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Anterior longitudinal ligament release is a proven method for restoring spinopelvic parameters. This technique is mostly described using either lateral or anterior approaches with paucity regarding a posterior method. This paper is the first to provide descriptive analysis of the neurovascular anatomy in the context of planning for a posterior endoscopic ALL release. A retrospective chart review was performed on patients underwent any lumbar surgery by a single surgeon. Anatomical data was obtained from pre-operative CT to describe the location of key neurovascular structures in relation to the ALL with focus on posterior approach. A total of 20 patients were included in data analysis. A posterior approach with endoscopic assistance would be feasible at L4/5 and L5/S1, where the bifurcation of the abdominal aorta has occurred with a vessel window that ranges from 18.85 mm to 33.45 mm with at least 2 mm space between the vessels and the corresponding disc spaces in the anterior-posterior dimension with slight predilection of the left side at the L5/S1 level to avoid any neurovascular structures. Our study confirmed the findings of previous studies examining the vascular anatomy associated with the lumbar spine. Interestingly, we found that direct midline would likely not be the best location for a posterior annulotomy, and that both the window between the iliac vessels as well as the distance in AP dimension between the spine and vessels increases as you descend the lumbar spine. This information will help guide future efforts to fully develop a safe and reproducible posterior endoscopic ALL release., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Ossification of the posterior longitudinal ligament (OPLL) of the lumbar spine is rare relative to that of the cervical spine but is often associated with more severe symptoms. Continuous lumbar OPLL is extremely rare. We herein describe a 48-year-old Chinese woman with lumbar spinal stenosis caused by continuous OPLL. She presented with a 5-year history of lower back pain and intermittent claudication. We performed percutaneous transforaminal endoscopic decompression by the posterolateral approach to achieve adequate decompression of the spinal canal up to the lower 1/3 level (0.9 cm) of the L1 vertebral body and down to the upper 1/2 level (1.3 cm) of the L2 vertebral body. After surgery, the patient's neurological function substantially improved, and her visual analog scale scores for the lower back and both lower extremities and her Oswestry disability index were significantly lower than those in the preoperative period. During the 12-month clinical follow-up period, the patient's neurological function was fully restored, and she regained her ability to walk normally. No surgery-related complications were observed. This case report describes a novel surgical approach that may be an effective treatment alternative for continuous lumbar OPLL.

Anterior column release is a powerful surgical technique for achieving spinopelvic balance in adult patients with sagittal plane deformities. We present an alternative strategy for focal deformity correction from a posterior-only approach. The purpose of this study was to evaluate the feasibility and efficacy of a novel surgical technique called posterior open-wedge diskectomy and anterior longitudinal ligament (ALL) release (POWAR). A cadaveric torso underwent POWARs at the L1-L4 intervertebral disc spaces. Baseline measurements of end-plate angle (EPA), anterior intervertebral disc height (ADH), and posterior intervertebral disc height (PDH) were obtained. These measurements were repeated after three stages of correction: posterior column compression alone, posterior column compression following Schwab grade 2 osteotomies, and posterior column compression following POWAR. A second cadaver underwent posterolateral spinal dissection to demonstrate the pertinent anatomical features relevant to this novel procedure. With each stage of correction, a sequential increase in EPA and ADH and a decrease in PDH were demonstrated. The large increase in ADH seen following POWAR confirmed successful release of the ALL. In situ investigation of the aorta and inferior vena cava following anterior exposure revealed no injury to the great vessels or surrounding structures. Ex vivo testing of the aorta and inferior vena cava took place at the L3-4 level. This testing demonstrated no injury or tears to either vessel. POWAR is a new surgical technique that can provide an alternative to three-column osteotomy for surgeons performing spinal reconstructions in adults through an open, posterior-only approach. Clin. Anat. 32:348-353, 2019. © 2018 Wiley Periodicals, Inc., (© 2018 Wiley Periodicals, Inc.)

Objective: To define radiologic parameters and the diagnostic accuracy of computed tomography (CT) scan on posterior ligamentous complex (PLC) injury, identified by magnetic resonance imaging (MRI) in patients with thoracolumbar (TL) fracture., Methods: We retrospectively analyzed 88 patients with TL fractures divided into 2 groups by PLC status evident on MRI: intact and ruptured. The parameters assessed included the anterior fractured vertebral body height (AVH) and posterior fractured vertebral body height, upper and lower AVH, anterior/posterior vertebral height ratio, AVH ratio, local kyphotic angle (LKA), region angle (RA), sagittal index (SI), Gardner angle (GA), Gardner index (GI), Cobb angle, interspinous distance (ISD), upper and lower ISD, ISD ratio, interspinous distance minus (ISDM), interspinous angle (ISA), and upper and lower ISA. The t test, Pearson χ 2 test, and multivariate logistic regression were used., Results: PLC rupture (vs. intact) was associated with RA, GA, GI, ISD, ISD ratio, and ISDM. The positive risk factors for PLC rupture were GA, LKA, SI, and RA. The negative risk factors for PLC rupture were SI greater than 20° and GI. PLC rupture was associated with the SI, upper interspinous distance, ISD ratio, ISDM, and ISA in those with type A1/A2 fractures and the GA, GI, ISD, ISD ratio, and ISDM in those with type A3/A4 fractures., Conclusions: An RA greater than 16°, SI greater than 20°, and GI greater than 24° were associated with PLC injury in patients with type A TL fractures, and an RA greater than 16° and SI greater than 20° predicted PLC injury in type A1 and A2 fractures. An SI greater than 20°, GI greater than 24°, LKA greater than 26°, and ISD ratio greater than 56% predicted PLC injury in type A3 and A4 fractures., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Lateral lumbar interbody fusion is powerful for correcting degenerative conditions, yet sagittal correction remains limited by anterior longitudinal ligament tethering. Although lordosis has been restored via ligament release, biomechanical consequences remain unknown. Investigators examined radiographic and biomechanical of ligament release for restoration of lumbar lordosis., Methods: Six fresh-frozen human cadaveric spines (L3-S1) were tested: (Miller et al., 1988) intact; (Battie et al., 1995) 8mm spacer with intact anterior longitudinal ligament; (Cho et al., 2013) 8mm spacer without intact ligament following ligament resection; (Galbusera et al., 2013) 13mm lateral lumbar interbody fusion; (Goldstein et al., 2001) integrated 13mm spacer. Focal lordosis and range of motion were assessed by applying pure moments in flexion-extension, lateral bending, and axial rotation., Findings: Cadaveric radiographs showed significant improvement in lordosis correction following ligament resection (P<0.05). The 8mm spacer with ligament construct provided greatest stability relative to intact (P>0.05) but did little to restore lordosis. Ligament release significantly destabilized the spine relative to intact in all modes and 8mm with ligament in lateral bending and axial rotation (P<0.05). Integrated lateral lumbar interbody fusion following ligament resection did not significantly differ from intact or from 8mm with ligament in all testing modes (P>0.05)., Interpretation: Lordosis corrected by lateral lumbar interbody fusion can be improved by anterior longitudinal ligament resection, but significant construct instability and potential implant migration/dislodgment may result. This study shows that an added integrated lateral fixation system can significantly improve construct stability. Long-term multicenter studies are needed., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Study Design: Cadaveric biomechanical study., Objective: To determine the degree of segmental correction that can be achieved through lateral transpsoas approach by varying cage angle and adding anterior longitudinal ligament (ALL) release and posterior element resection., Summary of Background Data: Lordotic cage insertion through the lateral transpsoas approach is being used increasingly for restoration of sagittal alignment. However, the degree of correction achieved by varying cage angle and ALL release and posterior element resection is not well defined., Methods: Thirteen lumbar motion segments between L1 and L5 were dissected into single motion segments. Segmental angles and disk heights were measured under both 50 N and 500 N compressive loads under the following conditions: intact specimen, discectomy (collapsed disk simulation), insertion of parallel cage, 10° cage, 30° cage with ALL release, 30° cage with ALL release and spinous process (SP) resection, 30° cage with ALL release, SP resection, facetectomy, and compression with pedicle screws., Results: Segmental lordosis was not increased by either parallel or 10° cages as compared with intact disks, and contributed small amounts of lordosis when compared with the collapsed disk condition. Placement of 30° cages with ALL release increased segmental lordosis by 10.5°. Adding SP resection increased lordosis to 12.4°. Facetectomy and compression with pedicle screws further increased lordosis to approximately 26°. No interventions resulted in a decrease in either anterior or posterior disk height., Conclusion: Insertion of a parallel or 10° cage has little effect on lordosis. A 30° cage insertion with ALL release resulted in a modest increase in lordosis (10.5°). The addition of SP resection and facetectomy was needed to obtain a larger amount of correction (26°). None of the cages, including the 30° lordotic cage, caused a decrease in posterior disk height suggesting hyperlordotic cages do not cause foraminal stenosis., Level of Evidence: N/A.

Purpose: Fresh-frozen intervertebral disc transplantation was determined to be an effective treatment for degenerative disc diseases in rhesus monkeys and in humans. Further research in improving different aspects of disc allografts transplantation is needed and will be investigated in large animal models. This study reports the detailed surgical technique of intervertebral disc transplantation without internal fixation and the important notes to ensure success in goats., Methods: Fifty-one male goats were used in this study. Ten goats were used as intervertebral disc allograft donors; the remaining forty-one goats were used to develop the surgical technique for intervertebral disc allograft transplantation. Radiographs, ex vivo MRI and gross observation were used to monitor the stability and healing of the disc allografts at 3 months, postoperatively., Results: Size matching of the disc allograft, preservation of the anterior longitudinal ligament and an appropriate portion of the annulus fibrosus at the recipient site were crucial for stable graft retention. Additionally, a slightly reduced height of the disc allograft compared to that of the recipient slot may avoid graft endplate fracture., Conclusions: Lumbar intervertebral disc transplantation without internal fixation can be successfully performed in goats.

Purpose: After total disc replacement with a ball-and-socket joint, reduced range of motion and progression of facet joint degeneration at the index level have been described. The aim of the study was to test the hypothesis that misalignment of the vertebrae adjacent to the implant reduces range of motion and increases facet joint or capsule tensile forces., Methods: A probabilistic finite element analysis was performed using a lumbosacral spine model with an artificial disc at level L5/S1. Misalignment of the L5 vertebra, the gap size of the facet joints, the transection of the posterior longitudinal ligament, and the spinal shape were varied. The model was loaded with pure moments., Results: Misalignment of the L5 vertebra reduced the range of motion up to 2°. A 2-mm displacement of the L5 vertebra in the anterior direction already led to facet joint forces of approximately 240 N. Extension, lateral bending, and axial rotation caused maximum facet joint forces between 280 and 380 N, while flexion caused maximum forces of approximately 200 N. A 2-mm displacement in the posterior direction led to capsule forces of approximately 80 N. Additional moments increased the maximum facet capsule forces to values between 120 and 230 N., Conclusions: Misalignment of the vertebrae adjacent to an artificial disc strongly increases facet joint or capsule forces. It might, therefore, be an important reason for unsatisfactory clinical results. In an associated clinical study (Part 2), these findings are validated.

The use of pedicle screws for short-segment implants has been known to be dangerous in patients who score a 7 or higher on McCormack's classification. The efficiency of ligamentotaxis of the posterior longitudinal ligament (PLL) and short-segment implants and fusion in relation to McCormack's classification has not been proven. The purpose of this study was to compare the clinical and radiological results of indirect decompression using PLL ligamentotaxis between patients with a high- (score of 7 or higher) or low-grade (score of 6 or less) fracture. Eighteen patients (19 levels) in the low-grade fracture group were compared with 23 patients (27 levels) in the high-grade fracture group. Clinical outcomes were measured using the Oswestry Disability Index (ODI) and visual analog scale (VAS) scores; radiologic measures were determined using the spinal canal area and mean sagittal diameter; and the complications were evaluated and compared. A significant improvement in each groups was found in the mean pre- and postoperative spinal canal area, mean sagittal diameter, Cobb's angle, and anterior vertebral height compression rate. A significant difference was found between the 2 groups in the mean pre- and postoperative spinal canal area, mean sagittal diameter, and anterior vertebral height compression rate. Moreover, the VAS and ODI scores continued to significantly improve at the last follow-up in each group. No difference was found in the prevalence of complications. Despite a high score, no significant difference was found in the clinical and radiological results and the complications. Therefore, indirect decompression using PLL ligamentotaxis was found to be a useful technique for patients who recieve a high McCormack's classification score., (Copyright 2013, SLACK Incorporated.)

Object: Traditional procedures for correction of sagittal imbalance via shortening of the posterior column include the Smith-Petersen osteotomy, pedicle subtraction osteotomy, and vertebral column resection. These procedures require wide exposure of the spinal column posteriorly, and may be associated with significant morbidity. Anterior longitudinal ligament (ALL) release using the minimally invasive lateral retroperitoneal approach with a resultant net lengthening of the anterior column has been performed as an alternative to increase lordosis. The objective of this study was to demonstrate the feasibility and early clinical experience of ALL release through a minimally invasive lateral retroperitoneal transpsoas approach, as well as to describe its surgical anatomy in the lumbar spine., Methods: Forty-eight lumbar levels were dissected in 12 fresh-frozen cadaveric specimens to study the anatomy of the ALL as well as its surrounding structures, and to determine the feasibility of the technique. The lumbar disc spaces and ALL were accessed via the lateral transpsoas approach and confirmed with fluoroscopy in each specimen. As an adjunct, 4 clinical cases of ALL release through the minimally invasive lateral retroperitoneal transpsoas approach were reviewed. Operative technique, results, complications, and early outcomes were assessed., Results: In the cadaveric study, sectioning of the ALL proved to be feasible from the minimally invasive lateral retroperitoneal transpsoas approach. The structures at most immediate risk during this procedure were the aorta, inferior vena cava, iliac vessels, and sympathetic plexus. The mean increase in segmental lumbar lordosis per level of ALL release was 10.2°, while global lumbar lordosis improved by 25°. Each level of ALL release took 56 minutes and produced 40 ml of blood loss on average. Visual analog scale and Oswestry Disability Index scores improved by 9 and 35 points, respectively. There were no cases of hardware failure, and as of yet no complications to report., Conclusions: This initial experience suggests that ALL release through the minimally invasive lateral retroperitoneal transpsoas approach may be feasible, allows for improvement of lumbar lordosis without the need of an open laparotomy/thoracotomy, and minimizes the tissue disruption and morbidity associated with posterior osteotomies.

Object: In the surgical treatment of spinal deformities, the importance of restoring lumbar lordosis is well recognized. Smith-Petersen osteotomies (SPOs) yield approximately 10° of lordosis per level, whereas pedicle subtraction osteotomies result in as much as 30° increased lumbar lordosis. Recently, selective release of the anterior longitudinal ligament (ALL) and placement of lordotic interbody grafts using the minimally invasive lateral retroperitoneal transpsoas approach (XLIF) has been performed as an attempt to increase lumbar lordosis while avoiding the morbidity of osteotomy. The objective of the present study was to measure the effect of the selective release of the ALL and varying degrees of lordotic implants placed using the XLIF approach on segmental lumbar lordosis in cadaveric specimens between L-1 and L-5., Methods: Nine adult fresh-frozen cadaveric specimens were placed in the lateral decubitus position. Lateral radiographs were obtained at baseline and after 4 interventions at each level as follows: 1) placement of a standard 10° lordotic cage, 2) ALL release and placement of a 10° lordotic cage, 3) ALL release and placement of a 20° lordotic cage, and 4) ALL release and placement of a 30° lordotic cage. All four cages were implanted sequentially at each interbody level between L-1 and L-5. Before and after each intervention, segmental lumbar lordosis was measured in all specimens at each interbody level between L-1 and L-5 using the Cobb method on lateral radiography., Results: The mean baseline segmental lordotic angles at L1-2, L2-3, L3-4, and L4-5 were -3.8°, 3.8°, 7.8°, and 22.6°, respectively. The mean lumbar lordosis was 29.4°. Compared with baseline, the mean postimplantation increase in segmental lordosis in all levels combined was 0.9° in Intervention 1 (10° cage without ALL release); 4.1° in Intervention 2 (ALL release with 10° cage); 9.5° in Intervention 3 (ALL release with 20° cage); and 11.6° in Intervention 4 (ALL release with 30° cage). Foraminal height in the same sequence of conditions increased by 6.3%, 4.6%, 8.8% and 10.4%, respectively, while central disc height increased by 16.1%, 22.3%, 52.0% and 66.7%, respectively. Following ALL release and placement of lordotic cages at all 4 lumbar levels, the average global lumbar lordosis increase from preoperative lordosis was 3.2° using 10° cages, 12.0° using 20° cages, and 20.3° using 30° cages. Global lumbar lordosis with the cages at 4 levels exhibited a negative correlation with preoperative global lordosis (10°, R = -0.756; 20°, -0.730; and 30°, R = -0.437)., Conclusions: Combined ALL release and placement of increasingly lordotic lateral interbody cages leads to progressive gains in segmental lordosis in the lumbar spine. Mean global lumbar lordosis similarly increased with increasingly lordotic cages, although the effect with a single cage could not be evaluated. Greater global lordosis was achieved with smaller preoperative lordosis. The mean maximum increase in segmental lordosis of 11.6° followed ALL release and placement of the 30° cage.

With regard to the literature, several factors are considered to have an impact on postoperative mobility after lumbar total disc replacement (TDR). As TDR results in a distraction of the ligamentous structures, theoretically the postoperatively disc height and ligamentous integrity have also an influence on biomechanics of a treated segment. The purpose of the study was to evaluate the influence of posterior longitudinal ligament (PLL) resection and segmental distraction on range of motion (ROM). Six human, lumbar spines (L2-L3) were tested with pure moments of ±7.5 Nm in a spine loading apparatus. The ROM was determined in all three motion planes. Testing sequences included: (1) intact state, (2) 10 mm prosthesis (PLL intact), (3) 10 mm prosthesis (PLL resected), (4) 12 mm prosthesis (PLL resected). The prosthesis used was a prototype with a constrained design using the ball-and-socket principle. The implantation of the 10 mm prosthesis already increased the disc height significantly (intact: 9.9 mm; 10 mm prosthesis: 10.6 mm; 12 mm prosthesis: 12.7 mm). Compared to the intact status, the implantation of the 10 mm prosthesis resulted in an increase of ROM for flexion/extension (8.6° vs 10.8°; P = 0.245) and axial rotation (2.9° vs 4.5°; P = 0.028), whereas lateral bending decreased (9.0° vs 7.6°; P = 0.445). The resection of the PLL for the 10 mm prosthesis resulted in an increase of ROM in all motion planes compared to the 10 mm prosthesis with intact PLL (flexion/extension: 11.4°, P = 0.046; axial rotation: 5.1°, P = 0.046; lateral bending: 8.6°, P = 0.028). The subsequent implantation of a 12 mm prosthesis, with resected PLL, resulted in a significant decrease of ROM in all motion planes compared to the 10 mm prosthesis with intact PLL (flexion/extension: 8.4°, P = 0.028; axial rotation: 3.3°, P = 0.028; lateral bending: 5.1°, P = 0.028). Compared to the intact status, the 12 mm prosthesis with resected PLL only decreased lateral bending significantly while the 10 mm prosthesis with intact PLL increased axial rotation significantly. The resection of the PLL during TDR results in a significant increase of ROM in all three principle motion planes. But it still remains unclear if this increase which is in median not more than 1° may alter the clinical results. Moreover, the destabilizing effect of PLL resection can be reversed using a higher implant. The prosthesis height seems more crucial than PLL preservation to maintain the primary stability after TDR.

Total disc arthroplasty (TDA) has been successfully used for monosegmental treatment in the last few years. However, multi-level TDA led to controversial clinical results. We hypothesise that: (1) the more artificial discs are implanted, the stronger the increases in spinal mobility and facet joint forces in flexion and extension; (2) deviations from the optimal implant position lead to strong instabilities. A three-dimensional finite element model of the intact L1-L5 human lumbar spine was created. Additionally, models of the L1-L5 region implanted with multiple Charité discs ranging from two to four levels were created. The models took into account the possible misalignments in the antero-posterior direction of the artificial discs. All these models were exposed to an axial compression preload of 500 N and pure moments of 7.5 Nm in flexion and extension. For central implant positions and the loading case extension, a motion increase of 51% for two implants up to 91% for four implants and a facet force increase of 24% for two implants up to 38% for four implants compared to the intact spine were calculated. In flexion, a motion decrease of 5% for two implants up to 8% for four implants was predicted. Posteriorly placed implants led to a better representation of the intact spine motion. However, lift-off phenomena between the core and the implant endplates were observed in some extension simulations in which the artificial discs were anteriorly or posteriorly implanted. The more artificial discs are implanted, the stronger the motion increase in flexion and extension was predicted with respect to the intact condition. Deviations from the optimal implant position lead to unfavourable kinematics, to high facet joint forces and even to lift-off phenomena. Therefore, multilevel TDA should, if at all, only be performed in appropriate patients with good muscular conditions and by surgeons who can ensure optimal implant positions.

A 72-year-old man presented with gas-containing disc herniations resulting in dual nerve root (exiting and traversing root) compression at the single level manifesting as lower back pain with the right anterolateral thigh and medial calf pain and no response to 4 weeks of conservative treatment. Physical examination revealed positive Lasegue's sign at 40°, but the patient had no evidence of neurological deficit. Magnetic resonance imaging showed two separate disc herniations, a posterocentral herniated disc that had migrated inferiorly at the L3-4 level and compressed the L4 traversing root, and another that had compressed the L3 exiting root in the extraforaminal area at the same level. Coronal computed tomography demonstrated the presence of gas in the spinal canal and extraforaminal area at the L3-4 level, and the vacuum phenomenon was also noted at the L3-4 intervertebral disc. Microscopic discectomy was performed using midline and paramedian approaches, and the presence of gas was confirmed by bubbles after pouring saline into the area intraoperatively. Histological examination revealed fibrous tissue. The patient was discharged with complete relief of pain. This is a rare case of symptomatic gas-containing disc herniations causing dual compression of exiting and traversing roots at a single disc level.

Background: thoracolumbar distraction injuries (AO classification type B) with damage to the posterior ligament complex (PLC) represent an indication for surgery but the use of X-ray and CT imaging often does not identify injuries of the PLC. The aim of this study was to evaluate the accuracy of ultrasound imaging in the assessment of the PLC status in thoracolumbar fractures of the spine., Material and Methods: in a prospective study the findings of the preoperative ultrasound examination were compared to the intraoperative findings., Results: over a period of 2 years a total of 24 patients with 27 thoracolumbar fractures (18 type A, 9 type B) were examined. In 22 cases ultrasound examination was possible and correct ultrasound findings were made in 20 cases (91%). The sensitivity was 83.3%, specificity 93.8%, positive predictive value 83.3% and negative predictive value 93.8%., Conclusion: the use of ultrasound examination in thoracolumbar fractures is a suitable diagnostic tool for injuries of the posterior ligament complex in addition to radiological imaging.

Study Design: Systematic literature review., Objective: A systematic review was designed to answer 3 primary research questions: (1) What is the most useful classification system for surgical and nonsurgical decision-making with regard to thoracolumbar (TL) spine injuries? (2) For a TL burst fracture with incomplete neurologic deficit, what is the optimal surgical approach and stabilization technique? (3) Is complete disruption of the posterior ligamentous complex an indication for surgical intervention for TL burst fractures?, Summary of Background Data: Despite a long history of descriptive and clinical series, there remains considerable controversy and wide variation in the treatment of traumatic TL spine injuries., Methods: A comprehensive search of the English literature was conducted using Medline and the Cochrane Database of Systematic Reviews. Standardized grading systems were used to assess the level of evidence and quality of articles impacting the research questions., Results: Recommendations for the primary research questions were as follows: (1) Thoracolumbar Injury Classification System seems to be the best system available for therapeutic decision-making for TL spine injuries (strength of recommendation: weak; quality of evidence: low). (2) There is no specific surgical approach in the case of a TL burst fracture with incomplete neurologic deficit that has any advantage with regard to neurologic recovery (strength of recommendation: weak; quality of evidence: low). (3) Complete disruption of the posterior ligamentous complex as determined collectively by morphologic criteria using plain radiographs and computed tomography is an indication for surgical intervention in TL burst fractures (strength of recommendation: strong; quality of evidence: low)., Conclusion: Based on this systematic review of the literature only very low to moderate quality studies could be identified to address clinical questions related to TL spine trauma. These findings suggest the need for further study, including emphasis on higher quality studies.

Background Context: There is no previous report on the intraspinal ganglion cyst of the posterior longitudinal ligament in a teenager., Purpose: To report a case of radiculopathy caused by a ganglion cyst of the posterior longitudinal ligament in a teenager., Study Design: Case report., Methods: A 17-year-old male with a 4-month history of left L5 radicular pain was found to have an intraspinal cystic lesion causing radicular compression. Magnetic resonance imaging showed a cystic lesion located in the ventral side of the dura. The patient suffered from severe leg pain. As a result, a surgical operation was therefore performed., Results: The cyst containing jelly-like components and a hemorrhage was punctured and then extirpated. It originated from the posterior longitudinal ligament. A histological study revealed the cyst to be without any synovial layers., Conclusions: This is the first report to describe a ganglion cyst originating from the posterior longitudinal ligament in a teenager. This possible etiology should be kept in mind for any other individuals displaying symptoms of spinal nerve root compression as well as disc herniation.

In thoracolumbar burst fracture the "reverse cortical sign" is a known entity that corresponds to a fragment of the posterior wall that has been flipped 180 degrees with the cancellous surface of the fragment facing posteriorly in the canal and the cortical surface (posterior wall) facing anteriorly. The identification of such reverse cortical fragment is crucial as ligamentotaxis is classically contraindicated as the posterior longitudinal ligament is ruptured. Recognition of such a flipped cortical fragment has relied so far on the axial CT. The advent of CT scans with sagittal reconstruction has allowed us to better describe such entities that have received little attention in the literature. The goal of this report was therefore to describe the appearance of the reverse cortical sign and its likes as they can appear on axial CT scans, sagittal reconstructions and MRI. During 1-year practice at our institution we had to treat three patients with thoracolumbar burst fracture associated with what looked like a reverse cortical sign on the axial CT scans. Further analysis of the sagittal reconstruction CT could differentiate the true reverse cortical sign from a new entity that we coined "the pseudoreverse cortical sign" as observed in two out of the three cases. In the pseudo reverse cortical sign what appears to be a flipped piece of posterior vertebral body is actually part of the superior or inferior endplate that is depressed into the comminuted vertebral body. In such cases the posterior longitudinal ligament appears to be in continuity and therefore such fracture can theoretically be treated with posterior ligamentotaxis as evidenced in one of our case. Careful analysis of the CT scan and specifically the sagittal reconstruction and MRI can differentiate two separate entities that may correspond to a different severity injury.

Objective: Available percutaneous procedures for lumbar disk herniation are not sufficiently effective for large herniations. Percutaneous intradiscal high-pressure injection of saline (IDHP) is designed to tear the thinned posterior longitudinal ligament (PLL), leading to significant reduction in mechanical compression of nerves by the herniation. We evaluated the effectiveness of this new therapy for patients with refractory lumbar herniation., Design: We studied 25 patients with lumbar disk herniation-associated radiculopathy refractory to nonsurgical treatments. Under fluoroscopy in the lateral position, a Tuohy needle was advanced into the herniated disk. Following intradiscal anesthesia, a control glass syringe with Luer lock was attached to the needle for high-pressure intradiscal injection of saline. Pain was scored with a visual analog scale (VAS), and physical activity was assessed using the Japanese Orthopaedic Association (JOA) score., Results: Tearing of the PLL was confirmed by a sudden loss of resistance to injection and leakage of contrast medium out of the disk into the epidural space. No adverse events were noted during and after IDHP apart from mild lumbago that disappeared within a week. IDHP resulted in tearing of extruded and sequestered herniated disks and PLL in 20 (80%) patients, and significant improvement of VAS and JOA scores throughout the 6-month observation period. The mean procedural time was 18 min. MRI confirmed the disappearance of herniated material after tearing. IDHP was unsuccessful in five patients., Conclusions: IDHP leads to prompt relief of pain, with good outcome in patients with lumbar disk large herniation resistant to medical treatment.

Objective: To investigate the clinical application and efficacy of lumbar vertebral canal expansion with preservation of posterior ligaments complex, and to study its biomechanical properties., Methods: Eight fresh lumbosacral cadaveric samples were divided into 3 groups. In group A, 8 intact lumbosacral cadaveric samples were used for biomechanical test. In group B, L3-5 laminectomy were, after the test in group A, performed and the posterior ligaments complex was preserved. In group C, the posterior ligaments complex was excised after the test in group B. In all 3 groups, the axial compression test, three-point bending test and torsional test were conducted. From June 2000 to June 2006, 309 patients (152 males and 157 females, aged 20-80 years with the average of 57.2 ) with lumbar canal stenosis received operation of the lumbar vertebral canal expansion with preservation of posterior ligaments complex. The course of disease was 3 months to 41 years. There were 55 patients suffering from pure lumbar canal stenosis, and 254 from lumbar canal stenosis combined with lumbar disc herniation, among which 105 were at L4,5 level, 56 at L4-S1 level, 86 at L5, S1 level, and 7 at L2,3 level. The therapeutic effect was assessed based on the JOA low back pain scoring system, the satisfaction degree of patient and radiographical observation., Results: The axial compression test was performed. In the position of forward bending, stress, strain and axial displacement were smaller in groups A, B than those in group C, and axial stiffness in groups A, B was higher than those in group C, and the difference was significant (P < 0.01). In the position of backward extension, there was no significant difference among 3 groups (P > 0.05). Concerning the three-point bending test, under the same bending moment, there was a significant difference in deflection, dip and bending rigidity between group A and group C, and also between group B and group C (P < 0.01), but no significant difference between group A and group B (P> 0.05). In the torsional test, under the same torsional angle, the torque in group B was bigger than that in group C (P < 0.01). Under the same torque, the torsional angle in group B was smaller than that in group C (P < 0.01), and the torsional stiffness in group B was higher than that in group C (P < 0.01). The complications included 7 cases of distraction of nerve root, 5 leakage of cerebrospinal fluid and 4 wound infection. All complications were treated and restored completely. All patients were followed up for 1-7 years. According to the JOA low back pain scoring system, the improvement rate averaged 86.0%. Of all the 309 cases, 163 were excellent, 112 good, 34 fair, and the choiceness rate was 89%. The satisfaction rate of patient was 87%. There was no radiographic vertebral instability postoperatively., Conclusion: The lumbar vertebral canal expansion with preservation of posterior ligaments complex is conducive to maintaining the stability of lumbar spine and have good clinical outcomes.

Thirty-six consecutive patients with burst fractures of the thoracolumbar spine and with a fractured posterior vertebral surface dislocated into the spinal canal without neurological symptoms were treated with the AO internal fixator. Computed tomography-aided planimetry of the spinal canal was undertaken preoperatively and within 1 week postoperatively to elucidate the effect of kyphosis correction and distraction on spinal canal widening (ligamentotaxis). The stenosis of the spinal canal area (SCA) was reduced from 29% preoperatively to 19% postoperatively (+10%) of the estimated original area, and the stenosis of the mid-sagittal diameter (MSD) reduced from 31 to 23% (+8%). The widening of the SCA was greater at the level of L1/L2 (+13%) than at L3/L4 (+6%). High preoperative canal compromise was associated with greater absolute spinal canal widening. Large trapezoid-shaped fragments resisted reduction by ligamentotaxis. Even though the effect of ligamentotaxis after operative treatment with the internal fixator was proven, a certain stenosis of the spinal canal remains in most cases. Especially for patients with fracture-related neurological symptoms, ligamentotaxis alone does not seem sufficient for the requested spinal decompression. Even an exact analysis of preoperative CT scans under consideration of the fracture level will not always allow an exact prognosis of the expected effect of ligamentotaxis.

Oncological principles for en bloc resection of bone tumors were initially developed for tumors of the long bone by orthopedic surgical oncologists. Recently, spine surgeons have adopted these principles for the treatment of vertebral column tumors. The goal of en bloc resection is to establish a surgical margin that can be designated marginal or wide. In this article, the principles of surgical oncology for bone tumors of the spine are briefly reviewed and the different surgical approaches used to remove these tumors in an en bloc fashion are described in detail.

Spine fractures with damage of the posterior wall of the vertebra often can be anatomically reconstructed by indirect reduction. Whether the posterior longitudinal ligament (PLL) is responsible for the reduction is still subject to debate. The aim of our investigation was to ascertain the role of the PLL in closed reduction of spine fractures by identifying the bony attachment points of this ligament. We performed a gross anatomical dissection, a light- and polarized microscopic investigation on 22 human cadaverous thoracic and lumbar spines to determine the points of attachment of the PLL. We found two layers of the PLL. The superficial layer runs from the first thoracic down to the third lumbar vertebra with a width of 0.4-1.0 cm and from there descends as a thin rudiment to the sacrum. The deep layer shows a segmental rhomboid structure. Lateral fibers are attached to the annulus fibrosus and at the rim of the adjacent vertebrae. Medial fibers are attached additionally to the posterior wall of the vertebral bodies by bridging the foramina basivertebralia. Since these foramina become enlarged in the caudal parts of the vertebral column, the number of attachment points at the posterior wall of the vertebral bodies decreases caudally. Good results for reconstruction of the posterior wall in vertebral fractures of the thoracic and upper lumbar spine can be explained by the anatomical situation of the PLL and stress the important role of the PLL in indirect reduction of spine fractures.

We report an unusual case of incarceration of small bowel between the 4th and 5th lumbar vertebrae in a patient with rheumatoid spondylitis. Incarceration of the loop of jejunum within the fracture or between dislocated lumbar vertebrae is an uncommon entity. The cases of traumatic jejunal entrapment have been previously reported in the literature [1, 2, 3, 4, 5, 6, 7, 8, 9, 11]: 2 cases occurred in adults and 8 in children. There has been no report on this injury in patients with rheumatoid spondylitis (Bechterew arthritis).

The presence of gas in the intervertebral disk space, known as the vacuum phenomenon, is a relatively common radiologic finding, especially on computed tomographic investigation. In a few cases, the gas can be collected into the lumbar spinal canal and can also compress the nerve root. To date only seven cases of symptomatic lumbar radiculopathy caused by a bubble of gas are reported in the literature. The presence of gas inside a narrowed disk and the collection of gas in the spinal canal suggest a communication between the two structures. A case of lumbar radiculopathy caused by a collection of gas in the spinal canal provided the authors the opportunity to study this rare condition by magnetic resonance imaging. Magnetic resonance imaging had not been used before in the referred cases and proved conclusively the discal origin of the gas.

The goal of this study was to evaluate the ability of Ray threaded fusion cages, when used in an anterior approach, to restore intervertebral height and to improve the functional and occupational performance of the patients. The present study was initiated because insertion of fusion cages through a posterior approach causes destruction of facet joints and violation of the spinal canal. The anterior approach for insertion of threaded fusion cages to accomplish lumbar interbody fusion was evaluated in a series of 13 patients suffering monosegmental disc disease. The patients' functional and occupational performance was evaluated using the Prolo score. Radiological measurements were used to evaluate disc height and degree of penetration into the endplates, and to confirm fusion. Seven of the 13 patients were short-term failures and had to be revised within 2 years. The study found that revised patients had poorer Prolo scores than non-revised patients. Although for the non-revised patients, the mean Prolo scores remained relatively stable during the 1st year, they dropped after 3 years. We were not able to identify any further clinical or radiological differences between the groups. These results indicate that although the anterior approach seems technically suitable for insertion of threaded fusion cages, destruction of the anterior longitudinal ligament and the anterior part of the annulus fibrosis appears to result in destabilisation of the motion segment.