摘要:

Study Design.This study evaluated the dimensions of the laminas from C2 to L5 using adult spine specimens.Objectives.To provide a set of quantitative data for the laminas from C2 to L5.Summary of Background Data.Anatomic evaluation of the pedicle and facet joint in the spine has been extensively reported. No detailed studies of the laminas from the cervical to the lumbar spines exist.Methods.Thirty-seven spines from C2 to L5 were directly evaluated for this study. Anatomic evaluation of the laminas included the laminar height, width, thickness, and angulation.Results.In general, the measurements were greater in male specimens than in female specimens, although significant differences (P< 0.05) between male and female specimens were noted in only three measurements. The greatest laminar height was at T11 (25.1 ± 2.5 mm), and the least was at C4 (10.4 ± 1.1 mm). The greatest laminar width was at L5 (15.7 ± 2.0 mm), and the least was at T4 (5.8 ± 0.8 mm). Laminar widths in the cervical region were slightly more than those in the thoracic region. The greatest laminar thickness was at T2 (5.0 ± 0.2 mm), whereas the least was at C5 (1.9 ± 0.6 mm). Laminar thickness tended to increase in the upper thoracic region and to decrease slightly in the lower thoracic region. The mean laminar thickness of the lower cervical region was least in the whole spine. The widest angle was at C3 (116.1 ± 8.8°) and T7 (112.3 ± 8.0°) and the narrowest was at C2 (99.1 ± 8.0°) and L3 (99.9 ± 6.3°). The slope angles of the laminas varied from 97.8 ± 3.0° at T9 to 129.0 ± 7.5° at L3.Conclusions.Surgical placement of sublaminar instruments may benefit from this quantitative study through the use of the provided anatomic parameters of the laminas.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.In part 1 of the study, the morphometry of thoracic pedicles and bony landmarks for pedicle screw placement were evaluated. In part 2, pedicle screws were inserted in fresh cadavers, using a different entry point in the left and right pedicles.Objectives.To identify the safest entry point and screw orientation for pedicle screws in the thoracic spine.Summary of Background Data.A few morphometric investigations have been performed on thoracic vertebrae, but the safest technique for screw insertion in thoracic pedicles has not been analyzed.Methods.Mean, range, and standard deviations of pedicle transverse diameter and pedicle orientation were measured in 99 dried thoracic vertebrae. We evaluated the position of the bottom of the superior facet and that of the superior border of the transverse process in relation to the center of the pedicle. The relation between the pedicle axis and the superior facet in the frontal plane was also assessed. In part 2 of the study, pedicle screws were inserted in fresh cadavers at the intersection between the superior border of the transverse process and the middle of the superior facet (entry point A) and between the former and the lateral two thirds of the facet (entry point B).Results.The smallest transverse diameter was found at T6 (mean 4.3 mm) where pedicles measured less than 5 mm in 68% of the specimens. In the frontal plane, the pedicle axis intersected the middle of the superior facet in 15% of specimens, the lateral two-thirds in 62%, and the lateral border of the facet in 23%. Of the 126 screws inserted in fresh human cadavers, 15 (24%) of the screws inserted using entry point A and 10 (16%) of those inserted using entry point B violated the pedicle cortex (P> 0.05). Six (10%) of the screws inserted using entry point A compared with no screw inserted using entry point B penetrated the anterior vertebral cortex (P= 0.03).Conclusions.Pedicles between T4 and T8 may not be wide enough for screw fixation. An entry point for pedicle screws located at the intersection between the superior border of the transverse process and the lateral two thirds of the superior facet seems more likely to be in line with the pedicle axis than do other entry points. In the lower thoracic vertebrae this entry point, in combination with insertion of the screws more medially oriented than the pedicle axis, significantly reduces the risk of violating the anterior vertebral cortex.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.Investigation of the effects of recombinant human cathepsin L on intervertebral discs and comparison with the effects of chymopapain.Objective.To evaluate the effects of cathepsin L on intervertebral discs as an agent for chemonucleolysis.Summary of Background Data.Cathepsin L is a typical cysteine proteinase that belongs to the papain superfamily. It plays a major role in intracellular proteolysis and is not believed to induce anaphylactic reactions.Methods.In vivo:Rabbit intervertebral discs were injected with recombinant human cathepsin L, its buffer solution, and chymopapain. After 1, 4, and 16 weeks the animals were killed, and radiologic and histologic examinations were performed.In vitro:The enzymatic actions of recombinant human cathepsin L and chymopapain on human intervertebral disc proteoglycans were examined immunohistochemically using antiproteoglycan antibodies.Results.In rabbit models, roentgenography showed that disc spaces treated with cathepsin L and chymopapain had become narrower 1 week after injection. Histologically, loss of safranin-O staining was observed in the anulus fibrosus of discs treated with cathepsin L. After 16 weeks, nucleus pulposus had regenerated with chondrocyte-like cells, and the safranin-O staining characteristics of the matrix also had recovered. In an immunohistochemical study, all components of the proteoglycan stained weakly after chymopapain digestion. After cathepsin L digestion, unsulfated chondroitin and core protein staining was weaker, but the chondroitin 6-sulfate staining was unaffected.Conclusions.Cathepsin L seems to be an effective agent for chemonucleolysis. Its enzymatic action on proteoglycan appears to be different from that of chymopapain.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.A prospective, randomized, blinded experimental trauma study.Study Objective.The effect of adenosine on arachidonic acid metabolites and lipid peroxidation was investigated in induced spinal cord injury.Summary of Background Data.Effects of adenosine in ischemia-reperfusion models have been studied, but no studies of adenosine's effect on direct trauma to the spinal cord have been reported.Methods.Thirty-seven adult Wistar albino rats were randomly divided into four groups and underwent laminectomy. Group 1 underwent a sham operation. Group 2 received an intravenous adenosine infusion of 100 μg/kg per minute for 30 minutes. In Group 3, a standard spinal cord trauma of 50 g.cm strength was established at the lower thoracic level with a "weight-drop" technique, and Group 4 received an infusion of adenosine (100 μg/kg per minute) for 30 minutes after the trauma.Results.Tissue prostaglandin E2activity was significantly higher in adenosine-treated trauma groups when compared with that in other groups (P< 0.0001). The difference in tissue leukotriene C4activity between control and trauma groups was significant (P< 0.05). Adenosine infusion after trauma limited the increases in lipid peroxidation, with the difference approaching significance atP= 0.06. The structure of myelin was well preserved in the adenosine-treated trauma group. However, the changes were irreversible in severely damaged areas.Conclusion.After acute spinal cord trauma, intravenous adenosine infusion of 100 μg/kg per minute could attenuate progression to secondary injury, but adenosine alone was not effective yet.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.A case report.Objectives.To document the rare condition of staphylococcal osteomyelitis of the odontoid process and to increase knowledge about the clinical characteristics and favorable outcome if patients are managed appropriately.Summary of Background Data.Osteomyelitis of the odontoid process caused byStaphylococcus aureusis a rare disease. A handful of cases have been reported within the last 30 years. Destructive odontoid peg involvement is most commonly associated with rheumatoid disease, which has a distinct clinical course compared with that of bacterial infection.Methods.Two patients with bacterial osteomyelitis of the odontoid peg underwent medical and surgical treatment. They were observed for 3 years. All authors were involved in the care of these patients.Results.Close monitoring of the patients' neurologic status and the use of noninvasive imaging techniques to evaluate the cervical spine led to an individualized treatment plan including antibiotic medication and transoral surgery with good outcomes in both cases.Conclusions.Awareness of the occurrence of bacterial osteomyelitis of the odontoid process, with or without neurologic symptoms, in patients with neck pain and fever may lead to earlier detection of this potentially critical condition, which has an excellent prognosis when treated early and appropriately.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.One-group, pretest-postest experimental research with repeated measures.Objective.To determine the effect of head postural modification on the flexor carpi radialis H-reflex in healthy subjects.Summary of Background Data.H-reflex testing has been reported to be useful in evaluating and treating patients with lumbosacral and cervical radiculopathy. The idea behind this technique is that postural modification can cause further H-reflex inhibition, indicating more compression of the impinged nerve root, or recovery, indicating decompression of the root. Such assumptions cannot be supported unless the influence of normal head postural modification on the H-reflex in healthy subjects is studied.Methods.Twenty-two healthy subjects participated in this study (14 men, 8 women; mean age, 39 ± 9 years). The median nerve of the subjects at the cubital fossa was electrically stimulated (0.5 msec; 0.2 pulses per second [pps] at H-max), whereas the flexor carpi radialis muscle H-reflex was recorded by electromyography. The H-reflexes were recorded after the subject randomly maintained the end range of head-forward flexion, backward extension, rotation to the right and the left, lateral bending to the right and the left, retraction and protraction. These were compared with the H-reflex recorded during comfortable neutral positions. Data were recorded after the subject maintained the position for 30 seconds, to avoid the effect of dynamic postural modification on the H-reflex. Four traces were recorded in each position. During recording, the H-reflex was monitored by the M-response to avoid any changes in the stimulation-recording condition.Results.Repeated multivariate analysis of variance was used to evaluate the significance of the difference among the H-reflex, amplitude, and latency, in various head positions. The H-reflex amplitude showed statistically significant changes (P< 0.001) with head postural modification. All head positions, except flexion, facilitated the H-reflex. Extension, lateral bending, and rotation toward the side of the recording produced higher reflex facilitation than the other positions. These results indicate that H-reflex changes may be caused by spinal root compression-decompression mechanisms. It may also indicate that relative spinal root decompression occurs in most head-neck postures except forward flexion.Conclusions.Head postural modification significantly influences the H-reflex amplitude but not the latency. This indicates that the H-reflex is a more sensitive predictor of normal physiologic changes than are latencies. The H-reflex modulation in various head positions may becaused by relative spinal root compression-decompression mechanisms.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

摘要:

Study Design.A case-control study.Objectives.To determine the risk factors for ossification of the posterior longitudinal ligament (OPLL) of the spine.Summary of Background Data.Previous epidemiologic studies conducted in Japan showed consuming vegetable protein and salt was a risk factor for OPLL. Dietary habits of the Taiwanese and Japanese people are similar. Whether the similar dietary habits play an important role in the high prevalence of OPLL in Taiwan was of interest.Methods.A case-control study was conducted in a tertiary teaching hospital. The study included 98 consecutive cervical spine patients with OPLL, with 98 age-matched patients with cervical spondylosis serving as control subjects. Radiologic examinations, clinical interviews, physical examinations, and risk factor questionnaires were administered to all the participants.Results.Compared with incidence in the control patients, the frequency of the ossification of the anterior longitudinal ligaments was significantly higher in OPLL patients with OPLL (31%vs.19%;P= 0.049), but there was no difference in incidence of ossification of the ligamentum flavum (13.3%vs.16.3%;P= 0.546). More OPLL patients preferred a high-salt diet (OPLL/CS, no:somewhat:yes = 23/38:18/25:57/35;, X2for trend = 6.3;P= 0.001) and pickled foods (OPLL/CS, no:somewhat:yes = 39/56:11/11:48/31; X2for trend = 6.7;P= 0.0099). Fewer patients with OPLL consumed meat daily (63%.vs.79%;P= 0.018). High-salt diet (odds ratio = 2.62) and daily meat intake (odds ratio = 0.39) showed persistent association with OPLL in a multivariate logistic regression.Conclusions.The similar dietary habits, particularly a high-salt and low meat intakes, may partially explain the high prevalence of OPLL in Taiwan and Japan. Modifying dietary habits may help prevent this disease, especially in those high-risk populations.

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID

ISSN:0362-2436    

出版商:OVID    

年代:1999

数据来源: OVID