too low in the other case. All errors in determination of the level to be fused occurred in patients who had extensive laminectomy at L4–S1.Conclusions.Determination of fusion level by direct observation and palpation of the anatomic landmarks is not reliable in patients who have had or require decompressive procedures. A lateral radiograph should be routinely obtained for accurate identification of the level to be fused.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.Comparison of the radiation dose between the traditional fluoroscopic approach and computed tomography (CT)–based computer-assisted surgery for pedicle screw placement was determined.Objectives.To evaluate the radiation dose delivered by fluoroscopy-controlled pedicle screw placementversusinsertion guided by computer. To define the CT computer-assisted protocol, involving lower radiation exposure for the patient, that still provides acceptable image quality.Summary of Background Data.There are no published data describing the dose delivered in CT-based image-guided surgery, and there are few studies in which the organ dose and the effective dose delivered during pedicle screw insertion that is performed traditionally with fluoroscopic control are described.Methods.Dose measurements were performed on two types (REMAB and RANDO) of anthropomorphic phantoms. Thermoluminescent dosimeters were used to measure the organ dose. Both phantoms were exposed to the fluoroscopic x-ray beam. The representative intraoperative scenario was determined by observation of 20 consecutive surgical interventions featuring pedicle screw implantation. For the CT dose measurement only, the REMAB phantom was used with two types of CT scanners. Three scanning protocols were evaluated: sequential, spiral optimized, and sequential optimized. Optimization of the scanning protocol included changes of anode current. The CT images were subsequently processed to achieve three-dimensional reconstruction of the lumbar spine for the computer-assisted intervention.Results.Organ and effective doses were higher in any of the CT examinations than in the fluoroscopic procedure. There was a slight difference between doses registered during optimized spiral scanning and doses in the calculated optimized sequential CT protocol. Optimized sequential scanning was associated with an effective dose 40% lower than that in nonoptimized sequential scanning. The small anatomic structures of the spine could be easily recognized on each of the three-dimensional reconstructions, and all of them were suitable for use in computer-assisted surgery.Conclusions.Percutaneous pedicle screw insertion in the lumbar region of the spine, performed using fluoroscopic control, requires a lower radiation dose than do CT scans necessary for computer-assisted surgery. The CT radiation dose can be significantly decreased by optimization of the scanner settings for computer-assisted surgery. The advantages of computer-assisted surgery justify CT scans, when based on correctly chosen indications.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.A case of bilateral failure of fusion of the C2 neural arch resembling a bipedicular fracture in a 9-year-old boy involved in a motor vehicle accident.Objectives.To describe the use of helical computed tomography and three-dimensional reconstruction images to identify the defect as congenital.Summary of Background Data.Congenital defects in the C2 neural arch are rare. Diagnostic difficulties arise when they are discovered during the assessment of patients after trauma, when they may resemble C2 arch fractures.Methods.Lateral cervical spine radiograph, transverse section computed tomography, and three-dimensional reconstruction images were used to delineate the anatomy of the defect.Results.The three-dimensional reconstruction views showed that normal alignment of the vertebrae was maintained, despite the pedicle defects.Conclusions.Differentiation of a C2 fracture from a congenital defect may be difficult. Reconstruction in three dimensions from helical computed tomography is a useful adjunct to conventional computed tomography in the evaluation of such patients.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.Case report.Objective.To provide additional information on possible relations between uterine and spinal manifestations of leiomyosarcoma.Summary of Background Data.Spinal metastases and primary spinal manifestation of leiomyosarcoma and other malignant smooth muscle tumors are rarely observed.Methods.Clinical and radiologic follow-up of a patient with a spinal tumor.Results.A 46-year-old women had rapidly progressive paraplegia caused by an extramedullary lesion in the extradural space at T2–T3, with spinal cord compression. After surgical decompression, the resected tumor was histologically classified as a leiomyosarcoma. Diagnostic work-up failed to detect the primary tumor site. Previous medical history had been uneventful except for hysterectomy 3 years earlier for a leiomyoma. Extended necroses and focal metaplasia were already described in the hysterectomy specimen indicating malignant disease; however, it was not definitely diagnosed. Multiple leiomyosarcoma metastases developed 22 months later.Conclusions.In retrospect, the origin of the leiomyosarcoma that manifested in the thoracic spine of the patient must be reconsidered. Rather than a primary dural leiomyosarcoma, this tumor represented the first evidence of recurrence of a missed diagnosis of early-stage uterine leiomyosarcoma.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID