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PURPOSE: To describe U-type sacral fracture characteristics amenable to percutaneous sacral screw fixation. METHODS: U-type sacral fractures were identified from a trauma registry at a level 1 trauma center from 2014 to 2020. Patient demographics, injury mechanism, fracture characteristics, and fixation construct were retrospectively retrieved. Associations between fracture pattern and surgical fixation were identified. RESULTS: 82 U-type sacral fractures were reviewed. Six treated with lumbopelvic fixation (LPF) and 76 were treated with percutaneous sacral screws (PSS) alone. Patients receiving LBF had greater sacral fracture displacement in coronal, sagittal, and axial planes compared to patients receiving PSS alone (P

AIMS: There is limited evidence to support the efficacy of sacral neuromodulation (SNM) for older adults with overactive bladder (OAB). This study aims to report outcomes following SNM among nursing home (NH) residents, a vulnerable population with high rates of frailty and comorbidity. METHODS: This is a retrospective cohort study of long-stay NH residents who underwent a trial of percutaneous nerve evaluation (PNE) or Stage 1 permanent lead placement (Stage 1) between 2014 and 2016. Residents were identified using the Minimum Data Set linked to Medicare claims. The primary outcome of this study was successful progression from trial to implant. Rates of 1-year device explant/revisions were also investigated. RESULTS: Trial of SNM was observed in 1089 residents (mean age: 77.9 years). PNE was performed in 66.9% of residents and 33.2% underwent Stage 1. Of Stage 1 procedures, 23.8% were performed with simultaneous device implant (single-stage). Overall, 53.1% of PNEs and 72.4% of Stage 1 progressed to device implant, which was associated with Stage 1 procedure versus PNE (adjusted relative risk [aRR]: 1.34; 95% confidence interval [95% CI]: 1.21-1.49) and female versus male sex (aRR: 1.26; 95% CI: 1.09-1.46). One-year explant/revision was observed in 9.3% of residents (6.3% for PNE, 10.5% for Stage 1, 20.3% single-stage). Single stage procedure versus PNE was significantly associated with device explant/revision (aRR: 3.4; 95% CI: 1.9-6.2). CONCLUSIONS: In this large cohort of NH residents, outcomes following SNM were similar to previous reports of younger healthier cohorts. Surgeons managing older patients with OAB should use caution when selecting patients for single stage SNM procedures.

Background and purpose Methods Results Conclusion Midline sacral meningeal cysts (MSMCs) are cerebrospinal fluid‐filled dural diverticula. Although widely considered asymptomatic, cases involving voiding difficulties or pain have been reported. The aims of this study were, firstly, to describe the clinical presentation of patients with symptomatic MSMCs, secondly, to assess the impact of the cyst on nerve root function, and, thirdly, to assess whether nerve root injury is more frequent in patients with MSMCs than those with Tarlov cysts (TCs).Consecutive patients with MSMCs presenting with at least one pelvic symptom participated in a cross‐sectional review of symptoms using validated questionnaires. Findings of pelvic neurophysiology (pudendal sensory evoked potentials, sacral dermatomal sensory evoked potentials, external anal sphincter electromyography) and urodynamic testing were collected retrospectively. The relationship between neurophysiology, magnetic resonance imaging findings and patients' symptoms were assessed using Fisher's and analysis of variance tests. Neurophysiology findings were compared with those of TC patients.Eleven female patients were included (mean age 42.3 ± 12.4 years). All reported urinary symptoms. Back pain (91%), radicular leg pain (91%), bowel symptoms (45%) and sexual dysfunction (75%) were also frequently reported. Nine patients (82%) had abnormal findings on neurophysiology; three patients (27%) had one abnormal test, and six (55%) had two abnormal tests. Patients with MSMCs were more likely to have at least two abnormal neurophysiology test results compared to TC patients (55% vs. 18%, respectively; p = 0.018).Our results indicate that MSMCs are indeed associated with injury to the sacral somatic innervation when symptomatic. MSMCs are more likely to cause sacral nerve root damage compared to TCs. [ABSTRACT FROM AUTHOR]

Purpose: The spinopelvic reconstruction poses significant challenges following total sacrectomy in patients with malignant or aggressive benign bone tumours encompassing the entire sacrum. In this study, we aim to assess the functional outcomes and complications of an integrated 3D-printed sacral endoprostheses featuring a self-stabilizing design, eliminating the requirement for supplemental fixation. Methods: We retrospectively analyzed patients with sacral tumours who underwent total sacrectomy followed by reconstruction with 3D-printed self-stabilizing endoprosthesis. Clinically, we evaluated functional outcomes using the 1993 version of the musculoskeletal tumour society (MSTS-93) score. Perioperative and postoperative complications were also documented. Results: 10 patients met final inclusion criteria. The median age was 49 years (range, 31–64 years). The median follow-up time was 26.5 months (range, 15–47 months). Median postoperative functional MSTS-93 was 22.5 (range, 13–25). The median operation time was 399.5 min (305–576 min), and the median intraoperative blood loss was and 3200 ml (2400–7800 ml). Complications include wound dehiscence in one patient, bowel, bladder, and sexual dysfunction in four patients, cerebrospinal fluid leak in one patient, and tumour recurrence in one patient. There were no mechanical complications related to the endoprosthesis at the last follow-up. Conclusion: The utilization of 3D-printed self-stabilizing endoprosthesis proved to be a viable approach, yielding satisfactory short-term outcomes in patients undergoing total sacral reconstruction without supplemental fixation. [ABSTRACT FROM AUTHOR]

Introduction: Musculoskeletal disorders (MSDs) often arise and develop during dentistry studies. The most affected regions are related to the spine. Possible associations between spinal curve parameters and MSDs have not yet been investigated amongst dentistry students. This longitudinal observational study aimed to determine whether spinal curve changes during dentistry studies, analyse the relationship between objective findings and subjectively declared MSDs and compare spinal curve parameters with those published in the literature. Materials and Methods: Seventy‐three dentistry students answered a questionnaire on MSDs, and were examined using the Spinal Mouse® device at the beginning, in the middle, and at the end of their 5‐year study. Results: The spinal curve exhibited a gender diversity in the lumbar lordosis angle, sacrum inclination, and thoracolumbar ratio. From the first to fifth study year, we observed an increase in the range of motions in the sagittal and frontal planes, an increase in the maximal extent of right lateral inclination, and a decrease in maximal left lateral inclination. Whole‐spine backward inclination increased only in women, and forward sacral inclination decreased. No statistically significant relationships were found between the objective findings and subjectively declared MSDs. Conclusions: The spinal curve shape differed between men and women and changed during dentistry studies. No objective markers or predictors of MSDs were found amongst the dentistry students. These findings can serve as a benchmark for further studies on the association between MSDs and objective findings. [ABSTRACT FROM AUTHOR]

Background: Pressure injuries (PIs) are among the most common skin and soft tissue wounds occurring in patients who are bedbound and/or immobile. PI management hinges on their prevention; however, reoccurrence poses a challenge to their management and requires a multidisciplinary approach. Here, the authors describe a lumbosacral rotation flap (LSRF) for the coverage of sacral PIs. Method: A single-centre, retrospective analysis of prospectively collected data was carried out. All patients undergoing LSRF for sacral PIs were included. Patients with active systemic sepsis, immune compromise, hepatic or renal dysfunction were excluded. All patients underwent preoperative optimisation and wound cultures to direct antibiotic therapy after surgery. Results: A total of nine patients underwent the procedure (seven male and two female). Mean age was 47.6 years with a mean ulcer size of 92.9 cm2. Bone biopsy indicated the presence of osteomyelitis in three patients. Of the LSRFs, two flaps showed minimal local complications in the form of marginal flap necrosis which was managed conservatively. All flaps healed well with no cases of flap loss or the need for secondary procedures. Conclusion: The results of this analysis showed that LSRF can be considered a first line of treatment of sacral PIs. They can be used to cover large defects. Due to their large base and flap size, readvancement in cases of recurrence is also possible. [ABSTRACT FROM AUTHOR]

Indian fossil Squamata and Anura are known from the Upper Cretaceous-lower Paleocene Deccan Trap associated sediments for over last one century. However, current knowledge on their taxonomy and stratigraphic implications is poor for their scarce and fragmentary nature and lack of any stratigraphic constraints. We report newly found fossil Squamata and Anura from the new intertrappean locality Bharudpura in Malwa Plateau and describe (i) Scincomorpha (Scincoidea) lizards based on taxonomic study of dentary, maxilla and osteoderms, (ii) Anguimorpha (Anguidae) lizards based on osteoderms, (iii) Squamata indeterminate based on a vertebrae and (iv) Anura (Ranidae, Ranoidea and Anuran indeterminate) based on a ilium, a sacral vertebrae and single dentary. Currently, it is not possible to ascertain if the different fossil specimens belong to a single or more taxa. The lowermost lava pile of Mandleshwar and Kalisindh formations, associated with multiple intertrappean beds including the new Bharudpura fossil locality, have yielded40Ar/39Ar plateau ages from 66.834 Ma, the oldest Deccan Trap flow dated so far in India to 66.352 Ma. The present study records their earliest occurrence in India, from intertrappean associated with oldest Deccan Trap lava pile that erupted during magnetochron C30n of Maastrichtian in the Malwa Plateau. [ABSTRACT FROM AUTHOR]

Background: Rod fracture (RF) is the most common cause of revision in adult spinal deformity (ASD) surgery, and various treatment strategies for preventing RF are reported in the literature. This retrospective study, involving 139 ASD patients (aged ≥65 years and a minimum 2-year follow-up) who underwent long-segment fixation from T10 to sacrum with pedicle subtraction osteotomy (PSO), analyzed long-term results, including radiographical parameters and the incidence of recurrent RF (re-RF), to determine the most effective revision method for preventing RF. Methods: Patients were classified into three groups according to the revision method performed for RF: simple rod replacement (RR group, n = 17), lateral lumbar interbody fusion around the PSO site (RR + LLIF group, n = 8), and accessory rod insertion (RR + AR group, n = 22). Baseline characteristics and radiographical and clinical parameters were analyzed. Results: RF occurred in 47 patients (34%) at an average of 28 months following primary deformity correction. Re-RF occurred in six patients (13%) at an average of 37 months. Re-RF occurred most commonly in the RR group (p = 0.048). Every re-RF in the RR group occurred at the PSO site; none occurred in the RR + LLIF group, and one in the RR + AR group occurred near the L4–5. After both primary deformity correction and revision surgery, spinopelvic parameters had shown favorable results, and clinical outcomes had improved in all three groups without significant intergroup differences. Conclusions: Accessory rod insertion or an additional LLIF around the PSO site seems to provide greater strength and stability to the previously fused segments than a simple rod replacement, which demonstrates the need for additional support in revision surgery for RF after a PSO. [ABSTRACT FROM AUTHOR]

Background: Operative treatment of fragility fractures of the pelvis has become a gold standard. Preoperative planning, including the assessment of the pathway for iliosacral screws, is crucial. The anchorage of the screw depends on the bone quality. Some recent studies have concentrated on assessing bone mineral density (BMD) with the use of Hounsfield unit (HU) values obtained from CT scans. The aim of the present study is to determine the best sacral levels of S1–S3 on the pathway of iliosacral screws for sacroiliac joint fixation. Methods: Patients admitted to the Independent Public Healthcare Center in Rypin between 1 of September and 1 of December in 2023, who had CT scans of the pelvis performed on them for different reasons, were included in this study. In total, 103 patients—56 men and 47 women—were enrolled in the study and consecutively separated into two groups of different ages: 18–60 years old (group A) and above 60 years old (group B). The volumetric bone density expressed in HU values was measured with sacral levels of S1, S2 and S3. Apart from the bodies of sacral vertebrae S1–S3, our measurements involved the ala of the ilium in the vicinity of the sacroiliac joint and the wing of the sacrum. All the measurements were performed on the pathway of presumptive iliosacral screws to stabilize the sacroiliac joint. Results: In group A (58 patients) the highest bone density in sacral bodies was found in S1 that gradually decreased to S3, while the opposite tendency was demonstrated in the ala of ilium. The HU values in the wing of the sacrum did not display statistical significance. In group B (45 patients), the highest bone density was also found in the sacral body S1 that decreased toward S3 but in the ala of ilium, the highest bone density was found with level S1 and lowest with level S2. In both groups, the highest bone density referred to the wing of the sacrum. Conclusion: While the perfect construct for posterior pelvic ring fixation remains unclear, our findings may imply that sacroiliac joint screws inserted into the wing of the sacrum of greater bone density could provide much more successful fixation in comparison to those anchored in the body of sacral vertebra of lesser bone density. [ABSTRACT FROM AUTHOR]

A sacral insufficiency fracture is a rarely reported complication after lumbosacral fusion. As the majority of those undergoing surgery are elderly patients with degenerative disease, osteoporosis is usually involved along with other reported risk factors such as female, obesity, and multi-segment fusion. Through two cases experienced by the authors, this paper reports a newly found risk factor (cement-augmented pedicle screw), and the fracture treatment process with a review of the relevant literature. [ABSTRACT FROM AUTHOR]

Background: Anatomical variations of Sacral hiatus play a pivotal role in Caudal epidural block (CEB) anaesthesia injections. Hence correct Anatomical location of the hiatus is vital during successful CEB. The present study was undertaken to dissect out the morphometric variations of sacral hiatus among young adult Odisha population. Materials and Methods: The study was conducted with 101 normal, dry human sacrum bones for multiple metric and non-metric analysis. Digital vernier calliper was used for metric study including measure sacral dimensions like anteroposterior diameter, transverse diameter, length of sacral hiatus and distance between the apex to mid-point of an imaginary line joining both S2 foramina, distance between mid-point of base to the midpoint of an imaginary line joining both S2 foramina, distance between apex to the highest point of right-side lateral crest/superolateral crest which corresponds to right side posterior superior iliac spine, distance between apex to the highest point of left side lateral crest/superolateral crest which corresponds to left side posterior superior iliac spine and distance between right and left superolateral sacral crest. Results: The mean length of Sacral Hiatus was 22.36 ± 8.61 mm. The mean transverse diameter of Sacral Hiatus was 15.40 ± 2.17mm. The mean antero-posterior diameter of sacral hiatus at apex was 5.19 ± 1.36 mm. Inverted U shape was most common. Most common level of apex of sacral hiatus with respect to sacral vertebra had been 4th Sacral vertebra and most common location of base of sacral hiatus in relation to the level of sacral/coccygeal vertebra had been found to be 5th Sacral vertebra. Summary and conclusion: The anatomical knowledge of multiple metric and non-metric variations of sacral hiatus are important in CEB anesthesia contributing to improved success of the procedure. [ABSTRACT FROM AUTHOR]

Purpose: Pelvic and sacral bone metastases cause significant morbidity. The primary aim of the study is to thoroughly evaluate the increase in functional capacity resulting from combined RF ablation and cementoplasty surgery applied to malignant bone metastases of the pelvic bones. Methods: Twenty patients who underwent RF ablation and cementoplasty for malign pelvic bone and sacrum metastases between January 2014 and December 2021 were retrospectively identified. The inclusion criteria were having a life expectancy of more than 1 month, being > 18 years old, and having at least 1 month of follow-up. The Visual Anlogue Scale (VAS) pain, Karnofsky Performance Status (KP), and Musculoskelatal Tumor Society (MSTS) scores were calculated. Results: VAS pain values decreased, and KP values increased postoperatively (p = 0.006 and p = 0,013). There was no statistically significant increase in MSTS (p > 0.05). The correlation relationships between lesion filling ratio and VAS pain, KP, and MSTS scores were not statistically significant (p > 0.05). Cement leakage was observed in 5 patients (25.0%), and no symptoms related to this leakage were observed. Conclusion: The pelvic region, given its close proximity to blood vessels, nerves, and joint areas, along with the distinct challenges associated with its surgery, requires separate evaluation. In studies evaluating applications in the isolated pelvic ring region, as in our study, functional gains have been most comprehensively assessed in this study, demonstrating that the procedure results in significant functional improvements. [ABSTRACT FROM AUTHOR]

In this study, we aimed to investigate whether multi-segment fusion or fusion-to-sacrum increases sacroiliac joint (SIJ) pathology compared with single-segment fusion or a non-fused sacrum. This study included 116 patients who underwent lumbar or lumbosacral fusion and were followed up for 2 years. The patients were classified into single-segment fusion (n = 46) and multi-segment fusion (more than two levels, n = 70) groups and then reclassified into the non-fused sacrum (n = 68) and fusion-to-sacrum groups (n = 48). Preoperative and postoperative radiographs were used to evaluate radiographic parameters, and computed tomography (CT) was used to evaluate SIJ degeneration. Low back pain (LBP) was assessed using a visual analog scale (VAS, 0–10). Baseline and postoperative values were compared using a paired sample t -test. LBP VAS scores significantly differed at 6 months (single-segment fusion, 3.04 ± 1.88; multi-segment fusion, 4.83 ± 2.33; P < 0.001) and 2 years postoperatively (single-segment fusion, 3.3 ± 2.2; multi-segment fusion, 4.78 ± 2.59; P = 0.094). There was no significant difference in SIJ degeneration, as assessed by CT scan, between the 2 surgical groups: 14 (30%) and 19 (27%) patients in the single-segment and multi-segment (P = 0.701) fusion groups, respectively. The LBP VAS scale showed comparable differences at 1 (non-fused sacrum, 3 ± 2.18; fusion-to-sacrum, 3.74 ± 2.28; P = 0.090) and 2 years postoperatively (non-fused sacrum, 3.29 ± 2.01; fusion-to-sacrum, 4.66 ± 2.71; P = 0.095). CT scan revealed that 18 (26%) and 15 (31%) patients in the non-fused sacrum and fusion-to-sacrum groups, respectively, developed SIJ arthritis; however, there was no significant intergroup difference (P = 0.574). SIJ degeneration occurs independent of the number of fused segments or sacrum involvement. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: The accurate identification of intraoperative levels is of paramount importance in spinal surgery, particularly in cases of obesity or anatomical anomalies affecting the thoracic spine. The aim of this work was to clarify whether the preoperative percutaneous placement of fiducial markers under local anesthesia only, with minimal discomfort to the patient, can be performed safely and efficiently. Methods: Patients treated at our institution between June 2019 and June 2020 for thoracic intraspinal lesions with preoperative percutaneous gold fiducial placement were analyzed. A total of 10 patients underwent CT-guided gold fiducial placement 2–48 h prior to surgery on an outpatient or inpatient basis. Patient characteristics, CT intervention time, and perioperative complications were recorded. Results: In all cases, the gold markers were placed under local anesthesia alone and were easily visualized intraoperatively with fluoroscopy. There was no preoperative dislocation or malposition. The procedure was performed without X-ray exposure to the neuroradiology interventionalist. The average CT intervention time from the planning scout to the final control time was 14.3 min. The percentage of anatomical norm variants in our observation group was high, as 2 of the 10 patients had lumbarization of the first sacral vertebra, resulting in a six-link lumbar spine. Conclusions: Preoperative CT-guided transcutaneous submuscular placement of gold markers under local anesthesia is a practical and safe method for rapid and accurate intraoperative level determination in thoracic spine surgery in a time-saving minimally invasive manner. The virtually painless procedure can be performed either preoperatively on an outpatient basis or as an inpatient procedure. [ABSTRACT FROM AUTHOR]

Background: The traditional approach for diagnosing piriformis syndrome (PS) is to rule out other causes of sciatica. This approach may lead to unnecessary radiological examinations and a waste of time. In contrast to the traditional approach, we aimed to first exclude PS and determine its prevalence by injecting patients with priformis tenderness. Methods: This observational cross-sectional study included patients diagnosed with PS who had sciatica and tenderness on palpation of the priformis muscle and whose pain was reduced by at least 50% with local injection. Age, sex, pain duration, presence of tenderness in the piriformis muscle, Freiberg test, PACE sign, FADIR, Visual Analog Scale (VAS) score, Douleur Neuropathique 4 Questions (DN4) score, and radiological findings were compared between patients who responded and those who did not respond to the priformis injection. Results: A total of 110 patients with sciatica were evaluated, of whom 66 with tenderness on palpation of the primiformis muscle underwent local injection. In 27 of the 66 patients (40.9%), a decrease in the NRS score of >50% was observed after injection, and PS was diagnosed. There were no statistically significant differences in age, sex, pain duration, Pace, FADIR test positivity, radiological findings, NRS, and DN4 scores, but Freiberg test positivity was statistically higher in patients diagnosed with PS. Conclusion: PS is more common than is thought to be a cause of sciatica. A positive Freiberg test is predictive for the diagnosis of PS, but it should be confirmed by tenderness of the priformis muscle and local injection. Many pathologies can be detected incidentally radiographically in PS; however, they are not predictive of the diagnosis. [ABSTRACT FROM AUTHOR]

Objective: To describe the frequency of MR and CT features of infectious sacroiliitis (ISI) and assess its extent and complications Materials and methods: This retrospective study included patients with ISI who were evaluated between 2008 and 2021 in a single center. Two radiologists reviewed MRI and CT images to determine the anatomical distribution (unilateral/bilateral, iliac/sacral bone, proximal/middle/distal), severity (bone marrow edema [BME]/periostitis/erosions), concurrent infection (vertebral/nonvertebral), and complications (abscess/probable adjacent osteomyelitis/cavitation/devitalized areas/sequestrum/pelvic venous thrombosis) of ISI. Interobserver reproducibility was assessed. Correlation analysis evaluated the effect of the causative microorganism on severity. Two human bodies were dissected to outline possible ways that ISI can spread. Results: Forty patients with ISI (40 years ± 22; 26 women) were evaluated. Ten patients had bilateral ISI. Concurrent vertebral infection was associated in 15% of cases. Reproducibility of sacral BME, periostitis, and reactive locoregional abnormalities was perfect (κ = 1). Reproducibility was low for erosion count (κ = 0.52[0.52–0.82]) and periarticular osteopenia (κ = 0.50[0.18–0.82]). Inflammatory changes were BME (42/42 joints), muscle edema (38/42), and severe periostitis along the ilium (33/37). Destructive structural changes occurred with confluent erosions (iliac, 20/48; sacral, 13/48), sequestrum (20/48), and cavitation (12/48). Complications occurred in 75% of cases, including periarticular abscesses (n = 30/47), probable adjacent osteomyelitis (n = 16/37), and pelvic thrombophlebitis (n = 3). Tuberculous ISI (6/40) correlated with sclerosis (rs = 0.45[0.16; 0.67]; p < 10−2) and bone devitalization (rs = 0.38[0.16; 0.67]; p =.02). The anatomical study highlighted the shared venous vascularization of sacroiliac joints, pelvic organs, and mobile spine. Conclusion: Complications of ISI are frequent, including abscesses, adjacent osteomyelitis, and periostitis. ISI had bilateral involvement nonrarely and is commonly associated with another spinal infection. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to assess the outcomes of wide resection for sacral osteoblastoma (OB). Materials and Methods: A review of our database revealed 6 cases of OB located in the sacrum. Localized pain in lesions that did not fully resolve although medical treatment was observed in all 6 cases. Surgical treatment consisted wide resection. The average time between diagnosis and surgery was 30 (24-36) months, and the average age at surgery was 14 (8-20) years. Results: Postoperatively, the mean follow-up period was 74.3 months (24-110). At final followup, we did not encounter any complications, recurrence, spinal instability, and neural damage were not observed as a result of the removal of lesions in the sacrum area. The preoperative mean Visual Analog Scale score was 8 before treatment and 0 at the final follow-up. Conclusion: Wide resection is a safe and effective treatment option for patients with sacral osteoblastoma. [ABSTRACT FROM AUTHOR]

Background: Caregivers are deeply concerned about children achieving independent walking, and evidence-based rehabilitation support is beneficial. However, current research is confined to a single study on spina bifida aperta, leaving a gap in understanding the timing of independent walking for lumbosacral lipomas. Objectives: This study aimed to examine the factors influencing independent walking in children with lumbosacral lipomas. Design: Retrospective cohort study. Methods: This retrospective cohort study included 124 children who underwent untethering surgery for lumbosacral lipomas. The age (in months) at which the children walked independently was used as the primary endpoint, and potential influencing factors, including the type of spinal lipoma, extent of lipoma removal, magnetic resonance imaging features, congenital anomaly complications, urinary/defecation management requirements, foot/toe symptoms, and orthotic device fabrications were analyzed. Results: Multiple logistic regression analysis showed that the most significant influencing factor for delayed independent walking was the presence of systemic combined anomalies (adjusted odds ratio = 15.5, P <.001), while non-systemic malformations, such as suburethral cleft, had limited effects. A subgroup analysis of 94 patients without systemic combined anomalies showed that the presence of a malformed conus medullaris was significantly associated with delayed independent walking (P =.014). The median age of independent walking in children with Morota's classification type 2 was 14 months, which is 1 month later compared to other types, although this difference was not significant (P =.055). Conclusion: Our findings suggest that complications arising from systemic combined anomalies and the presence of malformed conus medullaris are influencing factors in delays in independent walking in children with untethered lumbosacral lipomas. [ABSTRACT FROM AUTHOR]

Background: Ankylosing spondylitis (AS) is characterized by inflammation and osteoblastic changes in the sacroiliac joint. As a potential imaging method for the early assessment of AS, positron emission tomography (PET) can quantify systemic disease activity, which is conducive to monitoring the progression of disease activity and assisting in evaluating the efficacy of the treatment. Objective: The study was to evaluate the diagnostic value of aluminium-[18F]fuoride(Al18F)-labelled fibroblast activation protein inhibitor (FAPI) PET/computed tomography (CT) in AS and to investigate its ability to assess disease activity during the development of AS. Material and Methods: Twenty AS participants who met the Assessment of SpondyloArthritis international Society criteria and were in an active disease stage were included in this study from May 2022 to April 2023. Sixteen healthy controls were also inrolled. All participants underwent Al18F-NOTA-FAPI-04 PET/CT imaging after collecting clinical assessment and laboratory results. The correlation between positive joint count (PJC) and systemic joint standard uptake value ratio (SUVR, the mean SUVmax of the 5 highest joints/SUVmax of the uninvolved sacrum) on PET and clinical disease activity assessment and various laboratory tests were analyzed. Results: A total of 2820 joints were observed in 20 participants (median age 34.5,[21-61]range, 15 men), with a PJC of 1300 (46.7%), and 39 positive uptakes were found in 40 sacroiliac joints (97.5%). PET/CT images revealed FAPI-04 uptake in both sacroiliac joints in 2 participants without radiographic sacroiliitis in the early stages of AS and varying degrees of uptake in the sacroiliac joints and spinal joints in the remaining participants. PJC and SUVR were positively correlated with most clinical assessments and laboratory findings (P <.05), and SUVR of the sacroiliac joint was positively correlated with C-reactive protein (CRP) (mg/L; r = 0.498, P =.026). Conclusion: Al18F-NOTA-FAPI-04 PET/CT was highly sensitive to systemic arthritic changes in AS participants and correlated with clinical disease activity and laboratory tests. [ABSTRACT FROM AUTHOR]

BACKGROUND: Multifidus is an important lumbar muscle with distinct superficial and deep fibers responsible for torque production and stabilization, respectively. Its mechanical properties change when transitioning from lying to sitting positions, necessitating enhanced stability. It holds crucial clinical relevance to assess these layers separately, especially in the sitting posture, which demands increased neuromuscular control compared to the prone position. OBJECTIVE: To compare lumbar multifidus stiffness in lying versus sitting postures, analyzing both superficial and deep layers. METHODS: Supersonic Shear Imaging captured elastographic images from 26 asymptomatic volunteers in prone and seated positions. RESULTS: Left multifidus shear modulus in lying: 5.98 ± 1.80/7.96 ± 1.59 kPa (deep/superficial) and sitting: 12.58 ± 4.22/16.04 ± 6.65 kPa. Right side lying: 6.08 ± 1.97/7.80 ± 1.76 kPa and sitting: 13.25 ± 4.61/17.95 ± 7.12 kPa. No side differences (lying p = 0.99, sitting p = 0.43). However, significant inter-postural differences occurred. CONCLUSION: Lumbar multifidus exhibits increased stiffness in sitting, both layers affected, with superior stiffness in superficial versus deep fibers. Applying these findings could enhance assessing multifidus stiffness changes, for classifying tension-induced low back pain stages. [ABSTRACT FROM AUTHOR]

Schwannomas are benign and slow-growing peripheral nerve sheath neoplasms of Schwann cells. These are generally encountered in the neck, head, and flexor areas of the extremities. Even though many schwannomas are easily diagnosable, their variable morphology can occasionally create difficulty in diagnosis. In this study, we present a rare case of melanotic schwannoma of the sacrum, emphasizing the need for routine biopsy to understand the etiology. A 46-year-old man presented to the Department of Neurosurgery, Taipei Medical University Hospital, with buttock pain in the sacrum area for 1 year, which worsened in the last 1–2 months. The patient had no known history of trauma or malignancy. We evidenced an intradural extramedullary neurogenic tumor at the caudal end from S1 to S3. Histologic analysis revealed melanin deposition in the tumor cells. Round to oval tumor cells were positive for HMB-45 and S-100 proteins, suggestive of melanotic Schwannoma, which were removed by laminectomy. After 1 month, the tumor recurred and was further removed surgically. Conclusively, we observed the sacrum as an unusual anatomic site for the possible occurrence of melanotic schwannoma, especially in patients with no known history of trauma and malignancy. The possibility of melanotic schwannoma is very high. We hypothesize that melanotic schwannoma was possible because it occurred in the intradural and extramedullary regions of the spine. Hence, a routine biopsy should be performed to corroborate the exact cause and prevent incorrect presumptions. [ABSTRACT FROM AUTHOR]

Aim: This study aimed to evaluate the clinical characteristics and outcomes of recurrent sacrococcygeal germ cell tumors (SC-GCTs). Materials and Methods: This study was conducted with patients diagnosed with SC-GCTs between 2002 and 2022. Epidemiology, diagnostic and treatment methods, anatomic/histopathological classifications and recurrence were evaluated. Results: This study included 55 patients (Female/Male: 45/10). According to Altman's-classification, 16 patients (29.1%) were Type I, 14 (25.5%) Type II, 12 (21.8%) Type III and 13 (23.6%) Type IV. Histologically, 69.1% of the lesions were mature teratomas, 14.5% were immature teratomas, and 16.4% were malignant teratomas. Eleven patients developed recurrent sacrococcygeal teratoma (recurrence age: 5 months-12 years). According to Altman's classification, 2/11 patients were Type II, 5/11 patients were Type III, and 4/11 patients were Type IV. The pathological results of the original tumors were mature teratoma in 4/11 patients, immature teratoma in 4/11 patients, and malignant teratoma in 3/11 patients. Malignant relapse with yolk sac tumor was detected in 6/11 patients, mature teratoma in 4/11 patients, and immature teratoma in 1/11 patients. Conclusion: The risk of malignancy increases with age and Altman's Type III and IV. Recurrent tumors may have different histopathological types from the original tumor. The risk of recurrence as a malignant tumor after immature teratomas was higher than mature teratomas. [ABSTRACT FROM AUTHOR]

Objective: Complete resection is the curative treatment choice for recurrent gynecological malignancies. Laterally extended endopelvic resection (LEER) is an effective surgical salvage therapy for lateral recurrence. However, when a recurrent tumor occupies the ischial spine and sacrum, LEER is not indicated, and surgical salvage therapy is abandoned. Theoretically, complete resection of such a tumor is possible by additional pelvic bone resection along with the standard LEER. Nevertheless, owing to the anatomical complexities of the beyond-LEER procedure, 2 major issues should be solved: sciatic nerve injury and tumor disruption during pelvic bone amputation. To overcome these technical challenges, we applied a multidirectional beyond-LEER approach, a novel salvage surgical procedure, with an aim of demonstrating its technical feasibility. Methods: We created a simulation model of a laterally recurrent tumor that occupied the right ischial spine and sacrum in a Thiel-embalmed cadaver. Results: Multidirectional approaches, including laparoscopic, perineal, and dorsal phases, were safely applied. We laparoscopically marked the L4-L5-S1 complex and S2 nerve with different colored tapes, and by pulling them out into a dorsal surgical field, the sciatic nerve was safely preserved. The dissection lines of the multidirectional approaches were aligned using tapes as landmarks, and complete tumor clearance without tumor disruption was accomplished. By following the cadaveric training, the first laparoscopic-assisted beyond- LEER procedure was successfully performed in a patient with recurrent ovarian cancer. Conclusion: Using a Thiel-embalmed cadaver, we demonstrated the technical feasibility of a sciatic nerve-preserved beyond-LEER procedure, which was successfully performed in a patient with recurrent ovarian cancer. [ABSTRACT FROM AUTHOR]

Bertolotti syndrome (BS) is characterized by chronic pain and functional impairment associated with lumbosacral transitional vertebrae (LSTVs). The study aimed to investigate the histologic characteristics of the pseudoarticulation between the enlarged transverse process and sacrum seen in Castellvi 2a LSTV and explore the involvement of nervous tissue in pain generation. Immunohistochemical analysis using S100 protein staining was performed to assess the presence of nerve tissue. These changes included fibrillation, chondrocyte cloning, alterations in the proteoglycan matrix, and focal chondrocyte necrosis. Notably, no nerve tissue was observed in any of the specimens, as confirmed by negative S100 protein staining. The study findings suggest that nerve tissue is not involved in the nociceptive mechanisms underlying pain in BS. The histologic similarities between the pseudoarticulation and osteoarthritic joints indicate that pseudoarticulation itself may be a significant source of pain in BS. These insights contribute to our understanding of the pathophysiology of BS and support treatment paradigms prioritizing pain control with medications such as NSAIDs before considering surgical intervention. Future studies with larger sample sizes and in vivo models are needed to further validate these findings and explore the changes in joint histology under biomechanical forces in LSTVs. [ABSTRACT FROM AUTHOR]

To compare traumatic spinal injury patterns between motorcyclists and occupants of other nonheavy motor vehicles using data from the National Spinal Cord and Column Injury Registry of Iran. All drivers/riders and passengers of motorcycles, cars, pick-up trucks, and vans registered between January 2017 to July 2023, met the inclusion criteria for the present study. The logistic regression models were used to compare the patterns of vertebral fracture between the 2 groups. One thousand seven hundred twenty-six spinal fracture patients were identified, 385 (22.3%) motorcyclists and 1341 (77.7%) car occupants with mean ages 33.2 ± 14.3 and 36.1 ± 13.6 years, respectively (P < 0.001). Only 45 (11.7%) motorcyclists used helmets, whereas 856 (63.8%) car occupants used seat belts (P < 0.001). The average numbers of fractured vertebrae were 3.9 ± 1.4 and 3.7 ± 1.1 among car occupants and motorcyclists, respectively (P = 0.004). The proportions of motorcyclists and car occupants with injuries in each spinal region are as follows: lumbar (50.5% of motorcyclists vs. 40.4% of car occupants; P = 0.003), thoracic (39.2% vs. 30.9%; P = 0.01), cervical (24.3% vs. 37.0%; P < 0.001), and sacral (1.3% vs. 7.5%; P < 0.001). The AO Spine type C injuries were present in 6.1% of motorcyclists and 10.1% of car occupants (P = 0.03). Motorcyclists were younger, less educated, had a higher proportion of males, and less commonly used safety devices than car occupants. The most commonly fractured spine region among both groups was the lumbar region. The cervical and sacral vertebrae fractures were significantly more common in car occupants, whereas the thoracic and lumbar vertebrae fractures were significantly more common in motorcyclists. [ABSTRACT FROM AUTHOR]

Study Design. Retrospective cohort. Objective. Examine the relationship between compensatory pelvic retroversion, positive sagittal imbalance (measured by C2 tilt), and the C2 pelvic angle (C2PA) in patients before long spinal fusions; and to determine the association between changes in C2PA and pelvic tilt (PT) following long spinal fusions. Background. Adult spinal deformity surgical goals often include a PT target, yet patients frequently demonstrate persistent compensatory pelvic retroversion following surgery. Methods. Adults above 18 years old undergoing long spinal fusions (> 4 levels) with standing preoperative and postoperative radiographs were included. To examine drivers of preoperative sagittal balance, regression models were fit to estimate the association between preoperative C2PA and pelvic incidence with preoperative PT and C2 tilt. To predict postoperative change in PT, multivariable regression was used to estimate change in PT, adjusting for change in C2PA and preoperative C2 tilt. Results. Among the 80 patients identified, the median age was 61 (IQR: 45-72) and 46 (58%) were female. The median number of levels fused was 10 (IQR: 8-13) and 55 (69%) were instrumented to the sacrum/pelvis. Preoperative C2PA had a significant nonlinear association with preoperative PT (r2=0.81, P<0.001) and preoperative C2 tilt (r2= 0.41, P= 0.002). Postoperative change in PT was strongly associated with change in C2PA (β=0.81; P<0.001) and preoperative C2 tilt (β= 0.55; P< 0.001). Conclusions. Following long spinal fusions, change in PT (or lack thereof) can be reliably predicted based on change in C2PA and preoperative C2 tilt. In patients with normal preoperative C2 tilt, the change in C2PA is nearly equivalent to the change in PT, but in patients with more positive C2 tilt (sagittal imbalance), a greater change in C2PA will be required to achieve an equivalent change in PT. [ABSTRACT FROM AUTHOR]

A 5-year-old Japanese Black cow presented with astasia. Bovine leukemia virus (BLV) was detected in the peripheral blood with lower proviral load (PVL). No enlargement of surface lymph nodes or lymphocytosis was observed. Necropsy revealed no enlarged lymph nodes in the thoracic, abdominal, or pelvic cavity. Spinal epidural and peri-medullary adipose tissue was increased in the spinal canal of lumbar to sacral vertebrae, Histopathological examination revealed tumor invasion of the epidural adipose tissue, and a diagnosis of B-cell lymphoma was made. The PVL in tumor tissue was higher, and monoclonal integration of BLV was confirmed. It was a rare case of bovine enzootic leukosis that formed a solitary mass around the spinal cord which might cause hindlimb paresis. [ABSTRACT FROM AUTHOR]

Purpose: A systematic review and meta-analysis for incidence and risk factors of new-onset sacroiliac joint pain (SIJP) after spinal surgery aimed to provide evidence-based medical references for its early prevention, timely intervention, and appropriate treatment. Methodology: The protocol of the systematic review and meta-analysis was registered in the International Prospective Register of Systematic Review (PROSPERO) with the PROSPERO ID (CRD42023463177). Relevant studies were searched to January 2024 from the databases of PubMed, Embase, Cochrane Library, and Web of Science, and the types of studies were cohort studies, case-control studies, and cross-sectional studies. Study quality was assessed using the Newcastle-Ottawa Scale (NOS) and the Cross-Sectional/Prevalence Study Quality recommended by the Agency for Healthcare Research and Quality (AHRQ). Two authors conducted studies search, data extraction, and quality assessment independently. Meta-analyses were done using Stata 14.0 software. Results: Twelve observational studies with 3,570 spinal surgery patients were included. Ten were case-control studies, one was a cross-sectional study, and another was a cohort study, all of which were of moderate quality and above. The results of the meta-analysis showed that the incidence of new-onset SIJP after spinal surgery was 9.40%; females, no. of surgical segments, fusion to the sacrum, and postoperative pelvic tilt (PT) were significantly associated with the new-onset SIJP after spinal surgery. Meta-analyses for preoperative and postoperative controls of spondylopelvic parameters showed that postoperative lumbar lordosis (LL) in the SIJP group and postoperative LL and sacral slope (SS) of patients in the NoSIJP group had significant differences from preoperative. Conclusion: Available evidence suggests that an increased risk of new-onset SIJP after spinal surgery is associated with sex, multi-segmental surgery, fusion to the sacrum, and greater postoperative PT. [ABSTRACT FROM AUTHOR]

Sacral insufficiency fractures are known to occur primarily in older women without adequate trauma. While an association with low bone mineral density (ie, osteoporosis) has been reported, more detailed information on local bone quality properties in affected patients is not available. In the present study, core biopsies were obtained from the S1 sacral ala in patients with a bilateral sacral insufficiency fracture (type IV according to the fragility fractures of the pelvis classification) who required surgical stabilization. Dual energy X-ray absorptiometry (DXA) and laboratory bone metabolism analyses were performed. For comparison, control biopsies were acquired from skeletally intact age- and sex-matched donors during autopsy. A total of 31 biopsies (fracture: n = 19; control: n = 12) were evaluated by micro-computed tomography, histomorphometry on undecalcified sections, and quantitative backscattered electron imaging (qBEI). DXA measurements showed mean T-scores in the range of osteoporosis in the fracture cohort (T-scoremin −2.6 ± 0.8). Biochemical analysis of bone metabolism parameters revealed high serum alkaline phosphatase and urinary deoxypyridinoline/creatinine levels. In the biopsies, a loss of trabecular microstructure along with increased osteoid values were detected in the fracture patients compared with controls (osteoid volume per bone volume 5.9 ± 3.5 vs. 0.9 ± 0.5%, p <.001). We also found evidence of microfractures with chronic healing processes (ie, microcallus) as well as pronounced hypomineralization in the biopsies of the fracture cohort compared with the controls as evidenced by lower CaMean measured by qBEI (22.5 ± 1.6 vs. 24.2 ± 0.5 wt%, p =.003). In conclusion, this high-resolution biopsy study provides evidence of local hypomineralization in patients with sacral insufficiency fractures, pointing to reduced fracture resistance but also a distinct phenotype other than the predominant loss of trabeculae as in postmenopausal osteoporosis. Our data highlight the importance of therapies that promote bone mineralization to optimally treat and prevent sacral insufficiency fractures. Lay Summary: Sacral insufficiency fracture is a type of fracture occurring particularly in older women after low-energy trauma or repetitive physiologic loads. While it is suspected that diminished bone quality plays a causal role, it has not yet been investigated which aspects of bone quality are affected by means of a biopsy study. Here, the microstructure, turnover, and mineralization were investigated in biopsies obtained from patients with bilateral sacral insufficiency fractures during surgery. Compared with a control group of skeletally intact donors, the most striking finding in the biopsies of the fracture patients was impaired bone mineralization. Namely, high proportions of unmineralized osteoid and low bone matrix mineralization were detected by undecalcified histology and quantitative backscattered electron imaging, respectively. In addition, the trabeculae of some biopsies showed signs of chronic microfracture. Collectively, these results not only show that sacral insufficiency fractures belong to a spectrum different from classical osteoporosis-related fractures but also underline the importance of therapies that promote bone mineralization, for instance vitamin D and calcium supplementation. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective cohort study. Objectives: In patients undergoing adult spinal deformity (ASD) surgery we sought to: 1) report preoperative and postoperative lumbosacral fractional (LSF) curve and maximum coronal Cobb angles and 2) determine their impact on radiographic, clinical, and patient-reported outcomes (PROs). Methods: A single-institution cohort study was undertaken. The LSF curve was the cobb angle between the sacrum and most tilted lower lumbar vertebra. Coronal/sagittal vertical axis (CVA/SVA) were collected. Patients were compared between 4 groups: 1) Neutral Alignment (NA); 2) coronal malalignment only (CM); 3) Sagittal malalignment only (SM); and 4) Combined-Coronal-Sagittal-Malalignment (CCSM). Outcomes including postoperative CM, postoperative coronal vertical axis, complications, readmissions, reoperation, and PROs. Results: A total of 243 patients underwent ASD surgery with mean total instrumented levels of 13.5. Mean LSF curve was 12.1±9.9°(0.2-62.3) and mean max Cobb angle was 43.0±26.5° (0.0-134.3). The largest mean LSF curves were seen in patients with CM (14.6°) and CCSM (13.1°) compared to NA (12.1°) and SM (9.5°) (p=0.100). A higher LSF curve was seen in patients with fusion to the sacrum and instrumentation to the pelvis (p=0.009), and a higher LSF curve was associated with more TLIFs (p=0.031). Postoperatively, more TLIFs were associated with greater amount of LSF curve correction (p<0.001). Comparing the LSF and the max Cob angle among Qiu types, the highest mean max Cobb angle was in Qiu Type B patients (p=0.025), whereas the highest mean LSF curve was in Qiu Type C patients (p=0.037). Moreover, 82.7% of patients had a LSF curve opposite the max Cobb angle. The LSF curve was larger than the max Cobb angle in 22/243 (9.1%) patients, and most of these 22 patients were Qiu Type A (59.1%). Regarding correction, the max Cobb angle achieved more correction than the LSF curve, judged by the percent improved from preop (54.5% Cobb vs. 46.5% LSF, p=0.025) in patients with max cobb>20° and LSF curve >5°. The LSF curve underwent greater correction in Qiu Type C patients (9.2°) compared to Type A (5.7°) and Type B (5.1°) (p=0.023); however, the max Cobb angle was similarly corrected among Qiu Types: Type A 21.8°, Type B 24.6°, and Type C 25.4° (p=0.602). Minimal differences were seen comparing the preop/postop/change in LSF curve and max Cobb angle regarding postop CM, postop CVA, complications, readmissions, reoperation, and PROs. Conclusions: The LSF curve was highest in patients with CM, CCSM, and Qiu Type C curves. Most patients had a LSF curve opposite the max Cobb angle. The max Cobb angle was more often corrected than the LSF curve. The LSF curve underwent greater correction among Qiu Type C patients, whereas the max Cobb angle was similarly corrected among all Qiu Types. No clear trend was seen regarding postoperative complications and PROs between the LSF curve and max Cobb angle. [ABSTRACT FROM AUTHOR]

Background: Axial spondyloarthritis (axSpA) is a group of inflammatory diseases that may lead to ankylosis of the sacroiliac joint and spine. Fat lesion in the sacroiliac joint is an important feature in diagnosis and disease progression of axSpA. However, whether there is alteration of fatty acids (FAs) composition has not been investigated using MRI. Purpose: To investigate bone marrow FA composition of the sacroiliac joint in patients with axSpA compared to controls. Study Type: Prospective. Subjects: Eighty five participants (mean age, 32.3 ± 6.1 years): 48 axSpA (25 male, 23 female) and 37 non‐SpA controls (18 male, 19 female). Field Strength/Sequence: 3.0 T/Two multiple gradient‐echo chemical shift‐encoded (CSE) MRI which differed only in echo times (TEs) were scanned consecutively. Assessment: Axial multi‐echo CSE MRI was performed in the sacroiliac joints in vivo. Regions of interest (ROIs) were manually placed on subchondral bone with and without fat lesion in axSpA patients, and on subchondral bone without fat lesion in controls. FA composition was computed within the ROIs using a nonlinear least square method from literature. Statistical Tests: Intergroup comparisons were performed using t tests. Results: In axSpA, male patients had significantly higher monounsaturated FA compared to controls in areas with fat lesion in the sacrum (+12%) and in the ilium (+9%), and in areas without fat lesion in the sacrum (+10%). Significantly lower polyunsaturated FAs were found in areas with fat lesion in the sacrum (−10%) and ilium (−11%), and lower saturated FAs were found in areas without fat lesion in the sacrum (−6%). In female, patients with axSpA had significantly higher saturated FAs in areas with fat lesion in the ilium (+7%) in comparison to controls. Data Conclusion: FA composition of the sacroiliac joint alters in patients with axSpA, and it can be detected using CSE MRI based analysis. [ABSTRACT FROM AUTHOR]

Simple Summary: The vertebral canal dimensions are crucial for spinal health, as degenerative changes can significantly affect the spinal cord. Compression of spinal nerves at the lumbosacral junction causes cauda equina syndrome (CES), more common in dogs than cats. With regard to the limited information on feline vertebral canal dimensions, this study examined 50 cats, measuring the interpedicular (ID) and midsagittal (SD) diameters as well as the intervertebral disc width (IVDW) in 28 of these animals. The region between the first thoracic (Th1) and the first sacral vertebra (S1) was considered using dissected cats. All cats showed a notable narrowing of the spinal canal from L6 to S1 with the narrowest point at S1. The widest parts of the vertebral canal correspond with the spinal cord enlargements. IVDW was found to be fairly consistent up to Th10–Th11, with the widest discs present at L7–S1 in 95.65% of cats. These data aim to understand potential correlations between the vertebral canal dimensions and the IVDW in terms of predispositions to spinal diseases in cats, especially compressive myelopathies. Further studies should be conducted to investigate the influence of age, sex and breed. As part of the spine, the vertebral canal represents a central structure protecting the spinal cord running within it. Since alterations to the spinal canal and adjacent structures can have a significant impact on the spinal cord, knowledge of the physiological vertebral canal dimensions is essential. Compression of spinal nerves at the lumbosacral junction is the primary cause of cauda equina syndrome (CES). Although CES is common in dogs, it is rarely documented in cats. Given the lack of information on normal vertebral canal dimensions in cats, it is necessary to collect data and verify currently used measurements, to determine if and to what extent comparisons with dogs are valid. In 50 cats, interpedicular (ID) and midsagittal (SD) diameters were examined from the first thoracic (Th1) to the first sacral vertebra (S1). In 28 of these animals, the intervertebral disc width (IVDW) was measured. All data were gathered through gross anatomical dissection of the cats. Significant lumen reduction was evident in all cats from L6 to S1 with the narrowest point at S1. Narrowings were also found in the thoracic spine. The widest points coincide with the spinal cord enlargements. IVDW shows relatively constant values up to Th10–Th11 and peaks at L7–S1 in 95.65% of cats. While distinct similarities to dogs were observed, differences exist. The findings allow conclusions as to whether relations between the parameters and resulting predispositions to pathological changes can be derived. This could help the understanding of the pathogenesis of feline spinal diseases, particularly compressive myelopathies. Further studies are necessary to investigate the impact of age, sex and breed. [ABSTRACT FROM AUTHOR]

An articulated group of skeletal elements comprising a sacrum, both ilia and a first caudal vertebra, plus an isolated tooth found in immediate proximity to the bones, from the lower Cenomanian Chalk at Saint-Jouin-Bruneval (Seine-Maritime, Normandy, France) is described and attributed to a new genus and species of abelisaurid theropod, Caletodraco cottardi, on the basis of several characters of the sacrum and pelvis. The peculiar shape of the transverse process of the first caudal vertebra shows that Caletodraco cottardi differs from majungasaurine abelisaurids previously described from Europe, such as Arcovenator escotae, and belongs to the Furileusauria, a group of derived abelisaurids hitherto recognized only from South America. The presence of a furileusaurian abelisaurid in the Cenomanian of Normandy suggests that the biogeographical history of the Abelisauridae in Europe was more complex than hitherto admitted. Several previously described European abelisaurids, such as the Albian Genusaurus sisteronis, may in fact belong to the Furileusauria. [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.

Retrospective review of all spinal fusions > 3 levels involving the thoracolumbar and/or sacroiliac at a single institution, by a single surgeon between 3/12/2020 and 8/13/2021 were reviewed. All screws that were secondarily navigated after identified as misdirected on intraoperative CT scan were included. Neuromonitoring reports were culled for mA threshold to triggered EMG response for all redirected screws. Intraoperative, post-de novo screw placement images (fluoroscopy scout and intraoperative CT) and post-redirection intraoperative scoliosis films and post-operative scoliosis films were independently reviewed by a senior neuroradiologist. Fifty redirected screws in the thoracic, lumbar, sacral, and ilium were identified as misdirected and redirected via navigation. The new trajectory of all screws was confirmed satisfactory by independent review between a senior neuroradiologist and neurosurgeon. Four screws could not be verified by post-operative imaging (4/50, 8%). All triggered EMG stimulated > 15 mA. No screws required return to the operating room for revision. No patients experienced a post-operative deficit. Redirection of misdirected thoracolumbar and sacroiliac screws can be performed using intraoperative CT and navigation as a means to detect and directly visualize appropriate placement.

We report an uncommon case of primitive neuroectodermal tumor/ Ewing's sarcoma of the lumbar and sacral nerve plexus in a 17years old boy who presented with an intense pain in the lower back radiating to legs. Magnetic resonance imaging showed a soft tissue mass with thickening of lumbar and sacral spinal nerve roots (L5-S3 level), along with widening of the corresponding foramina. There was also posterior scalloping of L5/S1 vertebrae and invasion of the sacral bone. A Partial resection has been performed, and the ensuing histopathology confirmed the diagnosis of PNET/Ewing's sarcoma. MRI in conjunction with histopathology are the key to narrow down the differential diagnoses list. PNET of lumbosacral area remain scarce, and only few cases have been reported nowadays. Given to the aggressivity of these tumors, the prognosis is poor despite appropriate treatment.

Background: The authors believe that the L5-S1 facet joint injury in the setting of pelvic fractures is underappreciated by orthopedic traumatologists. The purpose of this study was to draw attention to the L5/S1 facet joint in the setting of pelvic ring injuries. Methods: This was a retrospective comparative study of all patients greater than or equal to 18 years of age with an acute pelvic ring injury (AO/OTA 62 B to C) presenting to a single level I trauma center. The primary objective was to determine demographic and injury characteristics associated with L5-S1 facet joint injuries in patients with pelvic ring injuries. The secondary objective was to determine the proportion of L5-S1 facet joint injuries that were missed on initial radiographic workup. Results: There were 476 patients included in the analysis, 53 (11.1%) of whom had an L5-S1 facet joint injury. Patients with an L5-S1 injury were more likely to be younger (44.1 vs. 53.2 years, p = 0.001) and experience a high energy mechanism of injury (95.0% vs. 78.0%, p = 0.002). Certain injury patterns were associated with L5-S1 facet joint injuries: any sacral fracture (96.2% vs. 73.8%, p < 0.001), Denis zone 2 fractures (43.4% vs. 20.1%, p < 0.001), Denis zone 3 fractures (34.0% vs. 4.7%, p < 0.001), bilateral displaced sacral fractures (18.9% vs. 3.5%, p < 0.001), and L5 transverse process fractures (64.2% vs. 18.0%, p < 0.001). Only 16.0% of radiology reports identified an L5-S1 injury. Conclusions: Orthopedic traumatologists should scrutinize imaging for L5-S1 facet joint injuries in the presence of pelvic ring injuries, especially in patients with certain sacral fracture patterns. [ABSTRACT FROM AUTHOR]

Żywot Mateusza (1968) w reżyserii Witolda Leszczyńskiego to w polskiej kinematografii film niezwykły. Krytyka polska i światowa wskazywała na odmienność filmu od standardowych propozycji repertuarowych: akcentowano nadzwyczajne efekty pracy operatora, podnoszono talent i siłę kreacji Franciszka Pieczki, odtwórcy głównej roli. Jeden z recenzentów mówił nawet o arcydziele. Prezentowany tekst jest interpretacją filmu po ponad pięćdziesięciu latach, próbą sprawdzenia jego aktualności. Autor odsłania, rzadko podkreślany, wymiar misteryjny, sakralny filmu (w Eliadowskim rozumieniu). Wskazuje na osobność i niewspółczesność tytułowego bohatera. Analizuje kilka istotnych znaczeniowo filmowych kadrów, starając się wydobyć najistotniejsze cechy światoodczucia Mateusza. Ostatecznie, pokazuje, że jego ustami wypowiedziane zostaje fundamentalne filozoficzne pytanie, które każe zastanowić się nad rzekomą oczywistością naszej relacji z rzeczywistością.

Study Design. Retrospective cohort study. Objective. To compare outcomes in anteriorly placed transforaminal lumbar interbody fusions (TLIFs) and anterior lumbar interbody fusions (ALIFs). Summary of Background Data. TLIF and ALIF are surgical techniques that have become more prevalent in recent years. Although studies have compared the two, none have considered TLIFs with anteriorly placed cages, which may serve as a better comparison to ALIFs. Patients and Methods. Patients undergoing TLIF or ALIF with posterior instrumentation from 2010 to 2020 at a tertiary care institution were retrospectively identified. TLIF cage position was assessed and those with anterior placement were included. Electronic medical records were reviewed to identify patient characteristics and patient-reported outcomes. Radiographic outcomes included posterior disc height (DH), lumbar lordosis (LL), sacral slope, pelvic incidence, and pelvic tilt. Statistical analysis was performed to compare the two groups. Results. Of the 351 patients, 108 had ALIF with posterior instrumentation and 207 had a TLIF. Preoperatively, patients undergoing TLIF had less LL (53.7° vs. 60.6°, P < 0.001), sacral slope (38.3° vs. 43.7°, P < 0.001), and pelvic incidence (60.1° vs. 66.1°, P < 0.001), all of which remained significant at 1-year and long-term follow-up (P < 0.001). The TLIF group had less ΔDH (1.51° vs. 5.43°, P < 0.001), ΔLL (1.8° vs. 2.97°, P = 0.038), and Δsegmental lordosis (0.18° vs. 4.40°, P < 0.001) at 1 year postoperatively. At 2 to 3 years, ΔDH (P < 0.001) and Δsegmental lordosis (P = 0.001) remained significant, but ΔLL (P = 0.695) did not. Patients in the TLIF group had higher Visual Analog Scale-Back scores 1 year postoperatively (3.68 vs. 2.16, P = 0.008) and experienced less improvement in Oswestry Disability Index (-17.1 vs. -28.6, P = 0.012) and Visual Analog Scale-Back (-2.67 vs. -4.50, P = 0.008) compared with patients undergoing ALIF. Conclusions. Our findings suggest that ALIF with posterior instrumentation performed superiorly in radiographic outcomes and patient-reported outcomes compared with anteriorly placed TLIFs. Anteriorly placed TLIF cages may not achieve the same results as those of ALIF cages. [ABSTRACT FROM AUTHOR]

Degenerative diseases of the lumbar spine decrease lumbar lordosis (LL). Anterior lumbar interbody fusion (ALIF) at the L5-S1 disc space improves segmental lordosis, LL, and sagittal balance. This study investigated reciprocal changes in spinopelvic alignment after L5-S1 ALIF. A retrospective chart review identified patients who underwent L5-S1 ALIF with or without posterior fixation at a single institution (November 1, 2016 to October 1, 2021). Changes in pelvic tilt, sacral slope, proximal LL (L1-L4), distal LL (L4-S1), total LL (L1-S1), segmental lordosis, pelvic incidence–LL mismatch, thoracic kyphosis, cervical lordosis, and sagittal vertical axis were measured on preoperative and postoperative radiographs. Forty-eight patients were identified. Immediate postoperative radiographs were obtained at a mean (SD) of 17 (20) days after surgery; delayed radiographs were obtained 184 (82) days after surgery. After surgery, patients had significantly decreased pelvic tilt (15.71° [7.25°] vs. 17.52° [7.67°], P = 0.003) and proximal LL (11.86° [10.67°] vs. 16.03° [10.45°], P < 0.001) and increased sacral slope (39.49° [9.27°] vs. 36.31° [10.39°], P < 0.001), LL (55.35° [13.15°] vs. 51.63° [13.38°], P = 0.001), and distal LL (43.17° [9.33°] vs. 35.80° [8.02°], P < 0.001). Segmental lordosis increased significantly at L5-S1 and decreased significantly at L2-3, L3-4, and L4-5. Lordosis distribution index increased from 72.55 (19.53) to 81.38 (22.83) (P < 0.001). L5-S1 ALIF was associated with increased L5-S1 segmental lordosis accompanied by pelvic anteversion and a reciprocal decrease in proximal LL. These changes may represent a reversal of compensatory mechanisms, suggesting an overall relaxation of spinopelvic alignment after L5-S1 ALIF. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study is to investigate whether the results of pelvimetry using original radiographic Martius images and the same images with high‐pass filtering applied ("edge images") would be consistent. Methods: A total of 30 primagravidas were included in this study. Three obstetricians independently measured the anteroposterior and transverse diameters of the pelvic inlet in the original and the edge images, recording the x‐ and y‐coordinates of the four endpoints. A Wilcoxon signed rank sum test was performed on the coordinate data to evaluate differences between the original and edge images. Results: In the analysis of all coordinate data, statistically significant differences were found in both x‐ and y‐coordinates of the sacral promontory point (SPP). In the y‐coordinate of the SPP, a statistically significant difference was found in 9 of 30 pairs of images, and in all 9 the anteroposterior diameter was shorter in the edge images compared to the original images due to the more caudal placement of the SPP. Conclusions: The coordinates of the SPP on original radiographs and their edge images were not consistent in pelvimetry using Martius images. Our results suggest that improved image contrast will allow obstetricians to better assess pelvic narrowing and cephalopelvic disproportion and even reduce radiographic dose, thereby reducing risks for pregnant women and their fetuses. [ABSTRACT FROM AUTHOR]

Study Design: A prospective study. Purpose: To assess fat–water-like tissue changes on the 1st sacral vertebra using novel magnetic resonance imaging (MRI) phantom-based F- and W-scores and evaluate their diagnostic performances in osteoporosis detection. Overview of Literature: Using an uncommonly advanced MRI technique, previous studies have found that fat–water changes were consistent with osteoporosis. The role of routine MRI sequences can be extended in this regard. The S1 vertebra is considered a crucial anatomical site in spine surgeries because it seldom suffers from fractures. Thus, S1 could indicate osteoporotic fat–water changes. Methods: Forty-two female volunteers (aged 62.3±6.3 years) underwent spine examination with both MRI (including a phantom) and dual-energy X-ray absorptiometry (DXA) following ethical approval. MRI phantom-based F- and W-scoreS1 were defined by normalizing S1 vertebral signal intensities (SIs) by coconut oil and water SIs of the phantom on T1- and T2-weighted imaging, respectively. Using receiver operating characteristic analysis, the diagnostic performances of the new scores for evaluating osteoporosis and vertebral fractures were investigated against standard areal bone mineral density measured with DXA (DXA-aBMD). Results: The F-scoreS1 and W-scoreS1 were greater (4.11 and 2.43, respectively) in patients with osteoporosis than those without osteoporosis (3.25 and 1.92, respectively) and achieved areas under the curve (AUCs) of 0.82 and 0.76 (p<0.05), respectively, for osteoporosis detection. Similarly, the mean F-scoreS1 and W-scoreS1 were higher (4.11 and 2.63, respectively) in patients with vertebral fractures than in those without fractures (3.30 and 1.82, respectively) and had greater AUCs (0.90 for W-scoreS1 and 0.74 for F-scoreS1) than DXA-aBMD (AUC, 0.26; p<0.03). In addition, the F- and W-scoreS1 demonstrated a strong correlation (r=0.65, p<0.001). Conclusions: The new S1 vertebral-based MRI scores were developed to detect osteoporotic changes and demonstrated improvements over DXA-aBMD in differentiating patients with vertebral fractures. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To evaluate the feasibility of endoscopic inspection of thoracolumbar and lumbar pedicle tracts in a canine largebreed model and its accuracy for the detection of breached versus nonbreached tracts. ANIMALS: 2 greyhound cadavers. METHODS: CT scans of 2 greyhound cadavers from the sixth thoracic vertebra to the sacrum were obtained. Fifty-six pedicles were randomized to have drill tracts with different modified Zdichavsky grades (nonbreached, partial/full medial breach, or partial/full lateral breach) using 3-D-printed guides. Endoscopy was performed on a single occasion from October 9 to 10, 2023, using a 1.9-mm 0-degree needle arthroscope in a randomized blinded fashion. The grading of drill tracts was performed on postoperative CT. Specificity, sensitivity, positive and negative predictive values, and time to assign endoscopic grade were investigated. RESULTS: Postoperative CT confirmed 43 nonbreached tracts, 7 medial breaches (partial/full), and 5 lateral breaches (partial/full). One tract was excluded because of guide misplacement. Intraosseous endoscopy was successfully performed in the remaining 55 drill tracts. Sensitivity to detect medial and lateral breaches was 71.4% and 60.0%. Negative predictive value was 93.1%. Specificity was 94.2%. Positive predictive value for detection of medial and lateral breaches was 83.3% and 54.5%. Median (range) time to assign an endoscopic grade was 118 (30 to 486) seconds. [ABSTRACT FROM AUTHOR]

Purpose: Spinopelvic sagittal alignment is crucial for assessing balance and determining treatment efficacy in patients with adult spinal deformity (ASD). Only a limited number of reports have addressed spinopelvic parameters and lumbosacral transitional vertebrae (LSTV). Our primary objective was to study spinopelvic sagittal parameter changes in patients with LSTV. A secondary objective was to investigate clinical symptoms and quality of life (QOL) in patients with LSTV. Methods: In this study, we investigated 371 participants who had undergone medical check-ups for the spine. LSTV was evaluated using Castellvi's classification, and patients were divided into LSTV+ (type II-IV, L5 vertebra articulated or fused with the sacrum) and LSTV- groups. After propensity score matching for demographic data, we analyzed spinopelvic parameters, sacroiliac joint degeneration, clinical symptoms, and QOL for these two participant groups. Oswestry Disability Index (ODI) scores and EQ-5D (EuroQol 5 dimensions) indices were compared between the two groups. Results: Forty-four patients each were analyzed in the LSTV + and LSTV- groups. The LSTV + group had significantly greater pelvic incidence (52.1 ± 11.2 vs. 47.8 ± 10.0 degrees, P = 0.031) and shorter pelvic thickness (10.2 ± 0.9 vs. 10.7 ± 0.8 cm, P = 0.018) compared to the LSTV- group. The "Sitting" domain of ODI (1.1 ± 0.9 vs. 0.6 ± 0.7, P = 0.011) and "Pain/Discomfort" domain of EQ-5D (2.0 ± 0.8 vs. 1.6 ± 0.7, P = 0.005) were larger in the LSTV + group. Conclusion: There was a robust association between LSTV and pelvic sagittal parameters. Clinical symptoms also differed between the two groups in some domains. Surgeons should be aware of the relationship between LSTV assessment, radiographic parameters and clinical symptoms. Level of evidence: 3. [ABSTRACT FROM AUTHOR]

Background: Sacroiliac joint (SIJ) motion has been documented using invasive and noninvasive kinematic techniques. No study has explored SIJ angular positions in functional postures using noninvasive techniques. The purpose of this study was to quantify SIJ positioning among different seated postures in a healthy population. Methods: Twelve female and 11 male healthy young participants participated. Left and right anterior and posterior superior iliac spines were manually digitized during standing, neutral sitting and four different seated postures. Rigid bodies recorded the kinematics of the lumbar spine. Angles calculated included transverse sacroiliac angle, innominate sagittal angle, sacral tilt, lumbar flexion-extension, lumbar lateral bend and lumbar axial twist. Findings: The observed range of angular positions was approximately 3 to 4 degrees across the SIJ-related angles. The main effect of seated posture was observed for all angles measured. The main effect of sex was observed for all angles except lumbar lateral bending. Females consistently experienced more posterior sacral tilt than males. Interaction effects between sex and posture were only observed at the right-transverse sacroiliac angle and sacral tilt. Previous sitting posture affected the subsequent neutral sitting posture for the right-transverse sacroiliac angle and lumbar spine angle. Interpretation: SIJ angular position differences among the seated postures were similar in magnitude to motions previously reported in participants undergoing prone passive hip abduction and external rotation. Sex differences, including greater sacral posterior tilt observed in females, likely reflect underlying morphological and physiological differences. Future studies should explore SIJ positioning during functional tasks in pathological populations to help elucidate the underlying causes of SIJ pain and inform treatment strategies. [ABSTRACT FROM AUTHOR]

To evaluate the possible impact of patients' sacral ratios (SRs) on response to biofeedback (BF) therapy in pediatric patients with lower urinary tract dysfunction (LUTD). In this retrospective cohort conducted from 2016 to 2018 in our tertiary medical center, we included the medical records of all pediatric patients with LUTD who were nominated for BF due to having abnormal uroflowmetry patterns and simultaneous increase in electromyography (EMG) activity. Ten sessions of weekly animated BF were performed for each patient. All patients underwent a complete urological evaluation, uroflowmetry with simultaneous EMG and post-void residual measurement before and after treatment. SRs were calculated based on plain anteroposterior lumbosacral radiographs. Patients were then divided into normal SR (≥0.74) and low SR (<0.74) and outcomes were compared between them. Of the total 86 patients included in our study, 48 (55.8%) had a normal SR (≥0.74), while 38 (44.2%) had a low SR (<0.74). Our data revealed that BF therapy significantly improved maximum and average urinary flow rates, urine volume, daytime urinary incontinence, enuresis, urinary urgency and constipation; irrespective of the patients' SRs (all P < 0.001). Our between-groups analyses showed that after the completion of BF, the SR ≥ 0.74 group had significantly higher maximum urinary flow rate (mean difference [95%CI]: 7.7 [5.4, 10.0], P < 0.001) (Figure) and urine volume (mean difference [95%CI]: 49.9 [19.5, 80.4], P = 0.002) and significantly lower diurnal urinary incontinence (4.2% vs. 21.1%, P = 0.020), enuresis (4.2% vs. 18.4%, P = 0.040) and constipation (2.1% vs. 23.7%, P = 0.004) compared to the SR < 0.74 group. SR has been proposed as a reliable indicator of bony pelvis growth and subsequent lumbosacral neurodevelopment. Additionally, larger SR values are associated with better postoperative sphincter function in children with urological and anorectal malformations. Our results demonstrated that after completion of BF, the normal SR group had a significantly better improvement of some of the uroflowmetry indicators and LUTD-associated symptoms compared to the low SR group. Our findings implied that although BF therapy is an efficient treatment for children with LUTD, irrespective of their sacral development; children with enhanced sacral development may benefit from better clinical response, especially in terms of LUTD-associated symptoms. [ABSTRACT FROM AUTHOR]

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We evaluated whether the clinical outcomes, including postoperative knee range of motion (ROM), after unicompartmental knee arthroplasty (UKA) were associated with the sagittal spinopelvic parameters and coronal alignment of the full lower extremity. Forty-two patients (50 knees: six men, seven knees; 36 women, 43 knees) who underwent medial UKA between April 2015 and December 2022 were included. Preoperative radiographic examinations of the index for sagittal spinopelvic alignment included the sagittal vertical axis (SVA), lumbar lordosis, sacral slope (SS), pelvic tilt (PT), and pelvic incidence. The anteroposterior hip-knee-ankle angle (HKAA) was calculated. The relationship of clinical outcomes and the risk of knee flexion angle ≤125° and knee flexion contracture ≥10° 1-year post-UKA with radiographic parameters were evaluated. Preoperative HKA angle affected postoperative knee flexion angle ≤125° (p = 0.017, 95% confidence interval [CI]: 0.473–0.930) in logistic regression analysis. Patients with a knee flexion angle ≤125° had a higher preoperative HKAA (9.8 ± 3.0°), higher SVA (83.8 ± 37.0 mm), and lower SS (23.7 ± 9.0°) than those with a flexion angle >125° (preoperative HKAA: 6.6 ± 4.0°, SVA: 40.3 ± 46.5 mm, SS: 32.0 ± 6.3°) (p = 0.029, 0.012, and 0.004, respectively). PT related to postoperative knee flexion contracture ≥10° (p = 0.010, 95% CI: 0.770–0.965) in the logistic regression analysis. Patients with flexion contracture ≥10° had higher PT (35.0 ± 6.6°) and SVA (82.2 ± 40.5 mm) than those with flexion contracture <10° (PT, 19.3 ± 9.0°; SVA, 42.4 ± 46.5 mm) (p = 0.001 and 0.028, respectively). The postoperative clinical outcome was correlated with the postoperative knee flexion angle and SVA (p = 0.036 and 0.020, respectively). The preoperative HKAA affected postoperative knee flexion angle, and the knee flexion contracture and clinical outcomes post-UKA were associated with PT and SVA, respectively. To predict outcomes for knee ROM and clinical scores after UKA, radiographic examination, including the sagittal spinopelvic parameters and the coronal view of the full lower extremity, is essential. [ABSTRACT FROM AUTHOR]

Currently, only birds have a pneumatic system, but in the past, this was common among several ornithodirans. Within Titanosauria, it was the saltasaurines that showed a high degree of postcranial pneumaticity. The objective of this work is analysing the extent of postcranial pneumaticity in saltasaurines and compare it with other derived titanosaurs. To carry out this work, presacral vertebrae, dorsal ribs, scapulae, coracoids and ilia of saltasaurines were analysed. The presacral vertebrae present a high degree of pneumatisation with a highly variable distribution of foramina, with some ‘foramina zones’, there is a homoplastic pattern of pneumaticity: presence of foramina connected to camellated tissue. With respect to the ilia, camellated tissue was recorded in all taxa. Instead, scapulae and coracoids, present camellated tissue in Saltasaurus and they cannot be pneumatised in Neuquensaurus. Comparing with other titanosaurs, we observe that there are ‘foramina zones’ for presacral and caudal vertebrae. It is also possible to establish that the pneumatisation of the dorsal ribs has a conservative pattern, not only in saltasaurines but also in the Saurischia clade, and the presence of pneumaticity in the ilia is frequent in the Lithostrotia and even outside, in rebbachisaurs. [ABSTRACT FROM AUTHOR]

Background: Sacral screw loosening is a typical complication after internal fixation surgery through the vertebral arch system. Bicortical fixation can successfully prevent screw loosening, and how improving the rate of bicortical fixation is a challenging clinical investigation. Objective: To investigate the feasibility of improving the double corticality of sacral screws and the optimal fixation depth to achieve double cortical fixation by combining the torque measurement method with bare hands. Methods: Ninety-seven cases of posterior lumbar internal fixation with pedicle root system were included in this study. Based on the tactile feedback of the surgeon indicating the expected penetration of the screw into the contralateral cortex of the sacrum, the screws were further rotated by 180°, 360°, or 720°, categorized into the bicortical 180° group, bicortical 360° group, and bicortical 720° group, respectively. Intraoperatively, the torque during screw insertion was recorded. Postoperatively, the rate of double-cortex engagement was evaluated at 7 days, and screw loosening was assessed at 1 year follow-up. Results: The bicortical rates of the 180° group, 360° group, and 720° group were 66.13%, 91.18% and 93.75%, respectively. There were statistically significant differences between the 180° group and both the 360° and 720° groups (P < 0.05). However, there was no statistically significant difference between the 360° group and the 720° group (P > 0.05).The rates of loosening of sacral screws in the 180° group, 360° group, and 720° group were 20.97%, 7.35% and 7.81%, respectively. There were statistically significant differences between the 180° group and both the 360° and 720° groups (P < 0.05). However, there was no statistically significant difference between the 360° group and the 720° group (P > 0.05). The bicortical 360° group achieved a relatively satisfactory rate of dual cortical purchase while maintaining a lower rate of screw loosening. Conclusion: Manual insertion of sacral screws with the assistance of a torque measurement device can achieve a relatively satisfactory dual cortical purchase rate while reducing patient hospitalization costs. [ABSTRACT FROM AUTHOR]