Axial Magnetic Resonance Imaging Research Articles

Differences in Retromalleolar Fibular Groove Morphology According to Level of Axial Computed Tomography Scans.

Studies have evaluated types of retromalleolar groove using axial magnetic resonance imaging at the level of 10 mm above the tip of the lateral malleolus. However, no evidence is available to support that this level is appropriate for evaluating retromalleolar groove morphology. To assess the influence of the level of axial computed tomography (CT) scans on the assessment of retromalleolar groove morphology. Cross-sectional study; Level of evidence, 3. The study population included 122 patients (mean age, 27.9 ± 11.8 years; 69 males, 53 female) who underwent CT scans to evaluate foot or ankle pathologies between 2020 and 2023. The shape of the retromalleolar groove (concave, flat, convex, or irregular) at 3 levels of axial CT scans (8, 10, and 12 mm above the tip of the lateral malleolus) was assessed independently by 2 orthopaedic surgeons. The length from the tip of the lateral malleolus to the proximal tip of the fossa of the lateral malleolus was also measured on coronal CT scans. The type of retromalleolar groove was significantly different according to the level of CT scans (8 vs 10 mm, P = .0001; 10 vs 12 mm, P = .0001; 8 vs 12 mm, P = .001). The type of retromalleolar groove was the same at all 3 levels in 31.1% of patients (38/122). The length from the tip of the lateral malleolus to the proximal tip of the fossa of the lateral malleolus was <10 mm in 17.2% of patients (21/122). The shape of the retromalleolar fibular groove was affected by the level at which the CT scan was obtained. Approximately 70% of the patients showed different types of retromalleolar grooves among the 3 CT scan levels.

Correlation between clinical disease activity and sacroiliac magnetic resonance imaging detection in axial spondyloarthropathy.

The study aimed to evaluate the correlation between the clinical disease activity of axial spondyloarthropathy (axSpA) and magnetic resonance imaging findings of the sacroiliac joint. Thirty-two patients (21 males, 11 females; mean age: 39.3±9.2 years; range, 18 to 55 years) who were diagnosed with axSpA according to the Assessment in Spondyloarthritis International Society classification criteria between November 2015 and August 2017 were included in this cross-sectional study. Visual Analog Scale (VAS), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Ankylosing Spondylitis Disease Activity Score (ASDAS)-erythrocyte sedimentation rate (ESR), and ASDAS-C-reactive protein (CRP) were used as the indicators of clinical activity. Magnetic resonance imaging of the sacroiliac joint was performed and the Spondyloarthritis Research Consortium of Canada (SPARCC) score was evaluated by a radiologist who was blinded to the clinical and laboratory parameters of the patients. The mean duration of symptom onset was 9.3±7.7 years, and the mean duration of diagnosis was 3.6±2.8 years. Human leukocyte antigen (HLA)-B27 was positive in 16 (50%) patients. There was no correlation between the SPARCC score and VAS, BASDAI, MASES, BASFI, ASDAS-CRP, ASDAS-ESR, ESR, and CRP values (p>0.05). In the HLA-B27 subgroup analyses, a statistically significant correlation was found between HLA-B27-negative patients and SPARCC score (r=0.639, p=0.008). No relationship was found between other clinical disease parameters and sacroiliac joint imaging findings, except for the relationship between the SPARCC and BASDAI in HLA-B27- negative patients with axSpA.

Does CISS MRI Reliably Depict the Endolymphatic Duct in Children with and without Vestibular Aqueduct Enlargement?

High-resolution CT is the mainstay for diagnosing an enlarged vestibular aqueduct (EVA), but MR imaging may be an appealing alternative, given its lack of ionizing radiation exposure. The purpose of this study was to determine how reliably MR imaging demonstrates the endolymphatic duct and endolymphatic duct enlargement in hearing-impaired children. We performed a retrospective review of temporal bone high-resolution CT and MR imaging of hearing-impaired children evaluated between 2017 and 2020. Vestibular aqueduct diameter was measured on high-resolution CT. The vestibular aqueducts were categorized as being enlarged (EVA+) or nonenlarged (EVA-) using the Cincinnati criteria. The endolymphatic ducts were assessed on axial high-resolution CISS MR imaging. We categorized endolymphatic duct visibility into the following: type 1 (not visible), type 2 (faintly visible), and type 3 (easily visible). Mixed-effect logistic regression was used to identify associations between endolymphatic duct visibility and EVA. Interreader agreement for the endolymphatic duct among 3 independent readers was assessed using the Fleiss κ statistic. In 196 ears from 98 children, endolymphatic duct visibility on MR imaging was type 1 in 74.0%, type 2 in 14.8%, and type 3 in 11.2%; 20.4% of ears were EVA+ on high-resolution CT. There was a significant association between EVA+ status and endolymphatic duct visibility (P < .01). Endolymphatic duct visibility was type 1 in 87.1%, type 2 in 12.8%, and type 3 in 0% of EVA- ears and type 1 in 22.5%, type 2 in 22.5%, and type 3 in 55.0% of EVA+ ears. The predicted probability of a type 3 endolymphatic duct being EVA+ was 0.997. There was almost perfect agreement among the 3 readers for distinguishing type 3 from type 1 or 2 endolymphatic ducts. CISS MR imaging substantially underdiagnoses EVA; however, when a type 3 endolymphatic duct is evident, there is a >99% likelihood of an EVA.

A possible correlation between facet orientation and development of degenerative cervical spinal stenosis

BackgroundPrevious studies have demonstrated the relationship between sagittal facet orientation and cervical degenerative spondylolisthesis. However, the associations between facet orientation and cervical spinal stenosis (CSS) have rarely been studied.MethodsOne hundred twenty patients with CSS (CSS group) and 120 healthy participants (control group) were consecutively enrolled. The cervical facet angles and anteroposterior diameter (A-P diameter) of spinal canal at each subaxial cervical levels were measured using axial magnetic resonance imaging. The intersection angle of the midsagittal line of the vertebra to the facet line represents the orientation of the facet joint.ResultsThe facet angles on the right side at C2- C3 and C3-C4 in CSS group and at C2- C3 in control group had significantly higher values than those of the other sides. Besides, the facet angles and A-P diameter of spinal canal in CSS group were significantly smaller than those in control group at all levels (p < 0.05).ConclusionsOur study demonstrated that patients with CSS have smaller axial cervical facet joint angles compared to the healthy individuals. Further studies are needed to elicit the specific underlying mechanism between sagittalization of the cervical facet joints and the pathology of CSS.

Prospective Validation of the Spinal Cord Shape Classification System in the Prediction of Intraoperative Neuromonitoring Data Loss: Assessing the Risk of Spinal Cord Data Loss During Spinal Deformity Correction.

The Spinal Cord Shape Classification System (SCSCS) class has been associated with spinal cord monitoring data loss during spinal deformity surgery. The objective of the current study was to prospectively validate the SCSCS as a predictor of spinal cord monitoring data loss during spinal deformity surgery. A prospective cohort study of consecutive patients who were undergoing primary deformity surgery at a single institution from 2018 to 2023 and whose major curve was in the spinal cord region was undertaken. Spinal cord morphology at the apex of the major curve on preoperative axial T2-weighted magnetic resonance imaging was used to categorize patients into 3 spinal cord shape types based on the SCSCS. The primary outcome was intraoperative neuromonitoring (IONM) data loss related to spinal cord dysfunction. Demographics and surgical and radiographic variables were compared between patients with IONM data loss and those without loss. Predictors of IONM loss were determined using bivariate and multivariable logistic regression analyses. A total of 256 patients (168 adult, 88 pediatric) were included and were separated into 3 SCSCS types: 110 (43.0%) with Type I, 105 (41.0%) with Type II, and 41 (16.0%) with Type III. IONM loss was observed in 30 (11.7%) of the 256 patients, including 7 (6.4%) of 110 with SCSCS Type I, 7 (6.7%) of 105 with Type II, and 16 (39.0%) of 41 with Type III. IONM loss was associated with SCSCS Type III, the preoperative deformity angular ratio, performance of 3-column osteotomies, greater operative time, greater transfusion volume, and greater postoperative sagittal corrections. SCSCS type was the strongest independent predictor of IONM data loss. SCSCS Type III had the greatest odds of IONM loss (odds ratio [OR] = 6.68, 95% confidence interval [CI] = 2.45 to 18.23 compared with Types I and II combined). The overall predictive performance with respect to IONM loss (area under the receiver operating characteristic curve = 0.827) was considered excellent. This prospective cohort study of patients undergoing spinal deformity correction confirmed that patients with a Type-III spinal cord shape had greater odds of IONM loss. Inclusion of the SCSCS in preoperative risk stratification and intraoperative management of spinal deformity corrective surgery is recommended. Prognostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Assessing Risk of Iatrogenic Peroneal Nerve Injury in All-Inside Lateral Meniscal Repair Between Standard Vs. Arthroscopic MRI.

Various studies have examined the risk of peroneal nerve injury with use of standard magnetic resonance imaging (MRI) of the knee. However, the position of the knee during standard MRI is different from that during an actual arthroscopic lateral meniscal repair. The purpose of the present study was to evaluate and compare the risk of peroneal nerve injury during simulated all-inside lateral meniscal repairs on the basis of MRI scans made with the knee in both positions. With use of axial MRI scans made with the knee in the standard position (i.e., in 30° of flexion) and in the actual position used during arthroscopic lateral meniscal repair (i.e., in a figure-of-4 position), direct lines were drawn to simulate the passage of a straight all-inside meniscal repair device from the anteromedial and anterolateral portals to the medial and lateral borders of the popliteus tendon. The distance from the closest passage of each line to the peroneal nerve was measured. If a line touched or passed through the peroneal nerve, a risk of iatrogenic injury was noted and a new line was drawn from the same portal to the outer border of the peroneal nerve. The danger area was measured from the first line to the new line along the joint capsule. In 28 Thai patients, the shortest distances from each line to the peroneal nerve were significantly shorter on the MRI scans made with the knee in the standard position than on those made with the knee in the arthroscopic position (p < 0.05 for all). All danger areas on the MRI scans that were made with the knee in the arthroscopic position were included within the danger areas on the scans that were made with the knee in the standard position. Standard MRI scans of the knee can be used to determine the risk of peroneal nerve injury at the time of arthroscopic lateral meniscal repair, although the risks are slightly overestimated. Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Degeneration of Cervical Multifidus Muscles Negatively Affects Physical Activity-related Quality of Life After Laminoplasty for Degenerative Cervical Myelopathy.

A retrospective cohort study. The study aimed to investigate the related factors affecting physical activity-related quality of life (QOL) after 2 years of cervical laminoplasty for degenerative cervical myelopathy (DCM), focusing on the degree of preoperative degeneration of the cervical multifidus muscles. The association between paraspinal muscle degeneration and clinical outcomes after spinal surgery is being investigated. The effect of preoperative degeneration of the cervical multifidus muscles in patients undergoing cervical laminoplasty is ambiguous. Patients who underwent laminoplasty for DCM and followed up for more than 2 years were reviewed. To evaluate physical QOL, the physical component summary (PCS) of the 36-Item Short-Form Health Survey (SF-36) was recorded at 2 years postoperatively. The degree of preoperative degeneration in the multifidus muscles at the C4 and C7 levels on axial T2-weighted magnetic resonance imaging (MRI) was categorized according to the Goutallier grading system. The correlation between 2-year postoperative PCS and each preoperative clinical outcome, radiographic parameter, and MRI finding, including Goutallier classification, was analyzed. Variables with a P value <0.10 in univariate analysis were included in multiple linear regression analysis. In total, 106 consecutive patients were included. The 2-year postoperative PCS demonstrated significant correlation with age ( R =-0.358, P =0.002), preoperative JOA score ( R =0.286, P =0.021), preoperative PCS ( R =0.603, P <0.001), C2-C7 lordotic angle ( R =-0.284, P =0.017), stenosis severity ( R =-0.271, P =0.019), and Goutallier classification at the C7 level ( R =-0.268, P =0.021). In multiple linear regression analysis, sex (β=-0.334, P =0.002), age (β=-0.299, P =0.013), preoperative PCS (β=0.356, P =0.009), and Goutallier classification at the C7 level (β=-0.280, P =0.018) were significantly related to 2-year postoperative PCS. Increased degeneration of the multifidus muscle at the C7 level negatively affected physical activity-related QOL postoperatively. These results may guide spine surgeons in predicting physical activity-related QOL in patients with DCM after laminoplasty. Level III.

Anatomic Variation of the Hamate Hook as a Potential Risk in Endoscopic Carpal Tunnel Release

The purpose of this study was to investigate the incidence of anomalies in patients who underwent endoscopic carpal tunnel release and their relationship with clinical outcomes. This retrospective study included 65 hands of 57 patients (8 men and 49 women; mean age, 64.9 years) who underwent endoscopic carpal tunnel release for carpal tunnel syndrome at our hospital between March 2016 and April 2022. The patients were diagnosed with carpal tunnel syndrome based on clinical observations and electrophysiological studies. On T2-weighted magnetic resonance axial images, the height of the hook of the hamate was measured from the bottom to the tip of the hook, and the total height of the hamate was measured from the dorsal surface of the hamate to the tip of the hook. A hook-to-height ratio of less than 0.34 was defined as hypoplastic, and its incidence was investigated. In addition, electrodiagnostic testing of sensory and motor nerve conduction of the median nerve and patient-reported outcome measurements, including Quick Disabilities of the Arm, Shoulder and Hand score, Boston carpal tunnel questionnaire, and visual analog scale score, were investigated at 6 months after surgery. Adverse events were collected from patient records. The mean hook-to-height ratio was 0.40. Hypoplasia with a ratio ≤0.34 was observed in seven hands (10.8%), and adverse events were observed only in the two cases that had a hypoplastic hook of the hamate (3.07%). The patient-reported outcome measurements and the result of electrodiagnostic testing at 6 months after surgery did not correlate with the height of the hook of the hamate. The incidence of a hypoplastic hook of the hamate is common in patients with carpal tunnel syndrome, and preoperative evaluation of the morphology of the hooks and indications for endoscopic carpal tunnel release in cases of hypoplastic hooks may help predict adverse events. Therapeutic Ⅳ.

The Success of Deep Learning Modalities in Evaluating Modic Changes

BackgroundModic changes are pathologies that are common in the population and cause low back pain. The aim of the study is to analyze the modic changes detected in magnetic resonance imaging (MRI) using deep learning modalities. MethodsThe sagittal T1, sagittal and axial T2-weighted lumbar MRI images of 307 patients, of which 125 were female and 182 were male, aged 19-86 years, who underwent MRI examination between 2016-2021 were analyzed. Modic changes (MC) were categorized and marked according to signal changes. Our study consists of two independent stages: classification and segmentation. The categorized data was first classified using convolutional neural network (CNN) architectures such as DenseNet-121, DenseNet-169, and VGG-19. In the next stage, masks were removed by segmentation using U-Net, which is the CNN architecture, with image processing programs on the marked images. ResultsDuring the classification stage, the success rates for modic type 1, type 2, and type 3 changes were 98%, 96%, 100% in DenseNet-121, 100%, 94%, 100% in DenseNet-169, and 98%, 92%, 97% in VGG-19, respectively. At the segmentation phase, the success rate was 71% with the U-Net architecture. ConclusionEvaluation of MRI findings of MC in the etiology of lower back pain with deep learning architectures can significantly reduce the workload of the radiologist by providing ease of diagnosis.

P696 Initiation of Vedolizumab did not provoke new-onset spondylarthritis in patients with inflammatory bowel disease: A Prospective Study Including Rheumatological and Blinded Imaging Assessments

Abstract Background Prior case series indicated a temporal relationship between use of vedolizumab and new-onset spondyloarthritis. Methods We aimed to evaluate the relationship between initiation of vedolizumab and development of new-onset spondyloarthritis in patients with inflammatory bowel disease, through serial clinical evaluation and magnetic resonance imaging. A single-centre prospective observational study of 24 patients with inflammatory bowel disease. Patients were eligible if they had active ulcerative colitis or Crohn’s disease and initiating vedolizumab, had no prior history of arthritis or spondyloarthritis and suitable for undergoing serial magnetic resonance imaging. Clinical evaluation was performed by a rheumatologist prior to first dose of vedolizumab and at weeks 8 and 24 weeks after administration. Axial magnetic resonance imaging was performed at baseline, weeks 8 and 24 and evaluated by a blinded central reader. Results Nine tumour necrosis factor inhibitor-naïve patients (4 male; mean age 53.2 yrs; 6 ulcerative colitis; 3 Crohn’s disease) and eight tumour necrosis factor inhibitor-experienced patients (7 male; mean age 48 yrs; 3 ulcerative colitis; 5 Crohn’s disease) completed all assessments. No patients developed new features of axial arthritis either on clinical or blinded radiological assessment at weeks 8 or 24, nor any features of peripheral spondyloarthritis including inflammatory oligoarthritis, enthesitis, dactylitis, or psoriasis (nail, body, or scalp). Both the tumour necrosis factor inhibitor-naive and tumour necrosis factor inhibitor-experienced patients demonstrated good intestinal response to vedolizumab. Conclusion Initiation of vedolizumab did not induce new features of axial or peripheral spondyloarthritis in tumour necrosis factor inhibitor-experienced or tumour necrosis factor inhibitor-naive patients with inflammatory bowel disease.

Lax Uterosacral Ligament and Urge Urinary Incontinence: MRI Findings in Symptomatic Patients Versus Healthy Volunteers

Introduction and hypothesisThe objective was to explore the association between urge urinary incontinence (UUI) and lax uterosacral ligaments (USL) using MRI.MethodsSixty-seven female participants were recruited prospectively: 41 continent volunteers (control group) and 26 patients with UUI. Static proton density- and T2-weighted turbo spin echo sequences of MR images were used. A radiologist employed a standardized grid system to record structural observations of the USLs on sequentially numbered axial MR images and then applied a four-point grading scale to assess ligament visibility. MR images were interpreted by a radiologist and a urologist, and then validated by an expert radiologist.ResultsThe comparison between the mean length of uterosacral ligaments in the control and UUI groups was highly statistically significant (p < 0.001). The mean length of the right USL was 38 ± 11 mm, and the left USL was 35 ± 12 mm in the UUI group. In the control group, the mean length of the USL was 22 ± 9 mm on the right side and 18 ± 9 mm on the left side, along their craniocaudal extent. The highest inter-observer agreement was on the level of origin and insertion (image numbers), whereas the lowest agreement was on the anatomical site of origin and insertion of the USL in both the control and UUI groups.ConclusionsThe average length of USLs in patients with UUI is significantly longer than that in healthy continent women, indicating laxity. Our findings support the relationship between the laxity of the USL and UUI symptoms and have therapeutic implications.

Surgical versus nonsurgical management of lumbar degenerative spondylolisthesis based on spinal canal cross-sectional area.

Disability and pain associated with lumbar degenerative spondylolisthesis (LDS) result in a significant burden on both the healthcare costs and patients' quality of life. Currently, there exists controversy regarding employment of either nonsurgical management (NSM) or surgical management (SM) in a clinical setting. Spinal canal cross-sectional area (SCA) has been an important morphological parameter for the analysis of LDS. However, there is lack of research about the comparative value of NSM and SM according to SCA. Moreover, previous research have not yet evaluated the clinical most suitable cutoff values of SCA. The objective of this research was to evaluate the effective of NSM and SM for LDS using SCA as an objective morphological parameter. The axial T2 magnetic resonance imaging images were obtained from each patient. We collected SCA samples from 149 patients with LDS. 72 patients underwent SM and the rest did NSM. We measured SCA at the L4/5 LDS on magnetic resonance imaging using a picture archiving and communications system. We measured SCA at the intervertebral disk posterior border, turning down to reach the facet joint side on the opposite edge at the L4/5 level. The average SCA value was 114.34 ± 48.11 mm2 in the NSM group and 69.88 ± 27.87 mm2 in the SM group. Therefore, the SM group had considerably lower SCA (P < .001). In view of the effectiveness of SCA as a prediction factor of surgical option, Receiver Operating Characteristic curve analysis show the optimal cutoff value for SCA as 83.21 mm2, with 70.8% sensitivity, 71.4% specificity, and an area under the curve of 0.80 (95% CI, 0.73-0.87). The narrower the SCA, the higher the probability of SM. Thus, it is proposed that to evaluate surgical decision making, the pain physician should carefully inspect the SCA.

Morphometric analysis of distal femur through MRI in Turkish population and review of the literature

Measurements of the distal femur are highly variable among different subjects. To obtain the best stability and longevity of the knee implants, anthropometric data of the distal femur is required. The aim of this study was to investigate the anatomical structure of the distal femur according to age and gender and to determine the changes in the groups, of the patients with meniscopathy and controls. A total of 488 patients were included in the study according to age groups (0-15, 16-30, 31-45, 46-60, 61 and above). Intercondylar width, intercondylar anteroposterior distance, medial condylar width, lateral condylar width, bicondylar width, medial condyle anteroposterior distance, and lateral condyle anteroposterior distance were measured on axial Magnetic Resonance Imaging (MRI). Intercondylar width, medial condylar width, lateral condylar width and bicondylar width were significantly higher in men in all age groups compared to women (p &lt; 0.05). Intercondylar anteroposterior distance, medial condyle anteroposterior distance and lateral condyle anteroposterior distance were statistically significantly higher in males than in females except 0-15 age group (p &lt; 0.05). There was no significant difference in medial and lateral anteroposterior distance values in men (p &gt; 0.05), and found to be statistically significant (p &lt; 0.05) on the right and left side in women. Although personalized implant production is expensive compared to today’s conditions, we think that age and gender changes should be considered in the selection of prosthesis, since the dimensions of the distal femur will affect the stability and duration of use of knee implants.

How to Choose Surgical Corridor in Left Oblique Approach Lumbar Interbody Fusion at the L5-S1 Segment: A Prospective Cohort Study

PurposeThere are two surgical corridors to L5-S1 lumbar interbody fusion via the left oblique approach: anterior to psoas-oblique lateral interbody fusion (ATP-OLIF) and oblique-anterior lumbar interbody fusion (O-ALIF). The aim of this study was to evaluate criteria to guide the selection of surgical corridors for L5-S1 lumbar interbody fusion via the left oblique approach. MethodsAccording to the structure of L5-S1 segment left common iliac vein (LCIV) in axial magnetic resonance image, the LCIV was divided into six types. O-ALIF was performed for type I and type II. ATP-OLIF was performed for type A and type B. For sexually active men, ATP-OLIF was chosen. Between April 2020 and April 2022, 22 patients were assigned to ATP-OLIF or O-ALIF based on the type of LCIV. Clinical outcomes and radiographic outcomes were assessed. ResultsThere were 11 cases in O-ALIF group (type I, n = 10; type II, n = 1) and 11 cases in ATP-OLIF group (type A, n = 8; type B, n = 3). No differences were observed in clinical outcomes (ODI, VAS, and complication rate), radiographic outcomes (mean disc height and segmental lordosis angle), length of hospital stay, operation time, and blood loss. No vascular injury occurred in either group. ConclusionsThis may be an appropriate criterion to guide the selection of surgical corridor for L5-S1 lumbar interbody fusion through the left oblique approach. O-ALIF was performed for type I and type II. ATP-OLIF was performed for type A and type B. For sexually active men, ATP-OLIF was chosen. According to this standard, the operation can be performed safely and with good clinical results.

Intra-abdominal Content Movement in Prone Versus Lateral Decubitus Position Lateral Lumbar Interbody Fusion (LLIF).

A prospective, anatomical imaging study of healthy volunteer subjects in accurate surgical positions. To establish if there is a change in the position of the abdominal contents in the lateral decubitus (LD) versus prone position. Lateral transpsoas lumbar interbody fusion (LLIF) in the LD position has been validated anatomically and for procedural safety, specifically in relation to visceral risks. Recently, LLIF with the patient in the prone position has been suggested as an alternative to LLIF in the LD position. Subjects underwent magnetic resonance imaging of the lumbosacral region in the right LD position with the hips flexed and the prone position with the legs extended. Anatomical measurements were performed on axial magnetic resonance images at the L4-5 disc space. Thirty-four subjects were included. The distance from the skin to the lateral disc surface was 134.9mm in prone compared with 118.7mm in LD ( P <0.0001). The distance between the posterior aspect of the disc and the colon was 20.3mm in the prone compared with 41.1mm in LD ( P <0.0001). The colon migrated more posteriorly in relation to the anterior margin of the psoas in the prone compared with LD (21.7 vs . 5.5mm, respectively; P <0.0001). 100% of subjects had posterior migration of the colon in the prone compared with the LD position, as measured by the distance from the quadratum lumborum to the colon (44.4 vs . 20.5mm, respectively; P <0.001). There were profound changes in the position of visceral structures between the prone and LD patient positions in relation to the LLIF approach corridor. Compared with LD LLIF, the prone position results in a longer surgical corridor with a substantially smaller working window free of the colon, as evidenced by the significant and uniform posterior migration of the colon. Surgeons should be aware of the potential for increased visceral risks when performing LLIF in the prone position. Level II-prospective anatomical cohort study.

COMPARING THE RISK ASSESSMENTS OF IATROGENIC PERONEAL NERVE INJURY IN ALL-INSIDE LATERAL MENISCAL REPAIR BETWEEN STANDARD KNEE MRIS AND SIMULATED ACTUAL ARTHROSCOPIC LATERAL MENISCAL REPAIR POSITION MRIS

Several studies have evaluated the risk of peroneal nerve (PN) injuries in all-inside lateral meniscal repair using standard knee magnetic resonance imaging (MRI) with the 30 degrees flexed knee position which is different from the knee position during actual arthroscopic lateral meniscal repair. The point of concern is “Can the risk of PN injury using standard knee MRIs be accurately determined”.To evaluate and compare the risk of PN injury in all-inside lateral meniscal repair in relation to both borders of the popliteus tendon (PT) using MRIs of the two knee positions in the same patients.Using axial MRI studies with standard knee MRIs and figure-of-4 with joint fluid dilatation actual arthroscopic lateral meniscal repair position MRIs, direct lines were drawn simulating a straight all-inside meniscal repair device from the anteromedial and anterolateral portals to the medial and lateral borders of the PT. The distance from the tip of each line to the PN was measured. If a line touched or passed the PN, a potential risk of iatrogenic injury was noted and a new line was drawn from the same portal to the border of the PN. The danger area was measured from the first line to the new direct line along the joint capsule.In 28 adult patients, the closest distances from each line to the PN in standard knee MRI images were significantly shorter than arthroscopic position MRI images (all p-values &lt; 0.05). All danger areas assessed in the actual arthroscopic position MRIs were included within the danger areas as assessed by the standard knee MRIs.We found that the standard knee MRIs can be used to determine the risk of peroneal nerve injury in arthroscopic lateral meniscal repair, although the risks are slightly overestimated.

Normal diameter of the optic nerve using magnetic resonance imaging: A retrospective Nigerian study.

The variations in the diameter of the optic nerve (ON) are important clinically in the diagnosis of conditions associated with the ON such as raised intracranial pressure, meningioma, optic neuritis, and Grave's orbitopathy. This study determined the normal diameters of the ON in adult Nigerians seen in a Hospital in Delta State. Axial T1-weighted brain magnetic resonance imaging images of 150 patients (75 males and 75 females) aged ≥20 years were retrieved from the hospital's radiological database and retrospectively used to evaluate the diameter of the ON on axial and coronal sections. The data were analyzed and summarized using descriptive statistics. The mean diameters were compared based on gender, side, and age groups and correlated with age using inferential statistics. The significance level was considered at 5%. The diameter of the ON measured 0.45 ± 0.07 cm on the coronal section, besides 0.50 ± 0.07 cm, and 0.46 ± 0.06 cm at 0.3 cm and 0.8 cm from the posterior pole of the globe, respectively, on the axial slices. The diameters were significantly larger in males than in females (P < 0.05) and were symmetrical. However, they lacked significant association with age (P > 0.05). The three diameters measured had a significant positive correlation with each other (P < 0.05). The study provides a normal range of ON diameter in the study center to aid in the diagnosis of raised intracranial pressure and pathologies involving the nerve and its sheath.

An Expanded Surgical Corridor of Oblique Lateral Interbody Fusion at L4-5: A Magnetic Resonance Imaging Study.

We introduced a new preoperative method, the "expanded surgical corridor," to evaluate the actual safety corridor, which may expand the possibility of performing oblique lateral interbody fusion (OLIF). Axial T2-weighted magnetic resonance images at the L4-5 disc level of 511 lumbar degenerative disease patients was evaluated. The distance between the medial edge of the left-sided psoas muscle and the major artery was measured as the conventional surgical corridor (CSc). The distance between the major vein and lumbar plexus was measured as the expanded surgical corridor (ESc). The mean CSc and ESc were 13.9 ± 8.20 and 37.43 ± 10.1 mm, respectively. No surgical corridor was found in 7.05% of CSc and 1.76% of ESc, small corridor ( ≤ 1 cm) was found in 27.40% of CSc and 0.59% of ESc, moderate corridor (1-2 cm) was found in 42.07% of CSc and 1.96% of ESc, and large corridor ( > 2 cm) was found in 23.48% of CSc and 95.69% of ESc. A total of 33.83% (45 of 133) of whom were preoperatively categorized as having a limited surgical corridor by conventional measurement, underwent OLIF L4-5 successfully. By using the ESc, only 2.35% were categorized as having a limited surgical corridor. The other 97.65% of the patients had an approachable corridor that could be successfully operated by experienced spine surgeons who employ meticulous surgical dissection and thorough understanding of the anatomical structures. The ESc may represent true accessibility to the disc space for OLIF, particularly at the L4-5 level.

Association of skeletal muscle oxidative capacity with muscle function, sarcopenia-related exercise performance, and intramuscular adipose tissue in older adults.

Muscle function and exercise performance measures, such as muscle endurance capacity, maximal strength, chair stand score, gait speed, and Timed Up and Go score, are evaluated to diagnose sarcopenia and frailty in older individuals. Furthermore, intramuscular adipose tissue (IntraMAT) content increases with age. Skeletal muscle oxidative capacity determines muscle metabolism and maintains muscle performance. This study aimed to investigate the association of skeletal muscle oxidative capacity with muscle function, exercise performance, and IntraMAT content in older individuals. Thirteen older men and women participated in this study. Skeletal muscle oxidative capacity was assessed by the recoveryspeed of muscle oxygen saturation after exercise using near-infrared spectroscopy from the medial gastrocnemius. We assessed two muscle functions, peak torque and time to task failure, and four sarcopenia-related exercise performances: handgrip strength, gait speed, 30-s chair stand, and Timed Up and Go. The IntraMAT content was measured using axial magnetic resonance imaging. The results showed a relationship between skeletal muscle oxidative capacity and gait speed but not with muscle functions and other exercise performance measures. Skeletal muscle oxidative capacity was not related to IntraMAT content. Skeletal muscle oxidative capacity, which may be indicative of the capacity of muscle energy production in the mitochondria, is related to locomotive functions but not to other functional parameters or skeletal fat infiltration.

Femoral Head Remodeling After Surgical Reduction of Developmental Hip Dislocations.

Developmental dysplasia of the hip is prevalent and is associated with dysplasia of both the femoral head and acetabulum. There is a paucity of literature describing femoral head remodeling after surgical reduction of developmentally dislocated hips. The purpose of this study was to describe and quantify changes in femoral head sphericity after closed or open reduction for developmental dysplasia of the hip. A retrospective cohort study was performed including patients with typical developmental hip dislocations who underwent closed or open reduction from 2009 to 2022 at a single institution and had immediate postoperative and average 3-week follow-up magnetic resonance imaging (MRI) scans. A subset of patients also had 3-year follow-up MRI scans. Patients with insufficient imaging or bony procedures at the time of reduction were excluded. We developed a technique to quantify femoral head "sphericity" by comparing differences in measured radii of the femoral head on axial and coronal plane MRI slices. We then calculated the variance of the radii for each plane and averaged these to calculate a combined variance. The variance was used to represent "sphericity," with a larger variance indicating a wider distribution of radii and thus a less spherical shape. A total of 74 patients (69 females) with 96 hips were included in this series. The median age of the child at the time of reduction was 8.7 months [interquartile range (IQR): 2.2]. Over half (58.3%) of the hips had a closed reduction, whereas the remaining were open reduced (41.7%). Immediately postoperatively, at the 3-week time point, and at the 3-year time point the median combined variance was 1.1 (IQR: 3.93), 0.51 (IQR: 1.32), and 0.31 (IQR: 0.50), respectively, indicating improved sphericity over time. Sphericity of the femoral head in developmental hip dislocations improves in both the immediate postoperative period, as well as the first few years after reduction. Further research is needed to evaluate the mechanism of remodeling, the ideal timing of reduction, and the relationship between femoral head and acetabular remodeling. Level IV-case series, therapeutic study.