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BACKGROUND: Low protein intake (LPI) has been suggested as a treatment for chronic kidney disease (CKD). However, protein intake is essential for bone health. METHODS: We studied the database of the National Health and Nutrition Examination Survey, 2005-2010. Basic variables, metabolic diseases, and bone density of different femoral areas were stratified into four subgroups according to different protein intake (DPI) (that is, 1.2 g/kg/day). RESULTS: Significant differences were found among all lumbar area bone mineral density (BMD) and T-scores (p 1.2 g/day/kg over L2 (relative risk (RR)=1.326, 95% confidence interval (CI)=1.062-1.656), subgroup >1.2 g/day/kg over L3 (RR = 1.31, 95%CI = 1.057-1.622), subgroup 1.2 g/day/kg over all L spines (RR = 0.333, 95%CI = 1.098-1.618). However, a higher risk of osteoporosis was observed only in the non-CKD group. There was an apparent trend of higher DPI coexisting with lower BMD and T scores in patients with CKD. For osteoporosis (reference:0.8-1.0 g/day/kg), lower (1.2 g/day/kg) was associated with higher risks in the non-CKD group, but not in the CKD group. CONCLUSIONS: In the CKD group, LPI for renal protection was safe without threatening L spine bone density and without causing a higher risk of osteoporosis.

PurposeHigh quality scan prescription that optimally covers the area of interest with scan planes aligned to relevant anatomical structures is crucial for error-free radiologic interpretation. The goal of this project was to develop a machine learning pipeline for oblique scan prescription that could be trained on localizer images and metadata from previously acquired MR exams.MethodsA novel Multislice Rotational Region-based Convolutional Neural Network (MS-R2CNN) architecture was developed. Based on this architecture, models for automated prescription sagittal lumbar spine acquisitions from axial, sagittal, and coronal localizer slices were trained. The automated prescription pipeline was integrated with the scanner console software and evaluated in experiments with healthy volunteers (N = 3) and patients with lower-back pain (N = 20).ResultsExperiments in healthy volunteers demonstrated high accuracy of automated prescription in all subjects. There was good agreement between alignment and coverage of manual and automated prescriptions, as well as consistent views of the lumbar spine at different positions of the subjects within the scanner bore. In patients with lower-back pain, the generated prescription was applied in 18 cases (90% of the total number). None of the cases required major adjustment, while in 11 cases (55%) there were minor manual adjustments to the generated prescription.ConclusionsThis study demonstrates the ability of oriented object detection-based models to be trained to prescribe oblique lumbar spine MRI acquisitions without the need of manual annotation or feature engineering and the feasibility of using machine learning-based pipelines on the scanner for automated prescription of MRI acquisitions.

Study Design. Retrospective cohort study. Objective. The purpose of this study is to determine which demographic, surgical, and radiographic preoperative characteristics are most associated with the need for subsequent fusion after decompression lumbar spinal surgery. Summary of Background Data. There is a relatively high rate of the need for repeat decompression or fusion after an index decompression procedure for degenerative spine disease. Nevertheless, there is a dearth of literature identifying risk factors for lumbar fusion following decompression surgery Methods. Patients 18 years or older receiving a primary lumbar decompression surgery within the levels of L3-S1 between 2011 and 2020 were identified. All patients had preoperative radiographs and 2 years of follow-up data. Chart review was performed for surgical characteristics and demographics. The sagittal parameters included lumbar lordosis (LL), segmental lordosis (SL), anterior disk height (aDH), posterior disk height (pDH), sacral slope (SS), and pelvic tilt (PT). Pelvic incidence (PI = PT+SS) and pelvic incidence minus lumbar lordosis (PI-LL) were calculated. In addition, the Roussouly classification was determined for each patient. Bivariant and multivariant analyses were performed. Results. Of the 363 patients identified in this study, 96 patients had a fusion after their index decompression surgery. Multivariable analysis identified involvement of L4-L5 level in the decompression [odds ratio (OR) = 1.83 (1.09-3.14), P = 0.026], increased L5-S1 segmental lordosis [OR = 1.08 (1.03-1.13), P = 0.001], decreased SS [OR = 0.96 (0.93-0.99), P = 0.023], and decreased endplate obliquity [OR = 0.88 (0.77-0.99), P = 0.040] as significant independent predictors of fusion after decompression surgery. Conclusions. This is one of the first studies to assess preoperative sagittal parameters in conjunction with demographic variables to determine predictors of the need for fusion after index decompression. We demonstrated that decompression at L4-L5, greater L5-S1 segmental lordosis, decreased sacral slope, and decreased endplate obliquity were associated with higher rates of fusion after decompression surgery. [ABSTRACT FROM AUTHOR]

Study Design. Retrospective review. Objective. The purpose of this study was to evaluate disparities in patient-reported outcome measures (PROM) completion rates and baseline function scores among newly presenting spine patients. Summary of Background Data. Prior studies have demonstrated that minority patients and those of low socioeconomic status may present with worse physical and mental health on PROMs. As PROMs are increasingly used in clinical care, research, and health policy, accurate assessment of health status among populations relies on the successful completion of PROM instruments. Methods. A retrospective review of 10, 803 consecutive new patients presenting to a single multidisciplinary spine clinic from June 2020 to September 2022 was performed. Univariate statistics were performed to compare demographics between patients who did and did not complete PROMs. Multivariable analysis was used to compare PROM instrument completion rates by race, ethnicity, and Social Vulnerability Index (SVI) and baseline scores among responders. Results. A total of 68.4% of patients completed PROMs at the first clinic visit. After adjusting for age, sex, body mass index, and diagnosis type, patients of non-White race (OR = 0.661, 95% CI = 0.599-0.729, P < 0.001), Hispanic ethnicity (OR = 0.569, 95% CI = 0.448-0.721, P < 0.001), and increased social vulnerability (OR = 0.608, 95% CI = 0.511-0.723, P < 0.001) were less likely to complete PROMs. In the multivariable models, patients of non-White race reported lower levels of physical function (β = -6.5, 95% CI = -12.4 to -0.6, P = 0.032) and higher levels of pain intensity (β = 0.6, 95% CI = 0.2-1.0, P = 0.005). Hispanic ethnicity (β = 1.5, 95% CI = 0.5-2.5, P = 0.004) and increased social vulnerability (β = 1.1, 95% CI = 0.4-1.8, P = 0.002) were each associated with increased pain intensity. Conclusions. Among newly presenting spine patients, those of non-White race, Hispanic ethnicity, and with increased social vulnerability were less likely to complete PROMs. As these subpopulations also reported worse physical function or pain intensity, additional strategies are needed to better capture patient- reported health status to avoid bias in clinical care, outcomes research, and health policy. Level of Evidence. 4. [ABSTRACT FROM AUTHOR]

Introduction: The aim of this study was to determine the short- and long-term effects of foam rolling (FR) on the pressure pain threshold and the range of motion of the lumbar spine in healthy subjects. Methods: 43 healthy subjects without back problems were randomly assigned to an experimental group (EG) or a control group (CG). The subjects in the EG underwent a 4-week FR program (12 sessions). The subjects in the CG received no intervention. Range of motion was measured using the modified-modified Schober test for flexion and fingertip-to-floor distance for lateral flexion. The pressure pain threshold was measured with a hand-held pressure algometer. The measurements were taken before and after the first FR, after the 4-week program and at the 1-, 3- and 6-month follow-up. The significance level was set at p ≤ 0.05 and the desired power of the test was 92%. Results: We found an improvement in flexion (p = 0.03) and lateral flexion (p < 0.001) in the EG after the first FR and recorded a significant improvement in all measured variables (flexion, lateral flexion and algometry: p < 0.001) at the end of the entire 4-week program. The effects were noticeable up to 6 months after the end of the program (p ≤ 0.03) and were statistically significantly better than in the CG (p ≤ 0.04). The calculated Cohen's d value was 1.15 for flexion, 1.06 for lateral flexion and 0.98 for algometry, which represents a large effect size. Discussion: FR improves the pressure pain threshold and mobility of the lumbar spine in healthy subjects. The effects are noticeable at least 6 months after the end of an FR program. [ABSTRACT FROM AUTHOR]

Purpose: To provide lumbar spine anatomical parameters relevant to the UBE technique and explore their intraoperative application. Methods: CT imaging data processed by Mimics for parametric measurements, including laminar abduction angle (LAA), laminar slope angle (LSA), minimum laminar height (MLH), distance between the inferior margin of the lamina and attachment of the ligamentum flavum onto the cephalad lamina (DLL), distance between the initial point and the middle of the articular process (DIA), and distance from the inferior margin of the lamina to the inferior border of the vertebral body (DLV), and were manually measured. Results: LAA and DIA gradually increase from L1 to L5. At L1, the DIA is approximately the length of 2 drill bits with a diameter of 3 mm (male: 7.77 ± 1.39 mm, female: 7.22 ± 1.09 mm), while at L5, it can reach the length of 4–5 drill bits (male: 14.96 ± 2.24 mm, female: 13.67 ± 2.33 mm). MLH, DLL, and DLV reach their maximum values at the L3 and decrease toward the cranial and caudal ends. The DLL is smallest at L5 (male: 9.58 ± 1.90 mm, female: 9.38 ± 2.14 mm), equivalent to the length of 3 drill bits, while the DLL at L3 is the length of 4–5 drill bits (male: 14.17 ± 2.13 mm, female: 14.01 ± 2.07 mm). Conclusion: Referring to the drill diameter during surgery can mark the extent of laminotomy. The characteristics of vertebral plate angles at different lumbar levels can provide references for preoperative incision design. [ABSTRACT FROM AUTHOR]

Purpose: To test equivalency of deep-learning 3D lumbar spine MRI with "CT-like" contrast to CT for virtual pedicle screw planning and geometric measurements in robotic-navigated spinal surgery. Methods: Between December 2021 and June 2022, 16 patients referred for spinal fusion and decompression surgery with pre-operative CT and 3D MRI were retrospectively assessed. Pedicle screws were virtually placed on lumbar (L1-L5) and sacral (S1) vertebrae by three spine surgeons, and metrics (lateral deviation, axial/sagittal angles) were collected. Vertebral body length/width (VL/VW) and pedicle height/width (PH/PW) were measured at L1-L5 by three radiologists. Analysis included equivalency testing using the 95% confidence interval (CI), a margin of ± 1 mm (± 2.08° for angles), and intra-class correlation coefficients (ICCs). Results: Across all vertebral levels, both combined and separately, equivalency between CT and MRI was proven for all pedicle screw metrics and geometric measurements, except for VL at L1 (mean difference: − 0.64 mm; [95%CI − 1.05, − 0.24]), L2 (− 0.65 mm; [95%CI − 1.11, − 0.20]), and L4 (− 0.78 mm; [95%CI − 1.11, − 0.46]). Inter- and intra-rater ICC for screw metrics across all vertebral levels combined ranged from 0.68 to 0.91 and 0.89–0.98 for CT, and from 0.62 to 0.92 and 0.81–0.97 for MRI, respectively. Inter- and intra-rater ICC for geometric measurements ranged from 0.60 to 0.95 and 0.84–0.97 for CT, and 0.61–0.95 and 0.93–0.98 for MRI, respectively. Conclusion: Deep-learning 3D MRI facilitates equivalent virtual pedicle screw placements and geometric assessments for most lumbar vertebrae, with the exception of vertebral body length at L1, L2, and L4, compared to CT for pre-operative planning in patients considered for robotic-navigated spine surgery. [ABSTRACT FROM AUTHOR]

Objective: To compare the clinical effects of oblique lumbar interbody fusion (OLIF) and lateral lumbar interbody fusion (LLIF) in the treatment of degenerative disc disease of the lumbar spine. Method: This was a retrospective study. The clinical data of 80 patients with lumbar disc degenerative disease who underwent surgery in Affiliated Hospital of Beihua University from May 2018 to May 2023 were selected. The patients were divided into LLIF group and OLIF group according to surgical methods. Compare the 36-Item Short- Form Health Survey(SF-36), Visual Analog Scale(VAS) scores, Oswesterly Disability Index(ODI), Japanese Orthopedic Association(JOA) scores, Cobb angle, and intervertebral height changes between two groups of patients pre- and posttreatment, and evaluate the differences in clinical efficacy and surgical complications. Result: Postsurgery, the SF-36 score, VAS score, ODI index, and JOA score of two groups were significantly better than presurgery(p<0.05); After three months of treatment, the improvement in OLIF group was better than LLIF group(p<0.05), while there was no statistically significant difference between the two groups at six months postsurgery(p>0.05). Six months postsurgery, the intervertebral space height and Cobb angle of the two groups were significantly improved compared to presurgery (p<0.05), but there was no significant difference between the groups(p>0.05). There was no difference in clinical efficacy and incidence between the two groups(p>0.05). Conclusion: LLIF and OLIF may be both safe and effective minimally invasive surgical methods for the treatment of degenerative disc disease of the lumbar spine. [ABSTRACT FROM AUTHOR]

To evaluate the feasibility of an ultrasound-guided technique targeting the medial branches of the dorsal ramus of the spinal nerves (DRSN) by injecting a dye solution at the caudal aspect of the base of lumbar mammillary processes [i.e. the retromammillary (RM) space]. Feasibility, descriptive, anatomical study. Eleven canine cadavers. Using anatomical dissections, the relationship between the mammillary processes and the branches of the DRSN of the thoracolumbar and lumbar spine was studied in two cadavers. Subsequently, ultrasound-guided RM injections were administered in nine cadavers, randomly assigned to low volume (LV; 0.01 mL kg–1) of a dye solution at multiple points from L3 to L6 on one side, and high volume (HV; 0.4 mL kg–1) at a single L4 point on the contralateral side. Gross anatomical dissections were immediately performed after the injections. The RM injections were feasible if ultrasonographic landmarks were identifiable in at least 80% of cases, and 80% of LV injections showed medial branch staining. A one-sample binomial test was used for testing feasibility. The medial branches emerged shortly after the DRSN exited the intervertebral foramen and traveled towards the caudal aspect of the base of the mammillary process, which served as the target injection point. With LV, 36 out of 36 (100%) injected medial branches were stained, meeting the criteria of feasibility (p < 0.001). The median (range) number of stained medial branches per cadaver were 4 (4–4) and 2 (1–3), with LV and HV, respectively. Although no lateral branches were stained with LV, 1 (0–2) was stained with HV. Neither ventral branch staining nor epidural spread was noted in any cadaver. Ultrasound-guided RM injections are feasible and allow for selective staining of the medial branch of the DRSN in canine cadavers at the lumbar spine. [ABSTRACT FROM AUTHOR]

Introduction/Aims: Nusinersen intrathecal administration can be challenging in spinal muscular atrophy (SMA) adults. We aimed to determine if the ultrasound (US)‐assistance reduces the number of needle attempts and needle redirections needed for intrathecal drug administration and its impact on the procedure time, the incidence of adverse events (AEs), and patient satisfaction in these patients. Methods: Fifty‐eight patients aged 18 years and older scheduled for intrathecal nusinersen injection were enrolled and randomized (1:1 ratio) into Group 1 (nusinersen infusion with US‐assisted technique) or Group 2 (nusinersen infusion with landmark‐based technique). The number of attempts, number of redirections, periprocedural time, AEs and patient satisfaction were reported. Continuous variables were compared with the Student t‐test or Wilcoxon rank sum test. Categorical variables were evaluated with the Chi‐square test or Fisher's exact test in case of expected frequencies <5. The p‐values <.05 were considered statistically significant. Results: There were no statistical differences in the number of attempts, AEs, or patient satisfaction between the two groups. The number of needle redirections was significantly lower in the ultrasound group versus landmark‐based group (p <.05) in both the overall group of patients and in the subgroup with difficult spines. The periprocedural time was about 40 seconds longer in US‐group versus landmark‐based group (p <.05). Discussion: In SMA adults, US assistance reduces the number of needle redirections needed for intrathecal drug administration. These results suggest that the US assistance may be advantageous for nusinersen therapy to reduce the therapeutic burden of intrathecal infusion. [ABSTRACT FROM AUTHOR]

Edema in the subcutaneous soft tissue of the lumbar spine is a frequent incidental finding in spinal magnetic resonance imaging, however, its exact explanation is yet to be determined. The aim of this paper is to provide a systematic literature review on posterior lumbar subcutaneous edema (LSE). The present systematic literature search was carried out in October 2023 using electronic databases: PubMed, Cochrane library, and Scopus. The current evidence suggests that lumbar edema is correlated with clinical data such as weight and age, and potentially female sex. Moreover, LSE is related to several specific conditions, including both systemic and spinal disorders, such as heart or kidney disorders, as well as low back pain and degenerative and/or inflammatory diseases. It is important to be aware that there is an association between LSE and a variety systemic and spinal disorders. [ABSTRACT FROM AUTHOR]

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Study Design: Multicenter prospective study. Objective: Patients with central sensitization (CS) are reported to be at high risk of poor outcomes after spinal surgery. However, the influence of CS on surgical outcomes for lumbar disc herniation (LDH) remains unknown. This study aimed to examine the association between preoperative CS and surgical outcomes in LDH patients. Methods: A total of 100 consecutive patients with LDH (mean age 51.2) who underwent lumbar surgery were included in this study. The extent of CS was evaluated using the central sensitization inventory (CSI), a screening tool for CS-related symptoms. The patients completed the following CSI and clinical outcome assessments (COAs) preoperatively and 12 months postoperatively: the Japanese Orthopaedic Association (JOA) score for back pain, JOA back pain evaluation questionnaire (JOABPEQ), and Oswestry Disability Index (ODI). The association between preoperative CSI scores, and preoperative and postoperative COAs was analyzed, and the postoperative changes were statistically evaluated. Results: The preoperative CSI score significantly decreased 12 months postoperatively. Preoperative CSI scores showed a significant correlation with most COAs; however, a significant correlation was only identified in the social function and mental health domains of JOABPEC postoperatively. Higher preoperative CSI showed worse preoperative COAs; however, all COAs significantly improved regardless of CSI severity. There were no significant differences in any COAs among the CSI severity groups 12 months postoperatively. Conclusions: The results of this study showed that lumbar surgeries significantly improved the COAs regardless of preoperative severity of CS in patients with LDH. [ABSTRACT FROM AUTHOR]

Contemporary injury tolerance of the lumbar spine for under-body blast references axial compression and bending moments in a limited range. Since injuries often occur in a wider range of flexion and extension with increased moment contribution, this study expands a previously proposed combined loading injury criterion for the lumbar spine. Fifteen cadaveric lumbar spine failure tests with greater magnitudes of eccentric loading were incorporated into an existing injury criterion to augment its applicability and a combined loading injury risk model was proposed by means of survival analysis. A loglogistic distribution was the most representative of injury risk, resulting in optimized critical values of Fr,crit = 6011 N, and My,crit = 904 Nm for the proposed combined loading metric. The 50% probability of injury resulted in a combined loading metric value of 1, with 0.59 and 1.7 corresponding to 5 and 95% injury risk, respectively. The inclusion of eccentric loaded specimens resulted in an increased contribution of the bending moment relative to the previously investigated flexion/extension range (previous My,crit = 1155 Nm), with the contribution of the resultant sagittal force reduced by nearly 200 N (previous Fr,crit = 5824 N). The new critical values reflect an expanded flexion/extension range of applicability of the previously proposed combined loading injury criterion for the human lumbar spine during dynamic compression. [ABSTRACT FROM AUTHOR]

BACKGROUND: Finite element analysis is a commonly used mathematical modeling method to analyze the biomechanics of the lumbar spine. By constructing finite element models of the complex tissues such as muscles, blood vessels, and nerves in the lumbar region, mechanical analysis is performed to elucidate the pathogenesis of lumbar spine disorders and the mechanical mechanisms of treatment approaches. OBJECTIVE: To review the progress of finite element analysis in understanding the pathogenesis and treatment modalities of lumbar spine disorders, and to propose a new clinical workflow for the implementation of finite element analysis, aiming to provide a reference for future studies and promote the widespread utilization of finite element analysis in clinical diagnosis and treatment. METHODS: The PubMed database was searched using English keywords “finite element analysis, lumbar vertebra”, while the WanFang and China National Knowledge Infrastructure (CNKI) databases were searched using Chinese keywords “finite element analysis, lumbar vertebra”. A total of 73 articles were included for review. RESULTS AND CONCLUSION: (1) Lumbar spine degeneration in non-slipped patients typically originates from the posterior annulus fibrosus, while in patients with lumbar spine spondylolisthesis, degeneration starts from the lumbar facet joints due to abnormal mechanical mechanisms. (2) Restoring vertebral body height can prevent adjacent-level degeneration, and finite element analysis-measured vertebral compression strength can serve as an effective predictor of fracture risk, replacing bone density measurements. (3) In lumbar spine fusion surgery, selecting fusion devices of appropriate height and placing them transversely can prevent device subsidence. Increased intervertebral strain, circumferential stress, and intervertebral pressure in adjacent segments after fusion surgery may contribute to the occurrence of degenerative changes in neighboring segments. (4) Finite element analysis results suggest that preoperative planning for transforaminal endoscopic surgery should include considerations for osteotomy size to avoid excessive destruction of the articular process, and intraoperatively, preferential selection of a technique that traverses the superior articular process for foraminal dilatation. (5) In percutaneous kyphoplasty, bilateral pedicle screw augmentation should be performed, distributing bone cement on both sides of the pedicle. More advanced non-aluminum glass polyalkenoate cement materials should be selected. (6) Traction therapy should be personalized based on individual patient characteristics, including customized traction angles and forces, to achieve optimal therapeutic effects. (7) Manual therapy can induce relative displacement between the herniated intervertebral disc and the nerve root, thereby reducing compression. (8) The workflow involving CT/MR-AI Plus FEA-AI Plus Surgical robots can enable more precise diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Patients with symptomatic lumbar spinal stenosis (sLSS) are often limited in their walking range because of worsening symptoms, which is thought to induce changes in the gait pattern. The aim of this study was to determine whether changes in gait pattern and muscle activity in these patients are elicited by a walking stress and differ from asymptomatic controls. Twenty patients with sLSS and 19 asymptomatic controls performed a 30-minute walking stress. Gait was assessed using seven inertial sensors and sagittal joint range of motion (ROM) was calculated during different phases of gait. Muscle activation of the gluteus medius, erector spinae and multifidus muscles was measured by surface electromyography (EMG) and integrated EMGs (normalized to the maximum during gait) were calculated. Differences between groups and time points (beginning and end) were assessed using mixed factorial analysis of variance. Patients had less knee extension ROM in terminal stance, less knee flexion ROM in swing and less overall hip flexion/extension ROM than controls (p ≤ 0.03). There were no functionally relevant changes in these parameters during the walking stress. The integrated EMG was greater in all muscles in patients than in controls and increased in both groups during the walking stress in the paraspinal but not in the gluteus medius muscle. There was no interaction between group and time for any of the parameters. Differences in gait pattern and muscle activity between patients with sLSS and controls are generally present, but are not amplified by a walking stress. • Patients with lumbar spinal stenosis had less knee and hip range of motion. • Gluteus medius and paraspinal muscle activity was greater in patients. • Muscle activity increased in patients and controls during the walking stress. • Differences in gait pattern were not amplified by a walking stress. • In symptomatic spinal stenosis, a prolonged walking stress may not be necessary. [ABSTRACT FROM AUTHOR]

Background: This study aimed to evaluate the impact of iliac crest height on clinical and radiological outcomes following oblique lateral interbody fusion (OLIF) at the L4–5 level. Methods: Data of patients who underwent single-level OLIF at the L4–5 level for degenerative spinal stenosis were retrospectively analyzed. The patients were categorized into three groups based on their iliac crest height measured relative to the L4 and L5 pedicles. Categorical and quantitative analyses, including univariate and multivariate logistic regressions, were performed to identify subsidence predictors. Clinical outcomes, including visual analog scale scores for back and leg pain, were assessed over a minimum 2-year follow-up. Results: No significant differences in cage obliquity were observed across the iliac crest height groups (axial angles, p = 0.39; coronal angles, p = 0.79). However, subsidence was significantly more common in patients with higher iliac crest heights, particularly at crest level III, where the subsidence rate reached 43% (p = 0.01). Subsidence was predominantly associated with damage to the L5 endplate, which occurred in 83% of subsidence cases at crest level III. A cutoff value of 12 mm for iliac crest height, above which the risk of subsidence significantly increased, was identified (AUC = 0.688, p = 0.042). Conclusions: Iliac crest height is a critical factor for predicting subsidence following OLIF at the L4–5 level. Surgeons should consider alternative strategies and meticulous preoperative planning in patients with an iliac crest height ≥ 12 mm to reduce the risk of adverse outcomes. Further studies are needed to validate these findings and to explore their long-term implications. [ABSTRACT FROM AUTHOR]

Study Design. Retrospective cohort study. Objective. To investigate the impact of age on the incidence of vascular complications in patients undergoing anterior lumbar approach surgery. Background. Anterior approach lumbar spinal surgery may facilitate the use of intervertebral devices with larger endplate coverage and increased lordosis. Despite the advantages of this approach, risks related to vascular injury in older patients have been described in the literature. Patients and Methods. In total, 751 consecutive patients with degenerative spinal pathology who underwent stand-alone anterior lumbar interbody fusion (ALIF), ALIF combined with posterior fusion and/or instrumentation (360), total disc replacement, or hybrid procedures (ALIF and total disc replacement) were included. Data collected included general patient descriptive data, surgery details, intraoperative vascular injury, and postoperative vascular complications (deep vein thrombosis and/or pulmonary embolism). Rates of vascular complications were compared across age groups. In addition, the mean age of patients was compared between those with versus without vascular complications. Results. Overall mean age was 50.4 years (range: 20--83 yr). The mean estimated blood loss was 91.3 mL (range: 10--2800 mL). A total of 15 patients, 2.0%, had vascular complications. There were 10 cases (1.3%) of intraoperative injury to iliac arteries or iliolumbar veins (mean blood loss was 721 mL, and all were repaired intraoperatively). Postoperatively, 6 patients (0.8%) developed deep vein thrombosis and/or pulmonary embolism (one patient had both). With respect to age, there were no significant differences in rates of intraoperative, postoperative, or combined vascular complication rates across the age group (P > 0.38). In addition, there were no statistically significant differences in the mean ages of patients with versus those without vascular complications (P > 0.17). Conclusion. Overall incidence of vascular complications was 2.0%. No relationship between vascular complications and age was demonstrated. These data suggest that increased age may not necessarily be an absolute contraindication for anterior lumbar approach surgery. [ABSTRACT FROM AUTHOR]

Background/Objectives: Various surgical approaches have been proposed for treating adjacent segment disease (ASD) after lumbar fusion. However, studies using oblique lumbar interbody fusion (OLIF) to treat ASD are lacking. The current study assessed the postoperative outcomes of single-level OLIF for ASD, comparing the results with those for patients undergoing transforaminal lumbar interbody fusion (TLIF). Methods: Patients who underwent single-level OLIF or TLIF for lumbar ASD were retrospectively included. Clinical outcomes, that is, the results of assessments using the Euroqol 5-Dimension quality of life scale (EQ-5D), the Oswestry Disability Index, and the visual analog scale, were evaluated. Radiologic parameters, including disc height (DH), segmental lordosis (SL), segmental coronal angle (SCA), lumbar lordosis, and pelvic incidence–lumbar lordosis mismatch, were also assessed. Results: A total of 65 patients were enrolled: 32 in the OLIF group and 33 in the TLIF group. The median follow-up time was 24.0 months in both groups. The clinical outcomes and radiologic parameters significantly improved in both groups postoperatively. According to intergroup comparisons, the OLIF group had significantly less blood loss and superior improvement in radiologic parameters (DH, SL, and SCA) whereas the TLIF group had significantly shorter operation times. For the OLIF patients who did not undergo posterior decompression, the operation time was similar to that of the TLIF group, but the surgical blood loss and length of hospital stay were significantly reduced compared with the TLIF group. Conclusions: Compared with TLIF, OLIF provides similar clinical outcomes, leads to less surgical blood loss, and has superior radiologic parameters; however, the operation time is significantly longer. OLIF without posterior decompression may be a superior option to TLIF for certain patients. [ABSTRACT FROM AUTHOR]

Objective: Spine fixation surgery affects the biomechanical environment in the sacroiliac joint (SIJ), which may lead to the SIJ pain or degeneration after surgery. The purpose of this study is to determine the impact of the number and position of fixed segments on the SIJs and provide references for surgeons to plan fixation levels and enhance surgical outcomes. Methods: The intact lumbar‐pelvis finite element (FE) models and 11 fixation FE models with different number and position of fixed segments were developed based on CT images. A 400N follower load and 10° range of motion (ROM) of the spine were applied to the superior endplate of L1 to simulate the flexion, extension, bending and torsion motion after surgery. The peak stress on the SIJs, lumbar intervertebral discs, screws and rods were calculated to evaluate the biomechanical effects of fixation procedures. Results: With the lowermost instrumented vertebra (LIV) of L5 or S1, the peak stress on SIJs increased with the number of fixed segments increasing. The flexion motion led to the greater von Mises stress on SIJ compared with other load conditions. Compared with the intact model, peak stress on all fixed intervertebral discs was reduced in the models with less than three fixed segments, and it increased in the models with more than three fixed segments. The stress on the SIJ was extremely high in the models with all segments from L1 to L5 fixed, including L1‐L5, L1‐S1 and L1‐S2 fixation models. The stress on the segment adjacent to the fixed segments was significant higher compared to that in the intact model. The peak stress on rods and screws also increased with the number of fixed segments increasing in the flexion, extension and bending motion, and the bending and flexion motions led to the greater von Mises stress on SIJs. Conclusion: Short‐term fixation (≤2 segments) did not increase the stress on the SIJs significantly, while long‐term segment fixation (≥4 segments) led to greater stress on the SIJs especially when all the L1‐L5 segments were fixed. Unfixed lumbar segments compensated the ROM loss of the fixed segments, and the preservation of lumbar spine mobility would reduce the risks of SIJ degeneration. [ABSTRACT FROM AUTHOR]

The golf swing has been associated with mechanical injury risk factors at many joints. One swing, the Minimalist Golf Swing, was hypothesised to reduce lumbar spine, lead hip, and lead knee ranges of motion and peak net joint moments, while affecting swing performance, compared to golfers' existing swings. Existing and MGS swings of 15 golfers with handicaps ranging from +2 to −20 were compared. During MGS downswing, golfers had 18.3% less lumbar spine transverse plane ROM, 40.7 and 41.8% less lead hip sagittal and frontal plane ROM, and 39.2% less lead knee sagittal plane ROM. MGS reduced lead hip extensor, abductor, and internal rotator moments by 17.8, 19.7 and 43%, while lead knee extensor, abductor, adductor and external rotator moments were reduced by 24.1, 26.6, 37 and 68.8% respectively. With MGS, club approach was 2° shallower, path 4° more in-to-out and speed 2 m/s slower. MGS reduced certain joint ROM and moments that are linked to injury risk factors, while influencing club impact factors with varying effect. Most golf injuries are from overuse, so reduced loads per cycle with MGS may extend the healthy life of joints, and permit golfers to play injury-free for more years. [ABSTRACT FROM AUTHOR]

As few anaesthetists provide lumbar erector spinae block for disc surgery, there is a need to provide training to enable a randomised controlled trial investigating analgesia after painful spinal surgery (NIHR153170). The primary objective of the study was to develop and measure the construct validity of a checklist for assessment of skills in performing lumbar and thoracic erector spinae fascial plane injection using soft-embalmed Thiel cadavers. Twenty-four UK consultant regional anaesthetists completed two iterations of a Delphi questionnaire. The final checklist consisted of 11 steps conducive to best practice. Thereafter, we validated the checklist by comparing the performance of 12 experts with 12 novices, each performing lumbar and thoracic erector spinae plane injections or fascia iliaca, serrato-pectoral (PEC II) and serratus injections, randomly allocated to the left and right sides of six soft-embalmed Thiel cadavers. Six expert, trained raters blinded to operator and site of block examined 120 videos each. The mean (95% confidence interval) internal consistency of the 11-item checklist for erector spinae plane injection was 0.72 (0.63–0.79) and interclass correlation was 0.88 (0.82–0.93). The checklist showed construct validity for lumbar and thoracic erector spinae injection, experts vs novices {median (interquartile range [range]) 8.0 (7.0–10.0 [1–11]) vs 7.0 (5.0–9.0 [4–11]), difference 1.5 (1.0–2.5), P <0.001}. Global rating scales showed construct validity for lumbar and thoracic erector spinae injection, 28.0 (24.0–31.0 [7–35]) vs 21.0 (17.0–24.0 [7–35]), difference 7.5 (6.0–8.5), P <0.001. The most difficult items to perform were identifying the needle tip before advancing and always visualising the needle tip. Instrument handling and flow of procedure were the areas of greatest difficulty on the global rating scale (GRS). Checklists and GRS scores correlated. There was homogeneity of regression slopes controlling for status, type of injection, and rater. Generalisability analysis showed a high reliability using the checklist and GRS for all fascial plane blocks (Rho [ρ2] 0.93–0.96: Phi [ϕ] 0.84–0.87). An 11-point checklist developed through a modified Delphi process to provide best practice guidance for fascial plane injection showed construct validity in performing lumbar and thoracic erector spinae fascial plane injection in soft-embalmed Thiel cadavers. [ABSTRACT FROM AUTHOR]

Osteoporosis is under-diagnosed while detectable by measuring bone mineral density (BMD) using quantitative computer tomography (QCT). Opportunistic screening for low BMD has previously been suggested using lumbar QCT. However, thoracic QCT also possesses this potential to develop upper and lower cut-off values for low thoracic BMD, corresponding to the current cut-offs for lumbar BMD. In participants referred with chest pain, lumbar and thoracic BMD were measured using non-contrast lumbar- and cardiac CT scans. Lumbar BMD cut-off values for very low (< 80 mg/cm3), low (80–120 mg/cm3), and normal BMD (> 120 mg/cm3) were used to assess the corresponding thoracic values. A linear regression enabled identification of new diagnostic thoracic BMD cut-off values. The 177 participants (mean age 61 [range 31–74] years, 51% women) had a lumbar BMD of 121.6 mg/cm3 (95% CI 115.9–127.3) and a thoracic BMD of 137.0 mg/cm3 (95% CI: 131.5–142.5), p < 0.001. Categorization of lumbar BMD revealed 14%, 35%, and 45% in each BMD category. When applied for the thoracic BMD measurements, 25% of participants were reclassified into a lower group. Linear regression predicted a relationship of Thoracic BMD = 0.85 * Lumbar BMD + 33.5, yielding adjusted thoracic cut-off values of < 102 and > 136 mg/cm3. Significant differences in BMD between lumbar and thoracic regions were found, but a linear relationship enabled the development of thoracic upper and lower cut-off values for low BMD in the thoracic spine. As Thoracic CT scans are frequent, these findings will strengthen the utilization of CT images for opportunistic detection of osteoporosis. [ABSTRACT FROM AUTHOR]

The complex biomechanics of the lumbar spine and its associated structures have been studied using finite element (FE) analysis. Several FE studies used simplified approaches to model the spinal ligaments, assuming that the significant effect of spinal ligaments is on the ranges of motion (ROM) rather than stress–strain distributions on the vertebral body. A comparison of different ligament configurations (tension-only and tension & compression) and their effects on ROM and stress–strain distribution is necessary to verify the above assumption. In this study, an FE model of the L1-L5 lumbar spine was developed and analyzed for three different cases of physiological movements (flexion, extension, and lateral bending). It was found that the spinal flexibility was almost equally constrained by both ligament configurations. The variation in ROM observed for tension-only ligament and tension & compression ligament model ranged between 0.5∘ and 4∘ under all loading cases. However, no considerable changes were observed in stress–strain distributions. The findings of this study indicate that assuming the impact of ligaments only in restricting the ROM is reliable and two-node tension-only or tension & compression elements are useful to model the spinal ligaments in FE studies. [ABSTRACT FROM AUTHOR]

BACKGROUND: Osteoporosis is a bone disease caused by decrease in bone mineral density (BMD). Quantitative computed tomography (QCT) has proven to be an effective tool to measure the BMD of the lumbar spine. Therefore, the objective of the study is to investigate the impact of intravenous contrast media (CM) on BMD of lumbar spine measured by QCT. METHODS: This is a prospective study and included a total of 141 patients (females: 71, males: 70) referred for contrast enhanced computed tomography (CECT) abdomen. First, the plain scan of abdomen was done. Contrast media was injected intravenously followed by acquisition of arterial and portovenous phase (PV) of abdomen. Plain, arterial and PV phases axial CT images were loaded on Philips BMD analysis application. A circular region of interest (ROI) measuring 30-40 mm2 was placed at all five lumbar vertebrae (L1-L5) and value of BMD was obtained in mg/cm3 RESULTS: Paired t-test was used to compare BMD in plain, arterial and PV phase. There was significant difference (p <0.05) in BMD (L1-L5) between plain (110.86±36.61 mg/cm3 ), arterial (117.04±37.95 mg/cm3 ) and PV phase (127.52±40.9 mg/cm3 ). The study also noted significant difference between males and females in BMD of lumbar spine (L1- L5) for plain and CECT abdomen (p <0.05). CONCLUSION: The BMD was highest for PV phase of the CECT abdomen. Therefore, the study concludes that BMD values are highly influenced by intravenous contrast media injections. [ABSTRACT FROM AUTHOR]

Background: Pediatric lumbar spondylolysis, a stress fracture of the lumbar spine, frequently affects young athletes, and nonoperative treatment is often the first choice of management. Because the union rate in lumbar spondylolysis is lower than that in general fatigue fractures, identifying risk factors for nonunion is essential for optimizing treatment. Purpose: To determine the risk factors for nonunion after nonoperative treatment of acute pediatric lumbar spondylolysis through multivariate analysis. Study Design: Case-control study; Level of evidence, 3. Methods: We analyzed 574 pediatric patients (mean age, 14.3 ± 1.9 years) with lumbar spondylolysis who underwent nonoperative treatment between 2015 and 2022. Nonoperative treatment included the elimination of sports activities, bracing, and weekly athletic rehabilitation, with follow-up computed tomography. Patient data, lesion characteristics, sports history, presence of spina bifida occulta at the lamina with a lesion or at the lumbosacral spine excluding the lesion level, and lumbosacral parameters were examined. Differences between the union and nonunion groups were investigated using multivariate analysis to determine the risk factors for nonunion. Results: Of the 574 patients, 81.7% achieved bone union. Multivariate analysis revealed that an L5 lesion and the progression of the main and contralateral lesion stages were significant independent risk factors for nonunion. An L5 lesion had a lower union rate than non-L5 lesions. As the main lesion progressed, the likelihood of nonunion increased significantly, and the progression of the contralateral lesion also showed a similar trend. Spina bifida occulta and lumbosacral parameters were not significant predictors of nonunion in this study. Conclusion: We identified the L5 lesion level and the progression of the main and contralateral lesion stages as independent risk factors for nonunion in pediatric lumbar spondylolysis after nonoperative treatment. These findings aid in treatment decision-making. When bone union cannot be expected with nonoperative treatment, symptomatic treatment is required without prolonged external fixation and rest, and without aiming for bone union. Individualized treatment plans are crucial based on identified risk factors. [ABSTRACT FROM AUTHOR]

Introduction: Revision lumbar fusion is most commonly due to nonunion, adjacent segment disease (ASD), or recurrent stenosis, but it is unclear if diagnosis affects patient outcomes. The primary aim of this study was to assess whether patients achieved the patient acceptable symptom state (PASS) or minimal clinically important difference (MCID) after revision lumbar fusion and assess whether this was influenced by the indication for revision. Methods: We retrospectively identified all 1–3 level revision lumbar fusions at a single institution. Oswestry Disability Index (ODI) was collected at preoperative, three-month postoperative, and one-year postoperative time points. The MCID was calculated using a distribution-based method at each postoperative time point. PASS was set at the threshold of ≤ 22. Results: We identified 197 patients: 56% with ASD, 28% with recurrent stenosis, and 15% with pseudarthrosis. The MCID for ODI was 10.05 and 10.23 at three months and one year, respectively. In total, 61% of patients with ASD, 52% of patients with nonunion, and 65% of patients with recurrent stenosis achieved our cohort-specific MCID at one year postoperatively with ASD (p = 0.78). At one year postoperatively, 33.8% of ASD patients, 47.8% of nonunion patients, and 37% of patients with recurrent stenosis achieved PASS without any difference between indication (p = 0.47). Conclusions: The majority of patients undergoing revision spine fusion experience significant postoperative improvements regardless of the indication for revision. However, a large proportion of these patients do not achieve the patient acceptable symptom state. While revision spine surgery may offer substantial benefits, these results underscore the need to manage patient expectations. [ABSTRACT FROM AUTHOR]

Purpose: To analyze of the results of spine surgical treatment of athletes with lumbar degenerative disease and development of a surgical strategy based on the preoperative symptoms and radiological changes in the lumbar spine. Methods: For 114 athletes with lumbar degenerative disease were included in the present study. Four independent groups were studied: (1) microsurgical/endoscopic discectomy (n = 35); (2) PRP therapy in facet joints (n = 41); (3) total disc replacement (n = 11); (4) lumbar interbody fusion (n = 27). We evaluated postoperative clinical outcomes and preoperative radiological results. The average postoperative follow-up was 5 (3;6), 3.5 (3;5), 3 (2;4) and 4 (3;5) years, respectively. The analysis included an assessment of clinical outcomes (initial clinical symptoms, chronic pain syndrome level according to the VAS, quality of life according to the SF-36 questionnaire, degree of tolerance to physical activity according to the subjective Borg Rating of Perceived Exertion Scale) and radiological data (Dynamic Slip, Dynamic Segmental Angle, degenerative changes in the facet joint according to the Fujiwara classification and disc according to the Pfirrmann classification; changes in the diffusion coefficient using diffusion-weighted MRI). Results: The median and 25–75% quartiles timing of return to sports were 12.6 (10.2;14.1), 2.8 (2.4;3.7), 9 (6;12), and 14 (9;17) weeks, respectively. We examined the type of surgical treatment utilized, as well as the preoperative clinical symptoms, severity of degenerative changes in the intervertebral disc and facet joint, the timing of return to sports, the level of pain syndrome, the quality of life according to SF-36, and the degree of tolerance to physical activity. We then developed a surgical strategy based on individual preoperative neurological function and lumbar morphological changes. Conclusions: In this retrospective study, we report clinical results of four treatment options of lumbar spine degenerative disease in athletes. The use of developed patient selection criteria for the analyzed surgical techniques is aimed at minimizing return-to-play times. [ABSTRACT FROM AUTHOR]

Introduction: The disco-vertebral junction (DVJ) of the lumbar spine contains thin structures with short T2 values, including the cartilaginous endplate (CEP) sandwiched between the bony vertebral endplate (VEP) and the nucleus pulposus (NP). We previously demonstrated that ultrashort-echo-time (UTE) MRI, compared to conventional MRI, is able to depict the tissues at the DVJ with improved contrast. In this study, we sought to further optimize UTE MRI by characterizing the contrast-to-noise ratio (CNR) of these tissues when either single echo or echo subtraction images are used and with varying echo times (TEs). Methods: In four cadaveric lumbar spines, we acquired 3D Cones (a UTE sequence) images at varying TEs from 0.032 ms to 16 ms. Additionally, spin echo T1- and T2-weighted images were acquired. The CNRs of CEP-NP and CEP-VEP were measured in all source images and 3D Cones echo subtraction images. Results: In the spin echo images, it was challenging to distinguish the CEP from the VEP, as both had low signal intensity. However, the 3D Cones source images at the shortest TE of 0.032 ms provided an excellent contrast between the CEP and the VEP. As the TE increased, the contrast decreased in the source images. In contrast, the 3D Cones echo subtraction images showed increasing CNR values as the second TE increased, reaching statistical significance when the second TE was above 10 ms (p < 0.05). Conclusions: Our study highlights the feasibility of incorporating UTE MRI for the evaluation of the DVJ and its advantages over conventional spin echo sequences for improving the contrast between the CEP and adjacent tissues. Additionally, modulation of the contrast for the target tissues can be achieved using either source images or subtraction images, as well as by varying the echo times. [ABSTRACT FROM AUTHOR]

Introduction: lumbar foraminal stenosis refers to the constriction of the lateral canal through which the nerve root exits the spinal canal in the lumbar spine. It occurs in 8-11% of patients aged over 40 years. Failure to detect and alleviate foraminal constriction can contribute to up to 60% of instances of unsuccessful lumbar surgery. This study aimed to develop an index to assess the extent of foraminal narrowing, thereby aiding decisions regarding direct or indirect foraminal decompression. Material and methods: a cross-sectional study was conducted, involving 49 patients, wherein measurements of all five lumbar foramina were taken using X-rays and simple magnetic resonance imaging. These measurements primarily focused on the foraminal width and the lower endplate, which were then correlated to establish a foraminal width/lower endplate index. Results: the foraminal width/lower endplate index < 10% yielded an odds ratio (OR) of 3.07 on lateral radiography, 3.59 on flexion radiography, and 4.01 on extension radiography. In MRI, an OR of 0.195 was found for the left foramina, while an OR of 3.07 was observed for the right foramina. Conclusion: this study paves the way for further exploration of preoperative and postoperative clinical outcomes across various surgical decompression methods guided by the FW/LE index. To enhance decision making, it is recommended to conduct research comparing pre- and postoperative clinical findings in individual patients, considering their FW/LE index measurements. [ABSTRACT FROM AUTHOR]

Injury mechanisms of the lumbar spine under dynamic loading are dependent on spine curvature and anatomical variation. Impact simulation with finite element (FE) models can assist the reconstruction and prediction of injuries. The objective of this study was to determine which level of individualization of a baseline FE lumbar spine model is necessary to replicate experimental responses and fracture locations in a dynamic experiment. Experimental X-rays from 26 dynamic drop tower tests were used to create three configurations of a lumbar spine model (T12 to L5): baseline, with aligned vertebrae (positioned), and with aligned and morphed vertebrae (morphed). Each model was simulated with the corresponding loading and boundary conditions from dynamic lumbar spine experiments. Force, moment, and kinematic responses were compared to the experimental data. Cosine similarity was computed to assess how well simulation responses match the experimental data. The pressure distribution within the vertebrae was used to compare fracture risk and fracture location between the different models. The positioned models replicated the injured spinal level and the fracture patterns quite well, though the morphed models provided slightly more accuracy. However, for impact reconstruction or injury prediction, the authors recommend pure positioning for whole-body models, as the gain in accuracy was relatively small, while the morphing modifications of the model require considerably higher efforts. These results improve the understanding of the application of human body models to investigate lumbar injury mechanisms with FE models. [ABSTRACT FROM AUTHOR]

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 PFGL1-4 for the upper three lumbar disk levels, as PFGL4-S1 for the lower two lumbar disc levels, and as PFGL1-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/m2. 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 PFGL1-4, PFGL1-S1, and VBQ at baseline (P < 0.05) that increased over time (P < 0.005). In the adjusted multivariable analysis, PFGL1-4 (β = -0.0195; P = 0.021), PFGL4-S1 (β = -0.0310; P = 0.007), and PFGL1-S1 (β = -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. [ABSTRACT FROM AUTHOR]

Objectives: To determine the characteristics of lumbar foraminal stenosis (LFS) on magnetic resonance (MR) images and their association with back pain and radiating leg pain in a population-based sample of Chinese subjects. Methods: This study was an extension of the Hangzhou Lumbar Spine Study, a cross-sectional study focusing on back pain and lumbar spine MR imaging findings. Questionnaire data, including demographics, lifestyle, occupational exposures, back pain and radiating leg pain were included. On lumbar spine MR images, disc degeneration was assessed using Pfirrmann grade and Modic changes were evaluated. Using Lee's scale, the L3-S1 intervertebral foramina were evaluated, with grade 2–3 representing substantial LFS and grade 0–1 no LFS. Characteristics of LFS were noted, and associations of LFS with back pain and radiating leg pain were examined. Results: Among the 644 study subjects, 141 (21.9%) had at least one LFS, and its occurrence was associated with greater age (OR = 1.93 for each 10 years, p < 0.001). Substantial LFS was associated with the presence of back pain (OR = 1.92, p = 0.001) and the intensity of the worst back pain (Coef = 8.30, p < 0.001) over the past 12 months, and disabling back pain during their lifetime (OR = 2.25, p < 0.001). Substantial LFS was also associated with leg pain (OR = 14.27, p < 0.001), with a sensitivity of 75.7% for the presence of radiating leg pain and a specificity of 81.4%. Conclusion: Substantial LFS on MR images was a common age-related degenerative phenotype in adults, and appears to be an independent risk factor for back pain and leg pain. [ABSTRACT FROM AUTHOR]

The association between low back pain and lumbar spine local dynamic stability (LDS) appears to be modulated by if and how someone catastrophizes about pain, suggesting that the cognitive perceptions of pain may influence an individual's ability to control lumbar spine motion. Previous work also demonstrates that directing cognitive resources and attentional focus can influence movement performance. Therefore, we aimed to examine whether distracting attentional focus would influence lumbar spine LDS during repetitive flexion-extension movements. Sixteen participants performed repetitive spine flexion-extension movements under two baseline conditions (pre- and post-), and while attentional focus was distracted by either an external sensory stimulus or a cognitive-motor dual-task, both targeted at the hands. Lumbar spine LDS was examined over 30 continuous movement repetitions using maximum Lyapunov exponents. In comparison to both Baseline and Post-Baseline trials, the perceived mental workload was significantly elevated during the cognitive-motor dual-task trial but not the external sensory stimulus trial. The only statistically significant effect on LDS occurred in the Post-Baseline trial, where LDS was higher than in the cognitive-motor dual-task. In combination with previous work, these findings suggest that distracting attentional focus during repetitive lumbar spine flexion-extension movements does not have a negative influence on lumbar spine LDS. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective Upright MRI Study. Objectives: Determine the relationship between lumbar disc herniation and presence of the nerve root sedimentation sign on upright kinematic MRI patients. Methods: T2-weighted axial upright kMRI images of 100 patients with the presence of disc herniation in at least 1 lumbar disc between L1/L2 and L5/S1 were obtained. Sedimentation sign, spinal canal anterior-posterior (AP) diameter, disc height, disc herniation size, type of herniation, and zone of herniation were evaluated. A positive sedimentation sign was defined as having either the majority of nerve roots running ventrally or centrally in the canal or conglomeration of the nerve roots at the mid-disc level. Herniation types were defined as either no herniation, disc bulge, protrusion, extrusion, or sequestration. Zones of herniation were categorized as either central, lateral, or far lateral. Results: The kappa value of intra-observer reliability was.915. The kappa value of disc levels with a negative sedimentation sign were seen more frequently (n = 326, 65.2%) than those with a positive sedimentation sign (n = 174, 34.8%). The spinal canal AP diameter was significantly decreased at the L3/L4 and L4/L5 level in patients with a positive sedimentation sign. Discs with a positive sedimentation sign had a larger average size of disc herniation compared to those with a negative sign at all levels. A relationship between positivity of the sedimentation sign and disc herniation type was significant at L2/L3, L3/L4, and L4/L5. Conclusions: Patients with a positive sedimentation sign were seen to have larger disc herniations and more severely degenerated discs. [ABSTRACT FROM AUTHOR]

Study Design: Cross-sectional radioanatomic study. Objective: To determine the feasibility of performing an anterior column realignment (ACR) using an anterior-to-psoas (ATP) approach at L1-L5. Methods: Axial magnetic resonance images (MRI) of the L1-L5 disc levels obtained at a single institution were obtained and analyzed. The feasibility of performing an ACR was assessed using a combination of the size of the left oblique corridor (OC), the psoas morphology using the modified Moro classification, and the anterior disc edge to great vessel distance. Results: Three hundred MRI studies obtained from 300 patients were included. All patients had a measurable left OC at the L1-L4 levels. Twenty patients (6.7%) had no measurable OC at the L4-L5 level. According to the modified Moro's classification, a high-rising psoas was seen in 4 patients (1.3%) at the L3-L4 level and 57 patients (19.0%) at the L4-L5 level. An ALL release was considered high risk due to no measurable space between the anterior disc edge and the great vessels in 54 patients (18.0%) at the L1-L2 level, 39 patients (13.0%) at the L2-L3 level, 119 patients (39.7%) at the L3-L4 level, and 226 patients (75.3%) at the L4-L5 level. Conclusion: ACR using an ATP approach is the most radioanatomically feasible at L2-L3. The L4-L5 level has the highest risk with regards to both the ATP approach and the ALL release for an ACR due to high rates of unmeasurable left OC and space between the anterior disc edge and the great vessels. [ABSTRACT FROM AUTHOR]

Introduction: Lumbar foraminal stenosis (LFS) occurs primarily due to degenerative changes in older adults, affecting the spinal foramina and leading to nerve compression. Characterized by pain, numbness, and muscle weakness, LFS arises from structural changes in discs, joints, and ligaments, further complicated by factors like inflammation and spondylolisthesis. Diagnosis combines patient history, physical examination, and imaging, while management ranges from conservative treatment to surgical intervention, underscoring the need for a tailored approach. Materials and Methods: This multicenter study, conducted over six years at a tertiary hospital, analyzed the volumetric dimensions of lumbar foramina and their correlation with nerve structures in 500 patients without lumbar pathology. Utilizing high-resolution MRI with a standardized imaging protocol, eight experienced researchers independently reviewed the images for accurate measurements. The study emphasized quality control through the calibration of measurement tools, double data entry, validation checks, and comprehensive training for researchers. To ensure reliability, interobserver and intraobserver agreements were analyzed, with statistical significance determined by kappa statistics and the Student's t-test. Efforts to minimize bias included blinding observers to patient information and employing broad inclusion criteria to mitigate referral and selection biases. The methodology and findings aim to enhance the understanding of normal lumbar foramina anatomy and its implications for diagnosing and treating lumbar conditions. Results: The study's volumetric analysis of lumbar foramina in 500 patients showed a progressive increase in foraminal volume from the L1/L2 to the L5/S1 levels, with significant enlargement at L5/S1 indicating anatomical and biomechanical complexity in the lumbar spine. Lateral asymmetry suggested further exploration. High interobserver and intraobserver agreement levels (ICC values of 0.91 and 0.95, respectively) demonstrated the reliability and reproducibility of measurements. The patient cohort comprised 58% males and 42% females, highlighting a balanced gender distribution. These findings underscore the importance of understanding foraminal volume variations for lumbar spinal health and pathology. Conclusion: Our study significantly advances spinal research by quantifying lumbar foraminal volumes, revealing a clear increase from the L1/L2 to the L5/S1 levels, indicative of the spine's adaptation to biomechanical stresses. This provides clinicians with a precise tool to differentiate between pathological narrowing and normal variations, enhancing the detection and treatment of lumbar foraminal stenosis. Despite limitations like its cross-sectional design, the strong agreement in measurements underscores the method's reliability, encouraging future research to further explore these findings' clinical implications. [ABSTRACT FROM AUTHOR]

BACKGROUND: Lumbosacral transitional vertebrae (LSTVs) are congenital anomalies that occur in the spinal segments of L5-S1. These vertebrae result from sacralization of the lowermost lumbar segment or lumbarization of the uppermost sacral segment. When the lowest lumbar vertebra fuses or forms a false joint with the sacrum (pseudoarticulation), it can cause pain and manifest clinically as Bertolotti syndrome. OBSERVATIONS: A 36-year-old female presented with severe right-sided low-back pain. Computed tomography was unremarkable except for a right-sided Castellvi type IIA LSTV. The pain proved refractory to physical therapy and lumbar epidural spinal injections, but targeted steroid and bupivacaine injection of the pseudoarticulation led to 2 weeks of complete pain relief. She subsequently underwent minimally invasive resection of the pseudoarticulation, with immediate improvement in her low-back pain. The patient continued to be pain free at the 3-year follow-up. LESSONS: LSTVs alter the biomechanics of the lumbosacral spine, which can lead to medically refractory mechanical pain requiring surgical intervention. Select patients with Bertolotti syndrome can benefit from operative management, including resection, fusion, or decompression of the pathologic joint.

Laparoscopic anterior lumbar interbody fusion (L-ALIF), which employs laparoscopic cameras to facilitate a less invasive approach, originally gained traction during the 1990s but has subsequently fallen out of favor. As the envelope for endoscopic approaches continues to be pushed, a recurrence of interest in laparoscopic and/or endoscopic anterior approaches seems possible. Therefore, evaluating the current evidence base in regard to this approach is of much clinical relevance. To this end, a systematic literature search was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using the following keywords: (laparoscopic OR endoscopic) AND (anterior AND lumbar). Out of the 441 articles retrieved, 22 were selected for quantitative analysis. The primary outcome of interest was the radiographic fusion rate. The secondary outcome was the incidence of perioperative complications. Meta-analysis was performed using RStudios metafor package. Of the 1,079 included patients (mean age, 41.8±2.9 years), 481 were males (44.6%). The most common indication for L-ALIF surgery was degenerative disk disease (reported by 18 studies, 81.8%). The mean follow-up duration was 18.8±11.2 months (range, 6-43 months). The pooled fusion rate was 78.9% (95% confidence interval [CI], 68.9-90.4). Complications occurred in 19.2% (95% CI, 13.4-27.4) of L-ALIF cases. Additionally, 7.2% (95% CI, 4.6-11.4) of patients required conversion from L-ALIF to open surgery. Although L-ALIF does not appear to be supported by studies available in the literature, it is important to consider the context from which these results have been obtained. Even if these results are taken at face value, the failure of endoscopy to have a role in the ALIF approach does not mean that it should not be incorporated in posterior approaches.

Objective The cortical bone trajectory (CBT) technology is an effective substitute for traditional pedicle screw (PS) technology. However, there is still controversy about the CBT screw technology placement strategy. The objective of this study was to simulate cortical screw placement with the help of three‐dimensional (3D) software, to discuss the differences in screws between genders and vertebral segments, and to explore a safer and more efficient strategy for cortical screw placement. Methods Mimics Medical software was used to construct a 3D model of the lumbar spine, and the placement of CBT screws was simulated. The volume of each vertebral body from L1 to L5, the pedicle isthmus height (IH), the pedicle isthmus width (IW), and the sagittal vertebral distance (SAVD) were measured. The transverse distance (TD) and the longitudinal distance (LD) between the ideal starting point (SP) and the clinical SP (the intersection Q of the midline of the superior articular process and the horizontal line 1 mm below the transverse process) were measured. The cephalad angle (CA), lateral angle (LA), maximum screw diameter (MSD), maximum screw length (MSL) of each trajectory of the L1 to L5 vertebral bodies, and the percentage of the screw insertion depth (PSID) into the vertebral body were measured. Data were statistically analyzed using Student's t‐test, one‐way analysis of variance (ANOVA), and Tukey's test. Results Vertebral anatomical parameters and CBT screw parameters differed between males and females. Female patients had lower IH, IW, SAVD, CA, LA, MSD, and MSL than males. IH was greatest in L1 (male, 17.81 mm; female, 16.12 mm) and the smallest in L5 (male, 14.11 mm; female, 13.05 mm). IW was smallest in L1 (male, 8.89 mm; female, 7.37 mm) and greatest in L5 (male, 16.59 mm; female, 15.43 mm). The MSD of males was smallest in L1 (6.05 mm) and greatest in L3 (7.06 mm); the MSD of females was smallest in L1 (5.13 mm) and greatest in L4 (6.64 mm). MSL was greatest at L3 (male, 33.63 mm; female, 32.28 mm) and smallest at L5 (male, 31.25 mm; female, 29.97 mm). CA was smallest in L1 (male, 22.80°; female, 21.92°) and greatest in L3 (male, 25.29°; female, 24.33°). LA was smallest in L1 (male 12.37°, female 11.27°) and greatest in L5 (male 13.56°, female 12.96°). Among the males, TD was smallest at L1 (−0.51 mm) and greatest at L5 (1.37 mm), while LD was greatest at L2 (3.46 mm) and smallest at L5 (2.40 mm). In females, TD was greatest at L1 (0.12 mm) and smallest at L3 (−0.51 mm), while LD was greatest at L1 (3.69 mm) and smallest at L5 (2.08 mm). In the overall sample, the incidence of SAVD and PSID gradually increased from L1 to L5. Conclusion The optimal screw placement strategy for CBT screws varies significantly according to sex and vertebral body segments, particularly noting the specificity of screw placement at L5. The optimal screw placement strategy should be selected based on the patient's sex and segment characteristics before surgery to maximize the safety and accuracy of CBT screw placement.

Objective: In this study, we aimed to compare the accuracies and efficiencies of dual-layer spectral computed tomography (CT), quantitative CT (QCT), and dual-energy X-ray absorptiometry (DXA) in diagnosing osteoporosis. Methods: From January to October, 2023, 30 outpatients, including 15 males (age (56.6±8.31) years old) and 15 females (age (65.13±7.16) years old), at the spine surgery department of Beijing Jishuitan Hospital were retrospectively analyzed. All patients underwent bilayer spectral CT, QCT, and DXA of the lumbar spine. Additionally, bone mineral density (BMD) values for the L1~L3 vertebral bodies and areal BMD values were measured using DXA. Based on the diagnostic criteria for osteoporosis using lumbar spine QCT and DXA, the study participants were divided into three groups: normal bone mass, abnormal/low bone mass, and osteoporosis groups. Accuracies of dual-energy spectral CT, QCT, and DXA for BMD measurements to diagnose osteoporosis were compared using Fisher’s exact test. Moreover, sensitivity and specificity of dual-energy spectral CT to measure volumetric BMD values for osteoporosis diagnosis were calculated using receiver operating characteristic curves. Results: A strong correlation was observed among the average BMD values for L1~L3 measured using all three methods (0.751~0.971). Accuracies of osteoporosis diagnosis using dual-energy spectral CT, QCT, and DXA were 66.7% (10/15), 53.3% (8/15), and 40% (6/15), respectively, in males and 93.3% (14/15), 86.7% (13/15), and 60% (9/15), respectively, in females, with statistically significant differences. Dual-energy spectral CT showed area under the curve values of 0.995 (sensitivity: 88.9%; specificity: 90.5%) and 0.784 (sensitivity: 60%; specificity: 93.3%) with QCT and DXA as reference standards, respectively, for osteoporosis diagnosis. Conclusion: Volumetric BMD values measured using dual-energy spectral CT were comparable to those measured using QCT for osteoporosis diagnosis, and both outperformed DXA in terms of diagnostic efficiency.

Abstract Background To establish a three-dimensional finite element model of the lumbar spine and investigate the impact of different fixation techniques on the biomechanical characteristics of oblique lumbar interbody fusion (OLIF). Methods The study aimed to establish and validate a comprehensive three-dimensional model of the lower lumbar spine (L3-S1) using the finite element method. L4-L5 was selected as the surgical segment, and four distinct OLIF surgical models were constructed: Stand-alone (SA), unilateral cortical bone trajectory screw (UCBT), bilateral cortical bone trajectory screw (BCBT), and bilateral pedicle screw (BPS). The models were underwent a pure moment of 10N·m to simulate lumbar extension, flexion, left bending, right bending, left and right rotation movements. Subsequently, the range of motion (ROM), cage stress, and fixation stress were calculated. Results In the L3-L5 segment, the BCBT group showed the most limited range of motion (ROM) under exercise load, indicating superior stability within this group. The ROM and cage stress values were found to be highest in the SA group. In contrast, the cage and internal fixation stress in the BPS group were observed to be lowest (9.91 ~ 53.83MPa, 44.93 ~ 84.85 MPa). With the exception of right bending and right rotation, the UCBT group demonstrated higher levels of internal fixation stress (102.20 ~ 164.62 MPa). Conclusions The study found that OLIF-assisted internal fixation improved segmental stability and reduced cage stress. The BPS group had advantages over the CBT group in preventing endplate damage and reducing the risk of cage subsidence. However, BCBT group has distinct merits in maintaining surgical segment stability, distributing stress load on the spinal motor unit, and reducing the likelihood of adjacent segment degeneration (ASD).

Objective Spine fixation surgery affects the biomechanical environment in the sacroiliac joint (SIJ), which may lead to the SIJ pain or degeneration after surgery. The purpose of this study is to determine the impact of the number and position of fixed segments on the SIJs and provide references for surgeons to plan fixation levels and enhance surgical outcomes. Methods The intact lumbar‐pelvis finite element (FE) models and 11 fixation FE models with different number and position of fixed segments were developed based on CT images. A 400N follower load and 10° range of motion (ROM) of the spine were applied to the superior endplate of L1 to simulate the flexion, extension, bending and torsion motion after surgery. The peak stress on the SIJs, lumbar intervertebral discs, screws and rods were calculated to evaluate the biomechanical effects of fixation procedures. Results With the lowermost instrumented vertebra (LIV) of L5 or S1, the peak stress on SIJs increased with the number of fixed segments increasing. The flexion motion led to the greater von Mises stress on SIJ compared with other load conditions. Compared with the intact model, peak stress on all fixed intervertebral discs was reduced in the models with less than three fixed segments, and it increased in the models with more than three fixed segments. The stress on the SIJ was extremely high in the models with all segments from L1 to L5 fixed, including L1‐L5, L1‐S1 and L1‐S2 fixation models. The stress on the segment adjacent to the fixed segments was significant higher compared to that in the intact model. The peak stress on rods and screws also increased with the number of fixed segments increasing in the flexion, extension and bending motion, and the bending and flexion motions led to the greater von Mises stress on SIJs. Conclusion Short‐term fixation (≤2 segments) did not increase the stress on the SIJs significantly, while long‐term segment fixation (≥4 segments) led to greater stress on the SIJs especially when all the L1‐L5 segments were fixed. Unfixed lumbar segments compensated the ROM loss of the fixed segments, and the preservation of lumbar spine mobility would reduce the risks of SIJ degeneration.

Background: A healthy lower back is essential for optimal spinal function and overall wellness. Magnetic resonance imaging (MRI) has become the gold standard in assessing lumbar spine disease. This article aims to evaluate the precision and efficacy of the lumbar offset distance (LOD) as a novel MRI parameter designed to determine the lumbar spine alignment. normally measured as we compared it to a new parameter based on length. MATERIALS AND METHODS: Supine sagittal magnetic resonance images of 101 patients who underwent lumbar spine MRI scans were analyzed. We focused on L1–L5 lumbar lordosis angle (LLA) and LOD to assess lumbar spine alignment. Diagnostic cutoff values for LOD measurements were determined, and their diagnostic accuracies were evaluated. Results: The normal LLA in our dataset was 23°–45°, and the normal LOD was 5–15 mm. Using linear regression, the range of 6–14 mm correlates to the LLA range of 20°–45°, which would define the standard lumbar offset as normal between 6 and 14 mm. Hence, lumbar hypolordosis was defined as

Grade 1 spondylolisthesis can be challenging to detect on magnetic resonance imaging (MRI), particularly for spinal surgeons and radiologists with limited experience interpreting spinal MRIs. This study aims to describe a unique sign described as a “mustache sign,” which may assist in detecting subtle Grade I spondylolisthesis on sagittal sequences on MRI of the spine. PATIENTS AND METHODS: A retrospective review of 50 lumbar spine MRI scans of patients with Grade I spondylolisthesis of L5/S1 performed over 3 years was conducted at a tertiary orthopedic spinal center in the United Kingdom. The scans were assessed for the presence of the “mustache sign” and findings were independently recorded by one musculoskeletal radiology registrar and one fellowship trained musculoskeletal radiologist with over 10 years of experience. Results: There were 35 females (70%) and 15 males (30%). The patient’s mean age was 54.3 years (13–82). The “mustache sign” was present in 13 (26%) of these patients. Twelve of 13 scans (92%) positive for the sign also demonstrated pars interarticularis defects (P < 0.001, Fisher’s Exact test), compared to those without the sign. There was excellent interobserver reliability with a kappa of 1. Conclusion: The “mustache sign” on MRI spine correlates well with the presence of Grade I spondylolisthesis. This ancillary sign can complement other previously described radiological findings on sagittal MRI sequences to confirm Grade I spondylolisthesis.

Introduction: Favorable short- and long-term outcomes have been reported for lumbar intervertebral total disc replacement (L-TDR). However, there is little evidence regarding the uptake of L-TDR in practice. The objective of this study was to analyze Australian-based population trends in L-TDR over the past 5 years. Methods: The 5-year incidence of L-TDR from 2019 to 2023 in adult patients was analyzed using the Medicare Benefits Schedule (MBS) database. Data were stratified by sex and year, with an offset term introduced using population data from the Australian Bureau of Statistics to account for population changes over the study period. Results: A total of 1558 L-TDRs were completed in Australia under the MBS in the 5 years of interest. The 5-year annual mean case volume was 311.6 cases per annum. A downtrend and plateau in the rate of L-TDR has been seen from 2021 onward. The distribution of L-TDR across ages showed a significantly higher concentration in the 35–44 and 45–54 age groups (P < 0.05). More operations were performed in males (n = 876, 56.2%) than females (n = 682, 43.8%). Conclusions: The uptake of L-TDR has declined throughout the 5-year study period in Australia. Despite modest use currently, the future of L-TDR will rely on more robust long-term outcome data.

Introduction: In high-grade spinal osteotomy involving large anterior column resection, restoration of the structural integrity of the posterior column at the osteotomy site can reduce postoperative instrumentation failure (IF). This study aimed to describe our technique of posterior strut bone grafting using an en bloc resected vertebral arch, which is useful for posterior column reconstruction after high-grade osteotomies during surgeries for spinal tumor and deformity in the lower lumbar spine. Technical Note: Using a posterior approach, en bloc resection of the targeted vertebral arch was performed in accordance with the surgical technique for total en bloc spondylectomy (TES). The posterior elements in the upper and lower adjacent vertebrae were separated by a significant space after vertebral body resection followed by cage insertion in TES or anterior column osteotomy followed by correction in deformity surgery. To create a new posterior column, the en bloc resected vertebral arch was placed at 90° rotation to bridge the upper and lower vertebral arches. Using this technique, an abundant amount of bone chips made from the resected vertebral elements were placed over the en bloc resected posterior arch as an additional bone graft. The technique was used in three patients who underwent TES for spinal tumors and in one patient who underwent grade 4 osteotomy for adult spinal deformity in the lower lumbar spine. One year after surgery, computed tomography showed that the structural integrity of bony fusion was successfully achieved between the en bloc resected arch and the posterior elements of the adjacent vertebrae in all patients and showed no postoperative IFs. Conclusions: This bone graft technique created new continuity of the posterior column after high-grade osteotomies in the lower lumbar spine. Bone fusion was achieved in the posterior elements to prevent IF after surgery.

Introduction: Few studies have assessed the minimum clinically important difference (MCID) of each Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) domain. This study assessed MCIDs of JOABPEQ in patients with lumbar spine disease by generation. Methods: We evaluated the JOABPEQ score of 805 consecutive patients with lumbar spine disease undergoing posterior surgery preoperatively and 1 year postoperatively. MCIDs of each JOABPEQ domain were determined using anchor- and distribution-based methods according to age. A question based on the concept of a health transition item was used as the anchor for the MCID decision. Results: Overall, MCIDs of the JOABPEQ were 28.6 and 27.3 points for pain-related disorder and gait disturbance, respectively. The MCID for the lumbar spine dysfunction domain did not reach 0.6 over the area under the curve. Regarding the differences among generations, MCIDs of pain-related disorder and gait disturbance domains differed slightly between the elderly and middle-aged. The psychological disorder domain did not reflect clinically meaningful changes in the elderly. MCIDs of the social life disturbance domain decreased with age. Conclusions: Focusing on achieving the ideal responsiveness of patient-reported outcomes across generations, MCIDs of the pain-related disorder and gait disturbance domains may be valuable for patients, regardless of age, when adopting the JOABPEQ for patients with lumbar spine disease undergoing surgery. This study only evaluated cases that underwent posterior lumbar surgery. Future research will necessitate conducting surveys concerning the outcomes of various treatments for lumbar spine disease.

Aims: To report the development of the technique for minimally invasive lumbar decompression using robotic-assisted navigation. Methods: Robotic planning software was used to map out bone removal for a laminar decompression after registration of CT scan images of one cadaveric specimen. A specialized acorn-shaped bone removal robotic drill was used to complete a robotic lumbar laminectomy. Post-procedure advanced imaging was obtained to compare actual bony decompression to the surgical plan. After confirming accuracy of the technique, a minimally invasive robotic-assisted laminectomy was performed on one 72-year-old female patient with lumbar spinal stenosis. Postoperative advanced imaging was obtained to confirm the decompression. Results: A workflow for robotic-assisted lumbar laminectomy was successfully developed in a human cadaveric specimen, as excellent decompression was confirmed by postoperative CT imaging. Subsequently, the workflow was applied clinically in a patient with severe spinal stenosis. Excellent decompression was achieved intraoperatively and preservation of the dorsal midline structures was confirmed on postoperative MRI. The patient experienced improvement in symptoms postoperatively and was discharged within 24 hours. Conclusion: Minimally invasive robotic-assisted lumbar decompression utilizing a specialized robotic bone removal instrument was shown to be accurate and effective both in vitro and in vivo. The robotic bone removal technique has the potential for less invasive removal of laminar bone for spinal decompression, all the while preserving the spinous process and the posterior ligamentous complex. Spinal robotic surgery has previously been limited to the insertion of screws and, more recently, cages; however, recent innovations have expanded robotic capabilities to decompression of neurological structures. Cite this article: Bone Jt Open 2024;5(9):809–817.

Aims: Patient dissatisfaction following primary total knee arthroplasty (TKA) with manual jig-based instruments has been reported to be as high as 30%. Robotic-assisted total knee arthroplasty (RA-TKA) has been increasingly used in an effort to improve patient outcomes, however there is a paucity of literature examining patient satisfaction after RA-TKA. This study aims to identify the incidence of patients who were not satisfied following RA-TKA and to determine factors associated with higher levels of dissatisfaction. Methods: This was a retrospective review of 674 patients who underwent primary TKA between October 2016 and September 2020 with a minimum two-year follow-up. A five-point Likert satisfaction score was used to place patients into two groups: Group A were those who were very dissatisfied, dissatisfied, or neutral (Likert score 1 to 3) and Group B were those who were satisfied or very satisfied (Likert score 4 to 5). Patient demographic data, as well as preoperative and postoperative patient-reported outcome measures, were compared between groups. Results: Overall, 45 patients (6.7%) were in Group A and 629 (93.3%) were in Group B. Group A (vs Group B) had a higher proportion of male sex (p = 0.008), preoperative chronic opioid use (p < 0.001), preoperative psychotropic medication use (p = 0.01), prior anterior cruciate ligament (ACL) reconstruction (p < 0.001), and preoperative symptomatic lumbar spine disease (p = 0.004). Group A was also younger (p = 0.023). Multivariate analysis revealed preoperative opioid use (p = 0.012), prior ACL reconstruction (p = 0.038), male sex (p = 0.006), and preoperative psychotropic medication use (p = 0.001) as independent predictive factors of patient dissatisfaction. Conclusion: The use of RA-TKA demonstrated a high rate of patient satisfaction (629 of 674, 93.3%). Demographics for patients not satisfied following RA-TKA included: male sex, chronic opioid use, chronic psychotropic medication use, and prior ACL reconstruction. Patients in these groups should be identified preoperatively and educated on realistic expectations given their comorbid conditions. Cite this article: Bone Jt Open 2024;5(9):758–765.