| 1. |
- Axelsson, Paul, et al.
(författare)
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Orthosis as prognostic instrument in lumbar fusion. No predictive value in 50 cases followed prospectively
- 1995
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Ingår i: Journal of Spinal Disorders. - 0895-0385. ; 8:4, s. 8-284
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate pain relief in a lumbar orthosis as a predictor for good clinical results after solid fusion, all patients scheduled for such a surgical procedure were preoperatively encouraged to use an orthosis, soft or rigid, for 3 weeks. Grade of back pain relief as a percent using the orthosis was assessed by the patients and was registered before surgery. After surgery, at 1-year follow-up, patients with nonunion demonstrated radiographically were excluded from the series. Thus, 50 patients with solid fusion could be identified and followed for at least 2 years prospectively. At follow-up these 50 patients graded the pain relief induced by the fusion. In the preoperative corset test, 31 patients experienced significant back pain relief, meaning a reduction of at least 50%. No applicable correlation was found, however, between outcome in this corset test and the eventual clinical result expressed as improvement/no improvement after solid fusion. The two types of orthoses did not differ in this aspect. We conclude that the orthosis, rigid or soft, is not a useful instrument when selecting patients for lumbar fusion.
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| 2. |
- Indahl, A, et al.
(författare)
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Sacroiliac joint involvement in activation of the porcine spinal and gluteal musculature.
- 1999
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Ingår i: Journal of spinal disorders. - 0895-0385. ; 12:4, s. 325-30
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Tidskriftsartikel (refereegranskat)abstract
- In the search for causes of low back pain, the sacroiliac joint has gained renewed interest as a possible pain generator. There is reason to believe that the sacroiliac joint plays a regulatory role involving reflex muscle activation, which controls trunk mobility and stability, as well as locomotion. The aim of this experimental study was to determine whether stimulation of nerves in the sacroiliac joint and joint capsule could elicit contractions in porcine gluteal or lumbar spinal muscles. Via a lateral retroperitoneal approach and using hypodermic needles, bipolar stimulating wire electrodes were inserted into the ventral area of the sacroiliac joint and directly under the surface of the capsular membrane, in 10 adolescent pigs (45 kg). This procedure was performed bilaterally, thus establishing two bilateral stimulation sites in the joints. Six electromyographic electrodes were unilaterally inserted into the following muscles: multifidus, gluteus medius, gluteus maximus, and quadratus lumborum. On stimulation within the ventral area of the joint, predominant responses occurred in both the gluteus maximus and quadratus lumborum muscles. However, when stimulating the capsule, the greatest muscular responses were detected in the multifidus muscles. This study addressed the possible regulatory function of the sacroiliac joint, namely, its involvement in activation of the spinal and gluteal muscles, which help control locomotion and body posture, as well as provide stability on the segmental level in the lumbar spine.
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| 3. |
- Kaigle Holm, Allison, 1964, et al.
(författare)
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In vivo dynamic stiffness of the porcine lumbar spine exposed to cyclic loading: influence of load and degeneration.
- 1998
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Ingår i: Journal of spinal disorders. - 0895-0385. ; 11:1, s. 65-70
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Tidskriftsartikel (refereegranskat)abstract
- The dynamic axial stiffness of the L2-3 motion segment subjected to vibratory loading under intact and injured states of the intervertebral disc was studied using an in vivo porcine model. Three groups of animals with the following states of the intervertebral discs were studied: intact disc, acutely injured disc, and degenerated disc. A miniaturized servo-hydraulic exciter was used to sinusoidally vibrate the motion segment from 0.05 to 25 Hz under a compressive load with a peak value of either 100 or 200 N. The dynamic axial stiffness of the intervertebral disc was calculated at 1-Hz intervals over the frequency range. The results showed that the dynamic axial stiffness was frequency dependent. A positive relationship was found between an increase in mean dynamic stiffness and load magnitude. An increase in mean stiffness with successive exposures at the same load magnitude was observed, despite the allowance of a recovery period between loading. The greatest difference was noted between the first and second load sets. No significant change in stiffness was found due to an acute disc injury, whereas a significant increase in mean stiffness was found for the degenerated disc group as compared with the intact group. The form of the frequency response curve, however, remained relatively unaltered regardless of the degenerated state of the disc. With heavier loads, repeated loading, and/or disc degeneration, the stiffness of the intervertebral disc increases. An increase in stiffness can mean a reduction in the amount of allowable motion within the motion segment or a potentially harmful increase in force to obtain the desired motion. This may locally result in greater stresses due to an altered ability of the disc to distribute loads.
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| 4. |
- Kaigle Holm, Allison, 1964, et al.
(författare)
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Muscular and kinematic behavior of the lumbar spine during flexion-extension.
- 1998
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Ingår i: Journal of spinal disorders. - 0895-0385. ; 11:2, s. 163-74
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Tidskriftsartikel (refereegranskat)abstract
- Reduction in lumbar muscular activity at full body flexion, known as flexion relaxation, has been studied in relation to overall trunk, lumbar spine, and hip flexion, but has not been evaluated in conjunction with motion on the segmental level. In this study, intervertebral motion in a lumbar motion segment, trunk flexion, and the electromyographic activity in the lumbar erector spinae muscles were simultaneously measured during dynamic flexion-extension in seven patients with chronic low back pain with symptoms suggesting segmental instability and in six asymptomatic controls. A linkage system, which attached directly to the spinous processes of a lumbar motion segment, was used to continuously measure the sagittal plane intervertebral motion, while a potentiometric goniometer measured trunk flexion; myoelectric activity was measured using surface electrodes. It was found that intervertebral motions, as well as trunk mobility, were significantly less in the patients, both in terms of range and pattern of motion. Flexion relaxation was demonstrated in the controls by a 78% decrease in myoelectric activity at full flexion, whereas in the patients, only a 13% reduction was found, with most of the patients experiencing no reduction at all. Flexion relaxation occurred only in subjects in whom intervertebral rotation had reached a stage of completion considerably before full trunk flexion was achieved. These findings suggest that persistent muscle activation, which restricts intervertebral motion, is a means by which the neuromuscular system provides stability to help protect diseased passive spinal structures from movements that may cause pain.
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| 5. |
- Karlsson, M K, et al.
(författare)
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Remodeling of the spinal canal deformed by trauma
- 1997
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Ingår i: Journal of Spinal Disorders. - 0895-0385. ; 10:2, s. 157-161
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Tidskriftsartikel (refereegranskat)abstract
- Computed tomography (CT) examinations and functional scores were evaluated in 28 patients with thoracolumbar fractures with intraspinal fragments, of whom 20 underwent operation. The cross-sectional area and the sagittal and frontal diameters of the spinal canal were measured after the injury, postoperatively, and at follow-up (mean, 6 years). The operative reduction significantly increased both diameter and area of the spinal canal. During follow-up, a further significant increase of the sagittal diameter and the area was noted, in both surgically and conservatively treated patients. There was no difference in remodeling between the groups. Six patients in the surgically treated group had neurologic deficits at admission, five had improved, and one remained unchanged at follow-up. The presence or absence of intraspinal fragments should not influence the treatment strategy per se in cases without neurologic signs.
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| 6. |
- Kjellby-Wendt, Gunilla, 1965, et al.
(författare)
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The predictive value of psychometric analysis in patients treated by extirpation of lumbar intervertebral disc herniation.
- 1999
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Ingår i: Journal of spinal disorders. - 0895-0385. ; 12:5, s. 375-9
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Tidskriftsartikel (refereegranskat)abstract
- The authors studied the predictive value of a psychometric evaluation of 50 patients (14 women, 36 men) with a mean age of 40 years who were treated by extirpation of a lumbar disc herniation. Patient satisfaction was evaluated by an unbiased observer. The Beck Depression Inventory (BDI), the State-Trait Anxiety Inventory (STAI), and a Pain Visual Analogue Scale (PVAS) were used to assess pain and psychological distress before surgery and 3 and 12 months after surgery. Two years after surgery, 37 patients were contented with the surgical outcome and 10 patients were not. Three patients did not return the questionnaire. Before surgery, the patients who later became discontented were more depressed, more anxious, and experienced more pain. In a discriminant analysis, a combination of BDI, STAI, and PVAS scores correctly classified 78% of the discontented and 76% of the contented patients. The study shows psychometric analysis is a valuable tool for predicting the outcome of surgical treatment for lumbar disc herniation.
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| 7. |
- Kääpä, Eeva, et al.
(författare)
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Proteoglycan chemistry in experimentally injured porcine intervertebral disk.
- 1994
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Ingår i: Journal of spinal disorders. - : Lippincott Williams & Wilkins. - 0895-0385 .- 1531-2305. ; 7:4, s. 296-306
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Tidskriftsartikel (refereegranskat)abstract
- An animal model of disk degeneration was used to study the concentration levels and types of proteoglycans in the different parts of the intervertebral disk. An annular incision was made with a scalpel blade into the anterior part of the porcine lumbar intervertebral disks via a retroperitoneal approach. Three months after injury the morphology of the injured disk had changed considerably. Disk height was diminished, and in the injured segment osteophytes had formed at the ventral edges of the vertebral body. The nucleus was small, fibrous, and yellowish. The annular lesion had healed by formation of granulation tissue, but the lamellar structure was partially destroyed. The concentration of inorganic [35S]sulfate had decreased across the whole disk, reflecting a decrease in the rate of solute transport. The concentration of incorporated [35S]sulfate had also decreased in the injured disks. The DNA concentration in the anterior annulus and in the nucleus had increased, whereas both the concentration of uronic acid and the ratio of chondroitin-6-sulfate to chondroitin-4-sulfate in the nucleus had decreased. Agarose gel electrophoresis combined with chondroitinase B digestion suggested the presence of dermatan sulfate proteoglycans in the injured annulus fibrosus. The morphology and chemical composition of the disks adjacent to the injured one were normal, and only a slight increase in the concentration of incorporated [35S]sulfate was observed in the disks above the injured one.
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