A comparative study of the anatomy and MRI images of the lumbar foraminal ligaments at the L1-L5 levels.

PURPOSE: The purpose of this study was to evaluate the ability of MRI images to reveal foraminal ligaments at levels L1-L5 by comparing the results with those of anatomical studies. METHODS: Eighty lumbar foramina were studied. First, the best MRI scanning parameters were selected, and the transverse and sagittal axes of each lumbar foramina were scanned to identify and record the ligament-like structures in each lumbar foramen. Then, the cadaveric specimens were anatomically studied, and all ligament structures in the lumbar foramina were retained. The number, morphology and distribution of ligaments under anatomical and MRI scanning were observed. Histological staining of the dissected ligament structures was performed to confirm that they were ligamentous tissues. Finally, the accuracy of ligament recognition in MRI images was statistically analyzed. RESULTS: A total of 233 foraminal ligaments were identified in 80 lumbar intervertebral foramina through cadaveric anatomy. The radiating ligaments (176, 75.5%) were found to be attached from the nerve root to the surrounding osseous structures, while the transforaminal ligaments (57, 24.5%) traversed the intervertebral foramina without any connection to the nerve roots. A total of 42 transforaminal ligament signals and 100 radiating ligament signals were detected in the MRI images of the 80 intervertebral foramina. CONCLUSION: The MRI can identify the lumbar foraminal ligament, and the recognition rate of the transforaminal ligament is higher than that of the radiating ligament. This study provides a new method for the clinical diagnosis of the relationship between the lumbar foraminal ligament and radicular pain.

The lumbar autonomic nerves in males: a few anatomical insights into anterior lumbar interbody fusion.

BACKGROUND CONTEXT: Lumbar autonomic nerve injury is an underappreciated complication of anterior lumbar spinal surgery. A detailed description of lumbar autonomic nerve anatomy would be helpful for surgeons to minimize the risk of this complication. PURPOSE: This study was designed to investigate the anatomical characteristics of lumbar autonomic nerves and provide a better understanding of these nerves for anterior lumbar spinal surgery. STUDY DESIGN: A dissection-based study of 10 embalmed male cadavers. METHODS: The lumbar autonomic nerves from 10 embalmed male cadavers were dissected in this study. The position of the lumbar sympathetic trunks was recorded. Distance between the initial sites of the lumbar splanchnic nerves (LSNs) and the corresponding lumbar vertebral inferior endplate, distance between the ipsilateral and adjacent LSNs, angles formed by the LSNs and the vertical axis were measured. This study has been supported by grants from Science and Technology Planning Project of Guangdong Province (CN) (Grant No. 2017B020210010) without potential conflict of interest-associated biases in the text of the paper. RESULTS: In this study, a total of 72 LSNs were identified in the 10 human cadavers. On average, the investigation found that the initial sites of the first, second, third, and fourth LSNs were 9 mm distal, 5 mm distal, 9 mm proximal, and 9 mm distal to the inferior endplates of the L1, L2, L3, and L4 vertebrae, respectively, with variations from 6 to 11 mm for each nerve among specimens. There was no significant difference in the angle between each lumbar splanchnic nerve and the vertical axis (H=2.461, p=.482), with an angle of approximately 50°±6°. The distance between the first and the second LSNs, the second and the third LSNs, or the third and the fourth LSNs were 24±6 mm, 22±8 mm, and 55±11 mm, respectively. The bilateral lumbar sympathetic trunks (N=57, 95%) were more likely to be located in the first third of the sagittal plane at the level of the L2/3, L3/4, and L4/5 intervertebral discs. CONCLUSIONS: The study found the same number and parallel courses of LSNs on each side, and on both the left and right side, the distance between the third and the fourth LSNs was much larger than the distance between the other two adjacent LSNs. The initial sites of 80.6% (n=58) of LSNs were superior to the inferior endplate of the L3 vertebra. Improved knowledge of lumbar autonomic nerve anatomy may be of great significance in reducing complications and improving surgical safety.

Clinical Anatomy and Possible Clinical Significance of the Postcentral Branches of Spinal Arteries in the L1-L5 Levels.

STUDY DESIGN: This was a dissection-based study of 10 embalmed human cadavers. OBJECTIVE: The objective of this study was to identify and describe the postcentral branches in the L1-L5 intervertebral foramina (IVF) and to determine their possible clinical significance. SUMMARY OF BACKGROUND DATA: The lower lumbar segmental arteries have been well studied. However, there are few articles with regard to the postcentral branches in the L1-L5 IVF. MATERIALS AND METHODS: Eighty L1-L5 IVF from 10 embalmed cadavers were studied with a surgical microscope, and the postcentral branches were identified. The branches, origin, insertion, and spatial orientation of the postcentral branches in the L1-L5 IVF were examined. The diameter of the arteries was measured using a Vernier caliper. RESULTS: In our study, the occurrence rate of a postcentral branch was 100.00% in the 80 IVFs. The postcentral branch was routinely divided into the following 2 types: type 1, postcentral branch main trunks (65.00%), which branch from the spinal arteries or lumbar arteries and then divide into 2 branches (superior and inferior branches), and type 2, superior and inferior branches, which branch straight from the spinal arteries (35.00%). The initial portion of the postcentral branches traveled around the anterolateral edge of the disk to the dorsum. CONCLUSIONS: Postcentral branches of spinal arteries are common structures in IVF; there are 2 types of postcentral branches. Thorough understanding of the spinal arteries before percutaneous endoscopic lumbar discectomy may be an important step in reducing intraoperative bleeding and ensuring clear visualization, which may result in significant benefits for patients.

The Anatomical Study and Clinical Significance of the Sinuvertebral Nerves at the Lumbar Levels.

STUDY DESIGN: A dissection-based study of 10 embalmed human cadavers. OBJECTIVE: The purpose of this study was to describe the sinuvertebral nerves at the lumbar level and to discuss their possible clinical significance. SUMMARY OF BACKGROUND DATA: Discogenic low-back pain is mediated by the sinuvertebral nerves. However, the detailed descriptions of the sinuvertebral nerves at the lumbar level are lacking. METHODS: One hundred L1-L5 intervertebral foramina from 10 embalmed cadavers were studied. The presence of the sinuvertebral nerves was noted. The quantity, origin, pathway, innervation range, and spatial orientations of the sinuvertebral nerves in the L1-L5 intervertebral foramina were examined. RESULTS: A total of 450 sinuvertebral nerves were identified in the 100 lumbar intervertebral foramina; sinuvertebral nerves were observed in 100.00% of the intervertebral foramina. The sinuvertebral nerves were routinely divided into the following two types: the sinuvertebral nerve deputy branch and sinuvertebral nerve main trunk. Three hundred twelve sinuvertebral nerve deputy branches were found; on average, there were approximately 3.12 (range, 1-8) branches in each intervertebral foramen. One hundred thirty-eight sinuvertebral nerve main trunks were found, and sinuvertebral nerve main trunks were observed in 97.00% of the intervertebral foramina. The initial portion of the sinuvertebral nerve was located along the posterior-lateral edge of the disc to the spinal canal. Sixty-one (44.20%) sinuvertebral nerve main trunks originated from the starting point of the gray ramus communicans of the nerve root; 77 (55.80%) sinuvertebral nerve main trunks originated from the anterior surface of the spinal ganglia of the nerve root. CONCLUSION: This is a systematic anatomy study that describes the sinuvertebral nerve at the lumbar level and may be of clinical importance to spinal surgeons. A comprehensive understanding of the distribution of sinuvertebral nerves may lead to significant benefits for patients undergoing percutaneous endoscopic treatment for discogenic low-back pain. LEVEL OF EVIDENCE: 4.

The Morphology and Clinical Significance of the Extraforaminal Ligaments at the T1-T12 Levels.

STUDY DESIGN: A dissection-based study of 10 embalmed human cadavers. OBJECTIVE: The purpose of this study was to describe the extraforaminal ligaments in the exit regions of the T1-T12 intervertebral foramina and to discuss their possible clinical significance. SUMMARY OF BACKGROUND DATA: The ligaments at the lumbar intervertebral foramina have been well studied. However, detailed descriptions of the extraforaminal ligaments at the T1-T12 levels are lacking. METHODS: Two hundred forty T1-T12 intervertebral foramina from 10 embalmed cadavers were studied. The presence of the ligament was noted. The quantity, morphology, distributions, proximal attachments, distal attachments, and spatial orientations of the extraforaminal ligaments in the exit regions of the T1-T12 intervertebral foramina were examined. The length, width, diameter, and thickness of the ligaments were measured with digital calipers by three independent investigators. RESULTS: A total of 564 extraforaminal ligaments were identified in the 229 intervertebral foramina; no ligaments were found in the other 11 intervertebral foramina, resulting in an occurrence rate of extraforaminal ligaments of 95.42%. One hundred thirty-six (24.11%) of the extraforaminal ligaments were radiating ligaments, and 428 (75.89%) were transforaminal ligaments. Radiating ligaments had a tendency to be abundant at T1 and T9-T12 and sparse at T2-T8. There were 245 (43.44%) ligaments at the anterior aspect of the exit regions of the intervertebral foramina, 225 (39.89%) ligaments at the posterior aspect, 64 (11.35%) ligaments at the inferior aspect, and 30 (5.32%) ligaments at the superior aspect. CONCLUSION: In the exit region of thoracic intervertebral foramina, there are two types of extraforaminal ligaments. They may serve as a protective mechanism against traction and play a role in the positioning of the nerves in the intervertebral foramen. Transforaminal ligaments may be an underlying cause of rib or chest pain after thoracic fracture and may be of clinical importance to surgeons. LEVEL OF EVIDENCE: N/A.

The use of chitosan/PLA nano-fibers by emulsion eletrospinning for periodontal tissue engineering.

OBJECTIVE: In this study, nanofibrous scaffolds base on pure polylactic acid (PLA) and chitosan/PLA blends were fabricated by emulsion eletrospinning. By modulating their mechanical and biological properties, cell-compatible and biodegradable scaffolds were developed for periodontal bone regeneration. METHODS: Pure PLA and different weight ratios of chitosan nano-particle/PLA nano-fibers were fabricated by emulsion eletrospinning. Scanning electron microscope (SEM) was performed to observe the morphology of nano-fibers. Mechanical properties of nano-fibers were tested by single fiber strength tester. Hydrophilic/hydrophobic nature of the nano-fibers was observed by stereomicroscope. In vitro degradation was also tested. Cells were seeded on nano-fibers scaffolds. Changes in cell adhesion, proliferation and osteogenic differentiation were tested by MTT assay and Alizarin Red S staining. Reverse transcription-polymerase chain reaction (RT-PCR) assay was used to evaluate the expression of (Toll-like receptor 4) TLR4, IL-6, IL-8, IL-1ß, OPG, RUNX2 mRNA. RESULTS: It is shown that the mean diameter of nano-fibers is about 200 nm. The mean diameter of chitosan nano-particles is about 50 nm. The combination of chitosan nano-particles enhanced the mechanical properties of pure PLA nano-fibers. By adding a certain amount of chitosan nano-particles, it promoted cell adhesion. It also promoted the osteogenic differentiation of bone marrow stem cells (BMSCs) by elevating the expression of osteogenic marker genes such as BSP, Ocn, collagen I, and OPN and enhanced ECM mineralization. Nonetheless, it caused higher expression of inflammatory mediators and TLR4 of human periodontal ligament cells (hPDLCs). CONCLUSION: The combination of chitosan nano-particles enhanced the mechanical properties of pure PLA nano-fibers and increased its hydrophilicity. Pure PLA nano-fibers scaffold facilitated BMSCs proliferation. Adding an appropriate amount of chitosan nano-particles may promote its properties of cell proliferation and osteogenic differentiation. The higher expression of inflammatory mediators caused by nano-fibers may be regulated via TLR4 pathway.

The Morphology and Possible Clinical Significance of the Intraforaminal Ligaments in the Entrance Zones of the L1-L5 Levels.

BACKGROUND: The extraforaminal ligaments between the L1-L5 lumbar spinal nerves and the tissues surrounding the intervertebral foramina (IVF) have been well studied. However, little research has been performed to describe the local anatomy of the entrance zones at the L1-L5 level. Detailed anatomic studies of the intraforaminal ligaments (IFLs) in the entrance zones at the L1-L5 levels have not been performed. OBJECTIVES: The objective of this study is to identify and describe the IFLs in the entrance zones of the L1-L5 IVF and to determine their possible clinical significance. STUDY DESIGN: A dissection-based study of 10 fresh-frozen human cadavers. SETTING: Guangdong Provincial Key Laboratory of Medical Biomechanics in Anatomy Department of Southern Medical University. METHODS: Eighty L1-L5 IVF from 10 fresh cadavers were studied, and the IFLs in the entrance zones were identified. The quantities, morphologies, origins, insertions, and spatial orientations of the IFLs in the entrance zones of the L1-L5 IVF were observed. The lengths, widths, diameters, and thicknesses of the ligaments were measured using a vernier caliper. Ten intraforaminal radiating ligaments were removed for histological examination. RESULTS: A total of 197 ligaments were identified in the entrance zones of the 80 L1-L5 IVF, including 191 (96.95%) radiating ligaments and 6 (3.05%) transforaminal ligaments. The thickest ligaments were observed at the L3-L4 IVF. The lengths of the ligaments varied from 0.59 to 11.92 mm. There were 66 (33.50%) ligaments in the superior aspect of the entrance zone of the IVF, 58 (29.44%) ligaments at the anterior aspect, 43 (21.83%) ligaments at the posterior aspect, and 30 (15.23%) ligaments at the inferior aspect. The morphologies of the IFLs were divided into 2 types: the strap type and the trabs type. Histological examination of the meningovertebral ligaments revealed fibrous connective tissue. LIMITATIONS: The major limitation of this study is the lack of actual clinical data from live patients. In addition, future medical biomechanics experiments are expected to contribute more objective data on the strength of the IFLs. CONCLUSIONS: In the lumbar spine, IFLs are common structures in the entrance zones of the L1-L5 IVF, and radiating ligaments are more likely to be present. KEY WORDS: Clinical Anatomy, microdissection, intraforaminal ligament, the entrance zone, L1-L5 intervertebral foramen, endoscopic spinal adhesiolysis, sacral hiatus, cerebrospinal fluid leakage, dural laceration.

Naringin protects myocardial cells from doxorubicin­induced apoptosis partially by inhibiting the p38MAPK pathway.

Doxorubicin (DOX) has been widely used to treat cancers as a first­line antitumor drug. However, it causes severe, irreversible, dose­dependent cardiotoxicity. To evaluate the protective effects of naringin (NRG) on cardiotoxicity, the authors investigated the molecular mechanism of the p38MAPK signaling pathway. H9c2 cells were treated for 24 h by using 5 µmol/l DOX without or with being pretreated by 1 µM NRG for 150 min or by 3 µM SB203580 for 60 min. Cell viability was detected by cell counting kit­8 assay. Intracellular reactive oxygen species (ROS) levels were detected based on the oxidative conversion of 2',7'­dichlorfluorescein­diacetate (cell­permeable) to dichlorofluorescein (fluorescent). The expression of p38MAPK was determined by western blotting. The expression level of p­p38MAPK in H9c2 cells, which was significantly increased by exposure to 5 µM DOX for 60 min (P<0.01), was significantly decreased by pretreatment with 1 µM NRG for 150 min beforehand (P<0.01). The viability of H9c2 cells pretreated for 150 min with 1 µM NRG was significantly enhanced compared with that using DOX directly (P<0.01). Intracellular ROS levels were significantly reduced by being pretreated with 1 µM NRG for 150 min or with 3 µM SB203580 for 60 min before the cells were exposed to 5 µM DOX. Collectively, NRG protected H9c2 cells against the cardiotoxicity induced by DOX through suppressing the expression and activity of the p38MAPK pathway. The findings provided valuable evidence for the possible use of NRG to relieve DOX­induced cardiotoxicity.

Morphology and Possible Clinical Significance of the Radiating Extraforaminal Ligaments at the L1-L5 Levels.

STUDY DESIGN: A dissection-based study of 10 fresh-frozen human cadavers. OBJECTIVE: The objective of this study was to identify and describe the radiating extraforaminal ligaments in the exit regions of the L1-L5 intervertebral foramina and to research their possible clinical significance. SUMMARY OF BACKGROUND DATA: The transforaminal ligaments at the L1-L5 intervertebral foramina have been well studied. However, detailed descriptions of the radiating extraforaminal ligaments at L1-L5 are lacking. METHODS: Eighty L1-L5 intervertebral foramina from 10 fresh cadavers were studied, and the extraforaminal ligaments were identified. The quantity, morphology, origin, insertion, and spatial orientation of the extraforaminal ligaments in the L1-L5 regions were examined. The length, width, diameter, and thickness of the ligaments were measured using a vernier caliper. RESULTS: A total of 224 extraforaminal ligaments were identified in the 80 L1-L5 intervertebral foramina, and the occurrence rate of extraforaminal ligaments was 100%. One hundred and eighteen (52.68%) of the extraforaminal ligaments were radiating ligaments, and 106 (47.32%) of the extraforaminal ligaments were transforaminal ligaments. There were 97 (43.30%) ligaments at the superior aspect of the exit regions of the intervertebral foramina, 51 (22.77%) ligaments at the anterior aspect, 44 (19.64%) ligaments at the inferior aspect, and 32 (14.29%) ligaments at the posterior aspect. The morphologies of the extraforaminal ligaments were divided into two types: the strap type and the trabs type. CONCLUSION: Radiating extraforaminal ligaments exist between spinal nerves and nearby structures. Radiating extraforaminal ligaments may be of clinical importance to surgeons. Dissecting the radiating extraforaminal ligaments before percutaneous endoscopic lumbar discectomy may be an important step in reducing postoperative pain, which may result in significant benefits for patients. LEVEL OF EVIDENCE: 3.

The morphology and clinical significance of the intraforaminal ligaments at the L5-S1 levels.

BACKGROUND CONTEXT: The extraforaminal ligaments between the L5 and S1 lumbar spinal nerves and the tissues surrounding the intervertebral foramina have been well studied. However, little research has been undertaken to describe the local anatomy of the intraforaminal portion of the L5-S1 spine and detailed anatomical studies of the intraforaminal ligaments (IFLs) of the L5-S1 have not been performed. PURPOSE: The objective of this study was to identify and describe the IFLs in relation to the L5-S1 intervertebral foramen (IVF) and to determine their clinical significance. STUDY DESIGN: A dissection-based study of five embalmed and five fresh-frozen human cadavers was carried out. METHODS: Twenty L5-S1 intervertebral foramina from five embalmed cadavers and five fresh cadavers were studied, and the IFLs were identified. The quantity, morphology, origin, insertion, and spatial orientation of the IFLs in the L5-S1 region were observed. The length, width, diameter, and thickness of the ligaments were measured with a vernier caliper. This study has been supported by grants from the National Natural Science Foundation of China (Grant No. 31271286) without potential conflict of interest-associated biases in the text of the paper. RESULTS: The IFLs could be found from the entrance zone (inside) to the exit zone (outside) of the L5-S1 IVF. These ligaments were found to be of two types: a radiating ligament, which connected the nerve root sleeves that radiated to the transverse processes and wall of the IVF, and a transforaminal ligament, which connected the structures around the IVF. In our study, the radiating ligaments were found more often than the transforaminal ligaments. CONCLUSIONS: The results demonstrate that IFLs are common structures in the IVF and that there are two types of IFLs: the transforaminal ligaments and the radiating ligaments. Transforaminal ligaments may be the potential cause of back pain. The radiating ligaments may contribute to dura laceration and epidural hemorrhage during endoscopic spinal adhesiolysis through the sacral hiatus, and an appreciation of this relationship might help reduce the risk of such complications.