Preclinical Evaluation of a Novel 3D-Printed Movable Lumbar Vertebral Complex for Replacement: In Vivo and Biomechanical Evaluation of Goat Model

Purpose. This was an in vivo study to develop a novel movable lumbar artificial vertebral complex (MLVC) in a goat model. The purpose of this study was to evaluate clinical and biomechanical characteristics of MLVC and to provide preclinical data for a clinical trial in the future. Methods. According to the preoperative X-ray and CT scan data of the lumbar vertebrae, 3D printing of a MLVC was designed and implanted in goats. The animals were randomly divided into three groups: intact, fusion, and nonfusion. In the intact group, only the lumbar vertebrae and intervertebral discs were exposed during surgery. Both the fusion and nonfusion groups underwent resection of the lumbar vertebral body and the adjacent intervertebral disc. Titanium cages and lateral plates were implanted in the fusion group. MLVC was implanted in the nonfusion group. All groups were evaluated by CT scan and micro-CT to observe the spinal fusion and tested using the mechanical tester at 6 months after operation. Results. The imaging results showed that with the centrum, the artificial endplates of the titanium cage and MLVC formed compact bone trabeculae. In the in vitro biomechanical test, the average ROM of L3-4 and L4-5 for the nonfusion group was found to be similar to that of the intact group and significantly higher in comparison to that of the fusion group ( P < 0.05 ). The average ROM of flexion, extension, lateral bending, and rotation in the L2-3 intervertebral space significantly increased in the fusion group compared with the intact group and the nonfusion group ( P < 0.001 ). There were no significant differences in flexion, extension, lateral bending, and rotation between the nonfusion and intact groups ( P > 0.05 ). The average ROM of flexion, extension, lateral bending, and rotation in the L2-5 intervertebral space was not significantly different between the intact group, the fusion group, and the nonfusion group, and there was no statistical significance ( P > 0.05 ). HE staining results did not find any metal and polyethylene debris caused by abrasion. Conclusion. In vivo MLVC can not only reconstruct the height and stability of the centrum of the operative segment but also retain the movement of the corresponding segment.

Anatomical features of the canine C2-C3 spinal cord vascular environment

OBJECTIVE Interarcuate branch (IAB) is a vascular structure, particularly developed in C2-3 intervertebral space, forming a dorsal bridge that connects ventral venous plexi in the vertebral canal. While precisely described in the human, the precise anatomical features of IABs have not been reported in the veterinary literature. The purpose of this study is to describe the features and relations of IABs in the C2-3 vertebral canal. ANIMALS 10 dogs were enrolled; 5 dogs for necropsy and 5 dogs for histology. PROCEDURES The ventral venous plexi in the cervical spine of 5 dogs were injected with latex and underwent vertebral canal dissection for visual assessment of the IAB. Two out of 5 dogs were injected with the addition of barium sulfate and underwent a CT scan. The C2-3 regions of 5 small-breed dogs were harvested for histological examinations. RESULTS IABs arose from the ventral venous plexus at the level of the intervertebral vein; they originated from 2 separate branches located caudally and cranially to the intervertebral foramen, forming a ventrodorsal triangle surrounding the spinal nerve root. No dorsal anastomosis was observed on the CT scan nor at dissection but were observed histologically. A cervical fibrous sheath was observed all around the vertebral canal. CLINICAL RELEVANCE IABs are voluminous venous structures at the C2-3 intervertebral space in dogs and found within a split of the cervical fibrous sheath, which is adherent to the interarcuate ligament and the ligamentum flavum. This anatomical description is paramount when planning an approach to the C2-3 intervertebral space.

Implications of Age, Gender and Lumbar Disc Level on Symptomatic Herniated Nucleus Pulposus

Background: A herniated-disc inside the spinal column is a condition applying displacement of nucleus pulposus from intervertebral space causing back pain. Objective: To analyse the association of age, gender and lumbar disc level with herniated nucleus pulposus. Study Design: Retrospective study Place and Duration of Study: Department of Neurosurgery, Shaikh Zayed Hospital, Lahore from 1st January 2011 to 31st January 2020. Methodology: One hundred and twenty patients to investigate association of herniated nucleus pulposus with age, gender and lumbar disc level were enrolled. Patient’s demographic, clinical and radiological assessments were completed for categorizing their condition and level of lumbar disc involvement. Results: There were 72.5% males and 27.5% females with a mean age of 48.6±1.26 years. The study revealed that 72.5% nucleus pulposus herniation cases were within the age group of 51-70 years. L5-S1 is more susceptible to nucleus pulposus herniation (62.5%) followed by L4-L5 (34.2%), L3-L4 (2.5%) and L1-L2 (0.8%). Conclusion: Elderly population with >51 years in males is highly prone for nucleus pulposus herniation with L5-S1 to be most affected lumbar spinal segments. Key words: Nucleus pulposus herniation, Vertebral column level, Lumbar disc level

Mechanical Changes of the Lumbar Intervertebral Space and Lordotic Angle Caused by Posterior-to-Anterior Traction Using a Spinal Thermal Massage Device in Healthy People

Background: The axial (horizontal) traction approach has been traditionally used for treatment of low back pain-related spinal disorders such as nuclear protrusion, primary posterolateral root pain, and lower thoracic disc herniation; however, it is known to have some technical limitations due to reductions of the spinal curve. Lumbar lordosis plays a pivotal function in maintaining sagittal balance. Recently, vertical traction and combination traction have been attracting attention due to improving therapeutic outcomes, although evidence of their clinical application is rare; therefore, this study was conducted to investigate the mechanical changes of lumbar intervertebral space, lordotic angle, and the central spinal canal area through vertical traction treatment using a spinal massage device in healthy participants. Methods: In total, 10 healthy subjects with no musculoskeletal disorders and no physical activity restrictions participated. The participants lay on the experimental device (CGM MB-1901) in supine extended posture and vertical traction force was applied in a posterior-to-anterior direction on the L3–4 and L4–5 lumbar sections at level 1 (baseline) and level 9 (traction mode). Magnetic resonance (MR) images were recorded directly under traction mode using the MRI scanner. The height values of the intervertebral space (anterior, center, and posterior parts) and lordosis angle of the L3–4 and L4–5 sections were measured using Image J software and the central spinal canal area (L4–5) was observed through superimposition method using the MR images. All measurement and image analyses were conducted by 2 experienced radiologists under a single-blinded method. Results: The average height values of the intervertebral space under traction mode were significantly increased in both L3–4 and L4–5 sections compared to baseline, particularly in the anterior and central parts but not in the posterior part. Cobb’s angle also showed significant increases in both L3–4 and L4–5 sections compared to baseline (p < 0.001). The central spinal canal area showed a slightly expanded feature in traction mode. Conclusions: In this pilot experiment, posterior-to-anterior vertical traction on L3–4 and L4–5 sections using a spinal massage device caused positive and significant changes based on increases of the intervertebral space height, lumbar lordosis angle, and central spinal canal area compared to the baseline condition. Our results are expected to be useful as underlying data for the clinical application of vertical traction.

Testing if Micro-CT Is Capable of Quantitating the Extent of Proteoglycan-Aggrecan Induced Axial Spondyloarthritis in Mice

ObjectiveInjections of proteoglycan aggrecan (PGA) have been reported to induce axial spondyloarthritis (ax-SpA) in BALB/c mice. It is considered to be a model for radiographic ax-SpA. However, evaluation of the extent of axial disease by histopathological assessment of every intervertebral space is labor-intensive. The objective of our paper is to test the feasibility of Micro Computed Tomography (Micro-CT) in rapidly enumerating the number of intervertebral spaces affected in each mouse.MethodsArthritis was induced in BALB/c mice by intraperitoneal injections of PGA. Involvement of several spinal segments, and selected sacroiliac and hip joints were evaluated by histopathology. The involvement of all intervertebral spaces, sacroiliac and hip joints was evaluated by Micro-CT.ResultsBALB/c mice injected with PGA developed histopathology of SpA-like axial lesions, including spondylitis, sacroiliac joint arthritis and hip joint arthritis. Micro-CT allowed us to clearly enumerate the number of lesions in each mouse.ConclusionMicro-CT allows quantitative assessment of the extent of axial involvement in PGA-induced mouse spondylitis. This can be a useful tool in assessing therapeutic interventions.

Clinical impact and imaging results after a modified procedure of ACDF: a prospective case-controlled study based on ninety cases with two-year follow-up

Study design This is a prospective case-controlled study. Background To analyze the postoperative axial pain and cage subsidence of patients presenting with cervical spondylotic myelopathy (CSM) after a modified procedure of ACDF (mACDF). Methods Ninety patients with CSM were prospectively collected from 2014 to 2018. The patients were divided into spread group and non-spread group (48:42 ratio) according to the cage placement with or without releasing the Caspar cervical retractor after decompression. Spread group received conventional ACDF and non-spread group received mACDF. Patients were followed-up for at least 24 months after surgery. Radiologic data, including height of intervertebral space and Cobb Angle, were collected. Nervous system function was obtained using JOA scores, and level of pain was assessed using VAS scores. Results A total of 90 patients were enrolled and the patients were divided into spread group (n = 48) and none-spread group(n = 42). Cage subsidence of (spread group vs none-spread group) was (0.82 ± 0.68 vs 0.58 ± 0.81) mm, (0.64 ± 0.77 vs 0.34 ± 0.46) mm, (0.48 ± 0.43 vs 0.25 ± 0.28) mm, and (0.45 ± 0.47 vs 0.17 ± 0.32) mm at 3 months, 6 months, 12 months and 24 months, respectively. The period exhibiting the most decrease of the height of intervertebral space was 3 months postoperatively. However, there was no statistical difference in the height of intervertebral space, JOA or VAS scores at the final follow-up between the two groups. Conclusions The mACDF can avoid excessive distraction by releasing the Caspar Cervical retractor, restore the “natural height” of cervical vertebra, relieve immediate pain after surgery, and prevent rapid Cage subsidence and the loss of cervical curvature.

Change in the postoperative intervertebral space height and its impact on clinical and radiological outcomes after ACDF surgery using a zero-profile device: a single-Centre retrospective study of 138 cases

Background The effects of postoperative intervertebral height (IH) changes on the clinical and radiological outcomes after anterior cervical decompression and fusion (ACDF) surgery using a zero-profile device remain unclear. Methods We retrospectively reviewed patients who had undergone ACDF using a zero-profile device from March 2012 to February 2016 at our institution. Based on the postoperative IH variation, the patients were divided into group A with postoperative IH 0 to 2 mm, group B with postoperative IH 2 to 4 mm, and group C with postoperative IH greater than 4 mm. Clinical efficacy was evaluated using JOA, VAS, and NDI scores in the groups. Imaging parameters including the IH, cervical lordosis, fusion rate, intervertebral foramen (IVF) diameter and complications such as subsidence, dysphagia, and ASD were also compared across the three groups. Results The average IH increased significantly from 6.72 mm preoperatively to 10.46 mm 1 week after surgery, and then gradually decreased to 7.48 mm at the final follow-up. The fusion rate was 61.90% in group A, 63.23% in group B, 53.57% in group C at 3 months, 73.81% in group A, 79.41% in group B, 67.86% in group C at 6 months, 90.48% in group A, 95.59% in group B, 92.86% in group C 1 year after surgery, and at the last follow-up, the fusion rate of three groups was all 100%. The IVF diameter was 6.52 ± 1.80 mm in group A, 9.55 ± 2.36 mm in group B, and 9.34 ± 1.62 mm in group C. ASD at the superior and inferior levels affected 11.90 and 16.67% patients in group A, 5.88 and 7.38% in group B, and 14.28 and 10.71% in group C. Regarding the 3 groups, the subsidence rates were 7.14, 4.41, and 14.29%, respectively. Conclusions No clear correlation was found between IH changes and clinical efficacy within a year of surgery. However, the IH may affect various complications after ACDF. If postoperative IH changes are maintained at 2 to 4 mm after a year, a satisfactory imaging parameters and relatively low complications may be achieved after ACDF surgery using a zero-profile device.

Correlation of palpation versus ultrasound-assisted approach for locating the level of lumbar puncture used for subarachnoid block in elective cesarean delivery

Aims: To correlate the level of lumbar puncture used for subarachnoid block in parturient undergoing elective cesarean delivery between palpation and ultrasound method; and to find its accuracy. Methods: This is an observational study, conducted in 314 parturient undergoing elective caesarean delivery under spinal anesthesia over the period of three months at Paropakar Maternity and Women's Hospital Kathmandu. The interspinous space identified by palpation method on lateral position for subarachnoid block and later the site confirmed by ultrasound. Results: In this study, intervertebral space identified by palpation was matched in 38.1% (i.e. 107 in 281 patients) when assessed with ultrasound (USG). In 166 (59.1%) patients, skin puncture level was determined by palpation was found to be one intervertebral space cephalic. In eight (2.8%) patients, one intervertebral space caudal while assed with USG. The correlation between intervertebral space determined by palpation and by ultrasonography was poor (correlation coefficient r=0.288).The kappa was 0.293±0.015. Conclusions: The level of lumbar puncture used for subarachnoid block in elective cesarean delivery by palpation method is poorly correlated (38.1%) with ultrasonographic identification of corresponding interspinous level.