Development of international consensus on a standardised image acquisition protocol for diagnostic evaluation of the sacroiliac joints by MRI: an ASAS-SPARTAN collaboration.

BACKGROUND: A range of sacroiliac joint (SIJ) MRI protocols are used in clinical practice but not all were specifically designed for diagnostic ascertainment. This can be confusing and no standard diagnostic SIJ MRI protocol is currently accepted worldwide. OBJECTIVE: To develop a standardised MRI image acquisition protocol (IAP) for diagnostic ascertainment of sacroiliitis. METHODS: 13 radiologist members of Assessment of SpondyloArthritis International Society (ASAS) and the SpondyloArthritis Research and Treatment Network (SPARTAN) plus two rheumatologists participated in a consensus exercise. A draft IAP was circulated with background information and online examples. Feedback on all issues was tabulated and recirculated. The remaining points of contention were resolved and the revised IAP was presented to the entire ASAS membership. RESULTS: A minimum four-sequence IAP is recommended for diagnostic ascertainment of sacroiliitis and its differential diagnoses meeting the following requirements. Three semicoronal sequences, parallel to the dorsal cortex of the S2 vertebral body, should include sequences sensitive for detection of (1) changes in fat signal and structural damage with T1-weighting; (2) active inflammation, being T2-weighted with fat suppression; (3) bone erosion optimally depicting the bone-cartilage interface of the articular surface and (4) a semiaxial sequence sensitive for detection of inflammation. The IAP was approved at the 2022 ASAS annual meeting with 91% of the membership in favour. CONCLUSION: A standardised IAP for SIJ MRI for diagnostic ascertainment of sacroiliitis is recommended and should be composed of at least four sequences that include imaging in two planes and optimally visualise inflammation, structural damage and the bone-cartilage interface.

Investigating the Bone Bruise Patterns in Pediatric Patients With Contact and Noncontact Acute Anterior Cruciate Ligament Tears: A Multicenter Study.

BACKGROUND: In adults with anterior cruciate ligament (ACL) tears, bone bruises on magnetic resonance imaging (MRI) scans provide insight into the underlying mechanism of injury. There is a paucity of literature that has investigated these relationships in children with ACL tears. PURPOSE: To examine and compare the number and location of bone bruises between contact and noncontact ACL tears in pediatric patients. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Boys ≤14 years and girls ≤12 years of age who underwent primary ACL reconstruction surgery between 2018 and 2022 were identified at 3 separate institutions. Eligibility criteria required detailed documentation of the mechanism of injury and MRI performed within 30 days of the initial ACL tear. Patients with congenital lower extremity abnormalities, concomitant fractures, injuries to the posterolateral corner and/or posterior cruciate ligament, previous ipsilateral knee injuries or surgeries, or closed physes evident on MRI scans were excluded. Patients were stratified into 2 groups based on a contact or noncontact mechanism of injury. Preoperative MRI scans were retrospectively reviewed for the presence of bone bruises in the coronal and sagittal planes using fat-suppressed T2-weighted images and a grid-based mapping technique of the tibiofemoral joint. RESULTS: A total of 109 patients were included, with 76 (69.7%) patients sustaining noncontact injuries and 33 (30.3%) patients sustaining contact injuries. There were no significant differences between the contact and noncontact groups in terms of age (11.8 ± 2.0 vs 12.4 ± 1.3 years; P = .12), male sex (90.9% vs 88.2%; P > .99), time from initial injury to MRI (10.3 ± 8.1 vs 10.4 ± 8.9 days; P = .84), the presence of a concomitant medial meniscus tear (18.2% vs 14.5%; P = .62) or lateral meniscus tear (69.7% vs 52.6%; P = .097), and sport-related injuries (82.9% vs 81.8%; P = .89). No significant differences were observed in the frequency of combined lateral tibiofemoral (lateral femoral condyle + lateral tibial plateau) bone bruises (87.9% contact vs 78.9% noncontact; P = .41) or combined medial tibiofemoral (medial femoral condyle [MFC] + medial tibial plateau) bone bruises (54.5% contact vs 35.5% noncontact; P = .064). Patients with contact ACL tears were significantly more likely to have centrally located MFC bruising (odds ratio, 4.3; 95% CI, 1.6-11; P = .0038) and less likely to have bruising on the anterior aspect of the lateral tibial plateau (odds ratio, 0.27; 95% CI, 0.097-0.76; P = .013). CONCLUSION: Children with contact ACL tears were 4 times more likely to present with centrally located MFC bone bruises on preoperative MRI scans compared with children who sustained noncontact ACL tears. Future studies should investigate the relationship between these bone bruise patterns and the potential risk of articular cartilage damage in pediatric patients with contact ACL tears.

CT in musculoskeletal imaging: still helpful and for what?

Computed tomography (CT) is a common modality employed for musculoskeletal imaging. Conventional CT techniques are useful for the assessment of trauma in detection, characterization and surgical planning of complex fractures. CT arthrography can depict internal derangement lesions and impact medical decision making of orthopedic providers. In oncology, CT can have a role in the characterization of bone tumors and may elucidate soft tissue mineralization patterns. Several advances in CT technology have led to a variety of acquisition techniques with distinct clinical applications. These include four-dimensional CT, which allows examination of joints during motion; cone-beam CT, which allows examination during physiological weight-bearing conditions; dual-energy CT, which allows material decomposition useful in musculoskeletal deposition disorders (e.g., gout) and bone marrow edema detection; and photon-counting CT, which provides increased spatial resolution, decreased radiation, and material decomposition compared to standard multi-detector CT systems due to its ability to directly translate X-ray photon energies into electrical signals. Advanced acquisition techniques provide higher spatial resolution scans capable of enhanced bony microarchitecture and bone mineral density assessment. Together, these CT acquisition techniques will continue to play a substantial role in the practices of orthopedics, rheumatology, metabolic bone, oncology, and interventional radiology.

Importance of the lumbar paraspinal muscles on the maintenance of global sagittal alignment after lumbar pedicle subtraction osteotomy.

OBJECTIVE: There are limited data about the influence of the lumbar paraspinal muscles on the maintenance of sagittal alignment after pedicle subtraction osteotomy (PSO) and the risk factors for sagittal realignment failure. The authors aimed to investigate the influence of preoperative lumbar paraspinal muscle quality on the postoperative maintenance of sagittal alignment after lumbar PSO. METHODS: Patients who underwent lumbar PSO with preoperative lumbar MRI and pre- and postoperative whole-spine radiography in the standing position were included. Spinopelvic measurements included pelvic incidence, sacral slope, pelvic tilt, L1-S1 lordosis, T4-12 thoracic kyphosis, spinosacral angle, C7-S1 sagittal vertical axis (SVA), T1 pelvic angle, and mismatch between pelvic incidence and L1-S1 lordosis. Validated custom software was used to calculate the percent fat infiltration (FI) of the psoas major, as well as the erector spinae and multifidus (MF). A multivariable linear mixed model was applied to further examine the association between MF FI and the postoperative progression of SVA over time, accounting for repeated measures over time that were adjusted for age, sex, BMI, and length of follow-up. RESULTS: Seventy-seven patients were recruited. The authors' results demonstrated significant correlations between MF FI and the maintenance of corrected sagittal alignment after PSO. After adjustment for the aforementioned parameters, the model showed that the MF FI was significantly associated with the postoperative progression of positive SVA over time. A 1% increase from the preoperatively assessed total MF FI was correlated with an increase of 0.92 mm in SVA postoperatively (95% CI 0.42-1.41, p < 0.0001). CONCLUSIONS: This study included a large patient cohort with midterm follow-up after PSO and emphasized the importance of the lumbar paraspinal muscles in the maintenance of sagittal alignment correction. Surgeons should assess the quality of the MF preoperatively in patients undergoing PSO to identify patients with severe FI, as they may be at higher risk for sagittal decompensation.

Importance of the cervical paraspinal muscles in postoperative patient-reported outcomes and maintenance of sagittal alignment after anterior cervical discectomy and fusion.

OBJECTIVE: The aim of this study was to investigate the influence of preoperatively assessed paraspinal muscle parameters on postoperative patient-reported outcomes and maintenance of cervical sagittal alignment after anterior cervical discectomy and fusion (ACDF). METHODS: Patients with preoperative and postoperative standing cervical spine lateral radiographs and preoperative cervical MRI who underwent an ACDF between 2015 and 2018 were reviewed. Muscles from C3 to C7 were segmented into 4 functional groups: anterior, posteromedial, posterolateral, and sternocleidomastoid. The functional cross-sectional area and also the percent fat infiltration (FI) were calculated for all groups. Radiographic alignment parameters collected preoperatively and postoperatively included C2-7 lordosis and C2-7 sagittal vertical axis (SVA). Neck Disability Index (NDI) scores were recorded preoperatively and at 2 and 4-6 months postoperatively. To investigate the relationship between muscle parameters and postoperative changes in sagittal alignment, multivariable linear mixed models were used. Multivariable linear regression models were used to analyze the correlations between the changes in NDI scores and the muscles' FI. RESULTS: A total of 168 patients with NDI and 157 patients with sagittal alignment measurements with a median follow-up of 364 days were reviewed. The mixed models showed that a greater functional cross-sectional area of the posterolateral muscle group at each subaxial level and less FI at C4-6 were significantly associated with less progression of C2-7 SVA over time. Moreover, there was a significant correlation between greater FI of the posteromedial muscle group measured at the C7 level and less NDI improvement at 4-6 months after ACDF. CONCLUSIONS: The findings highlight the importance of preoperative assessment of the cervical paraspinal muscle morphology as a predictor for patient-reported outcomes and maintenance of C2-7 SVA after ACDF.

Reliability assessment of the OMERACT whole-body magnetic resonance imaging scoring system for juvenile idiopathic arthritis.

Inter-reader reliability of a new scoring system for evaluating joint inflammation and enthesitis in whole body MRI (WBMRI) in juvenile idiopathic arthritis was tested. The scoring system grades 732 item-region combinations of bone marrow and soft tissue changes for commonly involved joints and entheseal sites. Five radiologists rated 17 WBMRI scans through an online rating platform. Item-wise reliability was calculated for 117 items with non-zero scores in >10 % of readings. Interquartile ranges of the five-reader Kappa reliability coefficients were 0.58-0.73 (range: 0.36-0.88) for the joints, 0.65-0.81 (range: 0.39-0.95) for the entheses, and 0.62-0.75 (range: 0.60-0.76) for chronic nonbacterial osteomyelitis-like lesions.

Association Between Severity of Cervical Central Spinal Stenosis and Paraspinal Muscle Parameters in Patients Undergoing Anterior Cervical Discectomy and Fusion.

STUDY DESIGN: Retrospective study. OBJECTIVE: The aim of this study was to evaluate the association between severity and level of cervical central stenosis (CCS) and the fat infiltration (FI) of the cervical multifidus/rotatores (MR) at each subaxial levels. SUMMARY OF BACKGROUND DATA: The relationship between cervical musculature morphology and the severity of CCS is poorly understood. METHODS: Patients with preoperative cervical magnetic resonance imaging (MRI) who underwent anterior cervical discectomy and fusion (ACDF) were reviewed. The cervical MR were segmented from C3 to C7 and the percent FI was measured using a custom-written Matlab software. The severity of the CCS at each subaxial level was assessed using a previously published classification. Grade 3, representing a loss of cerebrospinal fluid space and deformation of the spinal cord > 25%, was set as the reference and compared to the other gradings. Multivariable linear regression analyses were conducted and adjusted for age, sex, and body mass index. RESULTS: 156 consecutive patients were recruited. A spinal cord compression at a certain level was significantly associated with a greater FI of the MR below that level. After adjustment for the above-mentioned confounders, our results showed that spinal cord compression at C3/4 and C4/5 was significantly associated with greater FI of the MR from C3 to C6 and C5 to C7, respectively. A spinal cord compression at C5/6 or C6/7 was significantly associated with greater FI of the MR at C7. CONCLUSION: Our results demonstrated significant correlations between the severity of CCS and a greater FI of the MR. Moreover, significant level-specific correlations were found. A significant increase in FI of the MR at the levels below the stenosis was observed in patients presenting with spinal cord compression. Given the segmental innervation of the MR, the increased FI might be attributed to neurogenic atrophy. LEVEL OF EVIDENCE: 3.

Assessing intraoperative pedicle screw placement accuracy using biplanar radiographs compared to three-dimensional imaging.

To date, biplanar imaging (2D) has been the method of choice for pedicle screw (PS) positioning and verified for the anteroposterior view and (spinal midline) M-line method. In recent years, the use of intraoperative three-dimensional (3D) imaging has become available with the Gertzbein-Robbins system (GRS) to assess PS breach and positioning confirmation. The aim is to determine if 2D imaging is sufficient to assess PS position in comparison to advanced 3D imaging.Retrospective review of prospectively collected data from 204 consecutive adult patients who underwent posterior thoracic and lumbar instrumented fusion for degenerative spinal surgery by a single surgeon (2019-2022).Of the 204 patients, 187 (91.6%) had intraoperative images available for analysis. A total of 1044 PS implants were used; 922 (88.3%) were robotically placed. Postoperative CT scans were verified with M-line/GRS findings. Among 103 patients (50.5%) with a total of 362 screws, (34.7%) had postoperative CT, intraoperative 3D scan, and intraoperative 2D scan for analysis. Postoperative CT findings were consistent with all GRS findings, validating that 3D imaging was accurate. Screws (1%) were falsely verified by the M-line as 3D imaging confirmed false negative or positive findings.In our series, intraoperative 3D scan was as accurate as postoperative CT scan in assessing PS breach. A significant number of PS may be falsely read as accurate on 2D imaging, that is in fact inaccurate when assessed on 3D imaging. An intraoperative post-instrumentation 3D scan may be preferable to prevent postoperative recognition of a falsely verified screw on biplanar imaging.

The Reciprocal Relationship Between Lumbar Intervertebral Disk Degeneration and the MRI-based Vertebral Bone Quality Score.

STUDY DESIGN: Retrospective longitudinal study. OBJECTIVE: To investigate the association between lumbar intervertebral disk degeneration (DD) and the vertebral bone quality (VBQ) score. BACKGROUND: The VBQ score that is based on magnetic resonance imaging has been proposed as a measure of lumbar spine bone quality and is a significant predictor of healthy versus osteoporotic bone. However, the role of segmental contributing factors on VBQ is unknown. METHODS: Nonsurgical patients who underwent repeated lumbar magnetic resonance imaging scans, at least three years apart primarily for low back pain were retrospectively included. VBQ was assessed as previously described. DD was assessed using the Pfirrmann grading (PFG) scale. PFG grades were summarized as PFG L1-4 for the upper three lumbar disk levels, as PFG L4-S1 for the lower two lumbar disc levels, and as PFG L1-S1 for all lumbar disc levels. Multivariable linear mixed models were used with adjustments for age, sex, race, body mass index, and the clustering of repeated measurements. RESULTS: A total of 350 patients (54.6% female, 85.4% White) were included in the final analysis, with a median age at baseline of 60.1 years and a body mass index of 25.8 kg/m 2 . VBQ significantly increased from 2.28 at baseline to 2.36 at follow-up ( P = 0.001). In the unadjusted analysis, a significant positive correlation was found between PFG L1-4 , PFG L1-S1 , and VBQ at baseline ( P < 0.05) that increased over time ( P < 0.005). In the adjusted multivariable analysis, PFG L1-4 ( ß = -0.0195; P = 0.021), PFG L4-S1 ( ß = -0.0310; P = 0.007), and PFG L1-S1 ( ß = -0.0160; P = 0.012) were independently and negatively associated with VBQ. CONCLUSIONS: More advanced and long-lasting DD is associated with lower VBQ indicating less bone marrow fat content and potentially stronger bone. VBQ score as a marker of bone quality seems affected by DD.

Pre-operative bone quality deficits and risk of complications following spine fusion surgery among postmenopausal women.

Poor bone quality is a risk factor for complications after spinal fusion surgery. This study investigated pre-operative bone quality in postmenopausal women undergoing spine fusion and found that those with small bones, thinner cortices and surgeries involving more vertebral levels were at highest risk for complications. PURPOSE: Spinal fusion is one of the most common surgeries performed worldwide. While skeletal complications are common, underlying skeletal deficits are often missed by pre-operative DXA due to artifact from spinal pathology. This prospective cohort study investigated pre-operative bone quality using high resolution peripheral CT (HRpQCT) and its relation to post-operative outcomes in postmenopausal women, a population that may be at particular risk for skeletal complications. We hypothesized that women with low volumetric BMD (vBMD) and abnormal microarchitecture would have higher rates of post-operative complications. METHODS: Pre-operative imaging included areal BMD (aBMD) by DXA, cortical and trabecular vBMD and microarchitecture of the radius and tibia by high resolution peripheral CT. Intra-operative bone quality was subjectively graded based on resistance to pedicle screw insertion. Post-operative complications were assessed by radiographs and CTs. RESULTS: Among 50 women enrolled (age 65 years), mean spine aBMD was normal and 35% had osteoporosis by DXA at any site. Low aBMD and vBMD were associated with "poor" subjective intra-operative quality. Skeletal complications occurred in 46% over a median follow-up of 15 months. In Cox proportional models, complications were associated with greater number of surgical levels (HR 1.19 95% CI 1.06-1.34), smaller tibia total area (HR 1.67 95% CI1.16-2.44) and lower tibial cortical thickness (HR 1.35 95% CI 1.05-1.75; model p < 0.01). CONCLUSION: Women with smaller bones, thinner cortices and procedures involving a greater number of vertebrae were at highest risk for post-operative complications, providing insights into surgical and skeletal risk factors for complications in this population.

Intravenous Ketorolac Substantially Reduces Opioid Use and Length of Stay After Lumbar Fusion: A Randomized Controlled Trial.

STUDY DESIGN: A randomized, double-blinded, placebo-controlled trial. OBJECTIVE: To examine the effect of intravenous ketorolac (IV-K) on hospital opioid use compared with IV-placebo (IV-P) and IV acetaminophen (IV-A). SUMMARY OF BACKGROUND DATA: Controlling postoperative pain while minimizing opioid use after lumbar spinal fusion is an important area of study. PATIENTS AND METHODS: Patients aged 18 to 75 years undergoing 1 to 2 level lumbar fusions between April 2016 and December 2019 were included. Patients with chronic opioid use, smokers, and those on systemic glucocorticoids or contraindications to study medications were excluded. A block randomization scheme was used, and study personnel, hospital staff, and subjects were blinded to the assignment. Patients were randomized postoperatively. The IV-K group received 15 mg (age > 65) or 30 mg (age < 65) every six hours (q6h) for 48 hours, IV-A received 1000 mg q6h, and IV-P received normal saline q6h for 48 hours. Demographic and surgical details, opioid use in morphine milliequivalents, opioid-related adverse events, and length of stay (LOS) were recorded. The primary outcome was in-hospital opioid use up to 72 hours. RESULTS: A total of 171 patients were included (58 IV-K, 55 IV-A, and 58 IV-P) in the intent-to-treat (ITT) analysis, with a mean age of 57.1 years. The IV-K group had lower opioid use at 72 hours (173 ± 157 mg) versus IV-A (255 ± 179 mg) and IV-P (299 ± 179 mg; P = 0.000). In terms of opiate use, IV-K was superior to IV-A ( P = 0.025) and IV-P ( P = 0.000) on ITT analysis, although on per-protocol analysis, the difference with IV-A did not reach significance ( P = 0.063). When compared with IV-P, IV-K patients reported significantly lower worst ( P = 0.004), best ( P = 0.001), average ( P = 0.001), and current pain ( P = 0.002) on postoperative day 1, and significantly shorter LOS ( P = 0.009) on ITT analysis. There were no differences in opioid-related adverse events, drain output, clinical outcomes, transfusion rates, or fusion rates. CONCLUSIONS: By reducing opioid use, improving pain control on postoperative day 1, and decreasing LOS without increases in complications or pseudarthrosis, IV-K may be an important component of "enhanced recovery after surgery" protocols.

Relationship between lumbar spinal stenosis and axial muscle wasting.

BACKGROUND CONTEXT: Although the effect of lumbar spinal stenosis (LSS) on the lower extremities is well documented, limited research exists on the effect of spinal stenosis on the posterior paraspinal musculature (PPM). Similar to neurogenic claudication, moderate to severe spinal canal compression can also interfere with the innervation of the PPM, which may result in atrophy and increased fatty infiltration (FI). PURPOSE: This study aims to assess the association between LSS and atrophy of the PPM. STUDY DESIGN: Retrospective cross-sectional study. PATIENT SAMPLE: Patients undergoing MRI scans at a tertiary orthopedic center for low back pain or as part of a preoperative evaluation. OUTCOME MEASURES: The functional cross-sectional area (fCSA) and percent fatty infiltration (FI) of the PPM at L4. METHODS: Lumbar MRIs of patients at a tertiary orthopedic center indicated due to lower back pain (LBP) or as a presurgical workup were analyzed. Patients with previous spinal fusion surgery or scoliosis were excluded. LSS was assessed according to the Schizas classification at all lumbar levels. The cross-sectional area of the PPM was measured on a T2-weighted MRI sequence at the upper endplate of L4. The fCSA and fatty infiltration (FI) were calculated using custom software. Crude differences in FI and fCSA between patients with no stenosis and at least mild stenosis were tested with the Wilcoxon signed-rank test. To account for possible confounders, a multivariable linear regression model was used to adjust for age, sex, body mass index (BMI), and disc degeneration. A subgroup analysis according to MRI indication was performed. RESULTS: A total of 522 (55.7% female) patients were included. The median age was 61 years (IQR: 51-71). The greatest degree of moderate and severe stenosis was found at L4/5, 15.7%, and 9.2%, respectively. Stenosis was the least severe at L5/S1 and was found to be 2% for moderate and 0.2% for severe stenosis. The Wilcoxon test showed significantly increased FI of the PPM with stenosis at any lumbar level (p<.001), although no significant decrease in fCSA was observed. The multivariable regression model showed a significant increase in FI with increased LSS at L1/2, L2/3, and L3/4 (p=.013, p<.01 and p=.003). The severity of LSS at L4/5 showed a positive association with the fCSA (p=.019). The subgroup analysis showed, the effect of LSS was more pronounced in nonsurgical patients than in patients undergoing surgery. CONCLUSIONS: In this study, we demonstrated a significant and independent association between LSS and the composition of the PPM, which was dependent on the level of LSS relative to the PPM. In addition to neurogenic claudication, patients with LSS might be especially susceptible to axial muscle wasting, which could worsen LSS due to increased spinal instability, leading to a positive feedback loop.

Association Between Cervical Sagittal Alignment and Subaxial Paraspinal Muscle Parameters.

STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVE: The authors aim to investigate the association between muscle functional group characteristics and sagittal alignment parameters in patients undergoing anterior cervical discectomy and fusion. SUMMARY OF BACKGROUND DATA: The relationship between the morphology of cervical paraspinal muscles and sagittal alignment is not well understood. MATERIALS AND METHODS: Patients with preoperative cervical magnetic resonance imaging and cervical spine lateral radiographs in standing position who underwent anterior cervical discectomy and fusion between 2015 and 2018 were reviewed. Radiographic alignment parameters included C2 to 7 lordosis, C2 to 7 sagittal vertical axis (SVA), C2 slope, neck tilt, T1 slope, and thoracic inlet angle. Muscles from C3 to C7 were categorized into four functional groups: sternocleidomastoid group, anterior group, posteromedial group, and posterolateral group (PL). A custom-written Matlab software was used to assess the functional cross-sectional area (fCSA) and percent fat infiltration (FI) for all groups. Multivariable linear regression analyses were conducted and adjusted for age, sex, and body mass index. RESULTS: A total of 172 patients were included. Regression analyses demonstrated that a greater C2 to 7 SVA was significantly associated with a greater FI of the anterior group from C3 to C5 and with a higher fCSA of the PL group at C3 to C4, and C6 to 7. A larger C2 slope was significantly correlated with a greater FI of the anterior group at C3 to C4 and a higher fCSA of the PL group from C3 to C5. CONCLUSION: This work proposes new insights into the complex interaction between sagittal alignment and cervical paraspinal muscles by emphasizing the importance of these muscles in sagittal alignment. The authors hypothesize that with cervical degeneration, the stabilizing function of the anterior muscles decreases, which may result in an increase in the compensatory mechanism of the PL muscles. Consequently, there may be a corresponding increase in the C2 to C7 SVA and a larger C2 slope.

Association between severity of the cervical foraminal stenosis and paraspinal muscle parameters in patients undergoing anterior cervical discectomy and fusion.

OBJECTIVE: The cervical multifidus and rotatores muscles are innervated by the posterior rami of the spinal nerves of the corresponding level, and it has been hypothesized that cervical foraminal stenosis (CFS) affecting the spinal nerves results in changes in these muscles. The purpose of this study was to evaluate the relationship between the severity of CFS and fat infiltration (FI) of the multifidus and rotatores muscles. METHODS: Patients who received preoperative cervical MRI, underwent anterior cervical decompression and fusion between 2015 and 2018, and met inclusion and exclusion criteria were included. Multifidus and rotatores muscles were segmented bilaterally from C3 to C7, and the percent FI was measured using custom-written MATLAB software. The severity of the CFS was assessed by the Kim classification. Multivariable linear mixed models were conducted and adjusted for age, sex, BMI, and repeated measures. RESULTS: In total, 149 patients were included. Linear mixed modeling results showed that a more severe CFS at C3-4 was correlated with a greater FI of the multifidus and rotatores muscles at C4 (estimate 0.034, 95% CI 0.003-0.064; p = 0.031), a more severe CFS at C4-5 was correlated with a greater FI of the multifidus and rotatores muscles at C5 (estimate 0.037, 95% CI 0.015-0.057; p < 0.001), a more severe CFS at C5-6 was correlated with a greater FI of the multifidus and rotatores muscles at C6 (estimate 0.041, 95% CI 0.019-0.062; p < 0.001) and C7 (estimate 0.035, 95% CI 0.012-0.058; p = 0.003), and a more severe CFS at C6-7 was correlated with a greater FI of the multifidus and rotatores muscles at C7 (estimate 0.049, 95% CI 0.027-0.071; p < 0.001). CONCLUSIONS: These results demonstrated level- and side-specific correlations between the FI of the multifidus and rotatores muscles and severity of CFS. Given the segmental innervation of the multifidus and rotatores muscles, the authors hypothesize that the observed increased FI could be reflective of changes due to muscle denervation from CFS.

Frequency of Coexistent Spinal Segment Variants: Retrospective Analysis in Asymptomatic Young Adults.

BACKGROUND AND PURPOSE: Spinal segment variants are highly prevalent and can potentially lead to incorrect spinal enumeration and, consequently, interventions or surgeries at the wrong vertebral levels. Our aim was to assess the prevalence of spinal segment variants and to study the potential association among these variants in a population without histories of spine symptoms. MATERIALS AND METHODS: Consecutive computed tomography exams of 450 young adults originally evaluated for non-spinal conditions and without a history of spinal diseases from a single institution. In addition to using descriptive statistics for reporting frequencies of spinal segment variants, the association between these variants was studied by calculating odds ratios and their 95% confidence interval. Consecutive CT exams were evaluated to determine the total number of presacral segments, presence of cervical rib, thoracolumbar transitional vertebra, iliolumbar ligament, and lumbosacral transitional vertebra. RESULTS: The spinal segment distribution variants (an atypical number of presacral segments or an atypical distribution of thoracolumbar vertebrae), cervical rib, thoracolumbar transitional vertebra, and lumbosacral transitional vertebra were reported in 23.8%, 4.2%, 15.3%, and 26.4% of cases in our study population. The presence of a cervical rib or a thoracolumbar transitional vertebra was associated with concurrent lumbosacral transitional vertebra (OR = 3.28; 95% CI, 1.29-8.47 and 1.87; 95% CI, 1.08-3.20, respectively). The inability to visualize the iliolumbar ligament was also associated with the presence of cervical ribs (OR = 3.06; 95% CI, 1.18-7.80). CONCLUSIONS: In a population of asymptomatic young adults, spinal segment variants are both highly prevalent with a high rate of coexistence. When a spinal segment variant (eg, transitional vertebra) is diagnosed, additional imaging might be considered for accurate spine enumeration before interventions or operations.

An Updated Review of Magnetic Resonance Neurography for Plexus Imaging.

Magnetic resonance neurography (MRN) is increasingly used to visualize peripheral nerves in vivo. However, the implementation and interpretation of MRN in the brachial and lumbosacral plexi are challenging because of the anatomical complexity and technical limitations. The purpose of this article was to review the clinical context of MRN, describe advanced magnetic resonance (MR) techniques for plexus imaging, and list the general categories of utility of MRN with pertinent imaging examples. The selection and optimization of MR sequences are centered on the homogeneous suppression of fat and blood vessels while enhancing the visibility of the plexus and its branches. Standard 2D fast spin-echo sequences are essential to assess morphology and signal intensity of nerves. Moreover, nerve-selective 3D isotropic images allow improved visualization of nerves and multiplanar reconstruction along their course. Diffusion-weighted and diffusion-tensor images offer microscopic and functional insights into peripheral nerves. The interpretation of MRN in the brachial and lumbosacral plexi should be based on a thorough understanding of their anatomy and pathophysiology. Anatomical landmarks assist in identifying brachial and lumbosacral plexus components of interest. Thus, understanding the varying patterns of nerve abnormalities facilitates the interpretation of aberrant findings.

Differences in imaging and clinical characteristics are associated with higher rates of decompression-fusion versus decompression-alone in women compared to men for lumbar degenerative spondylolisthesis.

PURPOSE: The goals were to ascertain if differences in imaging/clinical characteristics between women and men were associated with differences in fusion for lumbar degenerative spondylolisthesis. METHODS: Patients had preoperative standing radiographs, CT scans, and intraoperative fluoroscopic images. Symptoms and comorbidity were obtained from patients; procedure (fusion-surgery or decompression-alone) was obtained from intraoperative records. With fusion surgery as the dependent variable, men and women were compared in multivariable logistic regression models with clinical/imaging characteristics as independent variables. The sample was dichotomized, and analyses were repeated with separate models for men and women. RESULTS: For 380 patients (mean age 67, 61% women), women had greater translation, listhesis angle, lordosis, and pelvic incidence, and less diastasis and disc height (all p ≤ 0.03). The rate of fusion was higher for women (78% vs. 65%; OR 1.9, p = 0.008). Clinical/imaging variables were associated with fusion in separate models for men and women. Among women, in the final multivariable model, less comorbidity (OR 0.5, p = 0.05), greater diastasis (OR 1.6, p = 0.03), and less anterior disc height (OR 0.8, p = 0.0007) were associated with fusion. Among men, in the final multivariable model, opioid use (OR 4.1, p = 0.02), greater translation (OR 1.4, p = 0.0003), and greater diastasis (OR 2.4, p = 0.0002) were associated with fusion. CONCLUSIONS: There were differences in imaging characteristics between men and women, and women were more likely to undergo fusion. Differences in fusion within groups indicate that decisions for fusion were based on composite assessments of clinical and imaging characteristics that varied between men and women.

Understanding the Interplay Between Paraspinal Muscle Atrophy and Lumbar Endplate Degeneration: A 3-Year Longitudinal Study.

STUDY DESIGN: Retrospective analysis of longitudinal data. OBJECTIVE: To assess the association between the paraspinal musculature (PM) and lumbar endplate degeneration. BACKGROUND: The PM is essential for spinal stability, while the vertebral endplate is pivotal for nutrient transport and force distribution. The clinical importance of both has been highlighted in recent literature, though little is known about their interaction. METHODS: We identified patients with lumbar MRI scans due to low back pain, with a 3-year interval between MRI scans. Endplate damage was assessed by the total endplate score (TEPS) at each lumbar level. The PM was evaluated for its functional cross-sectional area and fatty infiltration (FI) at the L4 level. We used a generalized mixed model to analyze the association between PM parameters and TEPS at timepoint one, adjusting for age, sex, BMI, diabetes, hypertension, and smoking status. The association with the progression of endplate damage was analyzed through an ordinal regression model, additionally adjusted for TEPS at baseline. RESULTS: In all, 329 patients were included, with a median follow-up time of 3.4 years. Participants had a median age of 59 and a BMI of 25.8 kg/m 2 . In the univariate analysis, FI of the posterior PM was significantly associated with TEPS at baseline (ß: 0.08, P <0.001) and progression of TEPS [Odds Ratio (OR): 1.03, P =0.020] after adjustment for confounders. The ß and OR in this analysis are per percent of FI. In a binary analysis, patients with FI≥40% had an OR of 1.92 ( P =0.006) for the progression of TEPS. CONCLUSIONS: This is the first longitudinal study assessing the relationship between PM and endplate degeneration, demonstrating the association between PM atrophy and the progression of endplate degeneration. This insight may aid in identifying patients at risk for degenerative lumbar conditions and guide research into preventive measures.