Dual-Energy X-Ray Absorptiometry Does Not Confirm Validity of the Craig's Test

The Craig's test is a clinical assessment used to quantify femoral version. The validity of the Craig's test has been called into question due to instances where the test exhibits relatively poor correlation with three-dimensional imaging. Our study purpose was to use dual-energy X-ray absorptiometry (DXA) to indirectly assess the validity of the Craig's test. Twenty-three volunteers (n = 46; each hip analyzed separately) received two hip DXA scans using two different methods of positioning. During the first scan, a standard-sized wedge, the conventional tool of hip positioning for DXA scans, was used to fixate the legs without regard for individual levels of femoral version. For the second scan, the participants' hips were manually positioned according to their degree of femoral version determined by the Craig's test. We hypothesized that the bone mineral density (BMD) values from the customized positions would be lower due to the X-ray beams hitting the femoral neck perpendicularly. A paired t-test revealed weak evidence of a difference between BMD readings of the conventional and customized positions (p-value = 0.065); moreover, contrary to our hypothesis, the BMD readings obtained in the standard position were lower than those obtained in the customized position, albeit not significantly. Our findings suggest that the Craig's test is not a valid clinical assessment of true femoral version. A secondary conclusion is that the widespread use of the standard wedge for hip positioning during DXA scans is a better option than trying to find a customized position that is based on findings of the Craig's test.

Bilateral hip DXA Reporting: 2023 Official Positions of the International Society for Clinical Densitometry

INTRODUCTION

This position development conference (PDC) Task Force examined the use and reporting of bilateral hip bone mineral density (BMD) measurements. This was deemed appropriate as increased availability of Dual-energy X-ray Absorptiometry (DXA) technology offering bilateral hip measurement resulted in more routine clinical use. The International Society for Clinical Densitometry Official Positions accept bilateral hip BMD measurement for clinical use but currently do not include recommendations for reporting those studies.

METHODS

Four key questions regarding bilateral hip reporting were proposed by the PDC Steering Committee. Relevant literature was identified using PubMed. Questions included whether bilateral hip measurements are appropriate for diagnostic classification or monitoring, as well as which bilateral hip regions of interest should be reported for diagnosis and monitoring. Additionally, the appropriate nomenclature for bilateral hip acquisition was defined.

RESULTS

The literature review demonstrated that bilateral hip measurement is appropriate and diagnostic classification should be based on the lowest T-score at the right or left side femoral neck or total hip; the mean T-score should not be used for diagnostic purposes. Mean bilateral total hip is preferred for BMD monitoring. The terms hip, or total hip were deemed appropriate nomenclature instead of femur or total proximal femur.

CONCLUSION

Bilateral hip acquisition is clinically appropriate and reporting and nomenclature standards are offered herein when a bilateral hip study is acquired. In terms of future research, the impact of discordant hips on diagnosis and monitoring was identified as a significant knowledge gap.

Relationship between the Hip Abductor Muscles and Abduction Strength in Patients with Hip Osteoarthritis

This study aimed to determine which muscle the gluteus maximus, gluteus medius, gluteus minimus (Gmin), or tensor fasciae latae (TFL) contributes most to hip abduction strength and to identify effective sites for cross-sectional area (CSA) Gmin and TFL measurement in hip osteoarthritis (OAhip) patients. Twenty-eight patients with OAhip were included. The muscle CSA and volume were determined using magnetic resonance imaging. Peak isometric strength was determined using hand-held dynamometry. Muscle volumes were normalized to the total muscle volume of hip abductors. Multiple regression analysis was performed. The difference between the CSA of Gmin and TFL was calculated, and correlations with volume and muscle strength were determined. Gmin volume was related to abductor muscle strength (p=0.042). The peak CSA of the Gmin correlated with muscle volume and strength. The CSA of the TFL correlated with volume, with no difference between the CSA of the most protruding part of the lesser trochanter and peak CSA. Gmin volume was strongly related to abductor muscle strength. Peak CSA is a useful parameter for assessing the CSA of the Gmin among patients with OAhip. The CSA of the TFL should be measured at the most protruding part of the lesser trochanter.

Update on contribution of hip labral tears to hip pain: A narrative review

Hip labral tears are found in 22-55% of individuals with hip pain, but labral tears without cysts are usually not responsible for hip pain, which originates mostly from other structures than the torn labrum, like osteochondral, but also tendinous injuries (rectus femoris, gluteus minimus, iliopsoas) or capsulo-ligamentous tears (iliofemoral ligaments, ligament teres). Those lesions are mainly the consequences of underlying unrecognized functional acetabular dysplasia, and/or femoroacetabular impingements. Although the early repair of labral tears in young sportsmen induces a marked and lasting relief, and might delay the onset of osteoarthritis, the microinstability fostered by labral damages seems less important than underlying dysplasias/impingements. This narrative review details recent findings on: (i) the various mechanisms of pain associated with labral tears; (ii) few evidence for hip microinstability induced by isolated labral tears; (iii) how to best detect labral tears, both clinically (including through IROP test) and on imaging (MRI, MRA, computed tomography arthrography, ultrasound). Some authors suggested to use pull-out tests during surgery, but pulling of hips do not seem to increase much diagnostic performances of ultrasounds. Ultrasound-guided intra-articular and peri-articular injections may tell how often hip pain is exclusively induced by peri-capsular injuries secondary to the acetabular dysplasia/femoro-acetabular impingements already responsible for labral tears. Further works could tell whether labral repair, tendinous debridement, plication of capsule, and/or focal denervation, may induce lasting reliefs of pain induced by the chronic contraction of surrounding muscles (rectus femoris, gluteus minimus, psoas), whose deep aponeuroses mix with the superficial fibres of the thick hip capsule.

Clinical characteristics and early prognosis of patients with SARS-CoV-2 infection undergoing joint arthroplasty during the COVID-19 pandemic

The present study reported early clinical outcomes and perioperative precautions for medical staffs during joint arthroplasty procedures in SARS-CoV-2-infected patients.The medical records of 8 patients with SARS-CoV-2 infection who underwent joint arthroplasty from January 19 to September 24, 2020 were retrospectively reviewed and analyzed. Perioperative precautions and follow-up (time length varies from 6 month to 13 months, 11 months in average) for SARS-CoV-2 infection of medical staffs were reported.All patients recovered well from both the primary disease and SARS-CoV-2 infection. Significant improved Visual analogue scale was observed with no major complications or recurrence of the COVID-19 at discharge. There was no evidence indicating SARS-CoV-2 infection in any health providers.Elective joint arthroplasties for patients in recovery period of SARS-CoV-2 infection could be continued under comprehensive preoperative evaluation and appropriate medical protection. For patients with currently confirmed or highly suspected COVID-19, the operation should be carried out only if it was essential.

Clinical Assessment and Treatment Options for Posterior Hip Pain

Diagnosis and treatment of posterior hip pain has increased due to advancements in clinical, anatomical, biomechanical, and related pathological understandings of the hip. Due to its complexity and close anatomical relationship with many osseous, neurovascular, and musculotendinous structures, posterior hip pain must be appropriately categorized based on its origin. Therefore, it is crucial that clinicians are able to determine whether patient complaints are of extra-articular or intra-articular nature so that they can implement the optimal treatment plan. In the current review article, we discussed posterior hip pain with an emphasis on the main differential diagnoses of deep gluteal syndrome, ischiofemoral impingement, and hamstring tear/hamstring syndrome. For the appropriate diagnosis and etiology of posterior hip pain, a thorough and conclusive clinical history is imperative. Physicians should rule out the possibility of spinal involvement by physical examination and if necessary, by magnetic resonance imaging (MRI). Furthermore, because of the vicinity to other, non-orthopedic structures, an obstetric and gynecologic history, general surgery history, and urologic history should be obtained. Following the collection of patient history clinicians should adhere to an established and efficient order of evaluation starting with standing then to seated, supine, lateral, and prone testing. Imaging assessment of posterior hip pain begins with a standard anterior-posterior pelvic radiograph, in addition to frog-leg lateral. MRI is pivotal for assessing soft tissue-related extra-articular causes of hip in patients with posterior hip pain. Non-surgical treatment is preferred in most cases of deep gluteal syndrome, ischiofemoral impingement, pudendal nerve entrapment, and proximal hamstring pathologies. Surgical treatment is saved as a last resort option in cases of failed non-surgical treatment.

Does Patient-specific Functional Pelvic Tilt Affect Joint Contact Pressure in Hip Dysplasia? A Finite-element Analysis Study

BACKGROUND

Although individual and postural variations in the physiologic pelvic tilt affect the acetabular orientation and coverage in patients with hip dysplasia, their effect on the mechanical environment in the hip has not been fully understood. Individual-specific, finite-element analyses that account for physiologic pelvic tilt may provide valuable insight into the contact mechanics of dysplastic hips, which can lead to further understanding of the pathogenesis and improved treatment of this patient population.

QUESTION/PURPOSE

We used finite-element analysis to ask whether there are differences between patients with hip dysplasia and patients without dysplasia in terms of (1) physiologic pelvic tilt, (2) the pelvic position and joint contact pressure, and (3) the morphologic factors associated with joint contact pressure.

METHODS

Between 2016 and 2019, 82 patients underwent pelvic osteotomy to treat hip dysplasia. Seventy patients with hip dysplasia (lateral center-edge angle ≥ 0° and < 20° on supine AP pelvic radiographs) were included. Patients with advanced osteoarthritis, femoral head deformity, prior hip or supine surgery, or poor-quality imaging were excluded. Thirty-two patients (32 hips) were eligible to this finite-element analysis study. For control groups, we reviewed 33 female volunteers without a history of hip disease. Individuals with frank or borderline hip dysplasia (lateral center-edge angle < 25°) or poor-quality imaging were excluded. Sixteen individuals (16 hips) were eligible as controls. Two board-certified orthopaedic surgeons measured sagittal pelvic tilt (the angle between the anterior pelvic plane and vertical axis: anterior pelvic plane [APP] angle) and acetabular version and coverage using pelvic radiographs and CT images. Intra- and interobserver reliabilities, evaluated using the kappa value and intraclass correlation coefficient, were good or excellent. We developed individual-specific, finite-element models using pelvic CT images, and performed nonlinear contact analysis to calculate the joint contact pressure on the acetabular cartilage during the single-leg stance with respect to three pelvic positions: standardized (anterior pelvic plane), supine, and standing. We compared physiologic pelvic tilt between patients with and without dysplasia using a t-test or the Wilcoxon rank sum test. A paired t-test or the Wilcoxon signed rank test with a Bonferroni correction was used to compare joint contact pressure between the three pelvic positions. We correlated joint contact pressure with morphologic parameters and pelvic tilt using the Pearson or the Spearman correlation coefficients.

RESULTS

The APP angle in the supine and standing positions varied widely among individuals. It was greater in patients with hip dysplasia than in patients in the control group when in the standing position (3° ± 6° versus -2° ± 8°; mean difference 5° [95% CI 1° to 9°]; p = 0.02) but did not differ between the two groups when supine (8° ± 5° versus 5° ± 7°; mean difference 3° [95% CI 0° to 7°]; p = 0.06). The mean pelvic tilt was 6° ± 5° posteriorly when shifting from the supine to the standing position in patients with hip dysplasia. The median (range) maximum contact pressure was higher in dysplastic hips than in control individuals (in standing position; 7.3 megapascals [MPa] [4.1 to 14] versus 3.5 MPa [2.2 to 4.4]; difference of medians 3.8 MPa; p < 0.001). The median maximum contact pressure in the standing pelvic position was greater than that in the supine position in patients with hip dysplasia (7.3 MPa [4.1to 14] versus 5.8 MPa [3.5 to 12]; difference of medians 1.5 MPa; p < 0.001). Although the median maximum joint contact pressure in the standardized pelvic position did not differ from that in the standing position (7.4 MPa [4.3 to 15] versus 7.3 MPa [4.1 to 14]; difference of medians -0.1 MPa; p > 0.99), the difference in the maximum contact pressure varied from -3.3 MPa to 2.9 MPa, reflecting the wide range of APP angles (mean 3° ± 6° [-11° to 14°]) when standing. The maximum joint contact pressure in the standing position was negatively correlated with the standing APP angle (r = -0.46; p = 0.008) in patients with hip dysplasia.

CONCLUSION

Based on our findings that individual and postural variations in the physiologic pelvic tilt affect joint contact pressure in the hip, future studies on the pathogenesis of hip dysplasia and joint preservation surgery should not only include the supine or standard pelvic position, but also they need to incorporate the effect of the patient-specific pelvic tilt in the standing position on the biomechanical environment of the hip.

CLINICAL RELEVANCE

We recommend assessing postural change in sagittal pelvic tilt when diagnosing hip dysplasia and planning preservation hip surgery because assessment in a supine or standard pelvic position may overlook alterations in the hip's contact mechanics in the weightbearing positions. Further studies are needed to elucidate the effect of patient-specific functional pelvic tilt on the degeneration process of dysplastic hips, the acetabular reorientation maneuver, and the clinical result of joint preservation surgery.

Interobserver agreement and clinical disparity between the Graf method and femoral head coverage measurement in developmental dysplasia of the hip screening: A prospective observational study of 198 newborns

Ultrasonography is the ideal tool for assessing hip morphology in infants younger than 6-month-old. This study assessed the interobserver agreement and clinical disparities of the 2 most widely used ultrasound (US) methods, the Graf method, and femoral head coverage (FHC) measurement.A prospective observational study (STROBE compliant) of 2024 newborns was conducted between January 2017 and December 2018. Hip US was conducted on all newborns with abnormal Barlow and Ortolani maneuvers as well as on 50 randomly selected normal newborns. The physical examination and US were performed by a senior pediatric orthopedic surgeon with musculoskeletal sonography certification. Three observers with different levels of experience interpreted the images by using the Graf method and FHC. We analyzed the intraclass correlation coefficient, Cohen kappa, and the disparity between the clinical findings of the 2 methods.A total of 198 newborns (9.8%) presented with clinical instability, including 193 subluxatable hips in 168 patients (84.8%) and 45 dislocatable/dislocated hips in 30 patients (15.2%). The mean age at US examination was 11.69 days (range: 0-18 days). The intraclass correlation coefficient was .71 (95% CI: 0.55-0.83) for FHC, 0.63 (95% CI: 0.38-0.78) for the alpha angle, and 0.47 (95% CI: 0.16-0.69) for beta angle. The Cohen kappa coefficients of Graf type were 0.19 (95% CI: 0.03-0.35), 0.39 (95% CI: 0.20-0.58), and 0.17 (95% CI: 0.02-0.32) between observers 1 and 2, observers 1 and 3, and observers 2 and 3, respectively. Based on the Graf method, 14% of the stable hips had abnormal USs; by contrast, 19.2% of the subluxatable hips and 17.8% of the dislocatable/dislocated hips had normal Graf morphologies. In USs interpreted using FHC, 16% of stable hips demonstrated abnormal coverage, whereas 13.5% of subluxatable hips and 4.4% of dislocatable/dislocated hips had normal FHC.Incidence of clinically detectable hip instability was 9.8% among newborns in our series. Both alpha angle and FHC ratio revealed substantial interobserver agreement while beta angle achieved moderate agreement. FHC ratio possesses higher sensitivity and similar specificity compared with the Graf method when screening unstable hips.Level II, development of diagnostic criteria on basis of consecutive patients.

Hip-Spine Relationship: Thoracolumbar Deformation in a Patient with Limited Hip Flexion: A Case Report

CASE

We describe thoracolumbar kyphosis with severe vertebral deformation in a 13-year-old boy with cerebral palsy, hip extension contractures, and history of hip flexion-adduction releases.

CONCLUSION

Patients with cerebral palsy and hip extension contractures may develop thoracolumbar kyphosis to maintain sitting balance. It is important to recognize hip extension contractures as the underlying cause of the compensatory kyphosis and to be familiar with treatment options that address the hips and the spine.

[CME Sonography 97: Ultrasound Pathologies of the Hip]

CME Sonography 97: Ultrasound Pathologies of the Hip Abstract. Hip pain has a broad differential diagnosis. A clinical examination is not enough to determine the underlying cause. In most cases, sonography helps to narrow the differential diagnosis or to make a specific diagnosis. Furthermore, ultrasound allows a targeted and anatomically precise diagnostic aspiration or therapeutic infiltration. Examples are used to illustrate different pathologies by region.

[CME Sonography 97/Answers: Ultrasound Pathologies of the Hip]

CME Sonography 97/Answers: Ultrasound Pathologies of the Hip Abstract. Abstract: Hip pain has a broad differential diagnosis. A clinical examination is not enough to determine the underlying cause. In most cases, sonography helps to narrow the differential diagnosis or to make a specific diagnosis. Furthermore, ultrasound allows a targeted and anatomically precise diagnostic aspiration or therapeutic infiltration. Examples are used to illustrate different pathologies by region.

The influence of adult hip shape genetic variants on adolescent hip shape: Findings from a population-based DXA study

OBJECTIVE

Hip shape is a well-recognized risk factor for hip osteoarthritis (OA) and hip fracture. We aimed to investigate whether the genetic variants known to be associated with adult hip shape were also associated with adolescent hip shape.

METHODS

Hip DXA scans, obtained in offspring from the Avon Longitudinal Study of Parents and Children (ALSPAC) at two time points (mean ages 13.8 and 17.8 years), were used to quantify hip morphology using a 53-point Statistical Shape Model (SSM). Principal component analysis was used to generate hip shape modes (HSMs). Genetic variants which had previously shown genome-wide significant association with specific HSMs in adults were tested for association with the same HSMs in adolescents (at each timepoint separately) using SNPTEST v2.

RESULTS

Complete genotypic and phenotypic data were available for 3550 and 3175 individuals at 14 and 18 years, respectively. The strongest evidence for association with adolescent hip shape was for a variant located near SOX9 (rs2158915) with consistent effects across both time points for HSM1 (age 14: beta -0.05, p = 9.9 × 10-8; age 18: -0.05, p = 3.3 × 10-6) and HSM5 (age 14: beta -0.07, p = 1.6 × 10-4; age 18: -0.1, p = 2.7 × 10-6). There was also strong evidence of association between rs10743612 (near PTHLH) and HSM1 (age 14: 0.05, p = 1.1 × 10-5; age 18: 0.04, p = 0.003) and between rs6537291 (near HHIP) and HSM2 (age 14: -0.06, p = 0.001; age 18: -0.07, p = 0.001) across both time points. The genes with the strongest associations with hip shape in adolescents, (SOX9, PTHLH and HHIP) are known to be involved in endochondral bone formation. HSM1 indicates narrower aspect ratio of the upper femur, whereas both HSM2 and HSM5 reflect variation in the femoral head size and femoral neck width, features previously found to be related to the risk of OA in later life. The SOX9 locus has previously been found to associate with increased risk of hip fracture.

CONCLUSION

In conclusion, variants implicated in endochondral bone formation appear to consistently influence hip shape between adolescence and adulthood, including those aspects related to risk of hip OA and/or fracture in later life.

Four-Year Teriparatide Followed by Denosumab vs. Continuous Denosumab in Glucocorticoid-Induced Osteoporosis Patients With Prior Bisphosphonate Treatment

OBJECTIVES

In our previous 24-month study, we observed that teriparatide had some advantages over denosumab for bone mineral density (BMD) in glucocorticoid-induced osteoporosis (GIO) patients with prior bisphosphonate treatment. We conducted this extension study to investigate whether the advantage of teriparatide obtained in the first 2 years would be maintained after the switch to denosumab.

MATERIALS AND METHODS

We switched patients who had completed 24-month daily teriparatide treatment to denosumab (switch group, n=18) and compared their BMD every 6 months up to 48 months with the group who continued to receive denosumab (denosumab group, n=16).

RESULTS

At 48 months, the lumbar spine BMD was significantly increased from baseline in both groups (denosumab: 10.4 ± 8.7%, p<0.001; switch: 14.2 ± 6.8%, p<0.001). However, a significant increase in femoral neck BMD from baseline occurred only in the switch group (11.2 ± 14.6%, p<0.05); denosumab (4.1 ± 10.8%). The total hip BMD increased significantly from baseline in both groups (denosumab: 4.60 ± 7.4%, p<0.05; switch: 7.2 ± 6.9%, p<0.01). Femoral neck BMD was significantly increased in the switch versus the denosumab group (p<0.05).

CONCLUSION

In GIO patients with prior bisphosphonate treatment, the advantage of teriparatide may be maintained after the treatment period. A continuous increase in BMD can be expected with teriparatide followed by denosumab.

Evaluation of Hip Pain and Management of Toxic Synovitis in the Ultrasound Era

ABSTRACT

The cause of acute onset hip pain in children can be difficult to determine. Once trauma is excluded, the workup revolves around determining whether there is a hip effusion and eliminating orthopedic emergencies. Point-of-care-ultrasound can be used as an adjunct in the workup. In this article, we review (1) differential diagnosis of hip pain, with a focus on toxic synovitis; (2) the evaluation of a hip for the presence of effusion, including the point-of-care ultrasound technique; and (3) the management of toxic synovitis.

Hip Structural Analysis Reveals Impaired Hip Geometry in Girls With Type 1 Diabetes

CONTEXT

Among patients with type 1 diabetes (T1D), the risk of hip fracture is up to 6-fold greater than that of the general population. However, the cause of this skeletal fragility remains poorly understood.

OBJECTIVE

To assess differences in hip geometry and imaging-based estimates of bone strength between youth with and without T1D using dual-energy x-ray absorptiometry (DXA)-based hip structural analysis.

DESIGN

Cross-sectional comparison.

PARTICIPANTS

Girls ages 10 to 16 years, including n = 62 with T1D and n = 61 controls.

RESULTS

The groups had similar age, bone age, pubertal stage, height, lean mass, and physical activity. Bone mineral density at the femoral neck and total hip did not differ in univariate comparisons but was lower at the femoral neck in T1D after adjusting for bone age, height, and lean mass. Subjects with T1D had significantly lower cross-sectional area, cross-sectional moment of inertia, section modulus, and cortical thickness at the narrow neck, with deficits of 5.7% to 10.3%. Cross-sectional area was also lower at the intertrochanteric region in girls with T1D. Among those T1D subjects with HbA1c greater than the cohort median of 8.5%, deficits in hip geometry and strength estimates were more pronounced.

CONCLUSIONS

DXA-based hip structural analysis revealed that girls with T1D have unfavorable geometry and lower estimates of bone strength at the hip, which may contribute to skeletal fragility and excess hip fracture risk in adulthood. Higher average glycemia may exacerbate effects of T1D on hip geometry.

Deep Learning for Osteoporosis Classification Using Hip Radiographs and Patient Clinical Covariates

This study considers the use of deep learning to diagnose osteoporosis from hip radiographs, and whether adding clinical data improves diagnostic performance over the image mode alone. For objective labeling, we collected a dataset containing 1131 images from patients who underwent both skeletal bone mineral density measurement and hip radiography at a single general hospital between 2014 and 2019. Osteoporosis was assessed from the hip radiographs using five convolutional neural network (CNN) models. We also investigated ensemble models with clinical covariates added to each CNN. The accuracy, precision, recall, specificity, negative predictive value (npv), F1 score, and area under the curve (AUC) score were calculated for each network. In the evaluation of the five CNN models using only hip radiographs, GoogleNet and EfficientNet b3 exhibited the best accuracy, precision, and specificity. Among the five ensemble models, EfficientNet b3 exhibited the best accuracy, recall, npv, F1 score, and AUC score when patient variables were included. The CNN models diagnosed osteoporosis from hip radiographs with high accuracy, and their performance improved further with the addition of clinical covariates from patient records.

Hip pain and its correlation with cam morphology in young skiers-a minimum of 5 years follow-up

BACKGROUND

There is conflicting evidence regarding the association between cam morphological changes and hip pain, and it remains unclear who with cam morphology will develop hip pain and who will not. This study aimed to investigate the correlation between cam morphology, hip pain, and activity level at a 5-year follow-up in young Alpine and Mogul skiers.

METHOD

All students (n = 76) at Åre Ski National Sports High School were invited and accepted participation in this prospective study at baseline. Magnetic resonance imaging (MRI) of both hips was conducted to evaluate the presence of cam morphology (α-angle ≥ 55°) and its size alongside the reporting of hip pain, type, and frequency of training by the Back and hip questionnaire, at baseline. After 5 years, the skiers were invited to complete a shortened version of the same questionnaire.

RESULTS

A total of 60 skiers (80%) completed the follow-up questionnaire, of which 53 had concomitant MRI data. Cam morphology was present in 25 skiers (47.2%, 39 hips). Hip pain at baseline and at follow-up was reported in 17 (28.3%) and 22 (36.7%) skiers, respectively. No correlations were found between the activity level, the frequency, and the size of cam morphology and hip pain, except for the right hip α-angle at 1 o'clock and hip pain in skiers with cam morphology at baseline (rs = 0.49; P = 0.03) and at follow-up (rs = 0.47; P = 0.04). A total of 73.3% skiers had retired, of which 48% reported this was due to injuries.

CONCLUSION

Hip pain was not shown to be correlated, or had a low correlation, with activity level and the presence and size of cam morphology in young skiers on a 5-year follow-up. Based on these results, cam morphology or activity level did not affect hip pain to develop during 5 years of follow-up in young skiers. Furthermore, this study highlights that almost 75% of young elite skiers had retired from their elite career with almost 50% reporting that this was due to injuries sustained from skiing.

Ultrasound Evaluation of Pediatric Orthopaedic Patients

Ultrasonography is a valuable tool that can be used in many capacities to evaluate and treat pediatric orthopaedic patient. It has the capability to depict bone, cartilaginous and soft-tissue structures, and provide dynamic information. This technique can be readily applied to a wide range of pediatric conditions, including developmental dysplasia of the hip, congenital limb deficiencies, fracture management, joint effusions, and many other musculoskeletal pathologies. There are many benefits of implementing ultrasonography as a regular tool. It is readily accessible at most centers, and information can be quickly obtained in a minimally invasive way, which limits the need for radiation exposure. Ultrasonography is a safe and reliable tool that pediatric orthopaedic surgeons can incorporate into the diagnosis and management of a broad spectrum of pathology.

Association of Computer-Assisted Virtual Preoperative Planning With Postoperative Mortality and Complications in Older Patients With Intertrochanteric Hip Fracture

IMPORTANCE

The outcomes of surgical treatment in patients with intertrochanteric hip fractures are unsatisfactory. Computer-assisted virtual preoperative planning may provide an opportunity to solve this treatment dilemma. Virtual preoperative planning is a technique based on dynamic 3-dimensional computed tomographic imaging, which allows precise evaluation of fracture details and simulation of reduction of fracture and internal fixation procedures before surgery is performed.

OBJECTIVE

To evaluate the association of computer-assisted virtual preoperative planning with the risk of 90-day all-cause mortality and postoperative complications.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study was conducted from using patient data from a level 1 trauma center database. A total of 1445 patients 65 years and older with intertrochanteric hip fractures between January 1, 2009, and March 31, 2018, were identified and divided into 2 cohorts: 558 patients received computer-assisted virtual preoperative planning (virtual planning group), and 887 patients received conventional preoperative planning (conventional planning group). Of the initial 1445 patients, 224 patients (93 patients in the virtual planning group and 131 patients in the conventional planning group) were excluded, resulting in 1221 patients in the final cohort. Data were analyzed from April 5 to October 5, 2019.

EXPOSURES

Computer-assisted virtual vs conventional surgical preoperative planning.

MAIN OUTCOMES AND MEASURES

Primary outcomes were 90-day all-cause mortality and postoperative complications (including myocardial infarction, heart failure, stroke, kidney failure, and sepsis). Secondary outcomes were 90-day outpatient visits, hospital readmissions, and reoperations.

RESULTS

Among 1221 patients who underwent hip surgery, the mean (SD) age was 73.2 (12.3) years, and 927 patients (75.9%) were women. A total of 465 patients (38.1%) were in the virtual planning group and 756 patients (61.9%) were in the conventional planning group. Among the 814 patients (407 patients in each group) who were matched by propensity score, the virtual planning group had a lower incidence of mortality (37 patients [9.1%] vs 55 patients [13.5%]; hazard ratio [HR], 0.64; 95% CI, 0.41-0.99; P = .04) and postoperative complications (25 patients [6.1%] vs 44 patients [10.8%]; HR, 0.54; 95% CI, 0.32-0.90; P = .02) compared with the conventional planning group. The incidence of outpatient visits was not substantially different in the virtual planning group (1.51 incidents per 30 person-days) compared with the conventional planning group (1.48 incidents per 30 person-days; incidence rate ratio [IRR], 0.90; 95% CI, 0.49-1.68; P = .75). Similar results were observed for the rate of hospital readmissions (0.99 incidents per 30 person-days in the virtual planning group and 1.01 incidents per 30 person-days in the conventional planning group; IRR, 0.91; 95% CI, 0.49-1.67; P = .76). However, the rate of reoperations was lower in the virtual planning group (0.76 incidents per 30 person-days) than in the conventional planning group (0.97 incidents per 30 person-days; IRR, 0.41; 95% CI, 0.22-0.76; P = .01).

CONCLUSIONS AND RELEVANCE

Among older patients with intertrochanteric hip fractures, computer-assisted virtual preoperative planning was associated with decreases in the risks of all-cause 90-day mortality, postoperative complications, and reoperations compared with conventional preoperative planning.

[Ultrasound of the Hip (Adapted According to SGUM Guidelines)]

Ultrasound of the Hip (Adapted According to SGUM Guidelines) Abstract. This review paper explains the simplified ultrasound anatomy of the hip. The adapted basic standard planes are described in detail according to SGUM guidelines and illustrated with a selection of high-resolution ultrasound images. A profound knowledge of the sonographic anatomy is essential for the detection of pathologies.

Sarcopenia and Hip-Structure Analysis Variables in Korean Elderly Population

The purpose of this study is comparing the hip-structure analysis (HSA) variables with the skeletal muscle index (SMI) in elderly patients with sarcopenia using nationwide representative data on the Republic of Korea (ROK). The survey data were collected from household interviews and direct standardized physical examinations conducted in specially equipped mobile examination centers. The data were collected in 2008 from 9744 participants. Patients under 65 years of age who were without data on the skeletal-muscle-mass and HSA variables were excluded. After these exclusions, a total of 744 participants (293 men and 451 women) were ultimately analyzed. The HSA measurements of the hip-bone geometry were analyzed using dual-energy X-ray absorptiometry. The appendicular SMI is defined as the sum of the arm and leg SMIs. Sarcopenia is defined according to the criteria for the Asia Working Group for Sarcopenia as SMIs of less than 5.4 kg/m² and 7.0 kg/m² for women and men, respectively. In the entire population, SMI was found to be positively correlated to HSA variables. After adjusting for age, body mass index, and energy intake in both the women and men groups, a statistically significant difference became evident in all variables between the SMI and the HSA. The present study suggests that skeletal-muscle loss negatively affects hip-bone-strength indices in elderly sarcopenia patients. Implementing strategies to increase SMI in the elderly population may be useful for reducing the vulnerability to hip fracture.

Muscular Maximal Strength Indices and Bone Variables in a Group of Elderly Women

The aim of the present study was to explore the relations between muscular maximal strength indices and bone parameters (bone mineral density [BMD], hip geometry indices, and trabecular bone score [TBS]) in a group of elderly women. This study included 35 healthy elderly women whose ages range between 65 and 75 yr (68.1 ± 3.1 yr). BMD (in gram per square centimeter) was determined for each individual by dual-energy X-ray absorptiometry at the whole body, lumbar spine (L1-L4), total hip (TH), and femoral neck (FN). L1-L4 TBS and hip geometry indices were also evaluated by dual-energy X-ray absorptiometry. Maximal muscle strength of bench press (1-repetition maximum [RM] bench press), maximal muscle strength of leg press (1-RM leg press), and handgrip were measured using validated methods. 1-RM bench press was positively correlated to TH BMD (r = 0.40; p < 0.05), FN BMD (r = 0.41; p < 0.05), FN section modulus (r = 0.33; p < 0.05), and FN cross-sectional moment of inertia (r = 0.35; p < 0.05). 1-RM leg press was positively correlated to TH BMD (r = 0.50; p < 0.01), FN BMD (r = 0.35; p < 0.05), FN cross-sectional area (r = 0.38; p < 0.05), and TBS (r = 0.37; p < 0.05). Handgrip was correlated only to FN cross-sectional moment of inertia (r = 0.43; p < 0.01). This study suggests that 1-RM bench press and 1-RM leg press are positive determinants of BMD in elderly women.

Effect of Positioning of the Region of Interest on Bone Density of the Hip

BACKGROUND

Large changes in positioning of the global region of interest (ROI) influence the measurement of bone mineral density (BMD) in the hip and forearm regions. However, it is unknown whether minor shifts in the positioning of the bottom of the global hip ROI affect the measurement of total hip BMD.

METHODS

The hip BMDs of 40 clinical densitometry patients were analyzed at baseline with the bottom of the global hip ROI positioned as usual, 10 mm distal to the base of the lesser trochanter (position 0). Then the hip was reanalyzed by shifting the bottom of the global hip ROI 1 mm proximally 10 times (positions +1 through +10) and then by shifting the bottom of the global hip ROI 1 mm distally 10 times (positions -1 through -10). The significance of the differences between mean values at the various distances from baseline was assessed using a Wilcoxon signed-rank test.

RESULTS

The mean total hip area, bone mineral content and BMD decreased as the bottom of the global hip ROI was shifted proximally; the decrease was significant when shifted by even 1 mm (p < 0.001). The mean total hip area, bone mineral content and BMD increased as the bottom of the global hip ROI was shifted distally; the increase was significant when shifted by even 1 mm (p < 0.001). The change in BMD with each 1 mm shift was uniform across the range studied from positions +10 through -10, and was approx 0.54%/mm. When the least significant change was based on 40 pairs of measurements, where each pair was comprised of the baseline scan and the same scan at -1 position, the least significant change was 0.01 g/cm².

CONCLUSIONS

The BMD of the total hip is sensitive to even minor changes in the positioning of the bottom of the global hip ROI. Although a 1 mm change in the bottom of the global hip ROI positioning would make little difference in the reported T-score, it could easily affect the determination of significance in changes in BMD over time.

Associations between Proton Pump Inhibitor and Histamine-2 Receptor Antagonist and Bone Mineral Density among Kidney Transplant Recipients

BACKGROUND

In the general population, use of proton pump inhibitor (PPI) has been linked to higher risk of osteoporotic fractures. PPI is commonly prescribed in kidney transplant recipients (KTRs). However, the effect of PPI on osteoporosis in KTRs is largely unstudied.

METHODS

A total of 1,774 adult KTRs in the Wisconsin Allograft Recipient Database with at least one eligible bone mineral density (BMD) measurement at least 3 months after transplantation were included in the analyses. Associations between use of PPI and histamine-2 receptor antagonist (H2RA) at 3 months after transplantation and subsequent slope of T-score were assessed.

RESULTS

A total of 1,478 (83.3%) participants were using a PPI at 3 months after transplantation. Compared to the use of H2RA, use of PPI was not significantly associated with annualized slope of hip T-score (β = -0.0039, 95% CI -0.00497 to 0.0021) or annualized slope of spine T-score (β = -0.017, 95% CI -0.049 to 0.083) after adjustment for potential confounders. Similarly, no significant association between use of PPI and slope of T-score was observed when defining PPI/H2RA exposure as use within 6 months of the initial BMD measurement, or only including participants with at least 2 BMD measurements, or stratified by different age and sex.

CONCLUSIONS

Use of PPI was not associated with an increased rate of BMD loss in KTRs. Our results support previous findings that PPI use does not have a significant effect on bone mineral loss.

Bone Mineral Density Among Men and Women Aged 35 to 50 Years

Context

Osteoporosis is characterized by low bone mineral density (BMD) and has been thought to only be a major health concern for postmenopausal women. However, osteoporosis and its risk factors have been greatly understudied in the middle-aged and male populations.

Objective

To assess the likelihood of low BMD and its association with related risk factors in early-middle-aged (defined in this study as 35-50 years) men and women.

Methods

Eligible men and women completed a questionnaire assessing calcium intake, hours per week of exercise, and other related risk factors associated with osteoporosis and osteopenia. The primary outcome variable, BMD, was attained using dual-energy x-ray absorptiometry scans taken at the femoral neck, trochanter, intertrochanteric crest, total femur, and lumbar spine.

Results

Of the 173 participants in this study, 23 men (28%) and 24 women (26%) had osteopenia at the femoral neck. In men, there was a significant and negative correlation between exercise and femoral neck BMD (r=-0.296, P=.01). In women, correlation analyses showed significant positive correlations between exercise and BMD of the trochanter (r=0.329, P=.003), intertrochanteric crest (r=0.285, P=.01), total femur (r=0.30, P=.01), and lumbar spine (r=0.29, P=.01).

Conclusions

Osteopenia was found in more than 25% of both male and female participants, which suggests that more osteoporosis screening and prevention programs need to be targeted to persons in the studied age group because osteopenia can lead to osteoporosis.

Bone Health Following Bariatric Surgery: An Update

Obesity rates are increasing rapidly, and bariatric surgery is currently the most effective tool for weight loss. Recently, bariatric surgery induced bone loss has gained attention. Such detrimental effect on bone is multifactorial and causes may include nutrient deficiencies, gut and gonadal hormonal changes, mechanical unloading, loss of lean mass, increased bone marrow fat, and increased risk of fall. This review describes the available evidence on bone loss and fracture risk following bariatric surgery and summarizes the guidelines on the topic. Increased bone resorption starts early postsurgery, and bone markers peak at 1-2 yr. Across studies, the drop in areal bone mineral density is inconsistent at the lumbar spine, while a 2%-5% drop at 6 mo and a 6%-10.5% at 9-12 mo are observed at the total hip. Conversely, studies using quantitative CT showed a 6%-7% decrease in volumetric bone mineral density at the lumbar spine at 6-12 mo postsurgery. These studies also report significant bone loss at the radius and tibia, in addition to alteration in bone microarchitecture. Fracture risk increases 2 yr after surgery, more so following malabsorptive procedures. Fractures were reported at axial, weight bearing sites and at appendicular sites. The available evidence is very heterogeneous, and mostly derived from studies on Roux-en-y gastric bypass in premenopausal women. Data on restrictive procedures is scarce. Our findings suggest that the early postoperative phase represents the "golden window" to intervene and promote bone health. More research is needed to determine the effect of different bariatric procedures on bone, to identify optimal interventions to prevent bone loss and to characterize high risk individuals who should be targeted.

The effect of previous treatment with bisphosphonate and renal impairment on the response to denosumab in osteoporosis: a 'real-life' study

PURPOSE

To investigate changes in bone mineral density (BMD) following denosumab after previous bisphosphonate therapy and the impact of chronic kidney disease (CKD) on response.

METHODS

A retrospective study of 134 patients (11 M, 123 F) aged [mean (SD)] 72 [11] years on denosumab was undertaken. Ninety-five patients had previously been on oral and 28 on iv bisphosphonate. Lumbar spine (LS), total hip (TH) and femoral neck (FN) BMD were measured before treatment and at 2.7 [1.2] years. GFR was < 35 ml/min in 24 patients (18%). Ninety-four (18 M, 76 F) patients aged 71 [11] years transitioning to zoledronate were also studied.

RESULTS

BMD improved following denosumab [mean (SEM) % change LS: 6.0 (0.62) p < 0.001, TH: 2.28 (0.64) p < 0.001, FN: 1.9 (0.77) p = 0.045]. Changes at the TH and FN were lower in patients with GFR < 35 ml/min (Group B) compared to those with GFR > 35 ml/min (Group A) [% change TH; Group A: 2.9 (0.72), Group B: - 0.84 (1.28), p = 0.015, FN; Group A: 2.76 (0.86), Group B: - 1.47 (1.53), p = 0.025]. % change in BMD at the FN and PTH were negatively associated (r = - 0.25, p = 0.013). BMD changes were not different at 12-18 months between patients on denosumab compared to zoledronate [% change at LS: denosumab: 3.97% (0.85), zoledronate: 2.6% (0.5), p = 0.19 TH: denosumab: 0.97% (0.58), zoledronate: 0.92% (0.6), p = 0.95).

CONCLUSION

Denosumab increases BMD following previous bisphosphonate treatment and is comparable to zoledronate. Lower response seen at the hip in CKD is related to PTH concentrations.

Sonoanatomy and Pathology of the Gluteus Minimus Tendon

Gluteus minimus disorders are a potential source of greater trochanteric or anterior hip pain. Disorders of the gluteus minimus tendon most commonly occur in conjunction with gluteus medius tendon abnormalities but can also occur in isolation. Understanding the sonoanatomy of the gluteus minimus muscle-tendon unit is a prerequisite for recognizing and characterizing gluteus minimus tendon disorders, which, in turn, guides treatment for patients with greater trochanteric or anterior hip pain syndromes.

Automated Muscle Segmentation from Clinical CT Using Bayesian U-Net for Personalized Musculoskeletal Modeling

We propose a method for automatic segmentation of individual muscles from a clinical CT. The method uses Bayesian convolutional neural networks with the U-Net architecture, using Monte Carlo dropout that infers an uncertainty metric in addition to the segmentation label. We evaluated the performance of the proposed method using two data sets: 20 fully annotated CTs of the hip and thigh regions and 18 partially annotated CTs that are publicly available from The Cancer Imaging Archive (TCIA) database. The experiments showed a Dice coefficient (DC) of 0.891±0.016 (mean±std) and an average symmetric surface distance (ASD) of 0.994±0.230 mm over 19 muscles in the set of 20 CTs. These results were statistically significant improvements compared to the state-of-the-art hierarchical multi-atlas method which resulted in 0.845 ± 0.031 DC and 1.556 ± 0.444 mm ASD. We evaluated validity of the uncertainty metric in the multi-class organ segmentation problem and demonstrated a correlation between the pixels with high uncertainty and the segmentation failure. One application of the uncertainty metric in active-learning is demonstrated, and the proposed query pixel selection method considerably reduced the manual annotation cost for expanding the training data set. The proposed method allows an accurate patient-specific analysis of individual muscle shapes in a clinical routine. This would open up various applications including personalization of biomechanical simulation and quantitative evaluation of muscle atrophy.

Use of Quantitative Computed Tomography to Assess for Clinically-relevant Skeletal Effects of Prolonged Spaceflight on Astronaut Hips

INTRODUCTION

In 2010, experts in osteoporosis and bone densitometry were convened by the Space Life Sciences Directorate at NASA Johnson Space Center to identify a skeletal outcome in astronauts after spaceflight that would require a clinical response to address fracture risk. After reviewing astronaut data, experts expressed concern over discordant patterns in loss and recovery of bone mineral density (BMD) after spaceflight as monitored by dual-energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT). The pilot study described herein demonstrates the use of QCT to evaluate absence of recovery in hip trabecular BMD by QCT as an indicator of a clinically actionable response.

METHODOLOGY

QCT and DXA scans of both hips were performed on 10 astronauts: once preflight and twice postflight about 1 wk and 1 yr after return. If trabecular BMD had not returned to baseline (i.e., within QCT measurement error) in 1 or both hips 1 yr after flight, then another QCT hip scan was obtained at 2 yr after flight.

RESULTS

Areal BMD by DXA recovered in 9 of 10 astronauts at 1 yr postflight while incomplete recovery of trabecular BMD by QCT was evident in 5 of 10 astronauts and persisted in 4 of the 5 astronauts 2 yr postflight.

CONCLUSION

As an adjunct to DXA, QCT is needed to detect changes to hip trabecular BMD after spaceflight and to confirm complete recovery. Incomplete recovery at 2 yr should trigger the need for further evaluation and possible intervention to mitigate premature fragility and fractures in astronauts following long-duration spaceflight.

Association between Uric Acid and Bone Mineral Density in Postmenopausal Women with Type 2 Diabetes Mellitus in China: A Cross-Sectional Inpatient Study

OBJECTIVE

To analyze the association between uric acid levels and bone mineral density in postmenopausal women with type 2 diabetes mellitus.

METHODS

We retrospectively analyzed 262 postmenopausal women with type 2 diabetes mellitus, to assess uric acid levels and bone mineral density using the T score of dual-energy X-ray absorptiometry.

RESULTS

(1) Women in the osteoporosis group demonstrated higher uric acid levels and lower estimated glomerular filtration rate (p < 0.05, respectively). (2) Uric acid levels were positively correlated with the hip and lumbar spine bone mineral density and T score (r = 0.17, p < 0.05; r = 0.25, p < 0.05; r = 0.17, p < 0.05; and r = 0.28, p < 0.05, respectively). Meanwhile, there was a positive relation between estimated glomerular filtration rate and hip bone mineral density (r = 0.22, p < 0.05). (3) Logistic regression analysis showed that age, body mass index, and diabetic duration are independent risk factors for osteoporosis in postmenopausal women with type 2 diabetes mellitus. The level of estimated glomerular filtration rate and uric acid levels were not independent effect factors for osteoporosis in menopausal women.

CONCLUSION

Uric acid levels are neither a protective factor nor a risk factor for osteoporosis in women with type 2 diabetes mellitus.

Right hip and pelvic pain

Follow-up imaging confirmed a clinical suspicion.

A Patient with Pediatric Septic Arthritis of the Hip Complicated with Osteomyelitis Responds to Clindamycin

A 5-year-old girl was referred to our institution with complaints of right hip pain and fever (39.0°C); blood tests and magnetic resonance imaging (MRI) were performed. Blood biochemical results revealed a high inflammatory reaction. MRI results revealed inflammation in the hip joint. She was diagnosed with pediatric septic arthritis of the hip, which required arthrotomy and lavage drainage. Treatment with intravenous vancomycin was initiated on the assumption that the causative bacterial species was Staphylococcus aureus. However, Group A Streptococcus pyogenes (GAS) was subsequently isolated from an intraoperative sample, and the antimicrobial agent was switched to aminobenzylpenicillin (ABPC). Clindamycin (CLDM) was added to the treatment regimen 14 days after surgery as MRI indicated the development and spread of osteomyelitis. Three months post-surgery, MRI findings indicated that the osteomyelitis had resolved and antimicrobial therapy was discontinued. To prevent the spread of osteomyelitis, a combination of CLDM and ABPC should be considered at an early stage, particularly in pediatric patients with GAS-induced septic arthritis.

Evaluation of Osseous Morphology of the Hip Using Zero Echo Time Magnetic Resonance Imaging

BACKGROUND

Femoroacetabular impingement syndrome (FAIS) is a common disorder of the hip resulting in groin pain and ultimately osteoarthritis. Radiologic assessment of FAI morphologies, which may present with overlapping radiologic features of hip dysplasia, often requires the use of computed tomography (CT) for evaluation of osseous abnormality, owing to the difficulty of direct visualization of cortical and subchondral bone with conventional magnetic resonance imaging (MRI). The use of a zero echo time (ZTE) MRI pulse sequence may obviate the need for CT by rendering bone directly from MRI.

PURPOSE/HYPOTHESIS

The purpose was to explore the application of ZTE MRI to the assessment of osseous FAI and dysplasia morphologies of the hip. It was hypothesized that angular measurements from ZTE images would show significant agreement with measurements obtained from CT images.

STUDY DESIGN

Cohort study (diagnosis); Level of evidence, 2.

METHODS

Thirty-eight hips from 23 patients were imaged with ZTE MRI and CT. Clinically relevant angular measurements of hip morphology were made in both modalities and compared to assess agreement. Measurements included coronal and sagittal center-edge angles, femoral neck-shaft angle, acetabular version (at 1-, 2-, and 3-o'clock positions), Tönnis angle, alpha angle, and modified-beta angle. Interrater agreement was assessed for a subset of 10 hips by 2 raters. Intermodal agreement was assessed on the complete cohort and a single rater.

RESULTS

Interrater agreement was demonstrated in both CT and ZTE, with intraclass correlation coefficient values ranging from 0.636 to 0.990 for ZTE and 0.747 to 0.983 for CT, indicating "good" to "excellent" agreement. Intermodal agreement was also shown to be significant, with intraclass correlation coefficients ranging from 0.618 to 0.904.

CONCLUSION

Significant agreement of angular measurements for hip morphology exists between ZTE MRI and CT imaging. ZTE MRI may be an effective method to quantitatively evaluate osseous hip morphology.

Polymorphisms of genes related to vitamin D metabolism and transportation and its relationship with the risk of osteoporosis: protocol for a multicentre prospective cohort study in China

INTRODUCTION

Osteoporotic fracture is one of the most common causes of disability and a major contributor to medical care costs in many regions of the world. The polymorphisms of genes related to vitamin D metabolism and transportation are associated with variation in bone mineral density and the risk of osteoporosis.

METHODS AND ANALYSIS

The China Community-based Cohort of Osteoporosis study is an observational, longitudinal, multicentre, prospective cohort study for middle-aged and older permanent residents of China, which has been ongoing in six cities since 2016. Female residents aged 45-80 years old and male residents aged 50-80 years old are identified through permanent resident lists. All the enrolled participants will complete questionnaires on their personal characteristics and histories. The bone mineral density of their lumbar vertebrae and left hip will be measured and serum bone metabolism parameters assessed. Polymorphisms of genes related to vitamin D metabolism and transportation will be detected, and their relationship with the risk of osteoporosis, and osteoporotic fracture, will be analysed. About 18 000 residents will be involved in the study.

ETHICS AND DISSEMINATION

The study was approved by Institutional Ethics Board of Longhua Hospital affiliated to Shanghai University of Traditional Chinese Medicine (2016LCSY065). Results will be published in peer-reviewed journals. The results of this study are expected to improve the understanding of the association between polymorphisms of genes related to vitamin D metabolism and transportation and the risk of osteoporosis and osteoporotic fracture among middle-aged and older residents of China.

TRIAL REGISTRATION NUMBER

NCT02958020.

Association between trunk and gluteus muscle size and long jump performance

The present study aimed to examine the sizes of trunk and gluteus muscles in long jumpers and its relation to long jump performance. Twenty-three male long jumpers (personal best record in long jump: 653–788 cm) and 22 untrained men participated in the study. T1-weighted magnetic resonance images of the trunk and hip were obtained to determine the cross-sectional areas of the rectus abdominis, internal and external obliques and transversus abdominis, psoas major, quadratus lumborum, erector spinae and multifidus, iliacus, gluteus maximus, and gluteus medius and minimus. The cross-sectional areas of individual trunk and gluteus muscles relative to body mass were significantly larger in the long jumpers than in untrained men (P < 0.001, Cohen’s d = 1.3–4.3) except for the gluteus medius and minimus. The relative cross-sectional area of the rectus abdominis of takeoff leg side was significantly correlated with their personal best record for the long jump (r = 0.674, corrected P = 0.004). Stepwise multiple regression analysis selected relative cross-sectional areas of the rectus abdominis and iliacus and the personal best record in 100-m sprint to predict the long jump distance (standard error of estimate = 22.6 cm, adjusted R² = 0.763). The results of the multiple regression analysis demonstrated that the rectus abdominis and iliacus size were associated with long jump performance independently of sprint running capacity, suggesting the importance of these muscles in achieving high performance in the long jump.

Comparison of Teriparatide and Denosumab in Patients Switching From Long-Term Bisphosphonate Use

CONTEXT

Teriparatide and denosumab are effective treatments for osteoporosis and typically reserved as second-line options after patients have used bisphosphonates. However, limited head-to-head comparative effectiveness data exist between teriparatide and denosumab.

OBJECTIVE

We compared changes in bone mineral density (BMD) between groups treated with teriparatide or denosumab after using bisphosphonates, focusing on the change in BMD while on either drug over 2 years.

DESIGN

Observational cohort study using electronic medical records from two academic medical centers in the United States.

PARTICIPANTS

The study population included osteoporotic patients >45 years who received bisphosphonates >1 year before switching to teriparatide or denosumab.

OUTCOME MEASURES

Annualized BMD change from baseline at the lumbar spine, total hip, and femoral neck.

RESULTS

Patients treated with teriparatide (n = 110) were compared with those treated with denosumab (n = 105); the mean (SD) age was 70 (10) years and median duration (interquartile range) of bisphosphonate use was 7.0 (5.6 to 9.7) years. Compared with denosumab users, teriparatide users had higher annualized BMD change at the spine by 1.3% (95% CI 0.02, 2.7%) but lower at the total hip by -2.2% (95% CI -2.9 to -1.5%) and the femoral neck by -1.1% (95% CI -2.1 to -0.1%). Those who switched to teriparatide had a transient loss of hip BMD for the first year, with no overall increase in the total hip BMD over 2 years.

CONCLUSIONS

Among patients who use long-term bisphosphonates, the decision of switching to teriparatide should be made with caution, especially for patients at high risk of hip fracture.

Comparison of regional bone marrow adiposity characteristics at the hip of underweight and weight-recovered women with anorexia nervosa using magnetic resonance spectroscopy

Bone marrow adiposity (BMA) is an underestimated tissue, with properties that may alter bone strength especially in diseases that fragilize bone such as anorexia nervosa. In the present study, we investigated the regional characteristics of BMA at the hip of 40 underweight and 36 weight-recovered anorexic women, along with 10 healthy women, using magnetic resonance spectroscopy at multiple anatomical subregions (acetabulum, femoral neck, proximal femoral diaphysis and greater trochanter) to measure bone marrow fat fraction (BMFF) and apparent lipid unsaturation levels (aLUL). Correlations between BMFF, aLUL, body fat percentage (BF), and bone mineral density (BMD) at the femoral neck and total hip, both measured using dual-energy X-ray absorptiometry, were assessed in anorexic patients. Whereas BMFF was significantly higher and aLUL significantly lower at the femoral neck of underweight and weight-recovered patients compared to controls (BMFF: 90.1 ± 6.7% and 90.3 ± 7.5% respectively versus 81.3 ± 8.1%; aLUL: 7.6 ± 1.4% and 7.3 ± 1.3% versus 9.2 ± 1.5%), BMFF and aLUL were not significantly different between the 2 subgroups of patients. Besides, three noteworthy features were observed between BMA and the other measured parameters in anorexic patients. First, synergic alterations of BMA were observed at all sites, with an inverse relationship between BMFF and aLUL (ρ = -0.88). Second, bone mineral compartment and BMA were associated, as a negative correlation between total hip BMD and BMFF was observed at all sites except the greater trochanter (ρ = [-0.32;-0.29]), as well as a positive correlation with aLUL at all sites except the proximal femoral diaphysis (ρ = [0.25;0.37]). Finally, we found a positive correlation between BF and BMFF at the femoral neck (ρ = 0.35), and a negative correlation between BF and aLUL at this same subregion (ρ = -0.33), which suggest a complex relationship between BMA and BF. Overall, BMA possesses regional specificities which may impair bone health, even after weight recovering.

Association Between the Elasticity of Hip Muscles and the Hip Migration Index in Cerebral Palsy

OBJECTIVES

Cerebral palsy (CP) increases the risk of hip displacement during childhood. Abnormal hip muscle forces have been proposed as the predisposing factors. In CP, the amount of hip displacement is commonly evaluated by the Reimers hip migration index (MI) on an anteroposterior pelvic radiograph. To the best of our knowledge, the association between the elasticity of hip muscles measured by shear wave elastography and the MI has not been studied yet. Herein, we aimed to analyze the correlation between the elasticity of hip muscles and the MI.

METHODS

Bilateral hips of 25 children with spastic CP were included prospectively in this study. Anteroposterior pelvic radiographs were used to measure the MI. Shear wave elastography was performed to evaluate the elasticity of muscles. The correlation between the MI and the elasticity of hip flexor and adductor muscle groups was assessed. Also, the association between the elasticity of agonist/antagonist muscles was analyzed.

RESULTS

The MI showed fair to good correlations with hip flexors and adductors for both readers (0.71 ≥ r ≥ 0.52). The mean MIs of the patients ± SDs were 22.64% ± 7.79% for reader 1 and 21.55% ± 8.83% for reader 2. The elasticity of agonist/antagonist muscle groups showed little/no to a weak correlation for both readers (0.32 ≥ r ≥ -0.07).

CONCLUSIONS

Although, hip flexor and adductor muscle elasticity showed a correlation with MI, it seems very hard to say that increased elasticity of hip flexor and adductor muscles causes hip dislocation.

Professional soccer is associated with radiographic cam and pincer hip morphology

PURPOSE

Femoroacetabular impingement (FAI) syndrome is characterized by a triad: symptoms, clinical signs and imaging findings. Some individuals, especially athletes, have only imaging alterations. The objective of this study was to evaluate the prevalence of cam and pincer morphology in professional soccer players compared with a control group of non-athletes and to investigate the association between the age at which players start playing competitive soccer more than three times per week and duration of the soccer career with the prevalence of these radiographic findings.

METHODS

The prevalence of cam and pincer morphology in sixty professional adult male soccer players and thirty-two male controls was determined using pelvic anteroposterior radiography. Data were recorded for all hips and correlated with the age at which the players started competitive soccer practice and with the duration of their soccer career.

RESULTS

The prevalence of morphological FAI in the soccer players was 92.5% versus 28.1% in the controls (p < 0.001). The duration of the soccer career was positively correlated with the alpha angle (p = 0.033) and negatively correlated with the retroversion index (p = 0.009). The age at which competitive play began was inversely correlated with the alpha angle (p < 0.001).

CONCLUSION

The study showed a high prevalence of cam and pincer morphology in Brazilian professional soccer players compared with controls. The duration of the soccer career was associated with an increased alpha angle and a decreased retroversion index, and the age at which competitive soccer participation began was negatively associated with alpha angle values. Finally, this manuscript provides data about the association between greater exposure to soccer and cam and pincer morphological changes in the hip; specifically, cam morphology was more common in patients who began participating in sports at earlier ages. This information serves as an alert for coaches of youth teams to manage the training load in youth athletes.

LEVEL OF EVIDENCE

III.

The synergetic effect of pelvic rotation and X-ray offset on radiographic angles of the acetabular cup

The objective of this study is to investigate the synergetic effect of the pelvic rotation and X-ray offset on the radiographic anteversion/inclination (RA/RI) angles of the acetabular cup using a mathematical model. A cone model for establishing the spatial relationship between a three-dimensional (3D) circle and its two-dimensional (2D) elliptical projection is utilized to quantify the relationship between the 3D RA/RI angles of the cup and their 2D counterparts with different types of pelvic rotations in pelvic/hip anteroposterior radiographs. The results reveal that the effect of inlet/outlet views on the 2D RA angle is similar to that of iliac/obturator views. The permissible ranges of pelvic rotation for the 2D RA angle with an acceptable bias are the 3D space formed by the limits of triple axial rotations. For a specified acceptable bias of the 2D RA angle, these ranges are almost equal between pelvic and hip radiographs. The combined inlet/obturator or outlet/iliac views can maintain the 2D RA angle of a pelvic radiograph within the same range of acceptable bias as that of a hip radiograph. For a 2D RA angle with an acceptable bias, the permissible range of pelvic rotation needs to be evaluated with equal attention in both radiographs. Graphical abstract The traditional methods for calculating the radiographic angles of the acetabular cup are based on the ellipse projection of the opening circle of the cup on radiographs. However, with varying locations of the X-ray source and pelvis rotations about different axes, the outline of this ellipse projection will change, and accordingly, the traditional method and calculating results will be inaccurate. In this study, a cone model for three-dimensional circle-to-two-dimensional ellipse projection is utilized to incorporate the effect of X-ray offset and quantify the relationships of the radiographic angles of the cup with the true orientation of the cup and pelvic rotations in either pelvic or hip anteroposterior radiographic situation.

Impact of Estimated Pre-Exposure Prophylaxis (PrEP) Adherence Patterns on Bone Mineral Density in a Large PrEP Demonstration Project

Bone mineral density (BMD) declines due to tenofovir-containing pre-exposure prophylaxis (PrEP) have varied among PrEP demonstration projects, potentially related to variable adherence. Characterization of BMD changes in highly adherent individuals, estimated via tenofovir-diphosphate (TFV-DP) levels in dried blood spots (DBS), can assist clinicians when counseling patients. Cisgender men who have sex with men and transwomen in the optional dual-energy X-ray absorptiometry (DXA) substudy of a large, international, open-label PrEP demonstration project, the iPrEx-open-label extension (OLE) study underwent DXA scans and DBS collection every 24 weeks, with average weekly dosing adherence patterns (2, 4, and 7 doses/week) estimated from validated TFV-DP cut-offs. The mean percent BMD change was estimated in strata of average weekly adherence by using a linear mixed-effects model to calculate the BMD decline in highly adherent individuals on PrEP for the first time. DXA/DBS data were available for 254 individuals over a median of 24 weeks in iPrEx-OLE from June 2011 to December 2013. The percent decline in spine BMD was monotonically associated with strata of increasing average weekly adherence (p < .001 trend); the p value for trends using hip BMD measurements was .07. Individuals with estimated daily adherence experienced a 1.2% decrease in spine BMD and a 0.5% drop in hip BMD. In highly adherent PrEP users, we found a lower-than-expected drop in BMD when compared with previous studies. This drop is likely not clinically significant for most PrEP users. However, for those at the highest risk of fracture who plan prolonged PrEP use, alternate PrEP strategies could be considered.

The impact of nonstandard hip rotation on densitometric results of hip regions and potential misclassification of diagnosis

The present study is intended to investigate the degree to which insufficient internal rotation could impact the densitometric results and change the diagnosis. A significant difference was found between the results in nonstandard compared with standard rotation and an increase in the BMD and T- and Z-scores from nonstandard to standard rotation. Likewise, a change in diagnosis was observed in a significant proportion of patients.

PURPOSE

To investigate the impact of nonstandard rotation of hip on the densitometric results of femoral neck and total femur region as well as the amount of change in diagnosis (i.e., misclassification of diagnosis) based on hip region.

METHODS

Ninety-seven patients (88 females and 9 males) were included in the study. After receiving informed consent, each subject underwent a densitometric scanning in two modes, one with standard rotation of the leg and the other with nonstandard rotation (i.e., the leg in relaxed position without applying the positioner to strap the foot to) of the same leg. All data were analyzed using the auto-analysis option of the HOLOGIC® software. Bone densitometric results, T- and Z-scores, rate of change in diagnosis, and also the agreement between the diagnoses in the two modes are calculated and compared by using a paired-sample t test and cross-tabulation.

RESULTS

The mean age of 97 patients was 56.91 ± 11.70 years. A significant difference was found in the BMDs, T-scores, and Z-scores of the neck and total femur regions of interest in standard and nonstandard rotations. We found an increase in the BMD of the femoral neck and total femur of 0.020 and 0.010 g/cm², respectively, from standard to nonstandard leg rotation and that this, in turn, led to a 0.4 and a 0.13 increases in T-scores of the neck and total femur, respectively, from standard to nonstandard rotation. In the diagnosis based on femoral neck only, the diagnosis changed in 17 (17.5%) patients, i.e., 12 (12.4%) from osteopenia to normal, 3 (3.1%) from osteoporosis to osteopenia, and 2 (2.0%) from below the expected range for age to within the expected range for age. There was only a change of one level in diagnosis.

DISCUSSION AND CONCLUSIONS

According to the results, the changes in the BMD and T- and Z-scores can be interpreted as underdiagnosis or, in simple terms, not finding the disease or underestimating the level of disease. Therefore, proper rotation of the leg is an important factor during densitometry. Any deviation from standard rotation changes the BMD of those regions, and thereby the T- and Z-scores accordingly, and thus the diagnosis.

The Prediction of Body Composition in African Americans From Spine and Hip Dual-Energy Absorptiometry

Body composition, the makeup of the body's fat and lean tissue, is associated with important health outcomes and provides useful clinical information. Although body composition can be measured with total body dual-energy X-ray absorptiometry (DXA), this is rarely performed. As an alternative to total body DXA measurement, methods for estimation of body composition have been developed. These methods use soft tissue measures from spine and hip DXA to predict body composition and include prediction equations previously published by Leslie and proprietary equations within General Electric densitometry software. However, these estimates have not been tested in African Americans (AA), an ethnicity with a different distribution of fat than Caucasians (CA). Therefore, we examined the performance of the existing models in 99 CA and 162 AA subjects over the age of 40 who had total body, spine, and hip DXA measurements. We observed that existing models estimated body composition well in CA but underestimated fat mass and overestimated lean mass in AA. AA subjects were then randomly divided into 2 equal-sized subgroups-the first to develop new prediction equations and the second to independently validate them. We found that body composition can be more accurately estimated using either a new model that we derived in AA subjects using backward stepwise elimination or by adding a fixed offset for AA to the previously published model. Our results demonstrate that body composition estimates from spine and hip DXA require consideration of race/ethnicity.