Automated detection, labelling and radiological grading of clinical spinal MRIs.

Spinal magnetic resonance (MR) scans are a vital tool for diagnosing the cause of back pain for many diseases and conditions. However, interpreting clinically useful information from these scans can be challenging, time-consuming and hard to reproduce across different radiologists. In this paper, we alleviate these problems by introducing a multi-stage automated pipeline for analysing spinal MR scans. This pipeline first detects and labels vertebral bodies across several commonly used sequences (e.g. T1w, T2w and STIR) and fields of view (e.g. lumbar, cervical, whole spine). Using these detections it then performs automated diagnosis for several spinal disorders, including intervertebral disc degenerative changes in T1w and T2w lumbar scans, and spinal metastases, cord compression and vertebral fractures. To achieve this, we propose a new method of vertebrae detection and labelling, using vector fields to group together detected vertebral landmarks and a language-modelling inspired beam search to determine the corresponding levels of the detections. We also employ a new transformer-based architecture to perform radiological grading which incorporates context from multiple vertebrae and sequences, as a real radiologist would. The performance of each stage of the pipeline is tested in isolation on several clinical datasets, each consisting of 66 to 421 scans. The outputs are compared to manual annotations of expert radiologists, demonstrating accurate vertebrae detection across a range of scan parameters. Similarly, the model's grading predictions for various types of disc degeneration and detection of spinal metastases closely match those of an expert radiologist. To aid future research, our code and trained models are made publicly available.

Diagnostic efficacy and clinical impact of image-guided core needle biopsy of suspected vertebral osteomyelitis.

OBJECTIVES: The diagnostic yield and clinical impact of image-guided core needle biopsy (ICNB) of suspected vertebral osteomyelitis in adults is heterogenous in published studies owing to small sample sizes, indicating the need for large cohort studies. METHODS: A retrospective analysis of ICNBs was performed from 2010 to 2021 for patients with imaging findings consistent with vertebral osteomyelitis. For each biopsy, a series of factors were analyzed, as well as if histopathology was diagnostic of osteomyelitis and if microbiological cultures were positive. In addition, it was recorded in what way biopsy influenced clinical management regarding antimicrobial treatment. A multivariate statistical analysis was performed to evaluate the factors associated with yield. RESULTS: A total of 570 biopsies performed on 527 patients were included. A histopathologic diagnosis of osteomyelitis was made in 68.4% (359 of 525) of biopsies, and microbiological cultures were positive in 29.6% (169 of 570). Elevated erythrocyte sedimentation rate was positively associated with a histopathologic diagnosis of osteomyelitis (odds ratio [OR] =1.96, P = 0.007) and positive cultures from bone cores (OR = 1.02, P ≤0.001) and aspirate (OR = 1.02, P ≤0.001). Increased total core length was positively associated with a histopathologic diagnosis of osteomyelitis (OR = 1.81, P = 0.013) and positive cultures from bone cores (OR = 1.65, P = 0.049). Clinical management was affected by ICNB in 37.5% (214 of 570) of cases. CONCLUSIONS: In this large cohort, ICNB yielded approximately 30% positive cultures and changed clinical management in over one-third of the patients.

Comparison of lumbar muscle morphology in patients with chronic nonspecific low back pain with and without clinical lumbar segmental instability.

OBJECTIVES: Evaluation of spinal muscle morphology may be critical because of its impact on segmental stability and control of the lumbar spine in the subset of patients with clinical lumbar segmental instability (LSI). The purpose of this study was to compare lumbar muscle morphology in CNLBP patients with clinical LSI, CNLBP patients without clinical LSI. METHODS: This case-control study included 30 patients with CNLBP (15 with clinical LSI and 15 without clinical LSI) and 15 subjects without LBP. Axial magnetic resonance images from the L2 to S1 lumbar levels were used to evaluate the morphology of the lumbar muscles. RESULTS: A significant increase in the muscle-to-fat infiltration index and a significant decrease in the relative muscle cross-sectional area (rmCSA) of the multifidus muscle at the L3-L4 to L5-S1 levels were observed in both CNLBP groups compared to the control group (p<0.05). The mean erector spinae mean rmCSA was significantly greater in the clinical LSI group compared to the control group (SMD = 0.853, 95% CI = 0.105 to -1.6, P = 0.044) and also compared to the CNLBP without clinical LSI (SMD = 0.894, 95% CI = -1.645 to -0.144, P = 0.030) at the L4-L5 level. CONCLUSIONS: The atrophic changes of the multifidus muscle, in CNLBP patients with or without clinical LSI was observed. However, hypertrophic changes of the erector spinae muscle at the L4-L5 lumbar level were observed only in the clinical LSI group. Psaos major did not show significant atrophic or hypertrophic changes.

Clinical findings and outcome in goats with discospondylitis and vertebral osteomyelitis.

BACKGROUND: Vertebral infections, including vertebral osteomyelitis, septic physitis, and discospondylitis, are rarely reported in goats, and when reported, have been largely limited to necropsy case reports. OBJECTIVE: Describe clinical findings and outcome in goats with vertebral infections evaluated by computed tomography (CT). ANIMALS: Five goats with vertebral osteomyelitis, septic physitis, and discospondylitis evaluated by CT. METHODS: Retrospective case series. RESULTS: The most common presenting complaints were progressive weakness, paresis and recumbency. Three goats were tetraparetic and 2 goats had pelvic limb paraparesis. Clinicopathologic findings included leukocytosis, mature neutrophilia, and hyperfibrinogenemia. The most common vertebrae affected were C7-T1. All 5 goats had discospondylitis with or without vertebral osteomyelitis and septic physitis. Computed tomographic evidence of spinal cord compression was present in 4/5 goats. Medical management (antimicrobials, physical therapy, analgesia, supportive care) was attempted in 4 goats, and 1 goat was euthanized at the time of diagnosis. All 4 goats that were treated regained ambulatory ability and survived to hospital discharge. CONCLUSIONS AND CLINICAL IMPORTANCE: Despite severity of CT imaging findings, goats with discospondylitis, septic physitis, and vertebral osteomyelitis can successfully return to ambulatory function. Additional studies are required to determine ideal treatment regimens.

'Tumour-like' lesion caused by cervical discal instability.

We present the case of a man in his 40s who sought medical attention due to central cord syndrome. MRI findings demonstrated contrast uptake, spinal swelling, syrinx formation and narrowing of the spinal canal. We encountered two potential scenarios:when malignancy is suspected, the patient would undergo a biopsy. However, if the lesion is ultimately determined to be benign, the patient would have been subjected to an avoidable risk of neurological damage associated with the procedure. Conversely, addressing the lesion as a result of a degenerative process (discal instability), performing an anterior approach for interbody fusion with an underlying malignant process could lead to substantial delays in the diagnosis, finally producing a poor outcome. A comprehensive imaging workup was conducted to rule out malignancy. We hypothesised that discal instability was responsible for the observed findings. The patient was successfully treated with anterior cervical decompression and fusion, without complications. Follow-up evaluations confirmed remission of the condition.

Safety and clinical contribution of computed tomography-guided biopsy for cervical spine lesion.

INTRODUCTION: The purpose is to clarify the safety and clinical contribution of computed tomography (CT)-guided percutaneous needle-biopsy for patients with cervical spine lesion. MATERIAL AND METHODS: Between June 2015 and August 2022, CT-guided percutaneous needle biopsies were performed for 15 cervical spine lesions of 15 patients (8 male, 7 female; 2-81 years old). The technical success, clinical contribution, and safety were evaluated. Technical success was defined as the completion of the biopsy procedure. Clinical contribution was defined as any contribution to the therapeutic strategy. Safety was assessed by the Common Terminology Criteria for Adverse Events, version 5.0. RESULTS: The technical success rate was 100%. In all 15 patients, nontarget organs (e.g., major vessels, spinal cord) could be avoided. The post-biopsy histological diagnoses were myeloma (n = 2), metastatic adenocarcinoma (n = 2), chordoma (n = 2), Langerhans cell histiocytosis (n = 3), and one case each of malignant lymphoma, schwannoma, pyogenic spondylitis, non-pyogenic spondylitis, degenerative change, and non-pathological fracture. All of these diagnoses contributed to the therapeutic strategy decisions. One case of grade 2 pain was observed, but no complications with grade 3 or more were observed during or after the biopsies. CONCLUSION: CT-guided percutaneous needle biopsies for cervical spine lesions were safe and clinically beneficial.

Do Modic changes contribute to lumbar instability or other way around? A retrospective study based on their types, extents, and affected lumbar segments.

BACKGROUND: Which types of Modic changes (MCs) and whether or how specific factors associated to MCs work on lumbar instability have yet to be well understood. The purpose of this study was to investigate the influences of the types of MCs, the extent of MCs lesion involvement, and different lumbar levels involved by MCs on lumbar instability. METHODS: This retrospective study included 263 adult subjects with MCs who underwent lumbar X-ray examinations in the neutral, flexion, and extension positions. All patients who met our inclusion criteria were examined with 1.5 Tesla magnetic resonance units. Two experienced authors with more than three-year clinical experience independently evaluated and measured the subjects' radiographic images. The subgroup analysis was performed to detect the differences in subjects' baseline characteristics and lumbar segmental motions among three types of MCs, the extent of MCs lesion involvement and different lumbar levels involved by MCs. RESULTS: There was a statistical difference in body mass index (BMI) between different involvement extent of MCs (p < 0.01), indicating that the subjects with high BMI are more likely to develop severe MCs. The subjects with Modic type 1 change (MC1) had a significant increase in lumbar angular motion than those with Modic type 2 change (MC2) and Modic type 3 change (MC3) (p < 0.01) and compared with MC3, a significant increase in lumbar translation motion was detected in subjects with MC1 and MC2 (p < 0.01). While, angular motion decreased, translation motion increased significantly as the extent of MCs lesion involvement aggravated (p < 0.01). However, there were no statistical differences in lumbar angular and translation motions between different lumbar levels involved by MCs (p > 0.05). CONCLUSIONS: Higher BMI might be a risk factor for the development of severe MCs. MC1 and MC2 significantly contribute to lumbar instability. The extents of MCs lesion involvement are strongly associated with lumbar instability. However, different lumbar levels involved by MCs have little effect on lumbar stability.

Langerhans Cell Histiocytosis in the Pediatric Spine Requiring Stabilization: A Literature Review and Report of 3 Cases.

CASE: This report describes 3 cases of Langerhans cell histiocytosis (LCH) of the cervical and thoracic spine in patients aged 4 to 10 years. Each patient had painful lytic spinal lesions with vertebral body collapse and posterior involvement suggesting instability requiring corpectomy, grafting, and fusion. All 3 patients were doing well at their most recent follow-up without pain or recurrence. CONCLUSION: Although LCH of the pediatric spine is usually successfully treated non-operatively, we recommend corpectomy and fusion when there is instability of the spinal column and/or severe stenosis. Posterior element involvement occurred in all 3 cases and may lead to instability.

Utility of the coned-down lateral view of the lumbosacral spine.

OBJECTIVE: At certain institutions and radiology practices, a routine lumbar radiographic exam may include 3 views: AP, lateral, and coned-down lateral of the lumbosacral junction. The purpose of this study is to determine whether the third coned-down-lateral view adds significant diagnostic information regarding pathology at the L4-L5 and L5-S1 levels. MATERIALS AND METHODS: This retrospective study includes patients (n = 74) who had a 3-view radiographic exam of the lumbar spine, as well as a CT or MRI within six months. The AP and lateral views were reviewed by three radiologists, both with and without the use of the third, coned-lateral view. Subsequently, the CT and MRI performed within 6 months was reviewed, and the results compared. The primary outcome was detection of abnormal alignment and disc disease at the L4-L5 and L5-S1 levels. RESULTS: For the combined findings of alignment and disc disease at each L4-L5 and L5-S1, there was disagreement between the 2-view and 3-view exams on 18 (of 296) evaluations. Of these 18, the 2-view and the 3-view exam each made positive findings on 9. By the binomial test, there is no evidence that either the 2-view or the 3-view exam tends to make more findings than the other (p = 1). Compared to CT/MRI, the 2-view exam agrees on 74.7 % of evaluations and the 3-view exam agrees on 75.3 %. There is therefore no evidence that the 3-view exam is more accurate than the 2-view exam. CONCLUSION: Elimination of the coned-down lateral view could reduce radiation exposure and imaging-related costs while maintaining diagnostic quality.

What does degeneration at the cervicothoracic junction tell us? A kinematic MRI study of 93 individuals.

PURPOSE: Current decision-making in multilevel cervical fusion weighs the potential to protect adjacent levels and reduce reoperation risk by crossing the cervicothoracic junction (C7/T1) against increased operative time and risk of complication. Careful planning is required, and the planned distal and adjacent levels should be assessed for degenerative disc disease (DDD). This study assessed whether DDD at the cervicothoracic junction was associated with DDD, disc height, translational motion, or angular variation in the adjacent superior (C6/C7) or inferior (T1/T2) levels. METHODS: This study retrospectively analyzed 93 cases with kinematic MRI. Cases were randomly selected from a database with inclusion criteria being no prior spine surgery and images having sufficient quality for analysis. DDD was assessed using Pfirrmann classification. Vertebral body bone marrow lesions were assessed using Modic changes. Disc height was measured at the mid-disc in neutral and extension. Translational motion and angular variation were calculated by assessing translational or angular motion segment integrity respectively in flexion and extension. Statistical associations were assessed with scatterplots and Kendall's tau. RESULTS: DDD at C7/T1 was positively associated with DDD at C6/C7 (tau = 0.53, p < 0.01) and T1/T2 (tau = 0.58, p < 0.01), with greater disc height in neutral position at T1/T2 (tau = 0.22, p < 0.01), and with greater disc height in extended position at C7/T1 (tau = 0.17, p = 0.04) and at T1/T2 (tau = 0.21, p < 0.01). DDD at C7/T1 was negatively associated with angular variation at C6/C7 (tau = - 0.23, p < 0.01). No association was appreciated between DDD at C7/T1 and translational motion. CONCLUSION: The association of DDD at the cervicothoracic junction with DDD at the adjacent levels emphasizes the necessity for careful selection of the distal level in multilevel fusion in the distal cervical spine.

Predictive factors for degenerative lumbar spinal stenosis: a model obtained from a machine learning algorithm technique.

BACKGROUND: Degenerative lumbar spinal stenosis (DLSS) is the most common spine disease in the elderly population. It is usually associated with lumbar spine joints/or ligaments degeneration. Machine learning technique is an exclusive method for handling big data analysis; however, the development of this method for spine pathology is rare. This study aims to detect the essential variables that predict the development of symptomatic DLSS using the random forest of machine learning (ML) algorithms technique. METHODS: A retrospective study with two groups of individuals. The first included 165 with symptomatic DLSS (sex ratio 80 M/85F), and the second included 180 individuals from the general population (sex ratio: 90 M/90F) without lumbar spinal stenosis symptoms. Lumbar spine measurements such as vertebral or spinal canal diameters from L1 to S1 were conducted on computerized tomography (CT) images. Demographic and health data of all the participants (e.g., body mass index and diabetes mellitus) were also recorded. RESULTS: The decision tree model of ML demonstrate that the anteroposterior diameter of the bony canal at L5 (males) and L4 (females) levels have the greatest stimulus for symptomatic DLSS (scores of 1 and 0.938). In addition, combination of these variables with other lumbar spine features is mandatory for developing the DLSS. CONCLUSIONS: Our results indicate that combination of lumbar spine characteristics such as bony canal and vertebral body dimensions rather than the presence of a sole variable is highly associated with symptomatic DLSS onset.

Reconstituting human somitogenesis in vitro.

The segmented body plan of vertebrates is established during somitogenesis, a well-studied process in model organisms; however, the details of this process in humans remain largely unknown owing to ethical and technical limitations. Despite recent advances with pluripotent stem cell-based approaches1-5, models that robustly recapitulate human somitogenesis in both space and time remain scarce. Here we introduce a pluripotent stem cell-derived mesoderm-based 3D model of human segmentation and somitogenesis-which we termed 'axioloid'-that captures accurately the oscillatory dynamics of the segmentation clock and the morphological and molecular characteristics of sequential somite formation in vitro. Axioloids show proper rostrocaudal patterning of forming segments and robust anterior-posterior FGF-WNT signalling gradients and retinoic acid signalling components. We identify an unexpected critical role of retinoic acid signalling in the stabilization of forming segments, indicating distinct, but also synergistic effects of retinoic acid and extracellular matrix on the formation and epithelialization of somites. Comparative analysis demonstrates marked similarities of axioloids to the human embryo, further validated by the presence of a Hox code in axioloids. Finally, we demonstrate the utility of axioloids for studying the pathogenesis of human congenital spine diseases using induced pluripotent stem cells with mutations in HES7 and MESP2. Our results indicate that axioloids represent a promising platform for the study of axial development and disease in humans.

Percutaneous spine biopsy: reaching those hard-to-reach places.

Cancer is a leading cause of death, with the spine being the most common site for skeletal metastasis. The spine is also a site for primary malignancy, such as sarcoma and chordoma, as well as non-neoplastic pathologies. An accurate diagnosis of spinal neoplastic diseases is crucial in determining appropriate management. With the advent of personalised oncology, the need to establish a definitive histopathologic diagnosis to guide management is more important than ever. Percutaneous biopsy has proven to be safe and efficient in establishing a reliable histopathologic diagnosis. The spine, however, can be a challenging site to biopsy, due to the proximity of critical neurovascular, respiratory, and gastrointestinal structures. Successful spine biopsy depends on several factors: suspected diagnosis, size of the lesion, location within the spine, modality for best imaging guidance, operator experience, technical equipment considerations, and desired approach and associated limitations. The specimen must also be obtained with a biopsy route amenable to any future surgical intervention, with surgical input often sought, frequently in a multidisciplinary setting, to confirm procedure-specific goals and expectations. Knowledge of the requisite local anatomy, procedural and patient-specific indications, and contraindications and various approaches that may be used to access different segments of the spine, potential complications, and how to address these are keys to a successful percutaneous spinal biopsy, even in the most challenging of circumstances.

Optimal screw positioning in cervical pedicles to avoid complications.

BACKGROUND: Cervical instability can be caused by a variety of factors, including trauma, tumors, or infection. The cervical transpedicular screw (CPS) is one of the most modern procedures for treating cervical instability. Despite the fact that numerous innovative techniques for CPS have been proposed, the appropriate screw entry points and screw directions have yet to be thoroughly established. The aim of this study is to determine the screw insertion angles and screw entry point distances based on reference points, pedicle axis lengths, and pedicle axis intersections for each vertebra from cervical (C) C2 to C7 in both right and left by gender and age groups. METHODS: In this study, computed tomography (CT) images of patients who underwent cervical examination for any reason were evaluated retrospectively. A total of 100 patients (59 men and 41 females), ranging in age from 18 to 79 years (mean 43 years), were randomly selected for the study. Patients with a history of cervical pathology or surgery were excluded. CT images turned into 3D reconstructed images and density settings were made so that bone tissue could be best observed using OsiriX software. Pedicle axis length (PAL), pedicle transverse angle (PTA), pedicle sagittal angle (PSA), distance of screw entry point to lateral notch (DLN), distance of screw entry point to inferior articular process (DIAP), and pedicle axis intersections were measured. RESULTS: According to our findings, the optimal entry point should be 2-4 mm medial to the lateral notch and 8-12 mm superior to inferior articular process. PTA ranges between 30 to 45°, while PSA ranges between 11 to 15°. Except for the C2 pedicles, which were slightly shorter, the pedicle axis lengths (PAL) were similar from C3 to C7 in the total group. The intersection of the right and left pedicle axes was determined to be the most in C4 (51.21% in females and 72.88% in males). DISCUSSION: This study has shown that intersections of the pedicle axis must be considered in both genders, especially in C4. Standardizing optimal entry points and trajectories is crucial for improving the CPS technique's safety and effectiveness.

Imaging of Spine Infections.

The incidence of spondylodiskitis has increased over the last 20 years worldwide, especially in the immunodepressed population, and it remains a complex pathology, both in terms of diagnosis and treatment. Because clinical symptoms are often nonspecific and blood culture negative, imaging plays an essential role in the diagnostic process. Magnetic resonance imaging, in particular, is the gold standard technique because it can show essential findings such as vertebral bone marrow, disk signal alteration, a paravertebral or epidural abscess, and, in the advanced stage of disease, fusion or collapse of the vertebral elements. However, many noninfectious spine diseases can simulate spinal infection. In this article, we present imaging features of specific infectious spine diseases that help radiologists make the distinction between infectious and noninfectious processes.

Long-term posterolateral spinal fusion in rabbits induced by rhBMP6 applied in autologous blood coagulum with synthetic ceramics.

Autologous bone graft substitute (ABGS) containing rhBMP6 in autologous blood coagulum (Osteogrow) is a novel therapeutic solution for bone regeneration. This study is aimed to investigate the long-term outcome of ABGS with synthetic ceramics (Osteogrow-C) in rabbit posterolateral spinal fusion (PLF) model. Osteogrow-C implants were implanted bilaterally between rabbit lumbar transverse processes. We compared the outcome following implantation of ABGS with ceramic particles of different chemical composition (TCP and biphasic ceramics containing both TCP and HA) and size (500-1700 µm and 74-420 µm). Outcome was analyzed after 14 and 27 weeks by microCT, histology, and biomechanical analyses. Successful bilateral spinal fusion was observed in all animals at the end of observation period. Chemical composition of ceramic particles has impact on the PLF outcome via resorption of TCP ceramics, while ceramics containing HA were only partially resorbed. Moreover, persistence of ceramic particles subsequently resulted with an increased bone volume in implants with small particles containing high proportion of HA. ABGS (rhBMP6/ABC) with various synthetic ceramic particles promoted spinal fusion in rabbits. This is the first presentation of BMP-mediated ectopic bone formation in rabbit PLF model with radiological, histological, and biomechanical features over a time course of up to 27 weeks.

SOX9+ enthesis cells are associated with spinal ankylosis in ankylosing spondylitis.

OBJECTIVE: Although cartilage degeneration and invasion of the subchondral bone plate in entheseal lesion has been considered to consequently lead bony ankylosis in ankylosing spondylitis (AS), no evident mechanisms are known. DESIGN: To identify histopathological and physiological changes in enthesitis-related ankylosis in AS, we performed molecular characterization of transcription factors and surface markers, and transcriptome analysis with human tissues. Entheseal tissue containing subchondral bone was obtained from the facet joints of 9 patients with AS and 10 disease controls, and assessed by using differential staining techniques. Enthesis cells were isolated, characterized, stimulated with TNF and/or IL-17A, and analysed by cell-based experimental tools. RESULTS: We found diffusely distributed granular tissue and cartilage in the subchondral bone in AS. Co-expression of SOX9, a specific transcription factor in cartilage, and matrix metalloproteinase 13 (MMP13) was found in the granular tissues within the subchondral bone from AS patients. Intriguingly, SOX9 expression was significantly higher in AS enthesis cells than controls and correlated with TNFR1 and IL-17RA expressions, which is important for high reactivity to TNF and IL-17A cytokines. Co-stimulation by TNF and IL-17A resulted in accelerated mineralization/calcification features, and increased OCN expression in AS enthesis cells. Furthermore, SOX9 overexpression in enthesis leads to promoting mineralization feature by TNF and IL-17A stimuli. Finally, OCN expression is elevated in the destructive enthesis of advanced AS. CONCLUSION: These findings provide insight into the links between inflammation and the mineralization of entheseal tissue as the initiation of spinal ankylosis, emphasizing the importance of SOX9+ enthesis cells.

Imaging of muscle and adipose tissue in the spine: A narrative review.

Interpretation of the morphology and characteristics of soft tissues, such as paravertebral muscles and fat, has always been a "relative blind spot" in the spine. The imaging features of the non-bony structures of the spine have been studied and reinterpreted, and changes in the non-bony structure are associated with spinal disease. Soft tissue parameters such as, the "paraspinal muscle cross-sectional area," "subcutaneous fat thickness," and the "paraspinal muscle fat infiltration rate" on computed tomography, magnetic resonance imaging and other imaging techniques are reproducible in the diagnosis, treatment and prognosis of spinal disorders and have the potential for clinical application. In addition, focus on the association between sarcopenia and spinal epidural lipomatosis with spinal disorders is increasing. Currently, there is no summary of studies on fat and muscle in the spinal region. Given this, within the context of recent research trends, this article provides a synthesis of research on adipose and muscle tissue in the spine, discusses advances in the study of the imaging manifestations of these structures in spinal disorders, and expands the perspectives.

Congenital spine deformities: timing of insult during development of the spine in utero.

The development of the spine and spinal cord occurs at the earliest weeks of gestation. Their development not only affects each other but also are most likely associated with anomalies in other systems. It is essential to recognize the stages of spine development to understand the cause of congenital spinal deformities and their influences on the postnatal growing spine. A vast majority of congenital spinal problems are not evident clinically. For instance, the presence of neural axis abnormalities, such as spinal dysraphism or syringomyelia, may be so subtle that patients never seek medical care. Certain vertebral formation disorders such as hemivertebrae may remain asymptomatic throughout life if they are balanced while those with congenital bars may develop severe deformity. Major defects in the spine are often associated with abnormalities of the other organs such as cardiovascular and genital urinary system that warrants close attention by multidisciplinary specialists. A thorough understanding of the basics of embryology, which serves as a window into the development of the spine, is necessary to enable the practitioner to appreciate why, when, and where the numerous spine deformities develop in utero. Besides, certain developmental defects manifest in adulthood including spondylolysis, degenerative disc disease, congenital spinal stenosis, and even tumors like cordoma. Thus, understanding embryology can assist to establish the proper diagnosis and ensure optimal treatment.

Application of a new percutaneous multi-function pedicle locator in minimally invasive spine surgery.

In this study, a new percutaneous multi-function pedicle locator was designed for personalized three-dimensional positioning of a pedicle in minimally invasive spine surgery (MISS) without computer-assisted navigation technology. The proposed locator was used in a number of patients during MISS, and its advantages were analyzed. Based on the position of a pedicle determined by computed tomography (CT) and fluoroscopic images of a patient, 6 lines and 2 distances were used to determine the puncture point of a pedicle screw on skin, while 2 angles were used to indicate the direction of insertion of a pedicle guide needle from the patient's body surface. The results of the proposed locator were compared with those of the conventional freehand technique in MISS. The potential benefits of using the locator included enhanced surgical accuracy, reduced operation time, alleviation of the harmful intra-operative radiation exposure, lower costs, and shortened learning curve for young orthopedists.