| 1. |
- Henriques, Thomas, et al.
(författare)
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Distractive flexion injuries of the subaxial cervical spine treated with anterior plate alone
- 2004
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Ingår i: Journal of Spinal Disorders & Techniques. - 1536-0652 .- 1539-2465. ; 17:1, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- The clinical and radiographic effect of anterior plate fixation alone was evaluated in 36 consecutive patients with distractive flexion (DF) injuries in the lower cervical spine. Mean follow-up time was 15 months. The aim of the present study was to determine whether anterior plate fixation alone provides sufficient stability when treating DF injuries in the cervical spine. Solid union was seen in 6 of 6 patients with stage 1 injury and in 15 of 17 patients with stage 2 injury. In the patients with stage 3 injury, 7 of 13 of the anterior fixations failed. These failures occurred mainly among the patients with severe neurologic injuries. We believe these findings substantiate the use of anterior plate alone for DF injuries at stage 1 and 2 but disqualify anterior plate fixation alone for DF injuries at stage 3, with neurologic injury present.
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| 2. |
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| 3. |
- Sterner, Ylva, et al.
(författare)
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The incidence of whiplash trauma and the effects of different factors on recovery
- 2003
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Ingår i: Journal of Spinal Disorders & Techniques. - : Lippincott Williams & Wilkins. - 1536-0652 .- 1539-2465. ; 16:2, s. 195-199
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Tidskriftsartikel (refereegranskat)abstract
- We performed a prospective study of patients with a whiplash trauma to the cervical spine to describe the incidence of these injuries and to evaluate prognostic factors for disability and recovery. A total of 356 patients were enrolled in the study. All the patients received a comprehensive questionnaire after the injury, and 296 cases responded to the follow-up protocol more than 1 year after the accident. Disability related to the whiplash trauma was used as the outcome variable for the assessment of prognostic factors. The annual incidence of acute whiplash trauma in the catchment area was 4.2 per 1,000 inhabitants and 3.2 per 1,000 for whiplash-associated disorder grades 1-3. Thirty-two percent reported persisting disability at follow-up. The following factors were significantly associated with a poor prognosis: pretraumatic neck pain, low educational level, female gender, and whiplash-associated disorder grades 2-3.
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| 4. |
- Svensson, Elisabeth, et al.
(författare)
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Reliability of the balanced inventory for spinal disorders, a questionnaire for evaluation of outcomes in patients with various spinal disorders
- 2012
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Ingår i: Journal of Spinal Disorders & Techniques. - : Lippincott Williams & Wilkins. - 1536-0652 .- 1539-2465. ; 25:4, s. 196-204
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Tidskriftsartikel (refereegranskat)abstract
- Study Design: An intrapatient reliability study of the previously validated 18-item questionnaire, the Balanced Inventory for Spinal disorders (BIS), in patients referred for planned spinal surgery. Statistical evaluation of the test-retest assessments was performed by a rank-based method that allows for separate analyses of the systematic and individual components of an observed disagreement. Objective: To evaluate the intrapatient reliability and the art of disagreement, when present, in assessing the extent to which pain affects perceived physical health, social life, mental health, and quality of life according to the BIS. For comparative reasons corresponding items in Short-Form-36 (SF-36) and Oswestry Disability Index (ODI) were also evaluated. Summary of Background Data: The questionnaires were filled in by 101 patients the evening before going to the clinic for planned spinal surgery and the following evening at the clinic. Results: The percentage agreement in test-retest assessments of the items varied from 52% to 84%. The important items of pain, physical activities, social life, overall mental health, and quality of life showed high levels of reliability. An intrapatient disagreement of more than 1 category was seen in 4 items of mental health and in physical health, only. The observed individual variability and the significant systematic decrease on the second occasion could be explained by the fact that the patients were at the hospital on the retest occasion. The variation in percentage agreements found, and the different reasons for disagreement in items speak against that memory alone could have caused the retest assessments. Conclusion: The comprehensive evaluation of test-retest reliability showed that the test-retest assessments on the BIS could be regarded as reliable, and the measures of reliability of the BIS items were on the same levels as for corresponding items of the SF-36 and the ODI questionnaires.
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| 5. |
- Abul-Kasim, Kasim, et al.
(författare)
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Optimization of Radiation Exposure and Image Quality of the Cone-beam O-arm Intraoperative Imaging System in Spinal Surgery.
- 2012
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Ingår i: Journal of Spinal Disorders and Techniques. - 1539-2465. ; 25:1, s. 52-58
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN: Retrospective study. OBJECTIVES: To optimize the radiation doses and image quality for the cone-beam O-arm surgical imaging system in spinal surgery. SUMMARY OF BACKGROUND: Neurovascular compromise has been reported after screw misplacement during thoracic pedicle screw insertion. The use of O-arm with or without navigation system during spinal surgery has been shown to lower the rate of screw misplacement. The main drawback of such imaging surgical systems is the high radiation exposure. METHODS: Chest phantom and cadaveric pig spine were examined on the O-arm with different scan settings: 2 were recommended by the O-arm manufacturer (120 kV/320 mAs, and 120 kV/128 mAs), and 3 low-dose settings (80 kV/80 mAs, 80 kV/40 mAs, and 60 kV/40 mAs). The radiation doses were estimated by Monte Carlo calculations. Objective evaluation of image quality included interobserver agreement in the measurement of pedicular width in chest phantom and assessment of screw placement in cadaveric pig spine. RESULTS: The effective dose/cm for 120 kV/320 mAs scan was 13, 26, and 69 times higher than those delivered with 80 kV/80 mAs, 80 kV/40 mAs, and 60 kV/40 mAs scans, respectively. Images with 60 kV/40 mAs were unreliable. Images with 80 kV/80 mAs were considered reliable with good interobserver agreement when measuring the pedicular width (random error 0.38 mm and intraclass correlation coefficient 0.979) and almost perfect agreement when evaluating the screw placement (κ value 0.86). CONCLUSIONS: The radiation doses of the O-arm system can be reduced 5 to 13 times without negative impact on image quality with regard to information required for spinal surgery.
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| 6. |
- Abul-Kasim, Kasim, et al.
(författare)
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Spinal Epidural Lipomatosis: A Common Imaging Feature in Scheuermann Disease.
- 2012
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Ingår i: Journal of Spinal Disorders and Techniques. - 1539-2465. ; 25:7, s. 356-361
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN: Retrospective study. OBJECTIVES: To find out if spinal epidural lipomatosis (SEL) occurs more commonly among patients with Scheuermann disease than in the general population. SUMMARY AND BACKGROUND: On the basis of our own radiologic and operative observation, SEL seems to occur frequently in patients with Scheuermann disease. METHODS: Magnetic resonance imaging of 87 individuals (72% male, average age 19±6 y) from 2 centers (29 consecutive patients with Scheuermann disease and 58 controls) were retrospectively evaluated by 2 neuroradiologists. Spinal epidural fat (EF) at seventh thoracic vertebra (EF7), maximum EF (EFmax), dural sac diameter at T7 and at the level of maximum EF (DS7 and DSmax) were measured. EF ratios at T7 (EFR7) and at maximum EF (EFRmax) were calculated as EF/DS. Body mass index (BMI) for study population and kyphosis severity for the patients were recorded. Mann-Whitney, Spearman correlation, and χ tests were performed dependent on the variable in question. RESULTS: EF7, DS7, EFmax, EFR7, and EFRmax was significantly higher among patients with Scheuermann disease (EFmax 5.7±2.4 mm) than among controls (EFmax 3.8±1.1 mm), P<0.001. Twelve patients with Scheuermann disease (41%) fulfilled our proposed criteria for the diagnosis of SEL (EFmax>6 mm+EFRmax>0.51) compared with 2 (3%) among controls (P<0.001). Patients with Scheuermann disease exhibited higher BMI than controls (24.9±5 kg/m vs. 22.9±4 kg/m, P=0.138). Logistic regression showed that the occurrence of SEL among patients with Scheuermann disease was independent of BMI (P=0.880). The degree of kyphosis in patients with Scheuermann's disease (62±20°) was correlated to the amount of the EF. CONCLUSIONS: As SEL occurs more frequently among patients with Scheuermann disease, spine magnetic resonance imaging should be routinely performed to screen each of these patients to avoid impending neurological injury during surgery, especially in those exhibiting SEL.
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| 7. |
- Ekström, Lars, 1959, et al.
(författare)
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In vivo porcine intradiscal pressure as a function of external loading
- 2004
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Ingår i: J Spinal Disord Tech. - 1536-0652. ; 17:4, s. 312-6
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Spinal loading during daily activity as it relates to the ability of the intervertebral disc to sustain its integrity has been a major issue in spinal research. The purpose of this investigation was to establish the relationship between the intervertebral disc pressure in the nucleus and the load applied to the motion segment in an in vivo porcine model. METHODS: Nine domestic pigs were used in this study. A miniaturized servohydraulic testing machine was affixed to the lumbar spine via four intrapedicular screws, which were inserted bilaterally into the L2 and L3 vertebrae. A pressure needle was inserted through the lateral part of the L2-L3 disc annulus and into the nucleus pulposus. Force, deformation, and intradiscal pressure data were collected during a loading scheme that consisted of applying a set of constant loads in increasing order, that is, 50, 100, 150, 200, and 250 N. Each load was applied for 30 seconds followed by 30-second restitution. RESULTS: Intradiscal nucleus pressure was found to correlate to the applied load in all cases. Linear regression analyses resulted in the following equation: intradiscal pressure (MPa) = 0.08 + 1.25E(-3)(load, N), r(2) = 0.81, n = 8. Intradiscal pressure was also highly linearly dependent on the stress. The intrinsic intradiscal pressure was found to be 81 +/- 5 kPa. The results also indicated that the pressure within the disc exhibited a creep behavior. CONCLUSION: In conclusion, pressure in the nucleus of the porcine intervertebral disc was linearly related to the applied load and stress.
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| 8. |
- Holm, Sten, 1948, et al.
(författare)
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Experimental disc degeneration due to endplate injury
- 2004
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Ingår i: J Spinal Disord Tech. - 1536-0652. ; 17:1, s. 64-71
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to create an experimental model of disc degeneration that closely mimicked human disc degeneration. In six domestic pigs, an L4 cranial endplate perforation into the nucleus pulposus was made. Three months postoperatively, compressive testing was performed on the L2-L4 motion segments, and intradiscal pressure was measured in the intervening discs. Histochemical and morphologic examinations were made on the excised degenerated and adjacent discs. A significant reduction in water content was observed in the outer anterior annulus of the degenerated disc. In the nucleus, the proteoglycan content was significantly reduced, as well as the cellularity, although not significantly. The nucleus lost its gel-like structure and was discolored, and there was delamination of annular layers. Intradiscal pressure in the nucleus was significantly lower in the degenerated disc. In conclusion, experimental degeneration of the intervertebral disc induced by endplate penetration resembled human disc degeneration, as exemplified by biochemical and structural changes.
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| 9. |
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| 10. |
- Kawchuk, G. N., et al.
(författare)
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Bulging of the inner and outer annulus during in vivo axial loading of normal and degenerated discs
- 2009
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Ingår i: Journal of Spinal Disorders & Techniques. - 1539-2465. ; 22:3, s. 214-8
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Tidskriftsartikel (refereegranskat)abstract
- STUDY DESIGN: Comparison of in vivo biomechanical outcomes between experimental and control group animals. OBJECTIVE: To quantify the in vivo bulging response of the inner and outer annulus in animals with and without disc degeneration. SUMMARY OF BACKGROUND DATA: Prior attempts to quantify the load-deformation response of the inner annulus have most often relied on in vitro preparations. Unfortunately, to visualize the inner annulus, these in vitro approaches rely on disc modifications that may result in nonphysiologic behaviors. In response to this problem, in vivo techniques were developed to quantify regional bulging of the inner and outer annulus during applied axial loading. METHODS: Two groups of pigs were tested: a normal group and a group having disc degeneration that was induced surgically 3 months earlier. Eight adolescent pigs were evaluated and for each animal, a miniature servohydraulic actuator was attached to the third and fourth lumbar vertebrae to deliver a cyclic axial loading protocol (300 N, 1 Hz, 10 cycles) whereas regional deformations of the annulus were visualized ultrasonically via retroperitoneal access. RESULTS: For the normal animals, image analysis demonstrated a significantly greater bulging of the inner annular region when compared with the outer annular region. In animals with disc degeneration, the inner and outer annular regions were equal in their bulging response, which ranged from 0 bulging to 37% greater than the average response of the normal animals. CONCLUSIONS: This work supports prior in vitro studies that observed maximal disc bulging in the inner annulus and minimal bulging in the external annulus. Results for this in vivo study suggest that this normal bulging gradient is lost with degenerative disc disease. Compared with in vitro approaches, this new in vivo technique has the potential to demonstrate disc behavior in a variety of loading conditions and/or with a variety of induced disc pathologies.
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