Anatomic parameters: direct intralaminar screw repair of spondylolysis.

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Anatomic parameters: direct intralaminar screw repair of spondylolysis.

Spine (Phila Pa 1976). 2014 Feb 1;39(3):E153-8

Authors: Menga EN, Jain A, Kebaish KM, Zimmerman SL, Sponseller PD

Abstract
STUDY DESIGN: Analysis via computed tomography imaging software.
OBJECTIVE: To determine parameters for ideal intralaminar screw trajectory and the feasibility of screw placement at L3, L4, and L5 laminae for pars defect fixation.
SUMMARY OF BACKGROUND DATA: To our knowledge, no studies provide anatomic parameters for ideal intralaminar screw trajectory for treating spondylolysis.
METHODS: We used advanced imaging software for 3-dimensional interactive viewing to analyze 20 randomly selected normal adolescent lumbar computed tomographic scans. The ideal intralaminar screw trajectory was drawn from the inferior lamina, a point chosen to maximize cortical diameter at the isthmus of the lamina and bisect the pedicle. We measured and evaluated ideal trajectory parameters for percutaneous screw placement for pars defect fixation at the L3 to L5 laminae.
RESULTS: The ideal pathway was the thick portion of the lamina between the inferior edge of the lamina and the pedicle. This area was close to the inferior articular process (axial plane), becoming more so at progressively caudal levels. At the ideal trajectory, the mean (standard deviation) coronal angle slightly decreased (L3-L5): 7.3° (5.1°), 6.6° (3.7°), and 4.2° (2.5°), respectively. The trajectory distance increased from cranial to caudal. These parameters increased (L3-L5): mean distance (transverse plane) between the starting point and middle of the spinous process, 1.2 (0.18 cm), 1.3 (0.2 cm), and 1.6 (0.3 cm), respectively; mean screw sagittal angle with respect to the posterior skin, 15.5° (5.0°), 24.3° (6.5°), and 43° (5.8°), respectively; and mean distance for guide wire entry, 28.8 (10.6 cm), 20.1 (5.4 cm), and 11.9 (2.1 cm), respectively.
CONCLUSION: At the ideal screw trajectory, pars fixation by intralaminar screw is uniformly feasible at L3 to L5 laminae, where most patients can accommodate a 4.5-mm screw.
LEVEL OF EVIDENCE: 2.

PMID: 24253779 [PubMed – indexed for MEDLINE]

Are Modic Changes Able to Help us in Our Clinical Practice? A Study of the Modic Changes in Young Adults During Working Age.

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Are Modic Changes Able to Help us in Our Clinical Practice? A Study of the Modic Changes in Young Adults During Working Age.

J Spinal Disord Tech. 2014 Oct 21;

Authors: Martínez-Quiñones JV, Aso-Escario J, González-García L, Consolini F, Arregui-Calvo R

Abstract
STUDY DESIGN:: Modic changes (VESC, Vertebral Endplate Spinal Changes) have been related to degenerative disc disease, and in past decades it was thought that their presence justified the surgical treatment, in particular spinal fusion.
OBJECTIVE:: The aim of the present study is to investigate its prevalence and features in a population of young workers suffering from low back pain, and explore the eventual relationship with the treatment applied in each case.
BACKGROUND DATA:: We conducted a retrospectively review of 450 Magnetic Resonance (MR) images from our Hospital, in patients with low back pain or sciatica and age below 40.
METHODS:: Age, sex, symptoms predominance, concurrence with other spine disease, VESC type, evolution, level/s of involvement and placement, affected disc location and extent of the disease, disc height and status of the endplate, were recorded. The applied treatment was divided in groups according to the degree of invasiveness of the procedure.
RESULTS:: Prevalence of VESC was 13.05% predominant in patients over 30 years, and 100% associated to disc degenerative changes. Most frequent features were: type I (54%), lower lumbar region (98%), along with a decreased disc height (68%) and distortion of the disc endplates (98%, P<0.01). The patients with VESC presented a favorable outcome with conservative treatment, but were more frequently associated with invasive treatment, compared with non-VESC patients (P<0.024).
CONCLUSIONS:: VESC prevalence increases with age, underlying the degenerative causative etiology. Surgical indication shouldn’t be stated on the basis of the VESC findings alone, the main factor for indicating surgery depends more on other associated degenerative spinal changes.

PMID: 25340321 [PubMed – as supplied by publisher]

Misdiagnosis and management of iatrogenic pseudoaneurysm of vertebral artery after Harms technique of C?-C? fixation.

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Misdiagnosis and management of iatrogenic pseudoaneurysm of vertebral artery after Harms technique of C₁-C₂ fixation.

Chin J Traumatol. 2012;15(6):355-9

Authors: Min L, Song YM, Xie XD, Wang CH, Liu LM

Abstract
Harms technique of C₁-C₂ fixation for atlantoaxial complex becomes more popular due to good fusion rate and low vertebral artery injury (VAI) rate. But considering the unique and variable anatomy of atlantoaxial complex, iatrogenic VAI will result in catastrophic consequences and provides particular surgical challenges for surgeons. To our knowledge, comparing with iatrogenic VAI in the screw hole, iatrogenic VAI in the “open space” is much rarer during the Harms technique of C₁-C₂ fixation. In this article, we present a case of iatrogenic vertebral artery pseudoaneurysm after Harms technique of posterior C₁-C₂ fixation. This case of iatrogenic VAI effectively treated by endovascular coil occlusion and external local compression was initially misdiagnosed as VAI by pedicle screw perforation. It can be concluded that intraoperative or postoperative computed angiography is very helpful to diagnose the exact site of VAI and the combination of endovascular coil occlusion as well as external local compression can further prevent bleeding and abnormal vertebral artery flow in the pseudoaneurysm. However, patients treated require further follow-up to confirm that there is no recurrence of the pseudoaneurysm.

PMID: 23186926 [PubMed – indexed for MEDLINE]