Multiscale topology optimization of pelvic bone for combined walking and running gait cycles

We propose a multiscale topology optimization procedure of pelvic bone using weighted compliance minimization. In macroscale optimization, a level set-based method is used, which gives a binary structure. In microscale optimization, cubic lattice-based homogenization is done while keeping the global geometry fixed. For the macroscale, a volume constraint equal to the volume of the pelvic bone is imposed, whereas, for the microscale, a mass constraint equal to the mass of the pelvic bone is imposed. The optimal geometries are compared with pelvic bone using different metrics and show good similarity with the same. Designed geometries are additively manufactured and experimentally tested for stiffness.

Twelve-month resistance and impact exercise program or risedronate provides a relative benefit to hip bone structure in postmenopausal women: results from a randomized controlled trial

Bone strength estimates are important for fracture prevention. This study compared bone strength changes in postmenopausal women with low bone mass who were assigned to 12 months of exercise, a bone medication, or control. Exercise and bone medications benefited structure at the hip. Structure should be considered in fracture prevention research.

PURPOSE

Exercise and bisphosphonates reduce fracture risk, but their impact on estimates of bone strength remains uncertain. This study compared changes in tibial bone strength using peripheral quantitative computed tomography (pQCT) and hip structure analysis (HSA) outcomes from dual-energy X-ray absorptiometry (DXA) scans in postmenopausal women with low bone mass assigned to 12 months of exercise, risedronate, or control.

METHODS

In this RCT, 276 postmenopausal women within 6 years of menopause were randomly assigned to three groups: exercise (92), risedronate (91), or control (93). Exercise included weighted jogging and progressive resistance exercises; risedronate treatment was 150 mg monthly; all groups received calcium and vitamin D. pQCT and DXA images were obtained at baseline and 6 and 12 months and compared between groups over time.

RESULTS

Participants had a mean (± SD) age of 54.5 (± 3.2) years with an average of 36.7 (± 40.7) months postmenopause. No significant differences were found between groups for the change in pQCT outcomes (volumetric bone mineral density, area, and strength estimates). At 12 months, mean percent differences (95% CI) in HSA measures between exercise and controls were as follows: intertrochanteric, cross-sectional area 2.25% (0.28, 4.12) (p = .03), cross-sectional moment of inertia (CSMI) 5.67% (1.47, 9.87) (p < .01), and section modulus (SM) 4.38% (1.02, 7.74) (p = .01), and narrow neck, average cortical thickness 2.37% (-0.08, 4.83) (p = .031). Mean percent differences (95% CI) in HSA measures between risedronate and control were as follows: intertrochanteric, CSMI 4.28% (-0.24, 8.81) (p = .03) and SM 3.35% (-0.21, 6.91) (p = .03), and shaft, subperiosteal width 0.82% (0.05, 1.58) (p = .047), CSMI 2.53% (0.88, 4.18) (p = .004), and SM 1.57% (0.34, 2.8) (p = .008). Exercise maintained neck-shaft angle compared to both control 1.27% (0.13, 2.41) (p = .04) and risedronate 1.31% (0.23, 2.39) (p = .03). All other differences for changes in HSA outcomes over time were not significantly different between the exercise and risedronate groups.

CONCLUSION

Exercise and bisphosphonates may influence structural and strength estimates at the hip, but not at peripheral sites (tibia). Neither exercise nor bisphosphonates were found to be superior in improving estimates of hip bone strength.

Shared decision-making for non-operative management versus operative management of hip fractures in selected frail older adults with a limited life expectancy: a protocol for a nationwide implementation study

BACKGROUND AND PURPOSE

Recent research has highlighted non-operative management (NOM) as a viable alternative for frail older adults with hip fractures in the final phase of life. This study aims to guide Dutch physicians and hospitals nationwide in a standardised implementation of shared decision-making regarding surgery or NOM in selected frail older adults with a hip fracture.

METHODS AND ANALYSIS

The patient population for implementation includes frail older adults aged ≥70 years with an acute proximal femoral fracture, nursing home care or a similar level of care elsewhere and at least one additional criterion (ie, malnutrition, severe mobility impairment or ASA≥4). The 2-year implementation study will be conducted in four phases. In phases 1 and 2, barriers and facilitators for implementation will be identified and an implementation protocol, educational materials and patient information will be developed. Phase 3 will involve an implementation pilot in 14 hospitals across the Netherlands. The protocol and educational material will be improved based on healthcare provider and patient experiences gathered through interviews. Phase 4 will focus on upscaling to nationwide implementation and the effect of the implementation on NOM rate will be measured using data from the Dutch Hip Fracture Audit.

ETHICS AND DISSEMINATION

The study was exempted by the local Medical Research Ethics Committee (MEC-2023-0270, 10 May 2023) and Medical Ethics Committee United (W23.083, 26 April 2023). The study's results will be submitted to an open access international peer-reviewed journal. Its protocols, tools and results will be presented at several national and international academic conferences of relevant orthogeriatric (scientific) associations.

TRIAL REGISTRATION NUMBER

NCT06079905 .

Retrospective analysis of urethral anastomosis with ancillary maneuvers and intraoperative biaxial defect measurements to achieve a tension free guidance system for redo PFUDD treatment

OBJECTIVES

Redo surgery for pelvic fracture urethral distraction defects (PFUDDs) is still a challenge. the long urethral defect makes it difficult while the high tension increase the recurrence rate. Although certain ancillary maneuvers can relieve tension, there is no consensus or guidelines for the prediction/planning of the selection. In this study, we present our experience with developing an intraoperative guidance system to achieve tension-free urethral anastomosis.

PATIENTS AND METHODS

A total of 91 recurrent PFUDD patients managed at our center between 2020 and 2022 were retrospectively analyzed. The patients underwent scar removing and urethral anastomosis. For the long defect and high-tension cases, 6 kinds of tension-relieving maneuvers were used respectively during the process of urethral anastomosis. Preoperative assessment of the urethrogram was done before surgery, while biaxial (vertical and horizontal) defect measurements were performed intraoperatively. The patients were followed-up for 12 months (8.9 ± 4.2), furthermore, recurrence and complications were analyzed.

RESULTS

The overall success rate was 86.81%. The mean defect in urethrogram was 2.9 ± 1.1 cm. 27 simple anastomosis was performed when the vertical plus horizontal defect was less than 2 cm with 11.11% recurrence. 24 cavernous septum splittings were performed when the horizontal defect was greater than 2 cm with 8.33% recurrence. 21 inferior pubectomies were performed when the horizontal defect was greater than 3 cm with 19.05% recurrence. 15 ancillary distal urethra manipulations (fully distal urethral mobilization, urethral suspension and corpus cavernosa folding) were performed when the vertical defect was 3 to 4 cm with 13.33 recurrence. 4 reroutings were performed when the vertical defect was greater than 4 cm with 25.00% recurrence.

CONCLUSIONS

Ancillary maneuvers are effective for reducing tension in redo urethral anastomosis. Measurement of divergent vertical and horizontal urethral defects could guide the selection of ancillary maneuvers. Combined tension-relieving maneuvers is recommended according to the defect direction and length to achieve a tension-free anastomosis.

Drying irreversibly affects the elastic behavior of pelvic cortical bone

Various studies have shown that the water content affects the elastic behavior of cortical bone. However, there is disagreement regarding the reversibility of the elastic behavior with rewetting. This study investigates this issue using an intrinsic approach, i.e., moisture manipulation and material testing were always carried out on the same specimen. The test results were then evaluated separately for each of several specimens. In total, 24 specimens of human cortical bone from the ischiopubic ramus were examined. The water content was varied in 11 steps, and the corresponding elastic moduli were determined using three-point bending tests within the elastic range. Moisture adjustment was achieved mainly using desiccators, accelerated by forced convection. Reference samples stored in the same manner were evaluated microscopically. The experiments confirmed the known correlation between water content reduction and stiffness increase of cortical bone. Complete drying increased the elastic modulus by about 83 %. By rewetting, the stiffness was significantly reduced again, though not only to the initial state, but even about 24 % below this. Thus, an irreversible alteration of the elastic behavior was observed. Decay of the reference samples was not observed. Therefore, decay is not the main reason for the significant loss of stiffness. In terms of the storage conditions for cortical bone specimens, an environment with 100 % relative humidity yielded the best match with the initial state. This storage method can therefore be recommended for biomechanical specimens used to determine in-vivo-like material parameters.

Extracranial Meningioma-Pelvic Bone on FDG PET/CT: A Rare of the Rarest Site

ABSTRACT

Meningiomas are benign extra-axial tumors of the central nervous system. Extracranial meningiomas are extremely rare (2%) and can develop as a direct extension from a primary intracranial meningioma or as a true primary extracranial meningioma originating from ectopic arachnoid cells. We report an extremely unusual case of a 61-year-old woman who was diagnosed with pelvic meningioma with the help of PET/CT and PET/CT-guided biopsy. The clinicopathological features of the patient and immunoprofile of the tumor are presented.

Evaluating AI-generated CBCT-based synthetic CT images for target delineation in palliative treatments of pelvic bone metastasis at conventional C-arm linacs

PURPOSE

One-table treatments with treatment imaging, preparation and delivery occurring at one treatment couch, could increase patients' comfort and throughput for palliative treatments. On regular C-arm linacs, however, cone-beam CT (CBCT) imaging quality is currently insufficient. Therefore, our goal was to assess the suitability of AI-generated CBCT based synthetic CT (sCT) images for target delineation and treatment planning for palliative radiotherapy.

MATERIALS AND METHODS

CBCTs and planning CT-scans of 22 female patients with pelvic bone metastasis were included. For each CBCT, a corresponding sCT image was generated by a deep learning model in ADMIRE 3.38.0. Radiation oncologists delineated 23 target volumes (TV) on the sCTs (TVsCT) and scored their delineation confidence. The delineations were transferred to planning CTs and manually adjusted if needed to yield gold standard target volumes (TVclin). TVsCT were geometrically compared to TVclin using Dice coefficient (DC) and Hausdorff Distance (HD). The dosimetric impact of TVsCT inaccuracies was evaluated for VMAT plans with different PTV margins.

RESULTS

Radiation oncologists scored the sCT quality as sufficient for 13/23 TVsCT (median: DC = 0.9, HD = 11 mm) and insufficient for 10/23 TVsCT (median: DC = 0.7, HD = 34 mm). For the sufficient category, remaining inaccuracies could be compensated by +1 to +4 mm additional margin to achieve coverage of V95% > 95% and V95% > 98%, respectively in 12/13 TVsCT.

CONCLUSION

The evaluated sCT quality allowed for accurate delineation for most targets. sCTs with insufficient quality could be identified accurately upfront. A moderate PTV margin expansion could address remaining delineation inaccuracies. Therefore, these findings support further exploration of CBCT based one-table treatments on C-arm linacs.

Shape phenotype of thigh fat and muscle and risk of major adverse cardiovascular events after fragility hip fracture

BACKGROUND

Although sarcopenia has been recognized as a predictor of mortality in elderly patients with hip fracture, the association of thigh fat and muscle with cardiovascular (CV) outcome remains unclear. We examined the impact of computed tomography (CT)-derived shape features of thigh fat and muscle on major adverse CV events (MACE) in elderly patients with hip fracture.

METHODS

We conducted a retrospective analysis of consecutive patients aged ≥65 years who presented with hip fracture confirmed on pelvic bone CT scan and underwent hip fracture surgery at our institution from April 2019 to December 2021. The cross-sectional area (CSA) and compactness (CM) of both the muscle and fat at the upper-thigh level were calculated from two-dimensional CT images using AVIEW Research (v1.1.38, Coreline Soft, Co. Ltd, Seoul, South Korea). The shape features of thigh fat and muscle were categorized into four groups based on the combination of CSA and CM: fat CSA (fat area [FA])/fat CM (FCM), muscle CSA (muscle area [MA])/muscle CM (MCM), FA/MCM and MA/FCM. In each of them, subjects were categorized into four subgroups: high CSA/high CM, high CSA/low CM, low CSA/high CM and low CSA/low CM. The primary outcome was MACE after 30 days of surgery, defined as a composite of all-cause death, acute myocardial infarction, stroke or hospitalization for heart failure.

RESULTS

Of 356 patients enrolled (median age, 82 years; 76.7% females), 72 (20.2%) had MACE over a median follow-up of 13.1 months (ranges 5.9-21.0 months). Patients with MACE had a significantly lower median FA (193.7 vs. 226.2 cm2 , P < 0.0001) and FCM (0.443 vs. 0.513, P = 0.001) compared with those without MACE, but no significant differences were found in MA, MCM and FA-MA ratio between the two groups. In a multivariate Cox regression analysis, low FA (<240.1 cm2 ) (adjusted hazard ratio [HR] 2.99, 95% confidence interval [CI] 1.39-6.44, P = 0.005) and low FCM (<0.477) (adjusted HR 2.00, 95% CI 1.10-3.63, P = 0.023) were associated with an increased risk of MACE. Among the shape phenotypes of thigh fat and muscle, the thigh fat phenotype of low FA/low FCM (adjusted HR 3.13, 95% CI 1.81-5.42, P < 0.0001 [reference, high FA/high FCM]) was found to be an independent predictor of MACE.

CONCLUSIONS

In elderly patients with fragility hip fracture, thigh CT-derived measures of FA and FCM may provide useful prognostic information for predicting adverse CV outcomes.

Comparison of artificial intelligence algorithm for the diagnosis of hip fracture on plain radiography with decision-making physicians: a validation study

OBJECTIVE

This study aimed to compare an algorithm developed for diagnosing hip fractures on plain radiographs with the physicians involved in diagnosing hip fractures.

METHODS

Radiographs labeled as fractured (n=182) and non-fractured (n=542) by an expert on proximal femur fractures were included in the study. General practitioners in the emergency department (n=3), emergency medicine (n=3), radiologists (n=3), orthopedic residents (n=3), and orthopedic surgeons (n=3) were included in the study as the labelers, who labeled the presence of fractures on the right and left sides of the proximal femoral region on each anteroposterior (AP) plain pelvis radiograph as fractured or non-fractured. In addition, all the radiographs were evaluated using an artificial intelligence (AI) algorithm consisting of 3 AI models and a majority voting technique. Each AI model evaluated each graph separately, and majority voting determined the final decision as the majority of the outputs of the 3 AI models. The results of the AI algorithm and labelling physicians included in the study were compared with the reference evaluation.

RESULTS

Based on F-1 scores, here are the average scores of the group: majority voting (0.942) > orthopedic surgeon (0.938) > AI models (0.917) > orthopedic resident (0.858) > emergency medicine (0.758) > general practitioner (0.689) > radiologist (0.677).

CONCLUSION

The AI algorithm developed in our previous study may help recognize fractures in AP pelvis in plain radiography in the emergency department for non-orthopedist physicians.

LEVEL OF EVIDENCE

Level IV, Diagnostic Study.

The floating hip injury: a descriptive study and case-control analysis

PURPOSE

A "floating hip" (FH) injury is a rare injury describing the simultaneous ipsilateral fracture of the femur and pelvis or acetabulum (P/A). We describe our experience with patients presenting with FH injuries and compare them to controls with similar P/A fractures but without femoral involvement.

METHODS

Medical records and radiographs of FH patients and controls presenting to our tertiary centre between 2015 and 2020 were reviewed. Follow-up data from outpatient clinical records were also extracted. The control group were extensively matched by age, sex, body mass index, fracture classification and energy of injury.

RESULTS

From 1392 recorded P/A fractures, 42 FH cases were identified (average age 39 years, 78.6% males). The most common femoral fracture was the midshaft (35.7%), followed by the neck of femur (26.2%). 90.5% of FH injuries were due to high-energy mechanisms. 64.3% of P/A fractures, and 100% of femoral fractures were managed surgically. Compared to controls, FH cases were more likely to have additional orthopaedic injuries (73.8% vs. 40.5%, p = 0.002), more total theatre admissions (mean 2.5 vs. 1.19, p < 0.001), longer hospital stays (28.3 vs. 14.9 days, p = 0.02), and a higher rates of post-op complications (53.8% vs. 20%, p = 0.025).

CONCLUSIONS

We report differences in the presentation, management, and outcomes of FH injuries versus controls, even after extensive matching for confounders. These differences may inform future treatment strategies for the FH injury.

Hemoglobin Levels Improve Fracture Risk Prediction in Addition to FRAX Clinical Risk Factors and Bone Mineral Density

CONTEXT

Anemia and decreasing levels of hemoglobin (Hb) have previously been linked to increased fracture risk, but the added value to FRAX, the most utilized fracture prediction tool worldwide, is unknown.

OBJECTIVE

To investigate the association between anemia, Hb levels, bone microstructure, and risk of incident fracture and to evaluate whether Hb levels improve fracture risk prediction in addition to FRAX clinical risk factors (CRFs).

METHODS

A total of 2778 community-dwelling women, aged 75-80 years, and part of a prospective population-based cohort study in Sweden were included. At baseline, information on anthropometrics, CRFs, and falls was gathered, blood samples were collected, and skeletal characteristics were investigated using dual-energy x-ray absorptiometry and high-resolution peripheral quantitative computed tomography. At the end of follow-up, incident fractures were retrieved from a regional x-ray archive.

RESULTS

The median follow-up time was 6.4 years. Low Hb was associated with worse total hip and femoral neck bone mineral density (BMD), and lower tibia cortical and total volumetric BMD, and anemia was associated with increased risk of major osteoporotic fracture (MOF; hazard ratio 2.04; 95% CI 1.58-2.64). Similar results were obtained for hip fracture and any fracture, also when adjusting for CRFs. The ratio between 10-year fracture probabilities of MOF assessed in models with Hb levels included and not included ranged from 1.2 to 0.7 at the 10th and 90th percentile of Hb, respectively.

CONCLUSION

Anemia and decreasing levels of Hb are associated with lower cortical BMD and incident fracture in older women. Considering Hb levels may improve the clinical evaluation of patients with osteoporosis and the assessment of fracture risk.

Topographic localization of the sacroiliac joint and superior gluteal artery branches on the posterolateral ilium

Latrogenic vascular injuries at the posterior ilium during sacroiliac screw placements are not uncommon. Though intra-operative imaging reduces the risk of such injuries, anatomical localization of the sacral segments using discrete topographical landmarks is not currently available. This descriptive study proposes the use of an anatomical grid system to localize the sacroiliac articulation on the posterolateral ilium. It also investigates the positional variability of the branches of the superior gluteal artery (SGA) within areas defined by the grid. 48 dried adult hip bones were examined to determine the position of the sacral articular surface on the posterolateral surface of the ilium. A novel grid-system was defined and used to map the positions of the articulation of the first two sacral segments on the posterolateral ilium. Superficial and deep branches of the SGA were dissected in donor cadavers and their courses were virtually overlayed on the grid system. The grid system localized the sacral articular surfaces within a defined area on the posterior ilium. Arterial distributions indicated the presence of the superficial branch of SGA more frequently over the screw insertion area (at an intermuscular plane), while the deep branch ran closer to the ilium but antero-inferior to the screw placement areas. This study proposes a new topographical perspective of visualizing SGA branches with respect to the cranial sacral segments. Precise localization of vascular anatomy may help to reduce potential risk of injury during sacroiliac screw placements.

A novel method for sorting and reassociating commingled human remains using deviation analysis

This study provides an innovative and novel method for sorting commingled human remains at the sacroiliac joint using deviation analyses. Virtual models were created at the University of Tennessee-Knoxville Donated Skeletal Collection from 69 os coxae and 66 sacra using an EinScan-Pro 2× + Handheld Surface Scanner. The shape of the auricular surfaces was analyzed in Geomagic Wrap 2017, and the congruency of the two auricular surfaces was measured using a deviation analysis. ROC curves were performed on a reference sample composed of 200 commingled and non-commingled joint pairs to identify threshold values that could help sort the commingled remains. A validation sample of 225 pairs was subsequently analyzed to demonstrate the efficacy of this new method on a sample of unknown individuals. Statistical analyses demonstrated that the deviation analysis values from sacroiliac joints of commingled pairs were significantly larger than those from non-commingled individuals (p < 0.0001). Based on the selected threshold values, 98%-100% of pairs were correctly sorted and reassociated. This novel and objective technique improves upon previously subjective strategies for sorting commingled remains and, in the future, will be applied to additional joint surfaces.

A novel image augmentation based on statistical shape and intensity models: application to the segmentation of hip bones from CT images

BACKGROUND

The collection and annotation of medical images are hindered by data scarcity, privacy, and ethical reasons or limited resources, negatively affecting deep learning approaches. Data augmentation is often used to mitigate this problem, by generating synthetic images from training sets to improve the efficiency and generalization of deep learning models.

METHODS

We propose the novel use of statistical shape and intensity models (SSIM) to generate augmented images with variety in both shape and intensity of imaged structures and surroundings. The SSIM uses segmentations from training images to create co-registered tetrahedral meshes of the structures and to efficiently encode image intensity in their interior with Bernstein polynomials. In the context of segmentation of hip joint (pathological) bones from retrospective computed tomography images of 232 patients, we compared the impact of SSIM-based and basic augmentations on the performance of a U-Net model.

RESULTS

In a fivefold cross-validation, the SSIM augmentation improved segmentation robustness and accuracy. In particular, the combination of basic and SSIM augmentation outperformed trained models not using any augmentation, or relying exclusively on a simple form of augmentation, achieving Dice similarity coefficient and Hausdorff distance of 0.95 [0.93-0.96] and 6.16 [4.90-8.08] mm (median [25th-75th percentiles]), comparable to previous work on pathological hip segmentation.

CONCLUSIONS

We proposed a novel augmentation varying both the shape and appearance of structures in generated images. Tested on bone segmentation, our approach is generalizable to other structures or tasks such as classification, as long as SSIM can be built from training data.

RELEVANCE STATEMENT

Our data augmentation approach produces realistic shape and appearance variations of structures in generated images, which supports the clinical adoption of AI in radiology by alleviating the collection of clinical imaging data and by improving the performance of AI applications.

KEY POINTS

• Data augmentation generally improves the accuracy and generalization of deep learning models. • Traditional data augmentation does not consider the appearance of imaged structures. • Statistical shape and intensity models (SSIM) synthetically generate variations of imaged structures. • SSIM support novel augmentation approaches, demonstrated with computed tomography bone segmentation.

Structural analysis of customized 3D printed plate for pelvic bone by comparison with conventional plate based on bending process

Pelvic bone fracture is highly complex, and its anatomical reduction is difficult. Therefore, patient-specific customized plates have been developed using three-dimensional (3D) printing technology and are being increasingly used. In this study, the reduction status in five representative pelvic fracture models was compared between two groups: the 3D printing plate (3DP) group using a patient-specific 3D printed plate after virtual reduction and the conventional plate (CP) group using a conventional plate by manual bending. The 3DP and CP groups included 10 and 5 cases, respectively. The fractured models were reduced virtually and their non-locking metal plates were customized using 3D printing. The process of contouring the conventional plates to fit the contact surface of the bone with the bending tool was conducted by an experienced pelvic bone trauma surgeon. The reduction and fixation achieved using the two different plate groups was compared, and the significance of differences in the results was analyzed using paired t-tests, after verifying the normality of data distribution. The vertex distances between the surface of the bone and the contact surface of the plate were significantly lower in the 3DP group than in the CP group (0.407 ± 0.342 and 2.195 ± 1.643, respectively, P = 0.008). Length and angular variations, which are measurements of the reduction state, were also lower in the 3DP group than in the CP group (length variation: 3.211 ± 2.497 and 5.493 ± 3.609, respectively, P = 0.051; angular variation: 2.958 ± 1.977 and 4.352 ± 1.947, respectively, P = 0.037). The customized 3D printed plate in the virtual reduction model provided a highly accurate reduction of pelvic bone fractures, suggesting that the customized 3D printed plate may help ensure easy and accurate reduction.

Two cases of pelvic trauma with survival in the necropolis of Qubbet el-Hawa (Egypt)

OBJECTIVE

To evaluate the presence of a trauma that results in pelvic ring disruption and its clinical implications in two individuals from ancient Egypt.

MATERIALS

Two complete skeletons of adult women, dated to the Middle Kingdom (c. 1980-1760 BCE), from two tombs in the necropolis of Qubbet el-Hawa (Aswan, Egypt).

METHODS

The anatomical elements were examined macroscopically in Egypt.

RESULTS

Unilateral sacroiliac luxation with disruption of the pubic symphysis was detected in both individuals. The presence of an overlapped symphysis was evident in female QH34aa. A healed fracture of the iliopubic ramus are present in female QH122. Antemortem bone alterations in the pelvis demonstrate that they survived the trauma.

CONCLUSIONS

Pelvic trauma due to a lateral compression was detected in the os coxae. Both women survived but probably had severe sequelae that impaired their quality of life. At least one of them might have received some type of medical treatment.

SIGNIFICANCE

Both cases shed light on pelvic fractures, their mechanisms of production, and their effects on bone and its functionality, as well as revealing possible associated lesions of soft tissues and vital organs.

LIMITATIONS

The pelvis, or at least the pubic symphysis, must be well preserved to allow the correct diagnosis of this type of lesion.

SUGGESTIONS FOR FURTHER RESEARCH

Studies are warranted on the detection of this type of fracture, focusing on the subtle bone changes that indicate its presence. There is also a need to develop methodologies that combine the study of bone and soft tissue alterations.

Little or No Differences in Hip Morphology Between Professional Dancers and Controls: A Systematic Review

OBJECTIVE

To systematically evaluate and synthesize the literature on bony hip morphology of professional dancers, as measured by 2D or 3D imaging techniques.

DATA SOURCES

A literature search was performed on November 20, 2020, using MEDLINE, Embase, and Cochrane. Clinical studies were eligible if they reported on hip morphology of professional dancers. Two independent reviewers screened titles, abstracts, and full-texts to determine eligibility; performed data extraction; and assessed the quality of eligible studies according to the Joanna Briggs Institute (JBI) checklist. This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines.

MAIN RESULTS

The search returned 1384 records; 449 were duplicates, 923 were excluded after title/abstract/full-text screening, and 12 were eligible, reporting on 447 individuals (352 professional dancers and 95 controls). The JBI checklist indicated that 11 studies scored ≥4 points. For professional dancers, lateral center edge angle was 22.4 to 30.8 degrees, acetabular version was 6.7 to 13.5 degrees, neck-shaft angle was 132.5 to 139.5 degrees, and femoral version was 4.7 to 14.4 degrees. Statistically significant differences between dancers and controls were found in some of the studies for acetabular version, neck-shaft angle, and femoral version, although only femoral version showed clinically relevant differences.

CONCLUSIONS

The bony hip morphology of professional dancers is similar to that of other athletes and age-matched controls, which is in contrast to the authors' clinical experience. We presume that the abnormal morphology we have seen at the clinic is only present in symptomatic dancers who require total hip arthroplasty (THA) and is not a general characteristic of all dancers. Further studies should compare the hip morphology of dancers undergoing THA with matched nondancers.

High-Intensity Exercise and Geometric Indices of Hip Bone Strength in Postmenopausal Women on or off Bone Medication: The MEDEX-OP Randomised Controlled Trial

To compare the effects of high-intensity resistance and impact training (HiRIT) to low-intensity, Pilates-based exercise (LiPBE) on proximal femur geometry and explore the influence of antiresorptive medication on those effects. Postmenopausal women with low bone mass, on or off antiresorptive bone medications were randomly allocated, stratified on medication intake, to eight months of twice-weekly, supervised HiRIT (Onero™) or LiPBE (Buff Bones®). 3D hip software was used to analyse proximal femur DXA scans. Outcomes included femoral neck (FN) and total hip (TH), volumetric (e.g. vBMC, vBMD) and geometric (e.g. cortical thickness, cross-sectional area [CSA], section modulus [Z]) indices of bone strength. Data were analysed using analysis of variance. Scans of 102 women were examined: LiPBE, 43; HiRIT, 37; LiPBE-med, 11; HiRIT-med, 11. HiRIT improved TH trabecular vBMC and vBMD (3.1 ± 1.1% versus - 1.2 ± 1.2%, p = 0.008; and 1.5 ± 1.0% versus - 1.6 ± 1.2%, p = 0.042, respectively) and FN and TH total vBMC (2.0 ± 0.8% versus - 0.2 ± 0.7%, p = 0.032; and 0.7 ± 0.4% versus - 0.8 ± 0.6%, p = 0.032, respectively), compared to losses in LiPBE. HiRIT also increased Z while LiPBE did not (p = 0.035). The combination of HiRIT and medication achieved greater improvements in FN total and trabecular vBMD, total BMC, CSA and Z than HiRIT alone. HiRIT improved geometric parameters of proximal femur strength, while LiPBE exercise was largely ineffective. Medication may enhance some HiRIT effects. Findings suggest reduced hip fracture risk in response to HiRIT.Trial registration number ACTRN12617001511325.

Greater length of hospital stay for concurrent hip and upper limb fractures compared to isolated hip fractures: a systematic review of 13 studies including 210,289 patients and meta-analysis

BACKGROUND

The impact of concurrent upper limb and fragility hip fractures has not been well defined. A greater understanding of this can guide decision making in the early peri-operative period and subsequent rehabilitation of such patients.

AIMS

To identify if patients with concurrent upper limb and fragility hip fractures have different outcomes and demographics than those with an isolated hip fracture.

METHODS

A search of MEDLINE and EMBASE was performed to identify cohort and case-control studies, comparing concurrent hip and upper limb fractures with isolated hip fractures. Meta-analysis was conducted using RevMan 5.4. Subgroup analyses were performed for concurrent distal radius and concurrent proximal humerus fractures.

RESULTS

13 studies were included reporting on 196,916 patients with an isolated hip fracture and 13,373 with concurrent hip and upper limb fractures. Patients with concurrent upper limb fractures had a significantly longer length of hospital stay (mean difference: 3.97 days, 95% CI: 1.36, 6.57, P=0.003) as compared to those with isolated hip fractures. Patients with concurrent upper limb fractures were significantly more likely to be female (OR: 0.57, 95% CI: 0.46, 0.70, P<0.00001), reside at home pre-injury (OR: 0.6, 95% CI: 0.37, 0.96, P=0.03) and have no cognitive impairment (OR: 0.54, 95% CI: 0.35, 0.84, P=0.006). Patients with concurrent distal radius fractures had significantly lower 90-day mortality (OR: 0.70, 95% CI: 0.49, 0.99, P=0.04) and 1-year mortality (OR: 0.68, 95% CI: 0.51, 0.90, P=0.008).

CONCLUSIONS

Concurrent fragility hip and upper limb fractures are associated with increased length of hospital stay. We recommend early, aggressive, individualised rehabilitation to help improve outcomes and early hospital discharge in this highly vulnerable patient group.

A survey of pelvic types on computed tomography images

BACKGROUND

In the medical literature several classifications of the pelvis according to its shape can be found. The most common classification distinguishes four general pelvis types: gynecoid, android, anthropoid and platypelloid. Natural childbirth may be significantly prolonged, difficult or even impossible if the pelvis shape is not in proportion to the size of the fetus. The objectives of our study were to calculate major diameters and conjugate diameters of the female bony pelvic ring and to determine the major pelvic types according to their shape. Based on the parameters obtained, we aimed to establish a relationship between some pelvic types and difficult childbirth.

METHODS

The study was prospective in design and included 54 female subjects of various ages who had been referred for computed tomography of the pelvis, as part of the diagnosis of an underlying condition. In each patient, five most important parameters in two planes were measured and the pelvic type was determined by using the brim index and a special formula for android type. All measurements were performed using the Vue PACS v 12.1.6.1005 program. The description of the pelvic inlet was used to confirm all pelvic types. Data on previous births were taken from the questionnaire filled out by the subjects during the radiological examination.

RESULTS

Gynecoid pelvic type was the most common in our sample (28 pelvises - 52%), followed by platypelloid type (11 pelvises - 20%), anthropoid type (8 pelvises - 15%) and finally android type (7 pelvises - 13%). There was a statistically significant difference in the diameter bispinous length (p<0.05) between the platypelloid and anthropoid pelvic types. Pathological degree of stenosis was present in seven pelvises (the first degree in six pelvises and the second degree in one pelvis). The frequency of cesarean section was 31.82% and this technique was most frequently used in the subjects with a gynecoid pelvic type. The duration of natural labor ranged from 4 to 18hours. There was no statistically significant difference in the duration of labor between subjects with different pelvic types.

CONCLUSIONS

Gynecoid pelvic type was present in more than half of our subjects. Although this type is considered ideal for labor, we have not established that it has a great influence on whether the labor will be performed naturally or by cesarean section, neither that it significantly affects the length of birth. The gross narrowing of the pelvic ring is present in non-gynecoid pelvic types. The data obtained will certainly be useful to the obstetrician when planning the labor and considering all the factors that may affect the course of birth.

Elevated Substance P Is a Risk Factor for Postoperative Delirium in Patients with Hip Fracture

Objective

Hip fractures are quite common worldwide, especially among the elderly, and are associated with a high incidence of postoperative delirium, which worsens functional results and increases death. The causes of postoperative delirium in patients with hip fractures are unknown, and a separate pathobiology has been hypothesized. Substance P is a neuropeptide that has been linked to a number of immune-inflammatory and neurological conditions. The purpose of this study was to see if serum substance P levels could predict postoperative delirium in a group of hip fracture patients.

Methods

A total of 148 hip fracture patients were enrolled in the study, all of whom had no substantial pre-existing medical or cognitive issues. Demographic and regular laboratory data were gathered as a starting point. ELISA was used to examine substance P levels before and after surgery (after 1 day). Patients were then divided into two groups: "postoperative delirium" and "no postoperative delirium." Intergroup comparisons, study of delirium prevalence rates in postoperative serum substance P quartile categories, and binary logistic regression for postoperative delirium category as outcome were all done.

Results

Except for serum low-density lipoprotein (LDL) levels, there were no statistically significant variations in preoperative substance P levels or other baseline characteristics between the two groups. The "postoperative delirium" group had significantly higher postoperative substance P levels than the "no postoperative delirium" group (46.36.1 versus 31.94.7 pg/ml). There was a significant difference in postoperative delirium rates between the quartile categories of postoperative substance P, with the fourth quartile having the highest rate. Regression analysis revealed that postoperative substance P levels were related with a significantly increased OR (1.265, CI: 1.172-1.283) of postoperative delirium.

Conclusion

In the current sample of hip fracture patients, a higher postoperative serum substance P level was linked to a higher risk of postoperative delirium. Further research into the utility of early postoperative serum substance P as a delirium indicator in hip fracture patients is needed.

Pelvic Ring Injury Mortality: Are We Getting Better?

OBJECTIVES

To determine if changes in pelvic trauma care and treatment protocols have affected overall mortality rates after pelvic ring injury.

DESIGN

Retrospective cohort study.

SETTING

Level I trauma center.

PATIENTS/PARTICIPANTS

A total of 3314 patients with pelvic ring injuries who presented to a single referral center from 1999 to 2018 were included in the study.

INTERVENTION

Pelvic ring management, years 1999-2006 versus years 2007-2018.

MAIN OUTCOME MEASUREMENTS

In hospital mortality. Other examined variables included change in patient demographics, fracture characteristics, date of injury, associated injuries, length of hospital stay, Abbreviated Injury Severity Score.

RESULTS

The composite mortality rate was 6.5% (214/3314). The earliest cohort presented a mortality rate of 9.1% [111/1224; 95% confidence interval (CI), 7.6%-10.8%] compared with the more recent cohort mortality rate of 4.9% (103/2090; 95% CI, 4.1%-5.9%). Overall mortality was significantly lower in the more recent period, a risk difference of 4.1% (95% CI, 2.3%-6.1%; P < 0.01). After adjusting for age and Abbreviated Injury Severity Score of the brain, chest, and abdomen, the mortality reduction was more pronounced with an adjusted risk difference of 6.4% (95% CI, 4.7%-8.1%; P < 0.01).

CONCLUSION

Significant improvement in the mortality rate of pelvic ring injuries has been demonstrated in recent years (4.9% vs. 9.1%) and the difference is even large when accounting for known confounders. Improvement appears to coincide chronologically with changes in trauma resuscitation and implementation of adjuvant treatments for managing patients with severe hemorrhagic shock. Although the exact benefit of each treatment awaits further research, these data might indicate improved care over time for these difficult patients.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Fracture of pubic rami during hip fracture fixation: a rare case of traction table-related injury

We present a case of an elderly and comorbid patient who was scheduled to undergo a hip fracture fixation using an intramedullary nail. Unfortunately, this was delayed by 3 weeks as the patient was unfit to undergo this procedure. She was placed onto the traction table and intraoperatively sustained a superior and inferior pubic rami fracture while attempting reduction on the traction table. Closed-reduction techniques using traction tables and perineal posts are not without morbidity. Risk factors such as osteoporosis and delayed-fixation should be accounted for when managing this complex and often frail group of patients.

Finite element derived femoral strength is a better predictor of hip fracture risk than aBMD in the AGES Reykjavik study cohort

Hip fractures associated with a high economic burden, loss of independence, and a high rate of post-fracture mortality, are a major health concern for modern societies. Areal bone mineral density is the current clinical metric of choice when assessing an individual's future risk of fracture. However, this metric has been shown to lack sensitivity and specificity in the targeted selection of individuals for preventive interventions. Although femoral strength derived from computed tomography based finite element models has been proposed as an alternative based on its superior femoral strength prediction ex vivo, such predictions have only shown marginal or no improvement for assessing hip fracture risk. This study compares finite element derived femoral strength to aBMD as a metric for hip fracture risk assessment in subjects (N = 601) from the AGES Reykjavik Study cohort and analyses the dependence of femoral strength predictions and classification accuracy on the material model and femoral loading alignment. We found hip fracture classification based on finite element derived femoral strength to be significantly improved compared to aBMD. Finite element models with non-linear material models performed better at classifying hip fractures compared to finite element models with linear material models and loading alignments with low internal rotation and adduction, which do not correspond to weak femur alignments, were found to be most suitable for hip fracture classification.

Do patients with type 2 diabetes have impaired hip bone microstructure? A study using 3D modeling of hip dual-energy X-ray absorptiometry

AIM

Patients with type 2 diabetes (T2DM) have more risk of bone fractures. However, areal bone mineral density (aBMD) by conventional dual-energy x-ray absorptiometry (DXA) is not useful for identifying this risk. This study aims to evaluate 3D-DXA parameters determining the cortical and trabecular compartments in patients with T2DM compared to non-diabetic subjects and to identify their determinants.

MATERIALS AND METHODS

Case-control study in 111 T2DM patients (65.4 ± 7.6 years old) and 134 non-diabetic controls (64.7 ± 8.6-year-old). DXA, 3D-DXA modelling via 3D-Shaper software and trabecular bone score (TBS) were used to obtain aBMD, cortical and trabecular parameters, and lumbar spine microarchitecture, respectively. In addition, biochemical markers as 25-hydroxyvitamin d, type I procollagen N-terminal propeptide (P1NP), C-terminal telopeptide of type I collagen (CTX), and glycated haemoglobin (HbA1c) were analysed.

RESULTS

Mean-adjusted values showed higher aBMD (5.4%-7.7%, ES: 0.33-0.53) and 3D-DXA parameters (4.1%-10.3%, ES: 0.42-0.68) in the T2DM group compared with the control group. However, TBS was lower in the T2DM group compared to the control group (-14.7%, ES: 1.18). In addition, sex (β = 0.272 to 0.316) and body mass index (BMI) (β = 0.236 to 0.455) were the most consistent and positive predictors of aBMD (p ≤ 0.01). BMI and P1NP were negative predictors of TBS (β = -0.530 and -0.254, respectively, p ≤ 0.01), while CTX was a positive one (β = 0.226, p=0.02). Finally, BMI was consistently the strongest positive predictor of 3D-DXA parameters (β = 0.240 to 0.442, p<0.05).

CONCLUSION

Patients with T2DM present higher bone mass measured both by conventional DXA and 3D-DXA, suggesting that 3D-DXA technology is not capable of identifying alterations in bone structure in this population. Moreover, BMI was the most consistent determinant in all bone outcomes.

NHBS-Net: A Feature Fusion Attention Network for Ultrasound Neonatal Hip Bone Segmentation

Ultrasound is a widely used technology for diagnosing developmental dysplasia of the hip (DDH) because it does not use radiation. Due to its low cost and convenience, 2-D ultrasound is still the most common examination in DDH diagnosis. In clinical usage, the complexity of both ultrasound image standardization and measurement leads to a high error rate for sonographers. The automatic segmentation results of key structures in the hip joint can be used to develop a standard plane detection method that helps sonographers decrease the error rate. However, current automatic segmentation methods still face challenges in robustness and accuracy. Thus, we propose a neonatal hip bone segmentation network (NHBS-Net) for the first time for the segmentation of seven key structures. We design three improvements, an enhanced dual attention module, a two-class feature fusion module, and a coordinate convolution output head, to help segment different structures. Compared with current state-of-the-art networks, NHBS-Net gains outstanding performance accuracy and generalizability, as shown in the experiments. Additionally, image standardization is a common need in ultrasonography. The ability of segmentation-based standard plane detection is tested on a 50-image standard dataset. The experiments show that our method can help healthcare workers decrease their error rate from 6%-10% to 2%. In addition, the segmentation performance in another ultrasound dataset (fetal heart) demonstrates the ability of our network.

Risk Factors for Mortality Associated With Pelvic Fractures at a Level I Trauma Center

Pelvic bone fractures are usually caused by high-energy trauma and are often accompanied by organ injuries. For hemodynamically unstable patients with pelvic bone fractures, knowing the anatomic type of fracture-whether it is a pelvic ring injury or an acetabular fracture-might be helpful in prioritizing treatment. A total of 302 patients with pelvic bone fractures who received treatment at the authors' level I trauma center between March 1, 2015, and February 28, 2017, were included in this study. Patients with pelvic bone fractures were enrolled in the Korea Trauma Data Bank and classified by anatomic type of pelvic bone fracture: pelvic ring injury, acetabular fracture, or combined fractures. The authors used t tests to analyze survival and death groups and multivariate regression to analyze mortality factors. Different types of pelvic bone fractures had significantly different mortality rates (P<.001). Forty-four (22.6%) of 195 patients with pelvic ring injuries and 6 (18.8%) of 32 patients with combined fractures died. Meanwhile, only 1 of 75 patients with isolated acetabular fractures died (1.3%). The mortality rate was lowest for type A pelvic ring injuries (8.2%) and highest for type C pelvic ring injuries (68.2%). The difference was statistically significant (P<.001). It is commonly acknowledged that age, combined injuries, higher Injury Severity Score, and lower initial systolic blood pressure are risk factors for mortality, but research has shown that classification and anatomic type of pelvic bone fracture are also highly related. [Orthopedics. 2021;44(6):e724-e728.].

SEMI-AUTOMATED 3D SEGMENTATION OF PELVIC REGION BONES IN CT VOLUMES FOR THE ANNOTATION OF MACHINE LEARNING DATASETS

Automatic segmentation of bones in computed tomography (CT) images is used for instance in beam hardening correction algorithms where it improves the accuracy of resulting CT numbers. Of special interest are pelvic bones, which-because of their strong attenuation-affect the accuracy of brachytherapy in this region. This work evaluated the performance of the JJ2016 algorithm with the performance of MK2014v2 and JS2018 algorithms; all these algorithms were developed by authors. Visual comparison, and, in the latter case, also Dice similarity coefficients derived from the ground truth were used. It was found that the 3D-based JJ2016 performed better than the 2D-based MK2014v2, mainly because of the more accurate hole filling that benefitted from information in adjacent slices. The neural network-based JS2018 outperformed both traditional algorithms. It was, however, limited to the resolution of 1283 owing to the limited amount of memory in the graphical processing unit (GPU).

The evolution of pelvic canal shape and rotational birth in humans

BACKGROUND

The human foetus typically needs to rotate when passing through the tight birth canal because of the complex shape of the pelvis. In most women, the upper part, or inlet, of the birth canal has a round or mediolaterally oval shape, which is considered ideal for parturition, but it is unknown why the lower part of the birth canal has a pronounced anteroposteriorly oval shape.

RESULTS

Here, we show that the shape of the lower birth canal affects the ability of the pelvic floor to resist the pressure exerted by the abdominal organs and the foetus. Based on a series of finite element analyses, we found that the highest deformation, stress, and strain occur in pelvic floors with a circular or mediolaterally oval shape, whereas an anteroposterior elongation increases pelvic floor stability.

CONCLUSIONS

This suggests that the anteroposterior oval outlet shape is an evolutionary adaptation for pelvic floor support. For the pelvic inlet, by contrast, it has long been assumed that the mediolateral dimension is constrained by the efficiency of upright locomotion. But we argue that the mediolateral elongation has evolved because of the limits on the anteroposterior diameter imposed by upright posture. We show that an anteroposteriorly deeper inlet would require greater pelvic tilt and lumbar lordosis, which compromises spine health and the stability of upright posture. These different requirements of the pelvic inlet and outlet likely have led to the complex shape of the pelvic canal and to the evolution of rotational birth characteristic of humans.

Health care utilization and excess costs after pelvic fractures among older people in Germany

Our study demonstrates a strong increase in utilization of inpatient health care and clear excess costs in older people in the first year after pelvic fracture, the latter even after adjustment for several confounders. Excess costs were particularly high in the first few months and mainly attributable to inpatient treatment.

INTRODUCTION

We aimed to estimate health care utilization and excess costs in patients aged minimum 60 years up to 1 year after pelvic fracture compared to a population without pelvic fracture.

METHODS

In this retrospective population-based observational study, we used routine data from a large statutory health insurance (SHI) in Germany. Patients with a first pelvic fracture between 2008 and 2010 (n=5685, 82% female, mean age 80±9 years) were frequency matched with controls (n=193,159) by sex, age at index date, and index month. We estimated health care utilization and mean total direct costs (SHI perspective) with 95% confidence intervals (CIs) using BCA bootstrap procedures for 52 weeks before and after the index date. We calculated cost ratios (CRs) in 4-week intervals after the index date by fitting mixed two-part models including adjustment for possible confounders and repeated measurement. All analyses were further stratified for men/women, in-/outpatient-treated, and major/minor pelvic fractures.

RESULTS

Health care utilization and mean costs in the year after the index date were higher for cases than for controls, with inpatient treatment being particularly pronounced. CRs (95% CIs) decreased from 10.7 (10.2-11.1) within the first 4 weeks to 1.3 (1.2-1.4) within week 49-52. Excess costs were higher for inpatient than for outpatient-treated persons (CRs of 13.4 (12.9-13.9) and 2.3 (2.0-2.6) in week 1-4). In the first few months, high excess costs were detected for both persons with major and minor pelvic fracture.

CONCLUSION

Pelvic fractures come along with high excess costs and should be considered when planning and allocating health care resources.

The obstetrical dilemma hypothesis: there's life in the old dog yet

The term 'obstetrical dilemma' was coined by Washburn in 1960 to describe the trade-off between selection for a larger birth canal, permitting successful passage of a big-brained human neonate, and the smaller pelvic dimensions required for bipedal locomotion. His suggested solution to these antagonistic pressures was to give birth prematurely, explaining the unusual degree of neurological and physical immaturity, or secondary altriciality, observed in human infants. This proposed trade-off has traditionally been offered as the predominant evolutionary explanation for why human childbirth is so challenging, and inherently risky, compared to that of other primates. This perceived difficulty is likely due to the tight fit of fetal to maternal pelvic dimensions along with the convoluted shape of the birth canal and a comparatively low degree of ligamentous flexibility. Although the ideas combined under the obstetrical dilemma hypothesis originated almost a century ago, they have received renewed attention and empirical scrutiny in the last decade, with some researchers advocating complete rejection of the hypothesis and its assumptions. However, the hypothesis is complex because it presently captures several, mutually non-exclusive ideas: (i) there is an evolutionary trade-off resulting from opposing selection pressures on the pelvis; (ii) selection favouring a narrow pelvis specifically derives from bipedalism; (iii) human neonates are secondarily altricial because they are born relatively immature to ensure that they fit through the maternal bony pelvis; (iv) as a corollary to the asymmetric selection pressure for a spacious birth canal in females, humans evolved pronounced sexual dimorphism of pelvic shape. Recently, the hypothesis has been challenged on both empirical and theoretical grounds. Here, we appraise the original ideas captured under the 'obstetrical dilemma' and their subsequent evolution. We also evaluate complementary and alternative explanations for a tight fetopelvic fit and obstructed labour, including ecological factors related to nutrition and thermoregulation, constraints imposed by the stability of the pelvic floor or by maternal and fetal metabolism, the energetics of bipedalism, and variability in pelvic shape. This reveals that human childbirth is affected by a complex combination of evolutionary, ecological, and biocultural factors, which variably constrain maternal pelvic form and fetal growth. Our review demonstrates that it is unwarranted to reject the obstetrical dilemma hypothesis entirely because several of its fundamental assumptions have not been successfully discounted despite claims to the contrary. As such, the obstetrical dilemma remains a tenable hypothesis that can be used productively to guide evolutionary research.

Current status and distribution of hip fractures among older adults in China

China is a middle-risk country for hip fracture at present, which differs from previous data that it was low-risk. By 2050, the total number of hip fractures in people older than 65 years is predicted to be 1.3 million.

INTRODUCTION

To assess hip fracture incidence in China and examine the heterogeneity of hip fracture in seven geographical regions of China.

METHODS

There were 238,230 hip fracture patients aged 65 years or older from 2013 to 2016 from a large national in-patients database (HQMS) involving 30.6 million hospitalizations. Taking into account the total national hospitalization rate per calendar year, we estimated the incidence of hip fracture per 100,000 residents older than 65 years in China overall and in seven geographical Chinese regions.

RESULTS

The proportion of men and women older than 65 years with hip fractures was 1.00:1.95. Between 2013 and 2016, the number of hip fractures per 100,000 people age 65+ was 278. China has vast territories; the number of hip fractures per 100,000 people over 65 years old was 202 in Northeast China and 374 in Northwest China. Northwest has higher altitude, lower population density, is less developed with lower urbanization than Northeast China which is low altitude, and highly urbanized.

CONCLUSIONS

China should no longer be regarded as a low-risk country for hip fracture. By 2050, the total number of hip fractures in people older than 65 years in China is predicted to be 1.3 million. Higher altitude areas had higher hip fracture rates than lower altitude, higher urbanized areas.

Proximal seminal vesicle displacement and margins for prostate cancer radiotherapy

INTRODUCTION

Guidelines recommend that the proximal seminal vesicles (PrSV) should be included in the clinical target volume for locally advanced prostate cancer patients undergoing radiotherapy. Verification and margins for the prostate may not necessarily account for PrSV displacement. The purpose was to determine the inter-fraction displacement of the PrSV relative to the prostate during radiotherapy.

METHODS

Fiducials were inserted into the prostate, and right and left PrSV (RSV and LSV) in 30 prostate cancer patients. Correctional shifts for the prostate, right and left PrSV and pelvic bones were determined from each patient's 39 daily orthogonal portal images relative to reference digitally reconstructed radiographs.

RESULTS

There was a significant displacement of the RSV relative to the prostate in all directions: on average 0.38 mm (95% confidence interval (CI) 0.26 to 0.50) to the left, 0.80-0.81 mm (CI 0.68 to 0.93) superiorly and 1.51 mm (CI 1.36 to 1.65) posteriorly. The LSV was significantly displaced superiorly to the prostate 1.09-1.13 mm (CI 0.97 to 1.25) and posteriorly 1.81 mm (CI 1.67 to 1.96), but not laterally (mean 0.06, CI -0.06 to 0.18). The calculated PTV margins (left-right, superior-inferior, posterior-anterior) were 4.9, 5.3-5.6 and 4.8 mm for the prostate, 5.2, 7.1-8.0 and 9.7 mm for the RSV, and 7.2, 7.5-7.6 and 8.6 mm for the LSV.

CONCLUSION

There is a significant displacement of the PrSV relative to the prostate during radiotherapy. Greater margins are recommended for the PrSV compared to the prostate.