Correlation between distal radial cortical thickness and bone mineral density

One-third Radius bone mineral density measurement utility in the diagnosis of osteoporosis: a comparative analysis with femoral and lumbar spine bone mineral density

Osteoporosis is defined by a BMD ≤ 2.5 SD below the young adult reference population. Standard dual-energy X-ray absorptiometry (DXA) scans for osteoporosis involve the femoral neck and lumbar spine, but alternative sites like the one-third radius (1/3 R) are only used when these sites are inaccessible. This study assessed the correlation and level of agreement between BMD at the 1/3 R, femoral neck, and lumbar spine to evaluate its diagnostic utility. Data from 43,801 patients referred for DXA scans in northwest England were analysed. Of these, 437 underwent 1/3 R scans. Demographic comparisons between patients with and without forearm scans were conducted. The primary analysis included patients with scans at the 1/3 R, lumbar spine, and bilateral femoral regions;(n = 183). Spearman's correlation assessed BMD relationships, Cohen's kappa analysed osteoporosis classification agreement, and Bland-Altman plots evaluated measurement bias. The cohort had a mean age of 65.7 years (SD 12.9), with 83.3% female and 41.2% reporting fractures. Patients who underwent 1/3 R scans (n = 437) were older, heavier, and had a higher body mass index (BMI). Correlation analysis showed only moderate associations between 1/3 R and femoral/lumbar spine BMD ;(r = 0.29 to 0.36, p < 0.001). Cohen's kappa demonstrated only slight agreement for 1/3 R, femoral neck and lumbar spine T-scores (κ = 0.14-0.29). Bland-Altman analysis revealed that 1/3 R scans systematically underestimated BMD relative to femoral and lumbar sites, with mean biases of -0.7 for femoral sites and -1.53 for lumbar spine. The 1/3 R BMD showed poor agreement and systematic underestimation compared to central sites, limiting its reliability for osteoporosis diagnosis. Future research should explore alternative peripheral weight-bearing sites and novel diagnostic technologies to assess BMD where central sites cannot be scanned.

Validity of an ultrasound device to measure bone mineral density

This study aims to examine the validity and reliability of the UltraScan650™, a portable ultrasound device, used to measure BMD at the 1/3rd radius position. Fifty-two female first responders and healthcare providers were assessed using DXA (forearm, femur, lumbar, and total body) and the UltraScan650™. Fat and lean mass were also assessed using the DXA. Pearson correlations, Bland-Altman plots, t-tests, and linear regressions were used to assess validity. Intra-class correlation (ICC) coefficients were used to assess reliability. Inter-rater reliability and repeatability were good (ICC = 0.896 [0.818; 0.942], p < 0.001) and excellent (ICC = 0.917 [0.785; 0.989], p < 0.001), respectively. BMD as measured by the UltraScan650™ was weakly correlated to the DXA (r = 0.382 [0.121; 0.593], p = 0.0052). Bland-Altman plots revealed that the UltraScan650™ underestimated BMD (-0.0569 g/cm2), this was confirmed with a significant paired t-test (p < 0.001). A linear regression was performed (0.4744 × UltraScan650™ + 0.4170) to provide more information as to the issue of agreement. Bland-Altman plots revealed a negligible bias, supported by a paired t-test (p = 0.9978). Pearson's correlation revealed a significant relationship (r = -0.771 [-0.862; -0.631], p < 0.0001) between adjusted UltraScan650™-DXA and the average of the two scans (i.e., adjusted UltraScan650™ and DXA), suggesting a proportional constant error and proportional constant variability in measurements of BMD from the UltraScan650™. The UltraScan650™ is not a valid alternative to DXA for diagnostic purposes; however, the UltraScan650™ could be used as a screening tool in the clinical and research setting given the linear transformation is employed.

Application of Machine Learning to Osteoporosis and Osteopenia Screening Using Hand Radiographs

PURPOSE

Fragility fractures associated with osteoporosis and osteopenia are a common cause of morbidity and mortality. Current methods of diagnosing low bone mineral density require specialized dual x-ray absorptiometry (DXA) scans. Plain hand radiographs may have utility as an alternative screening tool, although optimal diagnostic radiographic parameters are unknown, and measurement is prone to human error. The aim of the present study was to develop and validate an artificial intelligence algorithm to screen for osteoporosis and osteopenia using standard hand radiographs.

METHODS

A cohort of patients with both a DXA scan and a plain hand radiograph within 12 months of one another was identified. Hand radiographs were labeled as normal, osteopenia, or osteoporosis based on corresponding DXA hip T-scores. A deep learning algorithm was developed using the ResNet-50 framework and trained to predict the presence of osteoporosis or osteopenia on hand radiographs using labeled images. The results from the algorithm were validated using a separate balanced validation set, with the calculation of sensitivity, specificity, accuracy, and receiver operating characteristic curve using definitions from corresponding DXA scans as the reference standard.

RESULTS

There was a total of 687 images in the normal category, 607 images in the osteopenia category, and 130 images in the osteoporosis category for a total of 1,424 images. When predicting low bone density (osteopenia or osteoporosis) versus normal bone density, sensitivity was 88.5%, specificity was 65.4%, overall accuracy was 80.8%, and the area under the curve was 0.891, at the standard threshold of 0.5. If optimizing for both sensitivity and specificity, at a threshold of 0.655, the model achieved a sensitivity of 84.6% at a specificity of 84.6%.

CONCLUSIONS

The findings represent a possible step toward more accessible, cost-effective, automated diagnosis and therefore earlier treatment of osteoporosis/osteopenia.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

Unicortical Versus Bicortical Proximal Locking Screw for Prevention of Peri-Implant Fracture: A Biomechanical Analysis of an Osteoporotic Distal Radius Model

Purpose

Osteoporotic patients are at risk of peri-implant fractures after distal radius fixation. A unicortical screw in the proximal hole of the plate can theoretically decrease stress riser formation by eliminating the hole in the far bone cortex. This construct has been proposed in orthopedic literature to prevent peri-implant fractures but has not been tested in an osteoporotic distal radius model.

Methods

Eleven paired cadaver radii were harvested and plated with four-hole titanium volar distal radius plates. No osteotomies were created. The fixation constructs were identical except that group A used a bicortical proximal locking screw and group B used a unicortical proximal locking screw. Bone mineral density was estimated using radiographic measurements. The samples were potted and tested for four-point bending stiffness, torsion stiffness, and load to failure.

Results

Between the bicortical and unicortical screw groups, there was no significant difference in four-point bending stiffness (110.8 vs 106.2 N/mm, apex volar bending; 105.4 vs 107.1 N/mm, apex dorsal bending) or torsional stiffness (430.6 vs 427.6 N-mm/degree, internal rotation; 430.8 vs 429.7 N-mm/degree, external rotation). There was also no significant difference in load to failure with apex dorsal four-point bending (795.3 vs 770.0 N).

Conclusions

This study shows that a healed osteoporotic distal radius volar plate construct with a proximal unicortical locking screw is not statistically different from a bicortical screw in stiffness or load to failure in apex dorsal bending. Although a unicortical locking screw has been proposed as a mechanism to prevent stress risers at the proximal aspect of the distal radius plate, this study suggests no significant difference when compared with a bicortical locking screw.

Clinical relevance

There is no significant biomechanical advantage to unicortical over bicortical locking screws in the proximal hole of a distal radius plate to prevent diaphyseal peri-implant fractures in osteoporotic patients.

Assessing Bone Mineral Density Using Radiographs of the Hand: A Multicenter Validation

PURPOSE

Osteoporosis and fragility fractures incur substantial costs to quality of life and global health care systems. The current gold standard for quantifying bone density is dual-energy X-ray absorptiometry. Our hypothesis is that bone density can be accurately predicted with a simpler method using plain radiographs of the hand.

METHODS

This retrospective cohort study was undertaken in two centers in the United Kingdom, where the second metacarpal cortical percentage (2MCP) scores were calculated from radiographs. This study included patients who had sustained a distal radius fracture between 2020 and 2022 and had received both a posteroanterior radiograph of the hand and a dual-energy X-ray absorptiometry scan within 12 months of their radiograph and fracture. The Pearson correlation coefficient was calculated to determine the correlation between 2MCP scores and t-scores of the femoral neck on dual-energy X-ray absorptiometry scans.

RESULTS

Of the 188 patients, the 2MCP score significantly correlated with bone density t-scores of the femoral neck. A 2MCP score <50% demonstrated 100% sensitivity and 100% specificity for differentiating osteoporotic from normal subjects, whereas a 2MCP score <60% demonstrated 94.4% sensitivity and 83.0% specificity in differentiating osteopenic from normal subjects.

CONCLUSIONS

These data confirm that the likelihood of osteoporosis being present can be determined via the 2MCP score.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic I.

Thinner femoral cortical thickness in patients with destructive rheumatoid arthritis of the knee

BACKGROUND

The examination of femoral cortical bone thickness in patients with rheumatoid arthritis (RA) has been notably limited in prior research. We aimed to compare femoral cortical thickness in patients with rheumatoid arthritis (RA) and healthy controls and to investigate the association between femoral cortical thickness and clinical parameters within the RA group.

METHODS

Forty-four patients (58 limbs) with RA who underwent total knee arthroplasty were enrolled. Preoperative computed tomography images of the lower limbs were analyzed. The femoral cortex was divided into the proximal, central, and distal diaphysis regions and further into the anterior, posterior, medial, and lateral regions. The divisions were measured using Stradwin® software and standardized by femoral length. Femoral cortical thickness was compared between RA and healthy control (n = 25) groups. Correlation analyses between standardized cortical thickness and disease parameters were performed in the RA group.

RESULTS

The RA group had significantly lower standardized femoral cortical thickness at the anterior and medial distal diaphysis than healthy controls. Standardized proximal lateral and central lateral in the RA group were significantly larger than those in the healthy control groups. Standardized femoral cortical thickness was significantly correlated with bone mineral density (BMD) in 11 areas, except the posterior central diaphysis, and with body mass index in 8 areas, except the central posterior, distal lateral, distal anterior, and distal medial diaphysis.

CONCLUSIONS

Femoral cortical thinning was noted in patients with RA complicated with destructive knee, particularly at the anterior and medial distal diaphysis. Femoral cortical thickness was significantly correlated with BMD and body mass index (BMI); thus, patients with RA and low BMD and BMI should be cared for to prevent fragility fractures.

Feasibility of aluminum phantom radiography for osteoporosis detection in postmenopausal women with a fragility fracture of the distal radius compared to DXA and HR-pQCT

Recently, promising results have been reported for detection of osteoporosis with use of an aluminum phantom. Therefore, the aim of this study was to evaluate the feasibility of radiography-based bone mineral density (BMD) measurement using a graded aluminum phantom. This study included 27 postmenopausal women with a distal radius fracture. Aluminum phantom radiography of the healthy radius was conducted as well as high-resolution peripheral quantitative computed tomography (HR-pQCT) measurement of the ultradistal radius and dual energy X-ray absorptiometry (DXA) of the radius, spine, and hip. A strong correlation was observed between aluminum phantom radiography-based mean gray value (mGV) and DXA-derived BMD, especially for the ultradistal radius (ρ = 0.75; p < 0.001). A moderate correlation for the femoral neck (ρ = 0.61 and p < 0.001) between modalities was found. Radius mGV and HR-pQCT-derived BMD only showed a moderate correlation (ρ = 0.48; p < 0.09). Aluminum phantom radiography might serve as a cost efficient, highly available, low-radiation dose screening, and diagnostic method for osteoporosis additively to DXA measurements. Especially, an application in areas with constrained DXA availability and such as preoperative trauma settings would be beneficial. However, further investigation and assessment of specificity and sensitivity is needed.

Evaluation of the Relationship between Osteoporosis Parameters in Plain Hip Radiography and DXA Results in 156 Patients at a Single Center in Turkey

BACKGROUND

The aim of the current study is to determine the relationship between osteoporosis findings in plain X-ray and dual-energy X-ray absorptiometry (DXA) measurement results and to create an alternative diagnostic method for osteoporosis without DXA measurement when necessary.

METHODS

DXA values and hip radiographs of 156 patients were retrospectively analyzed. Singh index (SI), Dorr index (DI), cortical thickness index (CTI), and canal-to-calcar ratio (CCR) measurements from both plain hip radiographs were determined by two observers. The correlation of the DXA parameters (hip total T-score, femoral neck T-score, hip total Z-score, hip total bone mineral density [BMD], and femoral neck BMD) and osteoporosis markers on plain hip radiography (SI, DI, CTI, and CCR) was calculated. In addition, patients were evaluated by dividing them into three groups according to the level of their T-scores (normal, osteopenia, and osteoporosis). In addition, cut-off values were calculated for CTI and CCR.

RESULTS

The mean age was 68.27 ± 8.27 (50-85) years. There was a strong correlation between hip total T-score values and SI, DI, and CTI (r = 0.683, -0.667, and 0.632, respectively), and a moderate correlation (r = -0.495) with CCR. When both hips were compared, there were strong correlations between radiographic parameters (r = 0.942 for SI, 0.858 for DI, 0.957 for CTI, and 0.938 for CCR, all with p < 0.001). When patients divided into three groups according to the T-score level were compared in terms of SI, DI, CTI, and CCR, it was found to be directly related to osteoporosis level (all p < 0.001). In the differentiation of osteopenia and osteoporosis, the cut-off values were 50.4 degrees for CTI and 60.3 degrees for CCR.

CONCLUSION

Good correlations between hip total T-score values and SI, DI, CTI, and CCR (r = 0.683, -0.667, 0.632, and -0.495, respectively) indicate that the presence of osteoporosis can be detected by hip radiography findings without DXA.

Finite element analysis of bone mechanical properties using MRI-derived bound and pore water concentration maps

Ultrashort echo time (UTE) MRI techniques can be used to image the concentration of water in bones. Particularly, quantitative MRI imaging of collagen-bound water concentration (Cbw) and pore water concentration (Cpw) in cortical bone have been shown as potential biomarkers for bone fracture risk. To investigate the effect of Cbw and Cpw on the evaluation of bone mechanical properties, MRI-based finite element models of cadaver radii were generated with tissue material properties derived from 3 D maps of Cbw and Cpw measurements. Three-point bending tests were simulated by means of the finite element method to predict bending properties of the bone and the results were compared with those from direct mechanical testing. The study results demonstrate that these MRI-derived measures of Cbw and Cpw improve the prediction of bone mechanical properties in cadaver radii and have the potential to be useful in assessing patient-specific bone fragility risk.

Can Ultrasonographic Measurement of Bone Cortical Thickness Predict Osteoporosis?

RATIONALE AND OBJECTIVES

In this study, we aimed to describe a more accessible and safe diagnostic tool for osteoporosis or osteopenia diagnosis. We utilized cortical thickness (CoT) measurement of various bones via ultrasonography and evaluated the method's accuracy relative to bone mineral density (BMD) results determined by dual-energy X-ray absorptiometry (DXA).

MATERIALS AND METHODS

A total of 200 volunteers (all female) who agreed to participate in the study and had undergone BMD measurement (femoral or vertebral) were included in the study. Patients with normal BMD result (≥-1.0 T-score) were defined as controls. CoT measurements were made from three bones (radius, tibia, and second metatarsal) for each patient via ultrasonography.

RESULTS

Radius CoT and tibial CoT measurements of both femoral and vertebral osteoporotic or osteopenic patients were significantly higher compared to controls. Second metatarsal CoT of femoral osteoporotic and osteopenic patients was also found to be significantly higher than the control group. We found tibia CoT and radius CoT to have high sensitivity and positive predictive value in identifying patients with abnormal femoral T-scores (<-1). In multivariable analyzes, radius CoT was found to be independently predictive in distinguishing patients with abnormal T-score (<-1) from controls in both the femur and vertebral BMD groups.

CONCLUSION

Radius CoT and tibia CoT values appear to have value in predicting patients with abnormal T-scores measured via DXA. This method may be a very simple technique that can be used for early detection of osteoporosis and osteopenia, but its results need to be supported by more comprehensive studies.

Forearm bone mineral density as a predictor of reduction loss in distal radius fractures treated with cast immobilization

Objective

Many potential predictors have been identified and proposed for predicting late reduction loss in distal radius fractures. However, no report exists on whether the bone mineral density (BMD) of the forearm correlates with the loss of reduction in distal radius fractures. This study aimed to investigate whether forearm BMD can be used as a predictor of reduction loss in distal radius fractures treated with cast immobilization.

Methods

Ninety patients with distal radius fractures were divided into two groups according to the maintenance or loss of reduction evaluated from radiographs taken at least 6 weeks after their injury. Lumbar and forearm BMD (total and metaphysis) T-scores were measured and compared between the maintenance of reduction (MOR) group and the loss of reduction (LOR) group. Additionally, serologic markers (C-terminal telopeptide, osteocalcin, vitamin D) and radiologic risk factors (intra-articular fracture, ulnar fracture, dorsal comminuted fracture, volar hook) were evaluated and a logistic multiple regression analysis was performed to know the main risk factors of reduction loss.

Results

Reduction loss was observed in 38 patients (42.2%). The total and metaphyseal BMD of the forearm was less in the LOR group than in the MOR group. However, the difference was not statistically significant [−2.9 vs. −2.5 for total (p = 0.18), −2.3 vs. −2.0 for metaphysis (p = 0.17)]. Multiple logistic regression analysis showed initial dorsal comminution (p = 0.008) and ulnar variance (p = 0.01) were the main risk factors for reduction loss.

Conclusions

Forearm BMD was not a valuable prognostic factor for reduction loss in distal radius fractures. Initial dorsal comminution and ulnar variance rather than forearm BMD should be considered preferentially when predicting which patients are at high risk of reduction loss in distal radius fractures.

Radiographic indexes in AP hip radiographs prior to total hip arthroplasty reveal candidates with low BMD

Using anteroposterior (AP) hip radiograph, we measured several indexes to investigate the association with bone mineral density (BMD) before THA and found a highly effective index to predict femoral BMD. This technique is helpful for both patients and clinicians to identify potential candidates with low BMD to whom DXA examination is particularly recommended.

INTRODUCTION

The purpose of the study is to identify patients with low bone mineral density (BMD) prior to total hip arthroplasty with the help of AP hip radiographs.

METHODS

Indexes on AP hip radiographs and T-scores from DXA examination of the lumbar spine and the affected hip were acquired from patients before THA. Indexes measured on AP hip radiographs including the canal calcar ratio (CCR), canal flare index (CFI), morphological cortical index (MCI), canal bone ratio (CBR), and canal bone area ratio (CBAR). The relevance between indexes and the T-score of femora was evaluated by correlation analysis, and the diagnostic value of indexes for osteopenia was examined by receiver operating characteristic (ROC) curves.

RESULTS

A total of 81 patients were included. The average value of CBR-7, CBR-10, and CBAR (7-10) were highly related to the T-score of femora (r =  - 0.592, r =  - 0.634, and r =  - 0.631, respectively, p < 0.0001). Results of the intra- and interobserver variation assessment was excellent. CBR-7, CBR-10, and CBAR (7-10) were significantly different between the non-osteopenia and osteopenia groups (p < 0.0001). CBR-10 had the biggest area under curve (AUC), means the great diagnostic value for osteopenia in the proximal femora (AUC = 0.821, cutoff value = 0.3805).

CONCLUSION

The canal bone ratio at 10 × 10^-2 m under the level of the lesser trochanter proved to be a great indicator of femoral osteopenia. Trial registration Chinese Clinical Trail Registry, ChiCTR2000041016. Registered 16 December 2020-Retrospectively registered, http://www.chictr.org.cn/listbycreater.aspx .

Cortical bone thickness of the distal radius predicts the local bone mineral density

AIMS

The distal radius is a major site of osteoporotic bone loss resulting in a high risk of fragility fracture. This study evaluated the capability of a cortical index (CI) at the distal radius to predict the local bone mineral density (BMD).

METHODS

A total of 54 human cadaver forearms (ten singles, 22 pairs) (19 to 90 years) were systematically assessed by clinical radiograph (XR), dual-energy X-ray absorptiometry (DXA), CT, as well as high-resolution peripheral quantitative CT (HR-pQCT). Cortical bone thickness (CBT) of the distal radius was measured on XR and CT scans, and two cortical indices mean average (CBTavg) and gauge (CBTg) were determined. These cortical indices were compared to the BMD of the distal radius determined by DXA (areal BMD (aBMD)) and HR-pQCT (volumetric BMD (vBMD)). Pearson correlation coefficient (r) and intraclass correlation coefficient (ICC) were used to compare the results and degree of reliability.

RESULTS

The CBT could accurately be determined on XRs and highly correlated to those determined on CT scans (r = 0.87 to 0.93). The CBTavg index of the XRs significantly correlated with the BMD measured by DXA (r = 0.78) and HR-pQCT (r = 0.63), as did the CBTg index with the DXA (r = 0.55) and HR-pQCT (r = 0.64) (all p < 0.001). A high correlation of the BMD and CBT was observed between paired specimens (r = 0.79 to 0.96). The intra- and inter-rater reliability was excellent (ICC 0.79 to 0.92).

CONCLUSION

The cortical index (CBTavg) at the distal radius shows a close correlation to the local BMD. It thus can serve as an initial screening tool to estimate the local bone quality if quantitative BMD measurements are unavailable, and enhance decision-making in acute settings on fracture management or further osteoporosis screening. Cite this article: Bone Joint Res 2021;10(12):820-829.

Recycled windshield glass as new material for producing ultrasonic phantoms of cortical bone-healing stages

The quantitative ultrasound technique was used to evaluate bone-mimicking phantoms; however, these phantoms do not mimic the intermediate stages of cortical bone healing. We propose using windshield glass as an original material to produce phantoms that mimic the characteristics of three different stages of cortical bone healing. This material was processed via a route that included breaking, grinding, compacting, drying, and sintering in four temperature groups: 625 °C, 645 °C, 657 °C, and 663 °C. The parameters evaluated were the ultrasonic longitudinal phase velocity (cL), corrected (αc) ultrasonic attenuation coefficient, and bulk density (ρs). The results showed that the mean values ofcL,αc,andρsvaried from 2, 398 to 4, 406 m·s^-1, 3 to 10 dB·cm^-1, and 1, 563 to 2, 089 kg·m^-3, respectively. The phantoms exhibited properties comparable with the three stages of cortical bone healing and can be employed in diagnostic and therapeutic studies using ultrasound.

Correlation of Hounsfield Unit Measurements on Computed Tomography of the Shoulder With Dual-Energy X-ray Absorptiometry Scans and Fracture Risk Assessment Tool Scores: A Potential for Opportunistic Screening

BACKGROUND

The diagnosis of bone mineral density (BMD) abnormalities involves dual-energy x-ray absorptiometry (DXA), but few patients complete this after a fragility fracture. The assessment of BMD using Hounsfield unit (HU) measurements from computed tomography (CT) scans has been correlated with DXA results in previous studies. We aimed to evaluate the correlation between shoulder CT HU and DXA scores.

METHODS

Billing databases of 3 academic institutions were queried for patients who underwent both DXA and CT scan of the upper extremity within 1 year of each other. DXA T-scores for spine, hip, and femoral neck were recorded. BMD status was defined based on composite T-scores, using the lowest T-score in the spine, hip, or proximal femur. CT scans were measured for HU over 4 slices, recorded to create a bone column, then averaged. The patients' risks of major osteoporosis-related fracture and hip fracture were calculated using the Fracture Risk Assessment Tool.

RESULTS

In total, 300 patients were included. A positive correlation was found between composite T-scores and HU for glenoid and proximal humerus (0.36; 0.17). The proximal humerus HU was significantly associated with the BMD T-score for the hip (P = 0.01); the glenoid HU was significantly associated with BMD T-scores for the hip, spine, and femoral neck (P = 0.002; P = 0.001; P = 0.002). A 10-year risk of hip fracture >3% was associated with lower proximal humerus HU.

CONCLUSIONS

Our study is the first to discover significant correlations between HU at the glenoid and proximal humerus and risk factors as established by the Fracture Risk Assessment Tool scoring system.

LEVEL OF EVIDENCE

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

The Characteristics of Women with Subsequent Distal Radius Fracture after Initial Distal Radius Fracture

BACKGROUND

The purpose of this study was to investigate the characteristics of women with subsequent distal radius fracture (DRF) and to compare bone fragility variables in women with initial and subsequent DRF.

METHODS

We enrolled 227 women who experienced DRF (203 women with initial DRF and 24 women with subsequent DRF) between September 2016 and April 2019. We compared demographic characteristics and bone fragility variables, including bone mineral density, trabecular bone score, hip geometry, bicortical thickness of the distal radius, and fracture risk assessment tool (FRAX) scores between the 2 groups. To reduce bias, patients with subsequent DRF were propensity score-matched in a 1:2 manner with patients affected by initial DRF, and additional comparisons were performed.

RESULTS

Patients in the subsequent DRF group were older than those in the initial DRF group, but this difference was not significant (P=0.091). The proportion of patients receiving treatment with osteoporosis medication was significantly higher in the subsequent DRF group (41.7% vs. 19.2%, P=0.011). Bone fragility variables did not differ significantly between the 2 groups. However, the ten-year probability of major osteoporotic fractures based on FRAX scores was significantly higher in patients with subsequent DRF (7.5% vs. 10.8%, P<0.001). Similar results were observed when comparing the propensity score-matched initial and subsequent DRF groups.

CONCLUSIONS

These findings suggest that the occurrence of subsequent DRF after initial DRF can be attributed to multiple factors rather than bone fragility alone. Systematic and multidisciplinary management would be helpful in preventing the occurrence of subsequent DRF after the initial DRF.

Prenatal Developmental Trajectories of Fluctuating Asymmetry in Bat Humeri

Fluctuating asymmetry (random fluctuations between the left and right sides of the body) has been interpreted as an index to quantify both the developmental instabilities and homeostatic capabilities of organisms, linking the phenotypic and genotypic aspects of morphogenesis. However, studying the ontogenesis of fluctuating asymmetry has been limited to mostly model organisms in postnatal stages, missing prenatal trajectories of asymmetry that could better elucidate decoupled developmental pathways controlling symmetric bone elongation and thickening. In this study, we quantified the presence and magnitude of asymmetry during the prenatal development of bats, focusing on the humerus, a highly specialized bone adapted in bats to perform under multiple functional demands. We deconstructed levels of asymmetry by measuring the longitudinal and cross-sectional asymmetry of the humerus using a combination of linear measurements and geometric morphometrics. We tested the presence of different types of asymmetry and calculated the magnitude of size-controlled fluctuating asymmetry to assess developmental instability. Statistical support for the presence of fluctuating asymmetry was found for both longitudinal and cross-sectional asymmetry, explaining on average 16% of asymmetric variation. Significant directional asymmetry accounted for less than 6.6% of asymmetric variation. Both measures of fluctuating asymmetry remained relatively stable throughout ontogeny, but cross-sectional asymmetry was significantly different across developmental stages. Finally, we did not find a correspondence between developmental patterns of longitudinal and cross-sectional asymmetry, indicating that processes promoting symmetrical bone elongation and thickening work independently. We suggest various functional pressures linked to newborn bats’ ecology associated with longitudinal (altricial flight capabilities) and cross-sectional (precocial clinging ability) developmental asymmetry differentially. We hypothesize that stable magnitudes of fluctuating asymmetry across development could indicate the presence of developmental mechanisms buffering developmental instability.

Upper Extremity Fragility Fractures

The population of elderly patients is rapidly increasing in the United States and worldwide, leading to an increased prevalence of osteoporosis and a concurrent rise in fragility fractures. Fragility fractures are defined as fractures involving a low-energy mechanism, such as a fall from a standing height or less, and have been associated with a significant increase in the risk of a future fragility fracture. Distal radius fractures in the elderly often present earlier than hip and vertebral fractures and frequently involve underlying abnormalities in bone mass and microarchitecture. This affords a unique opportunity for upper extremity surgeons to aid in the diagnosis and treatment of osteoporosis and the prevention of secondary fractures. This review aims to outline current recommendations for orthopedic surgeons in the evaluation and treatment of upper extremity fragility fractures.

Long bone histomorphogenesis of the naked mole-rat: Histodiversity and intraspecific variation

Lacking fur, living in eusocial colonies and having the longest lifespan of any rodent, makes naked mole-rats (NMRs) rather peculiar mammals. Although they exhibit a high degree of polymorphism, skeletal plasticity and are considered a novel model to assess the effects of delayed puberty on the skeletal system, scarce information on their morphogenesis exists. Here, we examined a large ontogenetic sample (n = 76) of subordinate individuals to assess the pattern of bone growth and bone microstructure of fore- and hindlimb bones by using histomorphological techniques. Over 290 undecalcified thin cross-sections from the midshaft of the humerus, ulna, femur, and tibia from pups, juveniles and adults were analyzed with polarized light microscopy. Similar to other fossorial mammals, NMRs exhibited a systematic cortical thickening of their long bones, which clearly indicates a conserved functional adaptation to withstand the mechanical strains imposed during digging, regardless of their chisel-tooth predominance. We describe a high histodiversity of bone matrices and the formation of secondary osteons in NMRs. The bones of pups are extremely thin-walled and grow by periosteal bone formation coupled with considerable expansion of the medullary cavity, a process probably tightly regulated and adapted to optimize the amount of minerals destined for skeletal development, to thus allow the female breeder to produce a higher number of pups, as well as several litters. Subsequent cortical thickening in juveniles involves high amounts of endosteal bone apposition, which contrasts with the bone modeling of other mammals where a periosteal predominance exists. Adults have bone matrices predominantly consisting of parallel-fibered bone and lamellar bone, which indicate intermediate to slow rates of osteogenesis, as well as the development of poorly vascularized lamellar-zonal tissues separated by lines of arrested growth (LAGs) and annuli. These features reflect the low metabolism, low body temperature and slow growth rates reported for this species, as well as indicate a cyclical pattern of osteogenesis. The presence of LAGs in captive individuals was striking and indicates that postnatal osteogenesis and its consequent cortical stratification most likely represents a plesiomorphic thermometabolic strategy among endotherms which has been suggested to be regulated by endogenous rhythms. However, the generalized presence of LAGs in this and other subterranean taxa in the wild, as well as recent investigations on variability of environmental conditions in burrow systems, supports the hypothesis that underground environments experience seasonal fluctuations that may influence the postnatal osteogenesis of animals by limiting the extension of burrow systems during the unfavorable dry seasons and therefore the finding of food resources. Additionally, the intraspecific variation found in the formation of bone tissue matrices and vascularization suggested a high degree of developmental plasticity in NMRs, which may help explaining the polymorphism reported for this species. The results obtained here represent a valuable contribution to understanding the relationship of several aspects involved in the morphogenesis of the skeletal system of a mammal with extraordinary adaptations.

Association between forearm cortical bone properties and handgrip strength in women with distal radius fractures: A cross-sectional study

OBJECTIVES

Mechanical and biochemical bone properties are influenced by muscles. However, the muscle-bone interaction has not been fully elucidated regarding the upper extremities. The objective of the present study was to evaluate the mechanical muscle-bone interaction at the forearm by evaluating the relationship between the properties of three-dimensional (3D) forearm cortical bone models derived from conventional computed tomography (CT) images and handgrip strength (HGS).

METHODS

A total of 108 women (mean age, 75.2 ± 9.4 years; range, 62-101 years) with a distal radius fracture who took conventional CT scans for the assessment of the fracture were included in this study. Distal radius 3D models were reconstructed and the average cortical bone density (Cd) and thickness (Ct) of the region of interest (ROI), which might be affected by the forearm flexor muscles, were calculated using a 3D modeling software. Clinical parameters including HGS, lumbar and hip bone mineral densities (BMDs), and other demographic factors were also obtained. A multivariate linear regression analysis was performed to identify relevant factors associated with HGS.

RESULTS

HGS was found to be independently associated with height and Cd, but no significant difference was found between HGS and Ct, age, weight, as well as lumber and hip BMDs.

CONCLUSIONS

Cortical bone density might be associated with HGS, which is generated by the forearm flexor muscles. Hence, the mechanical muscle-bone interaction in the upper extremities could be supported by the present study.

Distal radial cortical bone thickness correlates with bone mineral density and can predict osteoporosis: a cohort study

PURPOSE

The purpose of this study was to evaluate the correlation of the bone mineral density (BMD) of the hip and lumbar spine with the distal radius cortical thickness (DRCT) measured on anteroposterior radiographs and establish a method for predicting osteoporosis.

METHODS

We assessed 147 patients aged ≥50 years with distal radius fractures who underwent wrist radiographs and dual-energy X-ray absorptiometry. The DRCT was measured and calculated at two levels of the distal radius of the injured wrist on the radiographs.

RESULTS

The intra-rater and inter-rater reliability of measures was excellent (intraclass correlation coefficient >0.85). In the Pearson correlation and simple linear regression analyses, the DRCT was positively correlated with hip BMD (r = 0.393, P < 0.01) and lumbar spine BMD (r = 0.529, P < 0.01). Each 1-mm increase in DRCT was associated with a 0.051-g/cm² increase in hip BMD (R² = 0.154, P < 0.01) and a 0.080-g/cm² increase in lumbar spine BMD (R² = 0.280, P < 0.01). A DRCT of 5.1 mm was selected as the cutoff point for predicting osteoporosis, with the highest Youden index of 0.560, 83.3% sensitivity, 72.7% specificity, and a 66.7% negative predictive value.

CONCLUSION

Cortical thickness measurements obtained from anteroposterior wrist radiographs were positively correlated with hip and lumbar spine BMD measurements. This technique is suggested as a rapid, inexpensive, and sensitive method for predicting osteoporosis.

LEVEL OF EVIDENCE

Diagnostic II.

Cortical thickness of the tibial diaphysis reveals age- and sex-related characteristics between non-obese healthy young and elderly subjects depending on the tibial regions

PURPOSE

This study aimed to evaluate the age- and sex-related characteristics in cortical thickness of the tibial diaphysis between non-obese healthy young and elderly subjects as reference data.

METHODS

The study investigated 31 young subjects (12 men and 19 women; mean age, 25 ± 8 years) and 54 elderly subjects (29 men and 25 women; mean age, 70 ± 6 years). Three-dimensional estimated cortical thickness of the tibial diaphysis was automatically calculated for 5000-9000 measurement points using the high-resolution cortical thickness measurement from clinical computed tomography data. In 12 assessment regions created by combining three heights (proximal, central, and distal diaphysis) and four areas of the axial plane at 90° (medial, anterior, lateral, and posterior areas) in the tibial coordinate system, the standardized thickness was assessed using the tibial length.

RESULTS

As structural characteristics, there were no differences in the medial and lateral thicknesses, while the anterior thickness was greater than the posterior thickness in all groups. The sex-related difference was not shown. As an age-related difference, elderly subjects showed greater or lesser cortical thickness than the young subjects, depending on the regions of the tibia.

CONCLUSIONS

Cortical thickness was different depending on sex, age, and regions in the tibia. The results of this study are of clinical relevance as reference points to clarify the causes of various pathological conditions for diseases.

LEVEL OF EVIDENCE

Level 3.

Evaluation of Hip Geometry Parameters in Patients With a Distal Radius Fracture

BACKGROUND

Patients with a distal radius fracture (DRF) have an increased risk of subsequent fractures including hip fractures. The purpose of this study was to evaluate whether women with a DRF have certain hip geometry parameters known to indicate susceptibility to hip fractures.

METHODS

We compared bone mineral density (BMD) and hip geometry parameters (hip axis length, neck shaft angle, mean cortical thickness, femur neck width, cross-sectional area [CSA], cross-sectional moment of inertia, section modulus, and buckling ratio) in 181 women with a DRF (DRF group) and 362 propensity score-matched women without a fracture (control group). We evaluated the associations between DRF and hip geometry parameters using logistic regression analysis.

RESULTS

The DRF group had lower hip BMD; lower cortical thickness, CSA, and section modulus; and higher buckling ratio than the control group (all p < 0.05). The occurrence of a DRF was significantly associated with decreases in neck shaft angle (odds ratio [OR], 1.047; 95% confidence interval [CI], 1.008-1.088) and CSA (OR, 3.114; 95% CI, 1.820-5.326) after adjusting for age, BMI, and total hip BMD.

CONCLUSIONS

In this study, women with a DRF were more likely than women without a DRF to have hip geometry parameters known to indicate susceptibility to hip fractures. Our results suggest that not only low hip BMD but also a decreased CSA could account for the increased risk of subsequent hip fracture in patients with a DRF.

Geometric semi-automatic analysis of radiographs of Colles' fractures

Fractures of the wrist are common in Emergency Departments, where some patients are treated with a procedure called Manipulation under Anaesthesia. In some cases, this procedure is unsuccessful and patients need to revisit the hospital where they undergo surgery to treat the fracture. This work describes a geometric semi-automatic image analysis algorithm to analyse and compare the x-rays of healthy controls and patients with dorsally displaced wrist fractures (Colles' fractures) who were treated with Manipulation under Anaesthesia. A series of 161 posterior-anterior radiographs from healthy controls and patients with Colles' fractures were acquired and analysed. The patients' group was further subdivided according to the outcome of the procedure (successful/unsuccessful) and pre- or post-intervention creating five groups in total (healthy, pre-successful, pre-unsuccessful, post-successful, post-unsuccessful). The semi-automatic analysis consisted of manual location of three landmarks (finger, lunate and radial styloid) and automatic processing to generate 32 geometric and texture measurements, which may be related to conditions such as osteoporosis and swelling of the wrist. Statistical differences were found between patients and controls, as well as between pre- and post-intervention, but not between the procedures. The most distinct measurements were those of texture. Although the study includes a relatively low number of cases and measurements, the statistical differences are encouraging.

Osteoporosis care after distal radius fracture reduces subsequent hip or spine fractures: a 4-year longitudinal study

We evaluated whether active osteoporosis care in patients experiencing their first distal radius fracture (DRF) reduces subsequent hip or spine fractures by comparing two cohorts. The incidence of subsequent fractures was significantly lower in the active care cohort than the other cohort in 4-year follow-up.

PURPOSE

Studies show that osteoporosis care in patients with osteoporotic fracture reduces subsequent fractures, but the impact of such active care in patients with distal radius fracture (DRF) has not been well studied. We evaluated how much osteoporosis care in patients experiencing their first DRF can reduce subsequent hip or spine fractures at 4-year follow-up.

METHODS

Active osteoporosis care by orthopedic surgeons for patients with DRF started from September 2009 at our institution, thus we had a unique opportunity to compare the two cohorts: pre-involvement (PreI) group (DRF before September 2009) and post-involvement (PostI) group (DRF from September 2009). We compared the two cohorts for subsequent hip or spine fracture incidence in the 4 years following DRF.

RESULTS

Overall, 1057 patients with a DRF (85% women; mean age, 70 years) were studied, of whom 205 patients were in PreI group and 852 in PostI group. Subsequent fractures occurred in 27 patients (2.6%), with a mean interval of 29 months after DRF. The incidence was significantly lower in the PostI group than in the PreI group (1.9% vs. 5.4%, p = 0.004), especially in hip fractures (0.4% vs. 2.9%, p = 0.002). The relative risk reduction was 65% for all subsequent fractures and 86% for hip fractures.

CONCLUSION

This study demonstrates that active osteoporosis care in patients with DRF significantly reduces subsequent fracture incidence even for the 4-year follow-up period. These findings add an evidence for the current proactive osteoporosis care programs such as fracture liaison services.

LEVEL OF EVIDENCE

Therapeutic level III.

Convolutional Neural Network for Second Metacarpal Radiographic Osteoporosis Screening

PURPOSE

Osteoporosis and osteopenia are extremely common and can lead to fragility fractures. The purpose of this study was to determine whether a computer learning system could classify whether a hand radiograph demonstrated osteoporosis based on the second metacarpal cortical percentage.

METHODS

We used the second metacarpal cortical percentage as the osteoporosis predictor. A total of 4,000 posteroanterior (PA) radiographs of the hand were standardized through laterality correction, vertical alignment correction, segmentation, proxy osteoporosis predictor, and full pipeline. Laterality was classified using a LeNet convolutional neural network (CNN). Vertical alignment classification used 2,000 PA x-rays to determine vertical alignment of the second metacarpal. We employed segmentation to determine which pixels belong to the second metacarpal from 1,000 PA x-rays using the FSN-8 CNN. The full pipeline was tested on 265 previously unseen PA x-rays.

RESULTS

Laterality classification accuracy was 99.62%, with a specificity of 100% and sensitivity of 99.3%. Rotation of the hand within 10° of vertical was accurate in 93.2% of films. Segmentation was 94.8% accurate. Proxy osteoporosis predictor was 88.4% accurate. Full pipeline accuracy was 93.9%. In the testing data set, the CNN had a sensitivity of 82.4% and specificity of 95.7%. In the balanced data set, 6 of 39 osteoporotic films were classified as nonosteoporotic; sensitivity was 82.4% and specificity, 94.3%.

CONCLUSIONS

We have created a series of CNN that can accurately identify osteoporosis from non-osteoporosis. Furthermore, our CNN is able to make adjustments to images based on laterality and vertical alignment.

CLINICAL RELEVANCE

Convolutional neural network and computer learning can be used as an adjunct to dual-energy x-ray absorptiometry scans or to screen and make appropriate referrals for further workup in patients with suspected osteoporosis.

Is there a significant decrease in the femoral cortical bone around Furlong® stems after 18 years of follow-up?

INTRODUCTION

In the context of total hip arthroplasty (THA), there are several reasons that have motivated the development of short stems. It has been postulated that short stems allow a better conservation of the bone stock if compared to conventional stems. As far as we have knowledge, the quantitative loss of diaphyseal bone stock in patients with standard femoral stems has not been fully described. The aim of this study was to provide evidences about the thickness of the cortical bone at the diaphysis in patients who have undergone unilateral THA with Furlong^® stems with a minimum follow-up of 18 years.

PATIENTS AND METHODS

A retrospective study of patients who underwent THA in a single hospital was performed. The inclusion criteria were patients who had undergone a non-cemented elective THA with a Furlong^® stem, minimum follow-up of 18 years, and contralateral femur and hip without history of previous surgical procedures. The follow-up analysis was performed by means of radiological examinations performed at the last follow-up visit. Data related to the sex, age at surgery and adverse events registered during the follow-up were gathered. The cortical thickness index (CTI) and cortical thickness (CT) assessed at the last follow-up visit in anteroposterior pelvic X-rays were analyzed, both in the operated hip and in the non-operated hip (which was used as control). Calibration of the measurements was done by means of using the circumference of the head of the THA.

RESULTS

The total number of patients who met the inclusion criteria was 22. There were 14 women and eight men. There were 12 left hips. The mean age at the time of surgery was 59.32 ± 6.83 (range 50-70) years. The mean follow-up was 20.86 ± 1.90 (range 18-24) years. The CTI was found to be 11.93% greater in the non-operated hips. The CT measured at 3 cm and 6 cm from lesser trochanter, and at 9 cm from the greater trochanter, was found to be 21.64%, 15.33% and 18.73% greater in the non-operated hips, respectively.

CONCLUSION

After a minimum of 18 years from the implantation of a Furlong^® stem, the bone density that surrounds the implant seems to involve a cortical bone ten percent less thick than the cortical bone of the non-operated contralateral side. With this stem, the cortical zones with less CT seem to be the lateral cortex at 9 cm from the greater trochanter, and the medial cortex at 3 and 6 cm from the lesser trochanter.

LEVEL OF EVIDENCE

III, retrospective case-control study.

Evaluation of the tibial cortical thickness accuracy in osteoporosis diagnosis in comparison with dual energy X-ray absorptiometry

Background:

Unlike public awareness around the world, osteoporosis is still underdiagnosed in most cases till bone fractures. Currently, the dual-energy X-ray absorptiometry (DEXA) is the gold standard diagnostic method of osteoporosis, but unfortunately this method is not available in all diagnostic centers, especially in developing countries.

Aims:

To evaluate the accuracy of tibial cortical thickness in the diagnosis of osteoporosis compared with DEXA.

Materials and Methods:

In this descriptive--analytic study, patients suspicious of osteoporosis who referred to Imam Khomeini Hospital, Ahvaz from 2016 --2017 were recruited. Data was collected for each patient including age, sex, radiography, and DEXA. The total thickness of the tibia cortex (sum of the two sides) was measured using knee anteroposterior radiography at 10 cm from the proximal tibial joint. The bone mineral density (BMD) was measured by DEXA method and reported as T-score.

Results:

In this study, 62 patients (90% female) were evaluated. The mean age of the patients was 57 years (range 45--80 years). T-score had a direct significant correlation with TCT level (r = 0.51, P < 0.0001). Also, T-score had a reverse and significant correlation with age of patients (r = −0.280, P = 0.028). The area under the curve (AUC) was 77%. Also, the sensitivity and specificity for the TCT level less than 4.37 mm (as cutoff point) was 100% and 39.1%, respectively.

Conclusion:

The findings of this study indicate that TCT has a direct significant correlation with the T-score obtained by the DEXA method. It has also been shown that TCT can be a relatively accurate diagnostic tool for predicting osteoporosis.

Wrist Fractures and Osteoporosis

Distal radial fractures account for up to 18% of all fractures in patients over 65 years of age, and osteoporosis is a predominant factor in these fractures. Fracture treatment may include closed reduction and casting/splinting, external fixation, and open reduction and internal fixation.

The Effect of Osteoporosis on the Outcomes After Volar Locking Plate Fixation in Female Patients Older than 50 Years With Unstable Distal Radius Fractures

PURPOSE

The aim of this study was to investigate the effect of osteoporosis on radiological and clinical outcomes after volar locking plate (VLP) fixation in women older than 50 years with unstable distal radius fractures (DRFs).

METHODS

We retrospectively reviewed data of 79 women older than 50 years with DRFs treated by VLP fixation. We collected patients' baseline data, including age and bone mineral density. We also measured the cortical thickness of the distal radius on plain radiographs and computed tomography to assess local bone density. Radiological outcomes included late displacement at 1 year after surgery, which was defined as a change in radiological parameters (radial inclination, volar tilt, and ulnar variance). Clinical outcomes were assessed with the Disabilities of the Arm, Shoulder, and Hand (DASH) and modified Mayo wrist score at 1 year after surgery. We compared mean values between the nonosteoporotic (group 1, T score > -2.5) and the osteoporotic groups (group 2, T score ≤ -2.5). We conducted linear and logistic regression analysis to investigate factors associated with poor outcomes.

RESULTS

There were 49 patients in group 1 and 30 patients in group 2. Radiological outcomes were similar in both groups. The mean DASH score was 14.9 (SD, 16.4) for group 1 and 12.5 (SD, 13.5) for group 2, and the mean modified Mayo wrist score was 87.6 (SD, 8.8) for group 1 and 88.2 (SD, 11.4) for group 2. There were no significant differences in clinical outcomes between groups. Simple and multivariable linear regression analysis showed only older age was associated with the change in volar tilt. Osteoporosis and cortical thickness were not associated with poor clinical outcomes on simple logistic regression analysis.

CONCLUSIONS

Osteoporosis and cortical thickness of the distal radius did not affect clinical outcomes after VLP fixation in women older than 50 years with unstable DRFs.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Cortical Thickness Index of the Proximal Femur: A Radiographic Parameter for Preliminary Assessment of Bone Mineral Density and Osteoporosis Status in the Age 50 Years and Over Population

BACKGROUND

Bone mineral density (BMD) is the indicator of bone quality in at-risk individuals. Along with the fracture risk assessment tool (FRAX), a quick assessment of BMD from routine radiographs may be useful in the case of lacking X-ray absorptiometry data. This study aimed to investigate the correlation of cortical thickness index (CTI) and canal flare index (CFI) with BMD and FRAX and to evaluate their ability to predict femoral neck BMD (nBMD) and FRAX in the general elderly population.

METHODS

A total of 560 volunteers (age ≥ 50 years) who underwent hip-spine X-ray, BMD scanning and FRAX calculation were retrospectively reviewed. CTI and CFI were measured on anteroposterior radiographs and analyzed for their correlation with BMD and FRAX and for their ability to predict nBMD. The ability of CTI to predict osteoporosis status (OPS) and fracture risk status (FRS) was also investigated and the threshold values were calculated. All the analyses were performed separately on male and female subjects.

RESULTS

Significant differences in CTI, CFI, nBMD and FRAX between males and females were observed. CTI and CFI demonstrated significant positive correlation with nBMD and FRAX (all p < 0.001) in both males and females. CTI, height, and weight significantly predicted nBMD. CTI statistically predicted OPS and FRS, and the values of 0.56 and 0.62 were computed as CTI thresholds for males and females, respectively.

CONCLUSIONS

CTI was significantly correlated with nBMD and it predicted nBMD at good prediction levels. Therefore, CTI may be used as a supportive tool in the assessment of OPS and FRS besides BMD and FRAX in clinical practice.

Parametric study of patient-specific femoral locking plates based on a combined musculoskeletal multibody dynamics and finite element modeling

A combined musculoskeletal multibody dynamics and finite element modeling was performed to investigate the effects of design parameters on the fracture-healing efficiency and the mechanical property of a patient-specific anatomically adjusted femoral locking plate. Specifically, the screw type, the thickness and material of the locking plate, the gap between two femoral fragments (fracture gap) and the distance between bone and plate (interface gap) were evaluated during a human walking. We found that the patient-specific locking plate possessed greater mechanical strength and more efficient fracture healing than the corresponding traditional plate. An optimal patient-specific femoral locking plate would consist of bicortical locking screws, Ti-6Al-4V material and 4.75-mm plate thickness with a fracture gap of 2 mm and an interface gap of 1 mm. The developed patient-specific femoral locking plate based on the patient-specific musculoskeletal mechanical environment was more beneficial to fracture rehabilitation and healing. The patient-specific design method provides an effective research platform for designing and optimizing the patient-specific femoral locking plate under realistic in vivo walking conditions, which can be extended to the design of other implants as well as to other physiological loading conditions related to various daily activities.

Evaluation of sarcopenia in patients with distal radius fractures

Sarcopenia is more prevalent in patients with distal radius fracture (DRF) than in age- and sex-matched controls. Lower appendicular mass index in men and weaker grip strength in both men and women increase the likelihood of DRF.

INTRODUCTION

Sarcopenia is a core component of physical frailty that predisposes older people to falls and negatively impacts the activities of daily living. The objectives of this study were to compare the prevalence of sarcopenia in patients with DRF with that in age- and sex-matched controls without DRF; and evaluate the association between sarcopenia and the occurrence of DRF.

METHODS

We prospectively recruited 132 patients over 50 years of age who sustained DRF due to fall and 132 age- and sex-matched controls without DRF. A definition of sarcopenia was based on the consensus of the Asian Working Group for Sarcopenia. Sarcopenic components including appendicular lean body mass, grip strength, and gait speed were compared between the two groups. Other factors assessed for the occurrence of DRF were age, gender, body mass index (BMI), lumbar, and hip bone mineral density (BMD) values. A conditional logistic regression analysis was conducted to evaluate the associations between sarcopenia and the occurrence of DRF.

RESULTS

A total of 39 (30%) of 132 DRF patients were sarcopenic, whereas 23 (17%) of the 132 controls were within the sarcopenic criteria (p = 0.048). The patient group had significantly lower lean body mass and weaker grip strength than those of the control group. However, there was no significant difference in gait speed between the two groups. According to regression analysis, lower appendicular mass index in men was associated with an increased incidence of DRF (odds ratio [OR] = 0.84, 95% confidence interval [CI] = 0.72, 0.95) while weaker grip strength and lower total hip BMD values were associated with the occurrence of DRF in both men (OR = 0.77, 95% CI = 0.63, 0.92; and OR = 0.79, 95% CI = 0.64, 0.94, respectively) and women (OR = 0.78, 95% CI = 0.64, 0.93, and OR = 0.73, 95% CI = 0.52, 0.92, respectively).

CONCLUSIONS

Sarcopenia is more prevalent in patients with DRF than in age- and sex-matched controls. Lower appendicular mass in men, weaker grip strength, and lower hip BMD in both men and women increase the likelihood of DRF.

Humeral head circle-fit method greatly increases reliability and accuracy when measuring anterior-posterior radiographs of the proximal humerus

Measurements made on routine A-P radiographs can predict strength/quality of the proximal humerus, as shown in terms of two easy-to-measure parameters: Cortical index (CI) and mean-combined cortical thickness (MCCT). Because of high variability inherent when using established methods to measure these parameters, we describe a new orientation system. Using digitized radiographs of 33 adult proximal humeri, five observers measured anatomical reference locations in accordance with: (i) Tingart et al. (2003) method, (ii) Mather et al. (2013) method, and (iii) our new humeral head Circle-Fit method (CFM). The Tingart and Mather methods measure CI and MCCT with respect to upper and lower edges of 20 mm tall rectangles fit to a proximal diaphyseal location where endosteal (Tingart) or periosteal (Mather) cortical margins become parallel. But high intra- and inter-observer variability occurs when placing the rectangles because of uncertainty in identifying cortical parallelism. With the CFM an adjustable circle is fit to the humeral head articular surface, which reliably and easily establishes a proximal metaphyseal landmark (M1) at the surgical neck. Distal locations are then designated at successive 10 mm increments below M1, including a second metaphyseal landmark (M2) followed by diaphyseal (D) locations (D1, D2 ⋯D6). D1 corresponds most closely to the proximal edges of the rectangles used in the other methods. Results showed minimal inter-observer variations (mean error, 1.5 ± 1.1 mm) when the CFM is used to establish diaphyseal locations for making CI and MCCT measurements when compared to each of the other methods (mean error range, 10.7 ± 5.9 to 13.3 ± 6.7 mm) (p < 0.001). © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2313-2322, 2017.

Current Trends in the Management of Distal Radius Fractures

This article discusses recent reports on distal radius fractures. The keyword "distal radius fracture" was used to query the PubMed database of the US National Library of Medicine. From the resulting list, articles published in the Journal of Hand Surgery (American Volume), the Journal of Hand Surgery (European Volume), and the Journal of Orthopaedic Trauma from April 2014 through December 2015 were reviewed. Related commentaries were also evaluated. Case series of fewer than 5 patients were excluded. The 65 studies and commentaries identified are categorized and summarized. [Orthopedics. 2017; 40(3):145-152.].

Simple Assessment of Global Bone Density and Osteoporosis Screening Using Standard Radiographs of the Hand

PURPOSE

Osteoporosis and fragility fractures have consequences both at the individual level and to the overall health care system. Although dual-energy x-ray absorptiometry (DXA) is the reference standard for assessing bone mineral density (BMD), other, simpler tools may be able to screen bone quality provisionally and signal the need for intervention. We hypothesized that the second metacarpal cortical percentage (2MCP) calculated from standard radiographs of the hand or wrist would correlate with hip BMD derived from DXA and could provide a simple screening tool for osteoporosis.

METHODS

Two hundred patients who had hand or wrist radiographs and hip DXA scans within 1 year of each other were included in this series. Mid-diaphyseal 2MCP was calculated as the ratio of the cortical diameter to the total diameter. We assessed the correlation between 2MCP and total hip BMD. Subjects were stratified into normal, osteopenic, and osteoporotic cohorts based on hip t scores, and thresholds were identified to optimize screening sensitivity and specificity.

RESULTS

Second metacarpal cortical percentage correlated significantly with BMD and t scores from the hip. A 2MCP threshold of less than 60% optimized sensitivity (88%) and specificity (60%) for discerning osteopenic subjects from normal subjects, whereas a threshold of less than 50% optimized sensitivity (100%) and specificity (91%) for differentiating osteoporotic from normal subjects.

CONCLUSIONS

By demonstrating that global BMD may be assessed from 2MCP, these data suggest that radiographs of the hand and wrist may have a role in accurately screening for osteopenia and osteoporosis. This simple investigation, which is already used ubiquitously for patients with hand or wrist problems, may identify patients at risk for fragility fractures and allow for appropriate referral or treatment.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

Evaluation of trabecular bone score in patients with a distal radius fracture

We compared bone mineral density (BMD) and trabecular bone score (TBS) in postmenopausal women with a distal radius fracture older than 50 years with controls. Total hip BMD was significantly different, but TBS was not different between two groups, suggesting TBS does not reflect microarchitectural changes of the distal radius.

INTRODUCTION

The purpose of this study was to determine whether trabecular bone score (TBS) has additive value for discriminating distal radius fracture (DRF) independent of BMD.

METHODS

We compared BMD and TBS in 258 postmenopausal women with a DRF older than 50 years of age with age- and body mass index (BMI)-matched controls who had no history of osteoporotic fracture. BMD was measured at the lumbar spine and hip using dual energy X-ray absorptiometry scans (GE Lunar Prodigy). TBS was calculated on the same spine image. A multivariate logistic regression analysis was used to analyze the odds ratio (OR) for the occurrence of DRF using age, BMI, lumbar spine BMD, total hip BMD, and TBS.

RESULTS

Patients with a DRF had significantly lower BMDs at hip (neck, trochanter and total) than those of controls: 0.752 ± 0.097, 0.622 ± 0.089, and 0.801 ± 0.099 in patients and 0.779 ± 0.092, 0.648 ± 0.089, 0.826 ± 0.101 in controls. However, lumbar spine BMD and TBS were not significantly different between the groups (p = 0.400 and 0.864, respectively). The multivariate analysis indicated that only total hip BMD was significantly associated with the occurrence of DRF (OR, 10.231; 95 % confidence interval, 1.724-60.702; p = 0.010).

CONCLUSIONS

TBS was not different between women with a DRF and those without a history of osteoporotic fracture, suggesting that TBS measured at the lumbar spine does not reflect early microarchitectural changes of the distal radius. Only total hip BMD is associated with the risk of DRF in Korean women.

Recent Update in the Diagnosis and Treatment of Bone Frailty in Patients with a Distal Radius Fracture

Distal radius fracture (DRF) is the most common upper extremity fracture in the elderly. Patients with a DRF have a two to fourfold higher risk of a subsequent fracture than those with no history of fractures, and DRFs occur on average 15 years earlier than hip fractures. Therefore, patients with a DRF offer physicians an important opportunity to diagnose and treat osteoporosis to prevent a secondary fracture. In this review, we provide recent update in the diagnosis and treatment of bone frailty in patients with a DRF.

Using Hounsfield Units to Assess Osteoporotic Status on Wrist Computed Tomography Scans: Comparison With Dual Energy X-Ray Absorptiometry

PURPOSE

Rates of evaluation and treatment for osteoporosis following distal radius fragility fractures remain low. As a subset of patients with these fractures undergo diagnostic computed tomography (CT) scan of the wrist, utilizing bone mineral density (BMD) measurements available with this imaging can be used to detect osteopenia or osteoporosis. This information may consequently prompt intervention to prevent a subsequent fracture. The purpose of this study was to determine if Hounsfield unit (HU) measurements at the wrist correlate with BMD measurements of the hip, femoral neck, and lumbar spine and to assess the ability of these HU measurements to detect osteoporosis of the hip.

METHODS

Forty-five female patients with distal radius fractures who underwent CT scan and dual energy x-ray absorptiometry scan as part of the management of their wrist fracture were identified. Bone mineral density measurements were made using the regional cancellous bone HU value at the capitate and compared with values obtained by a dual energy x-ray absorptiometry scan.

RESULTS

Hounsfield unit values at the capitate were significantly correlated with BMD and t scores at the femoral neck, hip, and lumbar spine. An HU threshold of 307 in the capitate optimized sensitivity (86%) and specificity (94%) for detecting osteoporotic patients.

CONCLUSIONS

By demonstrating that capitate HU measurements from clinical CT scans are correlated with BMD and t scores at the hip, femoral neck, and lumbar spine, our data suggest that clinical CT scans should have a role in detecting osteopenia and osteoporosis.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.