Hypotension in the Emergency Department and Contrast Extravasation on Computerized Tomography Predict Blood Transfusion in Low-Energy Pelvic Fractures.

INTRODUCTION: Although low-energy pelvic fractures seldom present with significant hemorrhage, early recognition of at-risk patients is essential. We aimed to identify predictors of transfusion requirements in this cohort. METHODS: A 7-y retrospective chart review was performed. Low-energy mechanism was defined as falls of ≤5 feet. Fracture pattern was classified using the Orthopedic Trauma Association/Arbeitsgemeinschaft für Osteosynthesefragen system as A, B, or C. Primary outcome was transfusion of ≥2 units of packed red blood cells in the first 48 h. Univariable analysis and logistic regression analysis were performed. A P value ≤0.05 was considered significant. RESULTS: Five hundred forty six patients were included with median (interquartile range) age of 86 (79-91) and median (interquartile range) Injury Severity Score of 5 (4-8). Five hundred forty one (99%) had type A fractures. Twenty six (5%) had the primary outcome and 17 (3%) died. Logistic regression found that systolic blood pressure <100 mmHg at any time in the Emergency Department, Injury Severity Score, and pelvic angiography were predictors of the primary outcome. Seventeen percent of those who had the primary outcome died compared with 2% who did not (P = 0.0004). Three hundred sixty four (67%) received intravenous contrast for computerized tomography scans and of these, 44 (12%) had contrast extravasation (CE). CE was associated with the primary outcome but not mortality. CONCLUSIONS: Hypotension at any time in the Emergency Department and CE on computerized tomography predicted transfusion of ≥2 units packed red blood cells in the first 48 h in patients with low-energy pelvic fractures.

Population affinity estimation using pelvic measurements based on computed tomographic data acquired from Japanese and Western Australian populations.

The present study analyzes morphological differences in the pelvis of Japanese and Western Australian individuals and investigates the feasibility of population affinity classification based on computed tomography (CT) data. The Japanese and Western Australian samples comprise CT scans of 207 (103 females; 104 males) and 158 (78 females; 80 males) adult individuals, respectively. Following volumetric reconstruction, a total of 19 pelvic landmarks were obtained on each sample, and 11 measurements, including two angles, were calculated. Machine learning methods (random forest modeling [RFM] and support vector machine [SVM]) were used to classify population affinity. Classification accuracy of the two-way models was approximately 80% for RFM: the two-way sex-specific and sex-mixed models for SVM achieved > 90% and > 85%, respectively. The sex-specific models had higher accurate classification rates than the sex-mixed models, except for the Japanese male sample. The classification accuracy of the four-way sex and population affinity model had an overall classification accuracy of 76.71% for RFM and 87.67% for SVM. All the correct classification rates were higher in the Japanese relative to the Western Australian sample. Our data suggest that pelvic morphology is sufficiently distinct between Japanese and Western Australian individuals to facilitate the accurate classification of population affinity based on measurements acquired in CT images. To the best of our knowledge, this is the first study investigating the feasibility of population affinity estimation based on CT images of the pelvis, which appears as a viable supplement to traditional approaches based on cranio-facial morphology.

Plate fixation of inferior ramus in pubis-ischium ramus improves mechanical stability in Tile B pelvic injures: a cadaveric biomechanical analysis and early clinical experience.

BACKGROUND: Management of inferior ramus of the pubis-ischium ramus remains controversial, and related research is sparse. The main intention of this study is to describe the biomechanical and clinical outcomes of pubis-ischium ramus fractures in Tile B pelvic injuries and to identify the feasibility and necessity of fixation of the inferior ramus of the pubis-ischium ramus. METHODS: This study comprised two parts: a biomechanical test and a retrospective clinical study. For the biomechanical tests, Tile B-type pelvic injuries were modeled in six cadaver specimens by performing pubis-ischium osteotomies and disruption of the anterior and interosseous sacroiliac ligaments. The superior and/or inferior rami of the pubis-ischium ramus were repaired with reconstruction plates and separated into three groups (A, B, and C). Specimens were placed in the standing position and were loaded axially with two-leg support for three cycles at 500 N. The displacements of sacroiliac joints at osteotomy were measured with Vernier calipers and compared using statistical software. To investigate the clinical outcomes of this technique, 26 patients were retrospectively analyzed and divided into a superior ramus fixation group (Group D) and a combined superior and inferior ramus of the pubis-ischium ramus fixation group (Group E). The main outcome measures were time of operation, blood loss, postoperative radiographic reduction grading, and functional outcomes. RESULTS: In the vertical loading test, Group E showed better pelvic ring stability than Group D (P < 0.05). However, the shift of the sacroiliac joints was almost identical among the three groups. In our clinical case series, all fractures in Group E achieved bony union. Group E demonstrated earlier weight-bearing functional exercise (2.54 ± 1.45 vs 4.77 ± 2.09; P = 0.004), earlier bony union (13.23 ± 2.89 vs 16.55 ± 3.11; P = 0.013), and better functional outcomes (89.77 ± 7.27 vs 82.38 ± 8.81; P = 0.028) than Group D. The incidence of sexual dysfunction was significantly lower in Group E than that in Group D (2/13 vs 7/13; P = 0.039). Bone nonunion occurred in two patients in Group D, and two patients in Group E had heterotopic ossification. None of the patients exhibited wound complications, infections, implant failures, or bone-implant interface failures. CONCLUSIONS: Fixation of the inferior ramus of a pubis-ischium ramus fracture based on conventional fixation of the anterior pelvic ring is mechanically superior in cadaveric Tile B pelvic injury and shows rapid recovery, good functional outcomes, and low incidence of complications.

The role of sarcopenia in fragility fractures of the pelvis - is sarcopenia an underestimated risk factor?

BACKGROUND: Fragility fractures of the pelvis (FFPs) represent a significant health burden, particularly for the elderly. The role of sarcopenia, an age-related loss of muscle mass and function, in the development and impact of these fractures is not well understood. This study aims to investigate the prevalence and impact of osteoporosis and sarcopenia in patients presenting with FFPs. METHODS: This retrospective study evaluated 140 elderly patients with FFPs. The diagnosis of sarcopenia was assessed by psoas muscle area (PMA) and the height-adjusted psoas muscle index (PMI) measured on computed tomography (CT) scans. Clinical data, radiological findings and functional outcomes were recorded and compared with the presence or absence of sarcopenia and osteoporosis. RESULTS: Our study cohort comprised 119 female (85.0%) and 21 (15.0%) male patients. The mean age at the time of injury or onset of symptoms was 82.26 ± 8.50 years. Sarcopenia was diagnosed in 68.6% (n = 96) patients using PMA and 68.8% (n = 88) using PMI. 73.6% (n = 103) of our study population had osteoporosis and 20.0% (n = 28) presented with osteopenia. Patients with sarcopenia and osteoporosis had longer hospital stays (p < 0.04), a higher rate of complications (p < 0.048) and functional recovery was significantly impaired, as evidenced by a greater need for assistance in daily living (p < 0.03). However, they were less likely to undergo surgery (p < 0.03) and the type of FFP differed significantly (p < 0.04). There was no significant difference in mortality rate, pre-hospital health status, age or gender. CONCLUSION: Our study highlights the important role of sarcopenia in FFPs in terms of the serious impact on health and quality of life in elderly patients especially when osteoporosis and sarcopenia occur together. Identifying and targeting sarcopenia in older patients may be an important strategy to reduce pelvic fractures and improve recovery. Further research is needed to develop effective prevention and treatment approaches that target muscle health in the elderly.

Preoperative supine pelvic incidence predicts standing pelvic incidence following S2AI fixation in patients with adult spinal deformity: a prospective study.

STUDY DESIGN: A prospective study. OBJECTIVE: The aim of this study was to investigate the PI change in different postures and before and after S2­alar­iliac (S2AI) screw fixation, and to investigate whether pre-op supine PI could predict post-op standing PI. Previous studies have reported PI may change with various positions. Some authors postulated that the unexpected PI change in ASD patients could be due to sacroiliac joint laxity, S2-alar-iliac (S2AI) screw placement, or aggressive sagittal cantilever technique. However, there was a lack of investigation on how to predict post-op standing PI when making surgical strategy. METHODS: A prospective case series of ASD patients undergoing surgical correction with S2AI screw placement was conducted. Full-spine X-ray films were obtained at pre-op standing, pre-op supine, pre-op prone, as well as post-op standing postures. Pelvic parameters were measured. Spearman correlation analysis was used to determine relationships between each parameter. RESULTS: A total of 83 patients (22 males, 61females) with a mean age of 58.4 ± 9.5 years were included in this study. Pre-op standing PI was significantly lower than post-op standing PI (p = 0.004). Pre-op prone PI was significantly lower than post-op standing PI (p = 0.001). By contrast, no significant difference was observed between pre-op supine and post-op standing PI (p = 0.359) with a mean absolute difference of 2.2° ± 1.9°. Correlation analysis showed supine PI was significantly correlated with post-op standing PI (r = 0.951, p < 0.001). CONCLUSION: This study revealed the PI changed after S2AI screw fixation. The pre-op supine PI can predict post-op standing PI precisely, which facilitates to provide correction surgery strategy with a good reference for ideal sagittal alignment postoperatively.

Can the Cartilaginous Thickness Determine the Risk of Malignancy in Pelvic Cartilaginous Tumors, and How Accurate is the Preoperative Biopsy of These Tumors?

BACKGROUND: Peripheral osteochondral tumors are common, and the management of tumors presenting in the pelvis is challenging and a controversial topic. Some have suggested that cartilage cap thickness may indicate malignant potential, but this supposition is not well validated. QUESTIONS/PURPOSES: (1) How accurate is preoperative biopsy in determining whether a peripheral cartilage tumor of the pelvis is benign or malignant? (2) Is the thickness of the cartilage cap as determined by MRI associated with the likelihood that a given peripheral cartilage tumor is malignant? (3) What is local recurrence-free survival (LRFS), metastasis-free survival (MFS), and disease-specific survival (DSS) in peripheral chondrosarcoma of the pelvis and is it associated with surgical margin? METHODS: Between 2005 and 2022, 289 patients had diagnoses of peripheral cartilage tumors of the pelvis (either pedunculated or sessile) and were treated at one tertiary sarcoma center (the Royal Orthopaedic Hospital, Birmingham, UK). These patients were identified retrospectively from a longitudinally maintained institutional database. Those whose tumors were asymptomatic and discovered incidentally and had cartilage caps ≤ 1.5 cm were discharged (95 patients), leaving 194 patients with tumors that were either symptomatic or had cartilage caps > 1.5 cm. Tumors that were asymptomatic and had a cartilage cap > 1.5 cm were followed with MRIs for 2 years and discharged without biopsy if the tumors did not grow or change in appearance (15 patients). Patients with symptomatic tumors that had cartilage caps ≤ 1.5 cm underwent removal without biopsy (63 patients). A total of 82 patients (63 with caps ≤ 1.5 cm and 19 with caps > 1.5 cm, whose treatment deviated from the routine at the time) had their tumors removed without biopsy. This left 97 patients who underwent biopsy before removal of peripheral cartilage tumors of the pelvis, and this was the group we used to answer research question 1. The thickness of the cartilage cap was recorded from MRI and measuring to the nearest millimeter, with measurements taken perpendicular in the plane that best allowed the greatest measurement. Patient survival rates were assessed using the Kaplan-Meier method with 95% confidence intervals as median observation times to estimate MFS, LRFS, and DSS. RESULTS: Of malignant tumors biopsied, in 49% (40 of 82), the biopsy result was recorded as benign (or was considered uncertain regarding malignancy). A malignant diagnosis was correctly reported in biopsy reports in 51% (42 of 82) of patients, and if biopsy samples with uncertainty regarding malignancy were excluded, the biopsy identified a lesion as being malignant in 84% (42 of 50) of patients. The biopsy results correlated with the final histologic grade as recorded from the resected specimen in only 33% (27 of 82) of patients. Among these 82 patients, 15 biopsies underestimated the final histologic grade. The median cartilage cap thickness for all benign osteochondromas was 0.5 cm (range 0.1 to 4.0 cm), and the median cartilage cap thickness for malignant peripheral chondrosarcomas was 8.0 cm (range 3.0 to 19 cm, difference of medians 7.5 cm; p < 0.01). LRFS was 49% (95% CI 35% to 63%) at 3 years for patients with malignant peripheral tumors with < 1-mm margins, and LRFS was 97% (95% CI 92% to 100%) for patients with malignant peripheral tumors with ≥ 1-mm margins (p < 0.01). DSS was 100% at 3 years for Grade 1 chondrosarcomas, 94% (95% CI 86% to 100%) at 3 years for Grade 2 chondrosarcomas, 73% (95% CI 47% to 99%) at 3 and 5 years for Grade 3 chondrosarcomas, and 20% (95% CI 0% to 55%) at 3 and 5 years for dedifferentiated chondrosarcomas (p < 0.01). DSS was 87% (95% CI 78% to 96%) at 3 years for patients with malignant peripheral tumors with < 1-mm margin, and DSS was 100% at 3 years for patients with malignant peripheral tumors with ≥ 1-mm margins (p = 0.01). CONCLUSION: A thin cartilage cap (< 3 cm) is characteristic of benign osteochondroma. The likelihood of a cartilage tumor being malignant increases after the cartilage cap thickness exceeds 3 cm. In our experience, preoperative biopsy results were not reliably associated with the final histologic grade or malignancy, being accurate in only 33% of patients. We therefore recommend observation for 2 years for patients with pelvic osteochondromas in which the cap thickness is < 1.5 cm and there is no associated pain. For patients with tumors in which the cap thickness is 1.5 to 3 cm, we recommend either close observation for 2 years or resection, depending on the treating physician's decision. We recommend excision in patients whose pelvic osteochondromas show an increase in thickness or pain, preferably before the cartilage cap thickness is 3 cm. We propose that surgical resection of peripheral cartilage tumors in which the cartilage cap exceeds 3 cm (aiming for clear margins) is reasonable without preoperative biopsy; the role of preoperative biopsy is less helpful because radiologic measurement of the cartilage cap thickness appears to be accurately associated with malignancy. Biopsy might be helpful in patients in whom there is diagnostic uncertainty or when confirming the necessity of extensive surgical procedures. Future studies should evaluate other preoperative tumor qualities in differentiating malignant peripheral cartilage tumors from benign tumors. LEVEL OF EVIDENCE: Level III, diagnostic study.

3D-Printed custom-made hemipelvic endoprosthetic reconstruction following periacetabular tumor resection: utilizing a novel classification system.

BACKGROUND: Customized 3D-printed pelvic implants with a porous structure have revolutionized periacetabular pelvic defect reconstruction after tumor resection, offering improved osteointegration, long-term stability, and anatomical fit. However, the lack of an established classification system hampers implementation and progress. METHODS: We formulated a novel classification system based on pelvic defect morphology and 3D-printed hemipelvis endoprostheses. It integrates surgical approach, osteotomy guide plate and prosthesis design, postoperative rehabilitation plans, and perioperative processes. RESULTS: Retrospectively analyzing 60 patients (31 males, 29 females), we classified them into Type A (15 patients: Aa = 6, Ab = 9), Type B (27 patients: Ba = 15, Bb = 12), Type C (17 patients). All underwent customized osteotomy guide plate-assisted tumor resection and 3D-printed hemipelvic endoprosthesis reconstruction. Follow-up duration was median 36.5 ± 15.0 months (range, 6 to 74 months). The mean operating time was 430.0 ± 106.7 min, intraoperative blood loss 2018.3 ± 1305.6 ml, transfusion volume 2510.0 ± 1778.1 ml. Complications occurred in 13 patients (21.7%), including poor wound healing (10.0%), deep prosthesis infection (6.7%), hip dislocation (3.3%), screw fracture (1.7%), and interface loosening (1.7%). VAS score improved from 5.5 ± 1.4 to 1.7 ± 1.3, MSTS-93 score from 14.8 ± 2.5 to 23.0 ± 5.6. Implant osseointegration success rate was 98.5% (128/130), with one Type Ba patient experiencing distal prosthesis loosening. CONCLUSION: The West China classification may supplement the Enneking and Dunham classification, enhancing interdisciplinary communication and surgical outcomes. However, further validation and wider adoption are required to confirm clinical effectiveness.

Does a novel 3D printed individualized guiding template based on cutaneous fiducial markers contribute to accurate percutaneous insertion of pelvic screws? A preliminary phantom and cadaver study.

BACKGROUND: Most 3D-printed guiding templates require dissection of soft tissues to match the corresponding surfaces of the guiding templates. This study sought to explore the accuracy and acceptability of the novel 3D printed individualized guiding templates based on cutaneous fiducial markers in minimally invasive screw placement for pelvic fractures. METHODS: The printed template was tested on five high-fidelity biomimetic phantom models of the bony pelvis and its surrounding soft tissues as well as on two fresh frozen cadavers. Four cutaneous fiducial markers were transfixed on each phantom model prior to performing CT scans to reconstruct their 3D models. Personalized templates for guiding screw insertion were designed based on the positions of the fiducial markers and virtually planned target screw channels after scanning, followed by 3D printing of the guide. Phase 1 consisted of five expert surgeons inserting one anterograde supra-pubic screw and one sacroiliac screw percutaneously into each phantom model using the 3D-printed guide. The deviation of screw positions between the pre-operative planned and post-operative actual ones was measured after registering their 3D modelling. A Likert scale questionnaire was completed by the expert surgeons to assess their satisfaction and acceptability with the guiding template. Phase 2 consisted of repeating the same procedures on the fresh frozen cadavers in order to demonstrate face, content and concurrent validity. RESULTS: In Phase 1, all ten screws were successfully implanted with the assistance of the guiding template. Postoperative CT scans confirmed that all screws were safely positioned within the bony pelvic channels without breaching the far cortex. The mean longitudinal deviation at the bony entry point and screw tip between the pre-operative planned and post-operative actual screw paths were 2.83 ± 0.60 mm and 3.12 ± 0.81 mm respectively, with a mean angular deviation of 1.25 ± 0.41°. Results from the Likert questionnaire indicated a high level of satisfaction for using the guiding template among surgeons. In Phase 2, results were similar to those in Phase 1. CONCLUSIONS: The 3D-printed guiding template based on cutaneous fiducial markers shows potential for assisting in the accurate insertion of percutaneous screws in the pelvis.

Unstable pelvic fractures in women: implications on obstetric outcome.

PURPOSE: Obstetric outcomes in women following pelvic injuries requiring surgical fixation is not thoroughly known. We aimed to evaluate if radiographic measurements (RMs) can be used to provide information on delivery methods outcome after these injuries, and to evaluate if metal work removal is required prior to delivery. METHOD: A retrospective study in a level 1 trauma centre of female patients with pelvic fractures treated operatively, aged 16-45 at the time of injury. Participants completed a questionnaire regarding their obstetric history. RM evaluating pelvic symmetry, displacement, and pelvimetry were conducted on postoperative radiographs and CT scans. Patients who gave birth after the injury were divided to two groups according to the delivery method: vaginal delivery (VD) and caesarean section (CS). These two groups RM were compared. RESULTS: Forty-four patients were included, comparison of the RM of patients who delivered by CS (9) and patients who had only VD (11) showed no significant difference between the groups. Two patients underwent a trial of VD who subsequently underwent urgent CS due to prolonged labour, their RM were below the average and their pelvimetry measurements were above the cut-off for CS recommendation. Eleven patients had uncomplicated VD, all had retained sacroiliac screws at the time of delivery and one patient had an anterior pubic plate. CONCLUSION: Postoperative RM did not show an effect on delivery method of women after pelvic fracture fixation. A relatively high number of patients who underwent normal vaginal delivery had retained sacroiliac screws. These findings can form the foundation for larger cohort studies.

Laparoscopic treatment of fourteen cases of pelvic ring disruption: a case series.

PURPOSE: Open surgical approaches for the treatment of anterior pelvic arc lesions are associated with several complications. We present the first retrospective descriptive case series on the use of laparoscopy as an alternative. METHODS: This descriptive, retrospective, single-centre study enrolled all patients who underwent laparoscopy for the treatment of pelvic ring disruption between May 2020 and March 2022. The primary outcome was the procedure failure rate based on conversion to open surgery. Secondary outcomes were the duration of the surgical procedure, x-ray exposure, length of hospitalisation, postoperative pain assessment, and functional scores at the last follow-up. RESULTS: The study included two females and 12 males. The mean age of the study participants was 44.2 (23-67) years. In total, nine (64.3%) patients had pubic symphysis disjunction, four (28.6%) had bilateral fractures of the obturator frames, and one (7%) had both. None of the patients required conversion to open surgery. The median operating times for symphysis pubis disruption, obturator frame fracture, and patients with both injuries were 90.0 (60-120), 135 (105-180), and 240 min, respectively. The median overall operating time was 102.5 (60-240) min. The median Iowa Pelvic Score and Majeed Functional Score at the last follow-up were 87 (70-99) and 84 (70-100), respectively. CONCLUSION: Laparoscopic internal fixation is a reliable treatment for pelvic ring disruption. The clinical and radiological outcomes of our patients suggest the usefulness of this technique as an alternative to open approaches.

I s pelvic support osteotomy (PSO) suitable for ordinary high-riding hip dysplasia?

PURPOSE: Pelvic support osteotomy (PSO) is regarded to provide pelvic stability and improve abductor function to delay or even avoid total hip arthroplasty (THA) in young patients with high-riding hip dysplasia. However, some of these patients eventually have to undergo THA. Because of the double-angulation deformity of the femur after PSO, subsequent THA is challenging. This study aimed to analyze whether PSO surgery is suitable for high-riding hip dysplasia and summarize orthopaedic strategy during THA for patients with previous PSO. METHODS: This case-control study included eight cases of THA for high-riding hip dysplasia patients with previous PSO (study group) and 24 cases of high-riding hip dysplasia patients without any hip surgical therapy (control group) by a 1:3 match (from May 2018 to January 2022). We compared demographics and joint function before and after THA between two groups and recorded all patients' preoperative imaging data, surgical procedures, postoperative imaging data, and complications. The surgical techniques for patients with previous PSO were highlighted. RESULTS: There was no statistical difference between the two groups in demographic (p > 0.05). The study group had worse hip Harris score (HHS), range of motion (ROM), visual analogue scale (VAS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) (p < 0.05) compared with the control group before THA. All patients had concurrent THA and osteotomy at the proximal femur, but the study group experienced longer operation time (p = 0.047) with more blood loss (p = 0.027) and higher complication rate compared with the control group (p = 0.009). At the last follow-up, the study group's HHS, ROM, VAS, and WOMAC were still worse than those in the control group. CONCLUSIONS: PSO did not improve the joint function of high-riding hip dysplasia patients but brought challenges to subsequent THA and affected the surgical outcomes. In short, we suggested that PSO is unsuitable for routine high-riding hip dysplasia patients.

Accuracy of cup placement and pelvic motion in total hip arthroplasty in the lateral decubitus position using a new computed tomography-based navigation system with augmented reality technology.

INTRODUCTION: This study aimed to investigate the accuracy of cup position and assess the changes in pelvic tilt during primary total hip arthroplasty (THA) in the lateral decubitus position using a new computed tomography (CT)-based navigation system with augmented reality (AR) technology. MATERIALS AND METHODS: There were 37 cementless THAs performed using a CT-based navigation system with AR technology in the lateral decubitus position and 63 cementless THAs performed using manual implant techniques in the lateral decubitus position in this retrospective study. Postoperative cup radiographic inclination and anteversion were measured using postoperative CT, and the proportion of hips within Lewinnek's safe zone was analyzed and compared between the two groups. The mean absolute values of navigation error were assessed. Intraoperative pelvic tilt angles were also recorded using navigation system. RESULTS: The percentage of cups inside Lewinnek's safe zone was 100% in the navigation group and 35% in the control group (p < 0.001). The mean absolute values of navigation error in inclination and anteversion were 2.9° ± 2.1° and 3.3° ± 2.4°, respectively. The mean abduction angle of the pelvis was 5.1° ± 4.8° after placing the patients in the lateral decubitus position and 4.1° ± 6.0° after cup placement. The mean posterior tilt angle was 6.8° ± 5.1° after placing the patients in the lateral decubitus position and 9.3° ± 5.9° after cup placement. The mean internal rotation angle was 14.8° ± 7.4° after cup placement. There were no correlations between the navigation error in inclination or anteversion and the absolute values of changes of the pelvic tilt angle at any phase. CONCLUSIONS: Although progressive pelvic motion occurred in THA in the lateral decubitus position, especially during cup placement, the CT-based navigation system with AR technology improved cup placement accuracy.

Mobility of the lumbo-pelvic-hip complex (spinopelvic mobility) and sagittal spinal alignment - implications for surgeons performing hip arthroplasty.

INTRODUCTION: The optimal positioning of the hip prosthesis components is influenced by the mobility and balance of the spine. The present study classifies patients with pathology of the spino-pelvic-hip complex, showing possible methods of preventing hip dislocations after arthroplasty. HYPOTHESIS: Hip-Spine Classification helps arthroplasty surgeons to implant components in more patient-specific position. MATERIALS AND METHODS: The group of 100 patients treated with total hip arthroplasty. Antero-posterior (AP) X-rays of the pelvis in a standing position, lateral spine (standing and sitting) and AP of the pelvis (supine after the procedure) were analyzed. We analyzed a change in sacral tilt value when changing from standing to sitting (∆SS), Pelvic Incidence (PI), Lumbar Lordosis (LL) Mismatch, sagittal lumbar pelvic balance (standing position). Patients were classified according to the Hip-Spine Classification. Postoperatively, the inclination and anteversion of the implanted acetabular component were measured. RESULTS: In our study 1 A was diagnosed in 61% of all cases, 1B in 18%, 2 A in 16%, 2B in 5%. 50 out of 61 (82%) in group 1 A were placed within the Levinnek "safe zone". In 1B, 2 A, 2B, the position of the acetabular component was influenced by both the spinopelvic mobility and sagittal spinal balance. The mean inclination was 43.35° and the anteversion was 17.4°. CONCLUSIONS: Categorizing patients according to Hip-Spine Classification one can identify possible consequences the patients at risk. Pathology of the spino-pelvic-hipcomplex can lead to destabilization or dislocation of hip after surgery even though implanted according to Lewinnek's indications. Our findings suggest that Lewinnek safe zone should be abandoned in favor of the concept of functional safe zones.

Evaluation of the superior pubic ramus and supra acetabular corridors using statistical shape modelling.

INTRODUCTION: The incidence of osteoporotic pelvic fractures is increasing. The broken anterior pelvic ring is preferentially fixed with long intramedullary screws, which require a good understanding of the patient-specific anatomy to prevent joint perforation. The aim of this study was to assess the variability of the superior pubic ramus and the supra acetabular corridors' length and width using statistical shape modelling. MATERIALS AND METHODS: A male and female statistical shape model was made based on 59 forensic CT scans. For the superior pubic ramus and the supra acetabular corridor the longest and widest completely fitting cylinder was created for the first 5 principal components (PC) of both models, male and female pelvises separately. RESULTS: A total of 59 pelvises were included in this study of which 36 male and 23 female. The first 5 principal components explained 75% and 79% of the pelvic variation in males and females, respectively. Within 3 PCs of the female statistical shape model (SSM) a superior pubic ramus corridor of < 7.3 mm was found, 5.5 mm being the narrowest linear corridor measured. Both corridors in all PCs of the male SSM measured > 7.3 mm. CONCLUSION: Within females a 7.3 mm and 6.5 mm screw won't always fit in the superior pubic ramus corridor, especially if a flat sacrum, a small pelvis or a wide subpubic angle are present. The supra acetabular corridor did not seem to have sex-specific differences. In the supra-acetabular corridor there was always enough space to accommodate a 7.3 mm screw, both in males and females.

Obstetricians are likely to elect for cesarean section in women with retained pelvic implants: a radiographic survey study.

PURPOSE: Women with a history of pelvic fracture undergo cesarean section (CS) at a higher rate than the general population. The purpose of our study is to query obstetricians on their preferences. METHODS: An electronic survey consisting of 22 radiographs of patients who underwent pelvic fixation was sent to obstetricians at 3 academic medical centers. For each radiograph, a hypothetical scenario was given, and the respondents were asked if they would elect for a vaginal delivery or CS. RESULTS: We collected 58 responses. The overall CS rate was 59%. Respondents were significantly more likely to elect for CS with trans-symphyseal fixation or sacroiliac fixation, independently (p < 0.001). DISCUSSION: Obstetricians are likely to elect for elective CS in the presence of pelvic implants especially in patients with trans-symphyseal and sacroiliac fixation. Based on there is an opportunity for collaboration between orthopedic trauma surgeons and obstetricians.

Accuracy of FAST in detecting intraabdominal bleeding in major trauma with pelvic and/or acetabular fractures: a retrospective cohort study.

PURPOSE: The Focused Assessment with Sonography for Trauma (FAST) is a tool to rapidly detect intraabdominal and intrapericardial fluid with point-of-care ultrasound. Previous studies have questioned the role of FAST in patients with pelvic fractures. The aim of the present study was to assess the accuracy of FAST to detect clinically significant intraabdominal hemorrhage in patients with pelvic fractures. METHODS: We included all consecutive patients with pelvic and/or acetabular fractures treated our Level 1 trauma center from 2009-2020. We registered patient and fracture characteristics, FAST investigations and CT descriptions, explorative laparotomy findings, and transfusion needs. We compared FAST to CT and laparotomy findings, and calculated true positive and negative findings, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). RESULTS: We included 389 patients. FAST had a sensitivity of 75%, a specificity of 98%, a PPV of 84%, and a NPV of 96% for clinically significant intraabdominal bleeding. Patients with retroperitoneal hematomas were at increased risk for laparotomy both because of True-negative FAST and False-positive FAST. CONCLUSION: FAST is accurate to identify clinically significant intraabdominal blood in patients with severe pelvic fractures and should be a standard asset in these patients. Retroperitoneal hematomas challenge the FAST interpretation and thus the decision making when applying FAST in patients with pelvic fractures.

Utilizing robotic-assisted navigation for pelvic instrumentation in pediatric patients with neuromuscular scoliosis: a technical note and case series.

Pelvic fixation is commonly used in correcting pelvic obliquity in pediatric patients with neuromuscular scoliosis and in preserving stability in adult patients with lumbosacral spondylolisthesis or instances of traumatic or osteoporotic fracture. S2-alar-iliac screws are commonly used in this role and have been proposed to reduce implant prominence when compared to traditional pelvic fusion utilizing iliac screws. The aim of this technical note is to describe a technique for robotically navigated placement of S2-alar-iliac screws in pediatric patients with neuromuscular scoliosis, which (a) minimizes the significant exposure needed to identify a bony start point, (b) aids in instrumenting the irregular anatomy often found in patients with neuromuscular scoliosis, and (c) allows for greater precision than traditional open or fluoroscopic techniques. We present five cases that underwent posterior spinal fusion to the pelvis with this technique that demonstrate the safety and efficacy of this procedure.

Opportunistic measures of bone mineral density at multiple skeletal sites during whole-body CT in polytrauma patients.

Whole-body CT in polytrauma patients revealed bone mineral density variations throughout the skeleton. Bone density was the highest in cranial bones and the lowest in proximal extremities and pelvis. Skeletal age-related changes were generally more pronounced than sex-related changes. Cranial bones did not follow the same aging pattern compared to other bones. INTRODUCTION: Whole-body CT (WBCT) in polytrauma patients enables the detection of numerous incidental findings, such as estimates of bone mineral density (BMD) at multiple skeletal sites. This could help in better understanding of age- and sex-related changes in BMD through skeleton. METHODS: Data were retrospectively retrieved from the WBCTs requested during a 2-year period. BMD, expressed in CT Hounsfield units (HU), was measured at frontal and occipital bone, four vertebrae (C4, Th7, L4, and S2), iliac bone, and proximal humerus and femur. Measurements were done on native and postcontrast scans. The population sample was age-, sex-, and visceral fat volume adjusted for analysis. RESULTS: A total of 296 patients were included, with a median age of 51 years. BMD varied from the highest HU in cranial bones (629 HU) to the lowest HU in the pelvic bones (114 HU), P < 0.001. Sex differences were independent predictors of BMD in cranial bones and proximal humerus. The age-related decline in BMD was significant in all other bones, but the association with age differed among the measurement's sites. Visceral fat showed the strongest correlation with the lumbar spine and iliac wing, although multivariate analysis revealed it was not an independent predictor of bone density, such as age and sex. CONCLUSIONS: BMD varies through skeleton, being the highest in the proximal axial skeleton. Age-related changes in BMD are significant and more pronounced than sex-related changes in almost all bones. Cranial bones do not follow the same pattern compared to other bones.

Imaging of pelvic ring fractures in older adults and its clinical implications-a systematic review.

Identifying the full scope of pelvic fracture patterns in older adults has gained clinical importance since the last decennium. CT is recommended as the golden standard; however, MRI has even greater diagnostic accuracy. Dual energy computed tomography (DECT) is a new and promising imaging technique, but the diagnostic accuracy in the context of pelvic fragility fractures (FFPs) has not been widely established. The aim was to provide insight into the diagnostic accuracy of different imaging techniques and the relevance for clinical practice. A systematic search was performed in the PubMed database. All studies that reported on CT, MRI or DECT imaging techniques in older adults who suffered a pelvic fracture were reviewed and, if relevant, included. Eight articles were included. In up to 54% of the patients, additional fractures were found on MRI compared to CT, and in up to 57% of the patients on DECT. The sensitivity of DECT for posterior pelvic fracture detection was similar to MRI. All patients without fractures on CT appeared to have posterior fractures on MRI. After additional MRI, 40% of the patients had a change of classification. DECT and MRI showed very similar results in terms of diagnostic accuracy. Over a third of all patients appear to have a more severe fracture classification after MRI, the majority changing to Rommens type 4. However, in only a few patients who changed of fracture classification, a change of therapy was advised. This review suggests that MRI and DECT scans are superior in diagnosing FFPs.

Baseline serum PINP level is associated with the increase in hip bone mineral density seen with Romosozumab treatment in previously untreated women with osteoporosis.

Baseline serum PINP value was significantly and independently associated with the increased bone mineral density (≥ 3%) in both total hip and femoral necks by 12 months of romosozumab treatment in patients with treatment-naive postmenopausal osteoporosis. PURPOSE: Some patients fail to obtain a sufficiently increased hip bone mineral density (BMD) by romosozumab (ROMO) treatment. This study aimed to investigate the prognostic factor for increased hip BMD with ROMO in patients with treatment-naive postmenopausal osteoporosis. METHODS: This prospective, observational, and multicenter study included patients (n = 63: mean age, 72.6 years; T-scores of the lumbar spine [LS], - 3.3; total hip [TH], - 2.6; femoral neck [FN], - 3.3; serum type I procollagen N-terminal propeptide [PINP], 68.5 µg/L) treated by ROMO for 12 months. BMD and serum bone turnover markers were evaluated at each time point. A responder analysis was performed to assess the patient percentage, and both univariate and multivariate analyses were performed to investigate the factors associated with clinically significant increased BMD (≥ 3%) in both TH and FN. RESULTS: Percentage changes of BMD from baseline in the LS, TH, and FN areas were 17.5%, 4.9%, and 4.3%, respectively. In LS, 96.8% of patients achieved ≥ 6% increased LS-BMD, although 57.1% could not achieve ≥ 3% increased BMD in either TH or FN. Multiple regression analysis revealed that only the baseline PINP value was significantly and independently associated with ≥ 3% increased BMD in both TH and FN (p = 0.019, 95% confidence interval = 1.006-1.054). The optimal cut-off PINP value was 53.7 µg/L with 54.3% sensitivity and 92.3% specificity (area under the curve = 0.752). CONCLUSIONS: In a real-world setting, baseline PINP value was associated with the increased BMD of TH and FN by ROMO treatment in treatment-naive patients.