摘要:

Study Design.This is a retrospective study of surgical correction of thoracolumbar kyphosis caused by ankylosing spondylitis.Objective.To report the surgical results of thoracolumbar kyphosis deformity corrected with transpedicular wedge osteotomy performed by a single surgeon at a university hospital.Summary of Background Data.There has not been a large series in the literature reporting on results of the Thomasen-type closing wedge osteotomy for correction of kyphosis deformity secondary to ankylosing spondylitis, nor has two-level osteotomy of this type in one patient ever been described.Methods.From 1991 through 1998, 92 transpedicular wedge osteotomies were performed in 78 patients with ankylosing spondylitis for correction of fixed flexion deformity of the thoracolumbar spine.Results.The mean amount of correction for each level of osteotomy was 34.5° (range, 15°-60°). The largest amount of overall correction for a single patient was 100°. Most of the osteotomies (64 of 92) were done at L2 and L3. Fourteen patients with severe deformity required staged two-level osteotomy. Excellent and good results were obtained in 77 patients (98.7%) at the final follow-up. There was no mortality, nor were there any major neurological complications.Conclusions.Transpedicular wedge osteotomy can effectively and safely correct kyphotic deformity of the thoracolumbar spine caused by ankylosing spondylitis, regardless of rigidity of the spinal curves. Two-level osteotomy can provide sufficient correction for severe cases.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.Cross-sectional study of 25 male golfers with chronic low back pain and 16 healthy controls of similar age.Objectives.To assess the association between functional capacity of the back extensors and the quadriceps muscles.Summary of Background Data.Chronic low back pain has been shown to lead to changes in muscle activation patterns of the abdominals and the gluteus maximus. The effect of chronic low back pain on lower limb function has not been investigated.Methods.Back extensor endurance was assessed by a Biering-Sørensen test; surface EMG was measured bilaterally on the erector spinae at T12 and L4–L5. Muscle inhibition in the quadriceps was assessed by applying an electrical twitch to the maximally contracted muscle. The associations between holding time, decrease in EMG median frequency (i.e., the slope of the regression line on median frequencyvs.time), and muscle inhibition were compared for study participants with chronic low back pain and controls.Results.Mean back extensor holding times were 88 ± 30 seconds for study participants with chronic low back pain and 92 ± 17 seconds for controls. Both groups showed bilaterally similar decreases in EMG median frequency at L4–L5 and T12; however, the slopes were significantly steeper at L4–L5 than T12. Study participants with chronic low back pain with poor back endurance had significantly higher muscle inhibition compared with study participants with chronic low back pain with good back endurance, whereas such an association was not evident in healthy controls.Conclusions.In golfers with chronic low back pain reduced back endurance was associated with significant inhibition of the knee extensors, indicating that this muscle group cannot be activated to a full extent. These findings suggest a possible association between back extensor fatigability and knee extensor dysfunction in male golfers with chronic low back pain.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.A comparative study of lumbar paraspinal muscle reflexes during sudden upper limb loading in healthy control subjects and patients with sciatica.Objectives.To assess reflex activation of paraspinal muscles during sudden upper limb loading.Summary of Background Data.Sudden upper limb loading and upper limb voluntary movements cause reflex activation of trunk muscles. A short latency response of ∼50 msec of lumbar muscles has been observed before, but the reflexes have not been studied in patients with sciatica.Methods.The paraspinal muscle responses for upper limb loading during unexpected and expected conditions were measured by surface EMG from 20 patients selected for an operation as a result of disc herniation-related chronic low back pain and 15 back-healthy controls. Pain, disability, and depression scores were recorded.Results.Short latency response of paraspinal muscles for unexpected upper limb loading was similar in healthy controls and patients with sciatica in supported standing. During normal standing anticipation shortened the lumbar reflex latency in healthy controls but not among the patients.Conclusions.The results provide evidence for impaired feed-forward control of lumbar muscles in patients with sciatica.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.The authors monitored a father and his six children, all of whom had idiopathic scoliosis for more than 13 years.Objective.To analyze the similarities and differences in curve pattern between the family members.Summary of Background Data.The etiology and pathogenesis of idiopathic scoliosis are not well understood. Genetic factors play an important role, as is shown by the high concordance in monozygotic twins.Methods.Radiographs from all family members were analyzed. Location and direction of the curve, Cobb angle, location of the apex, and rib-vertebra angle difference were compared.Results.A father and his six children had idiopathic scoliosis. The curves differed within the family and changed during follow-up. The father had a left convex thoracic scoliosis of 42°. Only three of the children had a curve of similar severity, and only four children had a left convex thoracic scoliosis. In three children the curve pattern changed during follow-up.Conclusions.This report of idiopathic scoliosis in a father and six children supports the present theories on a genetic origin of the disorder but also stresses the importance of dynamic processes in the development of scoliosis.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.A case report of anaerobic vertebral osteomyelitis after anal dilatation.Objectives.To present a patient with monomicrobial anaerobic vertebral osteomyelitis secondary to a previously undescribed source of infection.Summary of Background Data.A 17-year-old boy presented with low back pain 3 months after anal dilatation.Methods.Physical examination, technetium-99m bone scan, plain radiograph, CT, and MRI studies of the lumbar spine were used to clinically diagnose lumbar osteomyelitis. Culture material from the involved disc was positive forBacteroides fragilis.Results.The patient recovered after 8 weeks of treatment with oral metronidazole.Conclusions.Bacteroides fragilishematogenous osteomyelitis is a rare entity. This is the first reported case of such disease after anal dilatation.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.Randomized controlled trial (RCT).Objectives.To compare the effectiveness of training and equipment to reduce musculoskeletal injuries, increase comfort, and reduce physical demands on staff performing patient lifts and transfers at a large acute care hospital.Summary of Background Data.Back injury to nursing staff during patient handling tasks is a major issue in health care. The value of mechanical assistive devices in reducing injuries to these workers is unclear.Methods.This three-armed RCT consisted of a “control arm,” a “safe lifting” arm, and a “no strenuous lifting” arm. A medical, surgical, and rehabilitation ward were each randomly assigned to each arm. Both intervention arms received intensive training in back care, patient assessment, and handling techniques. Hence, the “safe lifting” arm used improved patient handling techniques using manual equipment, whereas the “no strenuous lifting” arm aimed to eliminate manual patient handling through use of additional mechanical and other assistive equipment.Results.Frequency of manual patient handling tasks was significantly decreased on the “no strenuous lifting” arm. Self-perceived work fatigue, back and shoulder pain, safety, and frequency and intensity of physical discomfort associated with patient handling tasks were improved on both intervention arms, but staff on the mechanical equipment arm showed greater improvements. Musculoskeletal injury rates were not significantly altered.Conclusions.The “no strenuous lifting” program, which combined training with assured availability of mechanical and other assistive patient handling equipment, most effectively improved comfort with patient handling, decreased staff fatigue, and decreased physical demands. The fact that injury rates were not statistically significantly reduced may reflect the less sensitive nature of this indicator compared with the subjective indicators.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.The mRNA levels of aggrecan and collagen were quantified in intervertebral disc cells cultured under three conditions: primary alginate culture, monolayer culture, and re-encapsulation in alginate after monolayer culture.Objectives.To compare the phenotype of intervertebral disc cells under different culture conditions and to investigate the reversibility of cell phenotype after re-encapsulation in alginate after monolayer culture.Summary of Background Data.The intervertebral disc contains heterogeneous populations of cells that vary with anatomic region. These cells possess significant differences in phenotype that can be preservedin vitro, although the effect of culture conditions on the phenotype of these cells is poorly understood.Methods.The intervertebral disc cells of 4–5-month-old pigs were isolated enzymatically from three anatomic zones: anulus fibrosus (AF), transition zone (TZ), and nucleus pulposus (NP). Gene expression levels of aggrecan and collagen Types I and II were measured using a quantitative reverse transcriptase–polymerase chain reaction.Results.Gene expression levels of anulus fibrosus and transition zone cells were shifted in monolayer compared with alginate, although the shift was partially reversed when re-encapsulated in alginate. However, NP cells appeared to be insensitive to culture conditions. Furthermore, characteristic patterns of gene expression among AF, TZ, and NP cells in primary alginate culture did not exist in monolayer culture, but they were also observed after re-encapsulation in alginate.Conclusion.The findings of this study suggest that anulus fibrosus and transition zone cells undergo a reversible shift in phenotype when cultured in monolayer compared with alginate. These differences suggest that the culture system exerts a strong influence on cell phenotype and may play a role in the response of these cells to biophysical and biochemical stimuliin vitro.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.The stress distributions within cadaveric lumbar intervertebral discs were measured for a range of loading conditions.Objectives.To examine the distribution of stress across the area of the intervertebral disc and to compare regional variations in peak stress during compression loading with various flexion angles.Summary of Background Data.The rate of disc degeneration and the occurrence of low back disorders increase with higher mechanical loading of the spine. The largest peak stresses occur in the anulus.Methods.Human lumbar L2–L3 and L4–L5 cadaver functional spinal units were obtained and tested. The distribution of disc stress was measured using a pressure probe with loads applied, pure compression and compression with 5° of either flexion or extension.Results.Stress profiles were recorded across the intervertebral disc at a compressive force of 1000 N and each of the three flexion-extension angles. The highest values (2.99 ± 1.31 MPa) were measured during extension–compression lateral to the midline of the disc in the posterior anulus. The pressure in the nucleus was relatively unchanged by flexion angle remaining about 1.00 MPa for a 1000-N compression.Conclusions.Pressure measurements of the cadaveric nucleus have been used to validate models of lumbar spine loading and to evaluate the risk of low back injury and disc herniation. Previous observations limited to midsagittal measurements of the nucleus did not identify the regions of highest stress. The highest values observed here within the posterolateral anulus correspond to common sites of disc degeneration and herniation.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Study Design.A radiologic study to compare the Torg–Pavlov ratios between patients with cervical spondylotic myelopathy and a nonspondylotic, nonmyelopathic population.Objectives.To determine and compare the Torg–Pavlov ratios between the two groups of patients.Summary of Background Data.Patients with congenital cervical spinal canal stenosis are more likely to develop cervical spondylotic myelopathy. The Torg–Pavlov ratio eliminates errors related to magnification, a problem with determination of spinal canal stenosis from direct measurements of plain cervical spine radiographs. There has only been one other study that directly compares the Torg–Pavlov ratio between patients with cervical spondylotic myelopathy and a normal control population.Methods.The preoperative plain lateral cervical spine radiographs of 28 patients with cervical spondylotic myelopathy requiring surgical decompression were compared with radiographs of 88 nonspondylotic, nonmyelopathic patients. The Torg–Pavlov ratio was computed for each level from C3 to C7.Results.The study showed that the Torg–Pavlov ratio is significantly smaller (P< 0.001) in myelopathic patients (mean 0.72 ± 0.08) compared with the control patients (mean 0.95 ± 0.14). This was so when individual levels and the mean values were compared. Age was also found to be a significant factor (P= 0.002), although lesser in magnitude when compared with the Torg–Pavlov ratio (P= 0.0001).Conclusions.The Torg–Pavlov ratio is significantly lower in patients with cervical spondylotic myelopathy compared with a nonspondylotic, nonmyelopathic population. It could possibly be used to predict the likelihood of developing cervical spondylotic myelopathy.

ISSN:0362-2436    

出版商:OVID    

年代:2001

数据来源: OVID