L4-5 Disc Research Articles

Comparison of the effects of different percutaneous endoscopic removal of nucleus pulposus by vertebral plate gap into the road in the treatment of L5 and S1 lumbar intervertebral disc protrusion

Objective To compare the clinical effect of different percutaneous endoscopic removal of nucleus pulposus vertebral plate gap into the road in the treatment of L5 and S1 lumbar intervertebral disc protrusion. Methods 120 cases with lumbar intervertebral disc protrusion in our hospital were randomly divided into group A and group B, 60 cases in each group.Group A was given the intervertebral foramen mirror vertebral plate gap into the way, group B was given the posterior intervertebral disc mirror reserves the yellow ligament treatment.The operation time, number of perspective, intraoperative blood loss, length of incision, visual analogue scale (VAS), hospitalization days, Oswestey disability index (ODI) before and after surgery were compared between two groups. The curative effect was evaluated by the Macnab criteria. Results The operation time, number of perspectives, intraoperative blood loss, surgical incision length, VAS score, hospitalization days in group A were (58.69±5.26)min, (2.56±0.52)times, (80.23±20.45)mL, (1.63±0.33)cm, (2.95±0.77)points, (4.98±0.84)d, respectively, those in group B were (60.36±5.31)min, (2.55±0.48)times, (75.69±2.96)mL, (1.56±0.21)cm, (2.98±0.69)points, (5.01±0.86)d, the differences between the two groups were not significant (all P>0.05). Immediate postoperation and postoperative 3 months, the ODI scores of group A were (36.96±10.58)points, (9.26±0.23)points, (6.35±0.44)points, respectively, and those of group B were (37.02±9.85)points, (9.42±0.65)points, (6.30±0.39)points, immediately after operation, postoperative 3 months, the ODI scores of the two groups were lower than before operation, compared with immediate postoperation, the ODI scores of postoperative 3 months were significantly reduced, the difference was statistically significant (P 0.05). The excellent rate of group A was 90.00%, which of group B was 91.67%, the difference between the two groups was not obvious (P>0.05). Conclusion Intervertebral foramen mirror the vertebral plate gap into the road and posterior intervertebral disc mirror reserves are yellow ligament in treatment of L5 and S1 lumbar intervertebral disc protrusion will achieve good operation effect, no obvious difference was found between the two methods, before undergoing surgery for the patients' individual condition and indications for judgment, and to choose appropriate surgical method. Key words: Intervertebral disk displacement; Discectomy, percutaneous; Surgical procedures, minimally invasive

The feasibility of building the oblique lumbar interbody fusion corridor: A CT image study

Objective To determine the radiographic feasibility of oblique lumbar interbody fusion (OLIF) corridor to treat lumbar disease at each lumbar disc level, including the corridor's numerical value and the influence of diaphragmatic crura and aorta abdominalis. Methods A retrospective CT study was conducted on 110 patients (including 69 males and 41 females, average age 47.95 years, range 16-83 years) that continuously collected and analyzed in the PACS system. The oblique corridor was defined as the area between the left lateral border of the aorta abdominalis(or iliac artery) and the right lateral border of the left psoas. The distances and angles of L1-2, L2-3, L3-4 and L4-5 levels were measured. Whether the change of diaphragmatic crura and aorta abdominalis affected the building of the corridor was also observed. Results The mean distances of oblique corridor to the levels of L1-L5 discs were: L1-2 15.90 mm, L2-3 14.82 mm, L3-4 17.57 mm, L4-5 11.16 mm. At the levels of L1-2 and L3-4, all of the images could build the corridor. But there were only 97.27% images allowing operation at both L2-3 and L4-5, and the other 3 cases couldn't build the corridor since the aorta abdominalis was very close to psoas, and the distance was almost 0 mm. The max mean distance was 36.79 mm at L3-4 level. The mean angles were: L1-2 36.98˚; L2-3 37.76˚; L3-4 40.96˚; L4-5 37.85˚. The significant difference was at L3-4, ranged from 13.09 to 61.93˚. The level of the aortic bifurcation was from the lower third of the L3 vertebral body to the middle third of the L5 vertebral body. The levels of left diaphragmatic crura's ending point in the lumbar was divided into four groups: 1) Group L1 vertebral body level: the level at L1 vertebral body and above, 5 cases (4.55%); Group L1-2 disc to L2 vertebral body level: at L1-2 disc and L2 vertebral body, 67 cases (60.91%); Group L2-3 disc to L3 vertebral body level: at L2-3 disc and L3 vertebral body, 36 cases (32.72%); Group L3-4 disc to L4 vertebral body level: at L3-4 disc and L4 vertebral body, 2 case (1.81%). Conclusion The OLIF corridor can be built successfully at L1-2 and L3-4. However, it may be difficult at L2-3 and L4-5 for some patients due to the aorta abdominalis which is too close to psoas. The angles of L1-L5 levels were similar. While the left diaphragmatic crura was mainly impact the corridor insertion at L1-2 and L2-3. And the level of the aortic bifurcation was mainly located at the upper endplate of L4 to the L4-5 disc (87%). Key words: Lumbar vertebrae; Spinal fusion; Aorta, abdominal; Diaphragm; Tomography, spiral computed

Anatomical considerations of the iliac crest on percutaneous endoscopic discectomy using a transforaminal approach

Background ContextPercutaneous endoscopic discectomy is a minimally invasive procedure for the surgical treatment of lumbar disc herniation (LDH). It can be performed under local anesthesia and requires a skin incision of only 8 mm, with minimal disruption of the spinal structures including ligaments and muscles. However, performing percutaneous endoscopic discectomy with a transforaminal approach (TF-PED) for the lower lumbar spine is associated with some anatomical problems, such as interference from the iliac crest. This study sought to assess the operability of TF-PED for the lower lumbar spine. PurposeThe purpose of this study was to assess a three-dimensional relationship between the trajectory of TF-PED and the iliac crest, and the operability of TF-PED at the lower lumbar disc levels (L4–L5 and L5–S1) using CT images. Study DesignThis is a retrospective study using 323 multiplanar abdominal computed tomography (CT) scans. Patient SampleWe retrospectively reviewed contrast-enhanced multiplanar abdominal CT scans of 323 consecutive patients (203 male and 120 female) in our hospital from April 2009 to March 2013. The mean age was 66.5 (range 15–89) years old. Outcome MeasuresThe operability of the TF-PED was the outcome measure. Materials and MethodsWe defined the tangent line in the iliac crest and the superior articular process of the caudal spine as the trajectory line of TF-PED, and evaluated the maximum inclination angle of the trajectory of the TF-PED (α angle) at the L4–L5 and the L5–S1 disc levels. Assuming the use of an oblique viewing endoscope at 25°, we defined α angle≥65° as the operability of TF-PED. Results(1) Relationship between iliac crest and disc level: The trajectory of the TF-PED interfered with the iliac crest at L4–L5 in 40.2% (right) and 54.5% (left) of the subjects, and at L5–S1 in 99.7% and 100% of the subjects. (2) The maximum inclination angle of the trajectory of TF-PED: the α angles were 84.3° and 82.3° at the L4–L5, and 56.8° and 55.2° at L5–S1. (3) Laterality of the α angle: At both disc levels, the mean age of the subjects with a laterality of ≥10° was significantly higher than that of subjects with a laterality of <10°. (4) Operability of TF-PED: At L4–L5, TF-PED could be performed in 94.4% and 90.4% of the subjects. In contrast, at L5–S1 the procedure could be performed in 24.1% and 19.2% of the subjects (male: 15.8% and 10.8%, female: 38.3% and 33.3%). ConclusionsFrom the results of this study, the trajectory of TF-PED can be limited by the surrounding anatomical structures. The maximum inclination angle indicated that treatment for the central type of LDH at the L5–S1 disc level was considered more difficult than that at the L4–L5 disc level because of the iliac crest. In the clinical setting, such anatomical particularities can be overcome by using a more perpendicular approach (hand-down technique) with the possible addition of a foraminoplasty. Moreover, we found that we must consider the laterality of the trajectory of TF-PED in terms of the patients' age or sex.

A Novel Combination of Percutaneous Endoscopic Lumbar Discectomy and Epiduroscopic Laser Neural Decompression for Down-migrated Disc Herniation

Although percutaneous endoscopic lumbar discectomy (PELD) is an effective treatment for herniated discs, its application in a disc with extensive migration is still challenging. As such, epiduroscopic laser neural decompression (ELND) provides a new view of the epidural space as well as an alternative treatment for a herniated disc and epidural fibrosis. In this paper the authors introduce the novel combination of PELD and ELND for high grade down-migrated disc herniation. An 87-year old woman presented with severe pain radiating down her leg due to high grade down-migrated disc herniation at L4-5. The therapeutic plan was organized into 3 steps. First, the patient underwent PELD to remove the paracentral extruded disc and open the epidural space between the traversing nerve root and disc space. Second, ELND was performed to remove the down-migrated disc and simultaneously push the free fragment to the L4-5 disc space. Lastly, repetitive free fragments were picked up and streamed upward using ELND. The patient reported significant reduction of pain after surgery. Postoperative magnetic resonance imaging (MRI) showed complete removal of the ruptured disc fragment. A combination of PELD and ELND may be an option of treatments for down-migrated disc herniation. Key words: Percutaneous endoscopic lumbar discectomy, epiduroscopic laser neural decompression, down-migrated disc herniation

A Radiographic Measurement of the Anterior Epidural Space at L4-5 Disc Level.

To observe the morphology character of the anterior epidural space at the L4-5 disc level and to provide an anatomical basis for safely and accurately performing a percutaneous endoscopic lumbar discectomy (PELD). Fifty-five cases with L5 S1 lumbar disc herniation were included in this study, and cases with L4-5 disease were excluded. When the puncture needle reached the epidural space at the L5 S1 level, iohexol was injected at the pressure of 50 cm H2 O during the PELD, then C-Arm fluoroscopy was used to obtain standard lumbar frontal and lateral images. The widths of epidural space at the level of the L4 lower endplate, the L5 upper endplate, as well as the middle point of the L4-5 disc were measured from the lumbar lateral X-ray film. Epidural space at the L4-5 disc plane performs like a trapezium chart with a short side at the head end and a long side at the tail end in the lumbar lateral X-ray radiograph, while the average widths of epidural space were 10.2 ± 2.5, 12.3 ± 2.3, and 13.8 ± 2.6 mm at the upper, middle, and lower level of the L4-5 disc. Understanding the morphological characteristics of epidural space will contribute to improving the safety of the tranforaminal percutaneous endoscopy technique.

Clinical and radiological factors related to the presence of motor deficit in lumbar disc prolapse: a prospective analysis of 70 consecutive cases with neurological deficit.

To analyse the clinic-radiological factors associated with neurological deficit following lumbar disc herniation. A prospective, cross-sectional study was performed in 140 cases of micro-discectomy following lumbar disc herniation. Group 1 included 70 consecutive patients with motor deficit and group 2 (controls) included 70 patients with intact neurology. Motor deficit was defined as the occurrence of motor power ≤3/5 in L2-S1 myotomes. Multiple clinical and radiological parameters were studied between the two groups. Patients with diabetes (p 0.004), acute onset of symptoms (p 0.036), L3-4 discs (p 0.001), sequestrated discs (p 0.004), superiorly migrated discs (p 0.012) and central discs (p 0.004), greater antero-posterior disc dimension (p 0.023), primary canal stenosis (p 0.0001); and greater canal compromise (p 0.002) had a significant correlation with the development of neurological deficit. The presence of four or more of these risk factors showed a higher chance of the presence of motor deficit (sensitivity of 74%, specificity of 77%). Age, sex, previous precipitating events, severity of pain, smoking, and number of herniations levels did not affect the occurrence of deficit (p>0.05 for all). Patients with or without bladder symptoms were similar with respect to all clinico-radiological parameters. However, the time delay since the occurrence of deficit was significantly shorter in patients with bladder involvement (p 0.001). Patients with diabetes, acute presentation, central, sequestrated and superiorly migrated discs, high lumbar disc prolapse, and greater spinal canal compromise are predisposed to the presence of motor deficit.

Hybrid Rigid-Deformable Model for Prediction of Neighboring Intervertebral Disk Loads During Flexion Movement After Lumbar Interbody Fusion at L3-4 Level.

Knowledge of spinal loads in neighboring disks after interbody fusion plays an important role in the clinical decision of this treatment as well as in the elucidation of its effect. However, controversial findings are still noted in the literature. Moreover, there are no existing models for efficient prediction of intervertebral disk stresses within annulus fibrosus (AF) and nucleus pulposus (NP) regions. In this present study, a new hybrid rigid-deformable modeling workflow was established to quantify the mechanical stress behaviors within AF and NP regions of the L1-2, L2-3, and L4-5 disks after interbody fusion at L3-4 level. The changes in spinal loads were compared with results of the intact model without interbody fusion. The fusion outcomes revealed maximal stress changes (10%) in AF region of L1-2 disk and in NP region of L2-3 disk. The minimal stress change (1%) is noted at the NP region of the L1-2 disk. The validation of simulation outcomes of fused and intact lumbar spine models against those of other computational models and in vivo measurements showed good agreements. Thus, this present study may be used as a novel design guideline for a specific implant and surgical scenario of the lumbar spine disorders.

Use of magnetic resonance imaging to detect occult spinal dysraphism in infants.

OBJECTIVE Cutaneous stigmata or congenital anomalies often prompt screening for occult spinal dysraphism (OSD) in asymptomatic infants. While a number of studies have examined the results of ultrasonography (US) screening, less is known about the findings when MRI is used as the primary imaging modality. The object of this study was to assess the results of MRI screening for OSD in infants. METHODS The authors undertook a retrospective review of all infants who had undergone MRI of the lumbar spine to screen for OSD over a 6-year period (September 2006-September 2012). All images had been obtained on modern MRI scanners using sequences optimized to detect OSD, which was defined as any fibrolipoma of the filum terminale (FFT), a conus medullaris ending at or below the L2-3 disc space, as well as more complex lesions such as lipomyelomeningocele (LMM). RESULTS Five hundred twenty-two patients with a mean age of 6.2 months at imaging were included in the study. Indications for imaging included isolated dimple in 235 patients (45%), asymmetrically deviated gluteal cleft in 43 (8%), symmetrically deviated (Y-shaped) gluteal cleft in 38 (7%), hemangioma in 28 (5%), other isolated cutaneous stigmata (subcutaneous lipoma, vestigial tail, hairy patch, and dysplastic skin) in 31 (6%), several of the above stigmata in 97 (18%), and congenital anomalies in 50 (10%). Twenty-three percent (122 patients) of the study population had OSD. Lesions in 19% of these 122 patients were complex OSD consisting of LMM, dermal sinus tract extending to the thecal sac, and lipomeningocele. The majority of OSD lesions (99 patients [81%]) were filar abnormalities, a group including FFT and low-lying conus. The rate of OSD ranged from 12% for patients with asymmetrically deviated gluteal crease to 55% for those with other isolated cutaneous stigmata. Isolated midline dimple was the most common indication for imaging. Among this group, 20% (46 of 235) had OSD. There was no difference in the rate of OSD based on dimple location. Those with OSD had a mean dimple position of 15 mm (SD 11.8) above the coccyx. Those without OSD had a mean dimple position of 12.2 mm (SD 19) above the coccyx (p = 0.25). CONCLUSIONS The prevalence of OSD identified with modern high-resolution MRI screening is significantly higher than that reported with US screening, particularly in patients with dimples. The majority of OSD lesions identified are FFT and low conus. The clinical significance of such lesions remains unclear.

Anatomical differences in patients with lumbosacral transitional vertebrae and implications for minimally invasive spine surgery.

OBJECTIVE The objective of this study was to investigate the neurovascular and anatomical differences in patients with lumbosacral transitional vertebrae (LSTV) and the associated risk of neurovascular injury in minimally invasive spine surgery. METHODS The authors performed a retrospective study of CT and MR images of the lumbar spine obtained at their institution between 2010 and 2014. The following characteristics were evaluated: level of the iliac crest in relation to the L4-5 disc space, union level of the iliac veins and arteries in relation to the L4-5 disc space, distribution of the iliac veins and inferior vena cava according to the different Moro zones (A, I, II, III, IV, P) at the L4-5 disc space, and the location of the psoas muscle at the L4-5 disc space. The findings were compared with findings on images obtained in 28 age- and sex-matched patients without LSTV who underwent imaging studies during the same time period. RESULTS Twenty-eight patients (12 male, 16 female) with LSTV and the required imaging studies were identified; 28 age- and sex-matched patients who had undergone CT and MRI studies of the thoracic and lumbar spine imaging but did not have LSTV were selected for comparison (control group). The mean ages of the patients in the LSTV group and the control group were 52 and 49 years, respectively. The iliac crest was located at a mean distance of 12 mm above the L4-5 disc space in the LSTV group and 4 mm below the L4-5 disc space in the controls. The iliac vein union was located at a mean distance of 8 mm above the L4-5 disc space in the LSTV group and 2.7 mm below the L4-5 disc space in the controls. The iliac artery bifurcation was located at a mean distance of 23 mm above the L4-5 disc space in the LSTV group and 11 mm below the L4-5 disc space in controls. In patients with LSTV, the distribution of iliac vein locations was as follows: Zone A, 7.1%; Zone I only, 78.6%; Zone I encroaching into Zone II, 7.1%; and Zone II only, 7.1%. In the control group, the distribution was as follows: Zone A only, 17.9%; Zone A encroaching into Zone I, 75%; and Zone I only, 7.1%. There were no iliac vessels in Zone II in the control group. The psoas muscle was found to be rising away laterally and anteriorly from the vertebral body more often in patients with LSTV, resulting in the iliac veins being found in the "safe zone" only 14% of the time, greatly increasing the risk of vascular injury. CONCLUSIONS In patients with LSTV, the iliac crest is more likely to be above the L4-5 disc space, which increases the technical challenges of a lateral approach. The location of the psoas muscle rising away laterally and ventrally in patients with LSTV compared with controls and with the union of the iliac veins occurring more often above the L4-5 disc space increases the risk for iatrogenic vascular injury at the L4-5 level in this patient population.

Asymmetrical and smaller size of trunk muscles in combat sports athletes with lumbar intervertebral disc degeneration.

BackgroundLumbar intervertebral disc degeneration (LDD) frequently occurs in athletes. Associations between LDD and trunk muscles still remain unclear.PurposeThis study examined whether there is an association between the prevalence of LDD and the symmetry and size of the cross-sectional areas (CSAs) of the trunk muscles in combat sports athletes.MethodsParticipants in this study were 151 collegiate male combat sports athletes. A total of 755 lumbar intervertebral discs from L1–2 to L5–S1 in 151 athletes were assessed using magnetic resonance imaging (MRI) and a comprehensive grading system of LDD (grades I–V). All 151 athletes were divided into 2 groups: LDD and non-LDD. CSAs of trunk muscles at the L3–4 disc level were measured using MRI.ResultsSixty-nine athletes had LDD at 1 or more disc levels (45.7 %). The LDD grade for the lower 2 disc levels was significantly higher than that for the other disc levels (p < 0.001). The CSAs of the left and right sides in trunk muscles were significantly asymmetrical, independent of the LDD which was prevalent in the disc levels (obliques: p = 0.040; quadratus lumborum: p < 0.001). The relative CSAs of trunk muscles to their body weight in the LDD group were significantly smaller than those in the non-LDD group (rectus abdominis: p = 0.011; obliques: p = 0.024; quadratus lumborum: p = 0.006; lumbar erector spinae plus multifidus: p = 0.001).ConclusionThis study suggests that the prevalence of LDD is associated with asymmetrical and relatively smaller CSAs of trunk muscles in combat sports athletes.

FACET GEOMETRY AND UNILATERAL LUMBAR DISC HERNIATION

Up to now there have been two contradictory opinions in regard to lumbar facet role in the development of disc degeneration and herniation. To reconfirm the clinical validity of facet arrangement in the development of early disc degeneration and herniation, this study was carried out. For this purpose, the relationship between lumbar unilateral disc protrusion and geometry of the facet joints in the transverse plane was investigated. Method: The facet geometry was measured at the L4 disc level in the 35 protruded disc patients and L5 disc level in the 19 protruded disc patients. The computed tomographic scan sections were made 2[Formula: see text]mm intervals. The discs of L4 and L5 levels in the patients without disc protrusion and patients with spine injury were used as control. Results: 1. The facet angle showed the different individual variance. Among the L[Formula: see text] disc herniation group, the mean facet angle in the protruded and opposite sides and control were [Formula: see text] (29–70[Formula: see text]), [Formula: see text] (29–65[Formula: see text]), and [Formula: see text] (30–65[Formula: see text]). Those values at L5-S1 level were [Formula: see text] (35–79[Formula: see text]), [Formula: see text] (36–79[Formula: see text]), and [Formula: see text] (36–79[Formula: see text]), respectively. 2. Transverse interfacet angle (TIFA) of the L[Formula: see text] protruded disc level and that of control were 97–14[Formula: see text] (59–125[Formula: see text]) and [Formula: see text] (66–127[Formula: see text]). Those of L5-S1 level were [Formula: see text] (70–132[Formula: see text]) and [Formula: see text] (76–151[Formula: see text]). 3. The angle difference between both sides in the case of the facet asymmetry at L[Formula: see text] disc level was [Formula: see text] (0–30[Formula: see text]), and that of the control was [Formula: see text] (0–15[Formula: see text]), and those of L5-S1 level were [Formula: see text] (0–24[Formula: see text]) and [Formula: see text] (0–24[Formula: see text]), respectively. Disc herniation developed toward the more obliquely aligned facet joint side in 19 (54.2%) out of the 35 patients at the L[Formula: see text] disc, while disc herniation at L5-S1 level developed toward the more obliquely aligned facet joint side in 11 (57.9%) out of the 19 patients. 4. Among the L[Formula: see text] disc level, the mean moment arm angles in the disc-protruded side, the opposite side and control were [Formula: see text] (16–40[Formula: see text]), [Formula: see text] (15–35[Formula: see text]), and [Formula: see text] (16–35[Formula: see text]). Those of L5-S1 level each were [Formula: see text] (21–36[Formula: see text]), [Formula: see text] (17–35[Formula: see text]), and [Formula: see text] (16–35[Formula: see text]), respectively. 5. At the L[Formula: see text] level, the mean non-dimensional facet depths in the disc-protruded side, the opposite side, and control were [Formula: see text] (0–0.36[Formula: see text]), [Formula: see text] (0–0.41[Formula: see text]), and [Formula: see text] (0.02–0.28[Formula: see text]). Those facet depths at L5-S1 level were [Formula: see text] (0.02–0.28[Formula: see text]), [Formula: see text] (0.02–0.2[Formula: see text]), and [Formula: see text] (0.02–0.28[Formula: see text]). Conclusion: The five parameters including facet angle showed clinically no significant correlation with the disc herniation.

Vertebral level and measurements of conus medullaris and dural sac termination with special reference to the apex of the sacral hiatus: anatomical and magnetic resonance imaging radiologic study

Anatomical orientation of the caudal space and termination level of conus medullaris (CMT) and dural sac (DST) has great significance for anaesthetists and neurosurgeons. This study aimed to explore the anatomical landmarks important to perform save spinal anaesthesia, lumber puncture and caudal analgesia through the correlation between the vertebral level of CMT, DST and sacral hiatus apex (SHA) in human cadavers and by using magnetic resonance imaging (MRI). Sixty adult cadavers (40 males, 20 females) and 200 (100 males, 100 females) MR lumbosacral images of 16-69-year-old persons were used in this study. Vertebral level of CMT, DST and SHA and their linear distances were determined in cadavers and MRI. Also, anteroposterior diameter at SHA, length and thickness of sacrococcygeal membrane were measured as well, and correlate these levels and their distances with age and sex. Mean and highest frequent number of MRI vertebral level of CMT was observed at lower third of L1 in men and L1-2 disc in women, that of DST at upper third of S2 in men and middle third of S2 in women, while SHA was seen at middle third of S4 in both men and women with no significant (p > 0.05) age or gender differences. In 5% of cases, CMT, DST and SHA were seen at vertebral level below L2, below S2-3 and above S3, respectively. However, mean vertebral level of CMT, DST, SHA was observed at L1L, S2M and S4U without sex differen-ce in cadaveric specimens, respectively. All linear distances of men MRI revealed significant difference (p < 0.05) compared with those of women except thickness of sacrococcygeal membrane and anterposterior diameter at SHA. Accurate knowledge of vertebral level of CMT, DST and SHA and the distances in-between might decrease the iatrogenic injury of dural sac, spinal cord and cauda equina.

Lumbar artery branches coursing vertically over the intervertebral discs of the lower lumbar spine: an anatomic study

Bleeding from the lumbar artery is a potential complication during the transpsoas approach to the lower lumbar intervertebral discs. In this anatomic study, the morphological relationships between the branches of the lumbar artery and the lower intervertebral disc were investigated to assess the risk of injury to the branches of the lumbar segmental arteries. We studied 88 sites (86 lumbar arteries) at the third and fourth lumbar vertebrae bilaterally in 22 formalin-fixed cadavers. The branches of the lumbar artery coursing along the lateral sides of the lower intervertebral disc [muscular branch, anastomotic branch, and branch supplying the spinal nerve and plexus (BSNP)] and the iliolumbar artery running upward over the L4-5 disc were identified. Branches crossing the intervertebral discs vertically were evaluated. Muscular branches with a lumen structure longer than 2cm coursed vertically over the middle third of the intervertebral disc in 3 of 88 sites (3.4%). Anastomotic branches ran downward in 13 of 88 (14.8%), and iliolumbar arteries ran upward on the posterior third of the lateral sides of the disc in 2 of 88 (2.3%). BSNPs ran downward through the posterior third of the disc at 18 of 88 sites (20.5%). Overall, the arterial branches coursed vertically over the posterior third of the lateral sides of the intervertebral discs in approximately 30% of subjects. Lumbar artery branches coursed vertically over the middle third and the posterior third of the lateral sides of the intervertebral discs in approximately 3 and 30% of subjects, respectively.

Acute psychosis induced by short-term treatment with methylprednisolone – a case report

Steroid treatment has been widely used for immunologic and inflammatory disorders. Psychiatric symptoms are not uncommon complications of the corticosteroid treatment. Correlations between the hypothalamic-pituitary-adrenal (HPA) axis and various psychoses have been already established in the specialty literature (modified HPA activity by drugs or not, glucocorticoid receptors downregulation, reduced hippocampal volume). The prevalence of corticosteroid-induced psychotic disorders varies around 5–6%. Most corticosteroid-induced symptoms start during the first few weeks after treatment initiation, but their onset can also be in the first 3–4 days. We would like to report the case of a 30-year-old woman who was taken to the psychiatry emergency room for psychomotor agitation, auditory and visual hallucinations, and bizarre delusions, disorganized thinking and modified behavior. The patient had no personal or family history of psychiatric illness. One month earlier, she was admitted in a neurosurgery ward and underwent lumbar surgery for L4–L5 disc protrusion; at discharge, eight days later, she began treatment with methylprednisolone 80 mg/day for three days. One week later, psychotic symptoms emerged that resulted in her hospitalization in our ward for apparent steroid-induced psychosis. Treatment with risperidone (up to 6 mg/day) and diazepam (10 mg/day, rapidly discontinued) was initiated. The endocrinology examination revealed modified plasmatic cortisol. The psychosis resolved several weeks later and the patient was discharged. Psychiatric complications induced by steroids underline the role of physicians that have to educate the patients and their families about these side effects and their early recognition.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Effect of Interbody Fusion on the Remaining Discs of the Lumbar Spine in Subjects with Disc Degeneration.

To study effects (stress loads) of lumbar fusion on the remaining segments (adjacent or not) of the lumbar spine in the setting of degenerated adjacent discs. A lumbar spine finite element model was built and validated. The full model of the lumbar spine was a parametric finite element model of segments L 1-5 . Numerous hypothetical combinations of one-level lumbar spine fusion and one-level disc degeneration were created. These models were subjected to 10 Nm flexion and extension moments and the stresses on the endplates and consequently on the intervertebral lumbar discs measured. These values were compared to the stresses on healthy lumbar spine discs under the same load and fusion scenarios. Increased stress at endplates was observed only in the settings of L4-5 fusion and L3-4 disc degeneration (8% stress elevation at L2,3 in flexion or extension, and 25% elevation at L3,4 in flexion only). All other combinations showed less endplate stress than did the control model. For fusion at L3-4 and degeneration at L4-5 , the stresses in the endplates at the adjacent level inferior to the fused disc decreased for both loading disc height reductions. Stresses in flexion decreased after fusion by 29.5% and 25.8% for degeneration I and II, respectively. Results for extension were similar. For fusion at L2-3 and degeneration at L4-5 , stresses in the endplates decreased more markedly at the degenerated (30%), than at the fused level (14%) in the presence of 25% disc height reduction and 10 Nm flexion, whereas in extension stresses decreased more at the fused (24.3%) than the degenerated level (5.86%). For fusion at L3-4 and degeneration at L2-3 , there were no increases in endplate stress in any scenario. For fusion at L4-5 and degeneration at L3-4 , progression of degeneration from I to II had a significant effect only in flexion. A dramatic increase in stress was noted in the endplates of the degenerated disc (L3-4 ) in flexion for degeneration II. Stresses are greater in flexion at the endplates of L3-4 and in flexion and extension at L2-3 in the presence of L3-4 disc disease and L4-5 fusion than in the control group. In all other combinations of fusion and disc disease, endplate stress was less for all levels tested than in the control model.

Morphometric Analysis of Lumbar Disc Space in the Turkish Population and Safe Discectomy Distance in Lumbar Disc Surgery.

Lumbar discectomy is a common surgical intervention in neurosurgical practice. Iatrogenic vascular injury during this surgery is a rare, but serious complication. In this study, our aim was to review the average safe depth of discectomy for both sexes. This study involved a total of 56 patients between 21 and 79 years old (28 male and 28 female) who had no surgical pathology as documented by lumbar magnetic resonance imaging study. Measurements at L3-4, L4-5, and L5-S1 were performed for both sexes as follows: 1 < sup > st < /sup > measurement, from the furthest lateral part of the dura to the end of the disc (right-left); 2 < sup > nd < /sup > measurement, the anteroposterior length of the cross-section passing through the midline of the disc; 3rd measurement; from the furthest lateral part of the dura to the furthest lateral part of the disc (right-left); 4th measurement, the length from right to left of the cross-section passing through the midline of the disc. Measurement 1 at L3-4, L4-5, and L5-S1, this value was estimated to be 35.9 and 36.7 mm, 35.9 and 36.9, and 34 and 34.9 mm in the right and left sides respectively, for female subjects. The corresponding values for males were 41.4 and 42.1, 40.6 and 40.9, and 37.4 and 37.7 mm at L3-4, L4-5, and L5-S1, respectively. Measurement 3 in L3-4, L4-5, and L5-S1 disc spaces on the right and left sides in female subjects were 14.8 and 16.3 mm, 15.7 and 17.2 mm, and 14.9 and 17.1 mm, respectively, with corresponding figures of 18.6 and 19.5, 19.7 and 20.6, and 18.2 and 18.6 mm among male participants. Measurement 2 and 4 in females for L3-4, L4-5, and L5-S1 were 38.4 and 52.3 mm, 38.9 and 53.4 mm, and 37 and 51.8 mm, respectively. The corresponding figures for males were 43.2 and 57.6 mm, 43.2 and 58.9 mm, and 40.1 and 56.7 mm, respectively. Determination of the safe discectomy depth in both males and females, as well as the use of marking disc punches to indicate the safe margins may help clinicians to avoid this unwanted complication.

Needle Tip Position and Bevel Direction Have No Effect in the Fluoroscopic Epidural Spreading Pattern in Caudal Epidural Injections: A Randomized Trial.

Background. Caudal epidural steroid injections (CESIs) are an effective treatment for pain. If the injection spreads in a specific pattern depending on the needle position or bevel direction, it would be possible to inject the agent into a specific and desired area. Objectives. We conducted a prospective randomized trial to determine if the needle position and bevel direction have any effect on the epidural spreading pattern in CESI. Methods. Demographic data of the patient were collected. During CESI, the needle position (middle or lateral) and direction (ventral or dorsal) were randomly allocated. Following fluoroscope-guided injection of 4 mL contrast media and 10 mL of injectates, the epidural spreading patterns (ventral or dorsal, bilateral or lateral) were imaged. Results. In the 210 CESIs performed, the needle tip position and bevel direction did not influence the epidural spreading patterns at L4-5 and L5-S1 disc levels. A history of Lumbar spine surgery was associated with a significantly limited spread to each disc level. A midline needle tip position was more effective than the lateral position in spreading to the distant disc levels. Conclusions. Neither the needle tip position nor the bevel direction affected the epidural drug spreading pattern during CESI.

Iatrogenic iliac arteriovenous fistula with aortic pseudoaneurysm formation post lumbar (L4-L5) laminectomy and pedicular screw fixation.

Nowadays lumbar laminectomy is a common surgery in daily practice and a very safe procedure, but it can result in sudden life threatening though infrequent vascular complications with greater than 50% mortality [1]. Such events usually require immediate intervention, so it is essential that anesthesiologists and surgeons be aware of this potential complication, its manifestation and treatment. The incidence of iatrogenic vascular complications in lumbar spine surgery is reported to be 0.01%-0.17% [1]. Although reported cases are few, unrecognised events are more than expected. However when one such event does occur, it can cause fatality in an otherwise healthy patient. We present a case of a 55-years-old male, American Society of Anesthesiologists physical status I with low backache since 10 years, underwent laminectomy and screw fixation for the same. On the ninth postoperative day he started developing right lower limb swelling associated with pain. Deep vein thrombosis was ruled out on venous doppler. On postoperative day 15, he started developing dyspnea, and generalized edema. Abdominal bruit was present and neck veins were engorged. On postoperative day 16, facial edema increased and hypotension developed. CT angiogram of chest and abdomen revealed distal right common iliac artery fistulous communication with common iliac vein with prominent inferior vena cava and hepatic vein, pseudo-aneurysm arising from site of fistula (4.2 × 3.8 × 3.1 cc), neck of aneurysm measuring 18.5 mm (Fig. 1). CT chest showed bilateral pleural effusion with ground glass opacities. Emergency aneurysm repair was done on the same day. Postoperatively he was shifted to the surgical intensive care unit for elective ventilation and monitoring due to massive fluid shifts intra-operatively and massive hemorrhage. He was later hemodynamically stable and kept in intensive care unit for 3 more days and subsequently shifted to ward on postoperative day 4. Further course in ward was uneventful and the patient was discharged on postoperative day 7. Fig. 1 (A) Three dimensional computerized tomography reconstruction shows right common iliac arteriovenous fistula with pseudoaneurysm (Arrow). (B) Computerized tomography Angiogram shows a right common iliac arteriovenous fistula with pseudo-aneurysm (Arrow). ... The L4-5 disc space is the most common site for a herniation of intervertebral disc [2]. Bifurcation of the aorta and inferior vena cava lies just anterior to this disc space, separated from it only by the anterior spinal ligament. The pathogenesis of iatrogenic vascular injury after spinal injury relates to the anatomical complexity of the aortic bifurcation and inferior vena cava confluence occurring at or below L4. They may present immediately in the intraoperative period or remain subclinical for days to years [3]. Bleeding from the wound is not a reliable sign as the self-sealing effect of the anterior annulus fibrosus and anterior longitudinal ligament may prevent any bleeding to be seen posteriorly. These tissues are tough and elastic, leading to blood leakage in the retroperitoneal space rather than the operating field. Signs and symptoms are equally wide ranging and include intra-operative and postoperative hypotension, associated fall in hematocrit, acute ischemia, distal pulse deficit, bruit, thrill, pulsatile abdominal mass, abdominal pain, expanding hematoma, limb edema and non-healing wounds. As the arterial injury drain directly into the low pressure venous system, hemorrhage is an uncommon presentation with arteriovenous fistula and hence it becomes very difficult to identify such injuries. An arteriovenous fistula should be suspected in a patient with a history of lower lumbar disc surgery followed by progressive swelling of a lower limb and associated bruit [4]. Thus, a high index of suspicion is needed amongst anesthesiologists given the rarity of complications and wide range of presentations.

Analysis of the Relationship between Hypertrophy of the Ligamentum Flavum and Lumbar Segmental Motion with Aging Process

Study DesignRetrospective cross-sectional study.PurposeTo investigate the relationship between ligamentum flavum (LF) hypertrophy and lumbar segmental motion.Overview of LiteratureThe pathogenesis of LF thickening is unclear and whether the thickening results from tissue hypertrophy or buckling remains controversial.Methods296 consecutive patients underwent assessment of the lumbar spine by radiographic and magnetic resonance imaging (MRI). Of these patients, 39 with normal L4–L5 disc height were selected to exclude LF buckling as one component of LF hypertrophy. The study group included 27 men and 12 women, with an average age of 61.2 years (range, 23–81 years). Disc degeneration and LF thickness were quantified on MRI. Lumbar segmental spine instability and presence of a vacuum phenomenon were identified on radiographic images.ResultsThe distribution of disc degeneration and LF thickness included grade II degeneration in 4 patients, with a mean LF thickness of 2.43±0.20 mm; grade III in 10 patients, 3.01±0.41 mm; and grade IV in 25 patients, 4.16±1.12 mm. LF thickness significantly increased with grade of disc degeneration and was significantly correlated with age (r=0.55, p<0.01). Logistic regression analysis identified predictive effects of segmental angulation (odds ratio [OR]=1.55, p=0.014) and age (OR=1.16, p=0.008).ConclusionsAge-related increases in disc degeneration, combined with continuous lumbar segmental flexion-extension motion, leads to the development of LF hypertrophy.

The Incidence and Risk Factors for Lumbar or Sciatic Scoliosis in Lumbar Disc Herniation and the Outcomes after Percutaneous Endoscopic Discectomy

Background: Some patients with lumbar herniated intervertebral disc disease (HIVD) suffer from both pain and lateral shift or trunk list. In addition to pain, patients have concerns regarding whether trunk list is reversible. Surgical treatment is performed when pain is intractable to conservative management, but a reversal of trunk list is an incidental outcome. Percutaneous lumbar endoscopic discectomy (PELD) is one of the surgical treatment options for lumbar HIVD, but no results concerning its effect on trunk list have been reported. Objectives: The objectives of the present study were to determine the incidence of, and risk factors for, trunk list scoliosis or lateral shift and to report the outcomes of trunk list after PELD. Study Design: Retrospective case study. IRB No. H 1111-025-384 Setting; University medical Center, Seoul, Korea. Methods: We selected 164 patients who were less than 60 years old, complained of unilateral leg pain, and underwent PELD. We measured the maximum trunk shift from the central sacral vertical line (CSVL-max) on preoperative whole spine radiographs and classified trunk list as CSVL-max ≥ 10 mm. CSVL-max was measured on serial radiographs taken at one, 3, 6, and 12 months postoperatively in patients with trunk list. Results: Twenty-nine patients (17.9%) had trunk list (M:F=10:19; mean age, 37.1 ± 11.24 years). Female gender (OR 4.28; 95% CI, 1.49 – 12.3) and HIVD at L4-5 (OR 5.6; 95% CI, 1.8 - 16.7) were risk factors for trunk list. Trunk list was normalized (CSVL-max &lt; 10 mm) in 15 (52%) patients after PELD, and the median time for normalization was 3 – 6 months. Prognostic factors for the recovery of trunk list were not identified. Limitations: Selection bias should be considered in interpreting these results. Conclusion: Trunk list, scoliosis or lateral shift, was observed in 18% of the patients at the time of surgery. Female gender and L4-5 disc herniation were risk factors for trunk list. Trunk list was reversible in more than 50% of patients within 6 months of PELD. Key words: Lumbar, scoliosis, lumbar/sciatic, trunk list, endoscope, disc, discectomy, sciatica, spine, percutaneous endoscopic discectomy