| 1. |
- Tveit, P, et al.
(författare)
-
Erector spinae lever arm length variations with changes in spinal curvature.
- 1994
-
Ingår i: Spine. - 0362-2436 .- 1528-1159. ; 19:2, s. 199-204
-
Tidskriftsartikel (refereegranskat)abstract
- Magnetic resonance imaging was used to study the effect of different curvatures in the lumbar spine on lever arm lengths of the erector spinae musculature. Eleven subjects were instructed to simulate static lifts while lying supine in a magnetic resonance camera with the lumbar spine either in kyphosis or lordosis. A sagittal image of the spine was obtained to analyze the lumbosacral angle and to guide the imaging of transverse sections through each disc (L1/L2 to L5/S1). Images were analyzed for lever arm lengths of the erector spinae muscle (ES) and the erector spinae aponeurosis (ESA), the latter functioning as a tendon for superiorly positioned ES muscle portions. The lumbosacral angle (between superior surfaces of S1 and L4) averaged 44 degrees in the lordosed, 26 degrees in the kyphosed and 41 degrees in a neutral supine position. In lordosis, the lever arm lengths were significantly longer than in kyphosis for all levels, averaging 60-63 mm (ES) and 82-86 mm (ESA). The corresponding values for kyphosis were 49-57 mm (ES) and 67-77 mm (ESA), respectively. Thus, there was a considerable effect (10-24%) of lumbar curvature on lever arm lengths for the back extensor muscles. The change in leverage will affect the need for extensor muscle force and thus the magnitude of compression in the lumbar spine in loading situations such as lifting.
|
|
| 2. |
- Axelsson, Paul, et al.
(författare)
-
Effect of lumbar orthosis on intervertebral mobility. A roentgen stereophotogrammetric analysis
- 1992
-
Ingår i: Spine. - 0362-2436. ; 17:6, s. 81-678
-
Tidskriftsartikel (refereegranskat)abstract
- To determine the stabilizing effect of external lumbar supports on the intervertebral mobility in the lower lumbar spine, seven patients with a posterolateral lumbosacral fusion without internal fixation were examined by roentgen stereophotogrammetric analysis in supine and erect positions 1 month after surgery, that is, after soft tissue healing but before fusion consolidation. Each patient was examined without lumbar support, with a molded, rigid orthosis and with a canvas corset with molded, plastic posterior support. Neither of the two types of lumbar support had any stabilizing effect on the sagittal, vertical, or transverse intervertebral translations. This study using roentgen stereophotogrammetric analysis confirms that lumbosacral orthosis has effect by restricting gross motions of the trunk rather than intervertebral mobility in the lumbar spine.
|
|
| 3. |
- Axelsson, Paul, et al.
(författare)
-
Lumbar orthosis with unilateral hip immobilization. Effect on intervertebral mobility determined by roentgen stereophotogrammetric analysis
- 1993
-
Ingår i: Spine. - 0362-2436. ; 18:7, s. 9-876
-
Tidskriftsartikel (refereegranskat)abstract
- To determine the additional stabilizing effect of unilateral hip fixation on external lumbar supports, nine patients with a posterolateral lumbosacral fusion without internal fixation were examined by roentgen stereophotogrammetric analysis. The roentgen stereophotogrammetric analysis was performed with the patients in supine and erect positions 1 month after surgery, that is, before fusion consolidation. Each patient was examined without lumbar support and with a molded, rigid thoracolumbosacral orthosis with extension to one thigh, thus immobilizing one hip. The additional hip immobilization had no consistent or significant stabilizing effect on the sagittal, vertical, or transverse intervertebral translations in the lower lumbar spine. This study using roentgen stereophotogrammetric analysis gave no support for including hip immobilization when using lumbar orthoses after spinal fusion in patients adequately cooperating to minimize gross body motions.
|
|
| 4. |
- Hagglund, Gunnar, et al.
(författare)
-
Growth in girls with adolescent idiopathic scoliosis
- 1992
-
Ingår i: Spine. - : Ovid Technologies (Wolters Kluwer Health). - 0362-2436. ; 17:1, s. 108-111
-
Tidskriftsartikel (refereegranskat)abstract
- The height development during childhood and puberty was analyzed in 54 girls with adolescent idiopathic scoliosis by the use of the Infancy Childhood Puberty growth model, which is based on healthy Swedish children. This model adjusts adolescent reference values for height for individual age at pubertal maturation. The scoliotic girls had an above-average height 2 years before the onset of the pubertal growth spurt. However, because they displayed an early pubertal maturation as well as a low pubertal gain in height, their values were only slightly higher than the reference mean values at maturity. The results indicate an increased growth hormone activity in childhood in girls with adolescent idiopathic scoliosis.
|
|
| 5. |
- Ohlin, Acke, et al.
(författare)
-
Complications after transpedicular stabilization of the spine. A survivorship analysis of 163 cases
- 1994
-
Ingår i: Spine. - 0362-2436. ; 19:24, s. 2774-2779
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES. The authors studied complications of transpedicular stabilization methods. SUMMARY OF BACKGROUND DATA. One hundred and sixty-three consecutive transpedicular stabilization procedures were performed between January 1987 and December 1991. The indications for stabilization were trauma (33 cases), metastatic spinal disorder (30 cases), spinal stenosis (33 cases), spondylolisthesis (27 cases), ankylosing spondylitis (6 cases), low back pain (22 cases), and miscellaneous (12 cases). METHODS. Patients records and the entire series of radiographs for each case were scrutinized by independent observers. All per- and postoperative complications, including implant loosening and fatigue, were recorded. Clinical and radiographic survivorship analyses of the implants were performed. RESULTS. Early complications were unusual and none were associated with permanent morbidity. The probability of not having the implant removed in the first postoperative year was 85%. There was a 40% risk of radiographic failure, defined as loosening or implant fatigue, at 6 months. The outcome was more favorable in cases in which anterior vertebral interbody fusion was also performed. CONCLUSIONS. Transpedicular fixation is a safe procedure with a low incidence of serious per- and early postoperative complications. The mechanical durability of transpedicular fixators used alone is a cause for concern.
|
|
| 6. |
- Olmarker, K, et al.
(författare)
-
Effects of chondroitinase ABC on intrathecal and peripheral nerve tissue. An in vivo experimental study on rabbits
- 1991
-
Ingår i: Spine. - 0362-2436. ; 16:1, s. 43-45
-
Tidskriftsartikel (refereegranskat)abstract
- The enzyme chondroitinase ABC has recently been suggested for use in chemonucleolysis. The effects of 200 U ml of chondroitinase ABC were studied on intrathecal and peripheral nerve tissue in rabbits. After the intrathecal (subarachnoid) application of 0.2 ml of either the diluent in the control group (N = 2) or chondroitinase in the study group (N = 4), no neurologic deficit was detected. Compared with the control group, no morphologic changes at the light microscopic level were induced in the spinal cord by chondroitinase. No neurophysiologic differences were detected between tibial nerves after exposure to 1 ml of the diluent (control, N = 8) or chondroitinase (the other leg) for 4 weeks, nor did the study group, compared with the control group, show any morphologic changes in the tibial nerves. Because the concentration of chondroitinase ABC tested was approximately 40 times higher than might be used clinically for chemonucleolysis, the present study indicates a wide margin of safety for unwanted side effects on nerve tissue.
|
|
| 7. |
|
|
