Imaging of Osteoporosis

Characteristics of distal radius fractures in east China-an observational cohort study of 1954 individual fractures

OBJECTIVE

To investigate the characteristics and seasonal patterns of distal radius fractures (DRFs) over the preceding five years, with the aim of establishing a clinical foundation for the prevention and management of such fractures within this region.

METHODS

Utilizing the Picture Archiving and Communication Systems (PACS), the clinical records of 1954 patients diagnosed with DRFs and admitted to the Affiliated Hospital of Jiangsu University between January 2017 and December 2021 were compiled. The analysis encompassed factors such as age, gender, visitation timing, fracture side, and presence of osteoporosis.

RESULTS

Out of the total 1954 distal radius fractures, 731 were males (37.4%) and the male to female ratio was 0.59:1. The median age of patients with DRFs was 56 years, with the 25th percentile being 38 years and the 75th percentile being 67 years. The average age was 50 years (standard deviation 23.3) and 1033 cases (52.7%) occurred on the left side, 885 cases (45.1%) on the right side, and 36 cases (1.8%) were bilateral, with the left side being the most frequently affected. The age group of 61-70 years (23.9%, 467/1954) exhibited the highest proportion, and the most prominent age group for males was 11-20 years (23.8%, 174/731), whereas for females it was 61-70 years (30.83%, 377/1223). In the 50 years and older group, there were 276 males and 991 females (ratio 1:3.59), with osteoporosis in 536 cases, accounting for 42.03% of the group. In terms of seasonal distribution, the highest incidence occurred during the summer and autumn months (55.1%, 1076/1954) and there were gender differences in different seasons.

CONCLUSION

In east China, DRFs were predominantly female and left-sided, with the highest proportion in the age group of 61-70 years and in summer and autumn. Furthermore, gender differences were observed between the warm and cold seasons.

Application of an Improved Ultrasound Full-Waveform Inversion in Bone Quantitative Measurement

Inspired by the large number of applications for symmetric nonlinear equations, an improved full waveform inversion algorithm is proposed in this paper in order to quantitatively measure the bone density and realize the early diagnosis of osteoporosis. The isotropic elastic wave equation is used to simulate ultrasonic propagation between bone and soft tissue, and the Gauss–Newton algorithm based on symmetric nonlinear equations is applied to solve the optimal solution in the inversion. In addition, the authors use several strategies including the frequency-grid multiscale method, the envelope inversion and the new joint velocity–density inversion to improve the result of conventional full-waveform inversion method. The effects of various inversion settings are also tested to find a balanced way of keeping good accuracy and high computational efficiency. Numerical inversion experiments showed that the improved full waveform inversion (FWI) method proposed in this paper shows superior inversion results as it can detect small velocity–density changes in bones, and the relative error of the numerical model is within 10%. This method can also avoid interference from small amounts of noise and satisfy the high precision requirements for quantitative ultrasound measurements of bone.

Osteoporosis: what the clinician needs to know?

Osteoporosis is a common condition and an important cause of disability. For this reason, early detection of the disease and patients at higher risk of bone fractures is compulsory. In the recent years, conventional quantitative methods have been spreading for the diagnosis of osteoporosis; moreover, new improvements in computed tomography (CT) and magnetic resonance imaging (MRI) have been made in this field and imaging findings may correlate to the morphological and structural changes within the bone.

Bone volume fraction and structural parameters for estimation of mechanical stiffness and failure load of human cancellous bone samples; in-vitro comparison of ultrasound transit time spectroscopy and X-ray μCT

Conventional mechanical testing is the 'gold standard' for assessing the stiffness (N mm^-1) and strength (MPa) of bone, although it is not applicable in-vivo since it is inherently invasive and destructive. The mechanical integrity of a bone is determined by its quantity and quality; being related primarily to bone density and structure respectively. Several non-destructive, non-invasive, in-vivo techniques have been developed and clinically implemented to estimate bone density, both areal (dual-energy X-ray absorptiometry (DXA)) and volumetric (quantitative computed tomography (QCT)). Quantitative ultrasound (QUS) parameters of velocity and attenuation are dependent upon both bone quantity and bone quality, although it has not been possible to date to transpose one particular QUS parameter into separate estimates of quantity and quality. It has recently been shown that ultrasound transit time spectroscopy (UTTS) may provide an accurate estimate of bone density and hence quantity. We hypothesised that UTTS also has the potential to provide an estimate of bone structure and hence quality. In this in-vitro study, 16 human femoral bone samples were tested utilising three techniques; UTTS, micro computed tomography (μCT), and mechanical testing. UTTS was utilised to estimate bone volume fraction (BV/TV) and two novel structural parameters, inter-quartile range of the derived transit time (UTTS-IQR) and the transit time of maximum proportion of sonic-rays (TTMP). μCT was utilised to derive BV/TV along with several bone structure parameters. A destructive mechanical test was utilised to measure the stiffness and strength (failure load) of the bone samples. BV/TV was calculated from the derived transit time spectrum (TTS); the correlation coefficient (R²) with μCT-BV/TV was 0.885. For predicting mechanical stiffness and strength, BV/TV derived by both μCT and UTTS provided the strongest correlation with mechanical stiffness (R²=0.567 and 0.618 respectively) and mechanical strength (R²=0.747 and 0.736 respectively). When respective structural parameters were incorporated to BV/TV, multiple regression analysis indicated that none of the μCT histomorphometric parameters could improve the prediction of mechanical stiffness and strength, while for UTTS, adding TTMP to BV/TV increased the prediction of mechanical stiffness to R²=0.711 and strength to R²=0.827. It is therefore envisaged that UTTS may have the ability to estimate BV/TV along with providing an improved prediction of osteoporotic fracture risk, within routine clinical practice in the future.

7T MRI of distal radius trabecular bone microarchitecture: How trabecular bone quality varies depending on distance from end-of-bone

PURPOSE

To use 7T magnetic resonance imaging (MRI) to determine how trabecular bone microarchitecture varies at the epiphysis, metaphysis, and diaphysis of the distal radius.

MATERIALS AND METHODS

The distal radius of 24 females (mean age = 56 years, range = 24-78 years) was scanned on a 7T MRI using a 3D fast low-angle shot sequence (0.169 × 0.169 × 1 mm). Digital topological analysis was applied at the epiphysis, metaphysis, and diaphysis to compute: total trabecular bone volume; trabecular thickness, number, connectivity, and erosion index (a measure of network resorption). Differences and correlations were assessed using standard statistical methods.

RESULTS

The metaphysis and epiphysis had 83-123% greater total bone volume and 14-16% greater trabecular number than the diaphysis (both P < 0.0001). The erosion index was significantly higher at the diaphysis than the metaphysis and epiphysis (both P < 0.01). The most elderly volunteers had lower trabecular number (<66 years mean 0.29 ± 0.01; ≥66 years, 0.27 ± 0.02, P < 0.05) and higher erosion index (<66 years mean 1.18 ± 0.17; age ≥66 years, mean 1.42 ± 0.46, P < 0.05) at the epiphysis; differences not detected by total trabecular bone volume.

CONCLUSION

7T MRI reveals trabecular bone microarchitecture varies depending on scan location at the end-of-bone, being of overall higher quality distally (epiphysis) than proximally (diaphysis). Age-related differences in trabecular microarchitecture can be detected by 7T MRI. The results highlight the potential sensitivity of 7T MRI to microarchitectural differences and the potential importance of standardizing scan location for future clinical studies of fracture risk or treatment response.

LEVEL OF EVIDENCE

3 J. Magn. Reson. Imaging 2017;45:872-878.

Reverse shoulder arthroplasty for the management of proximal humerus fractures

The use of reverse shoulder arthroplasty is becoming increasingly popular for the treatment of complex three- and four-part proximal humerus fractures in the elderly compared with the often unpredictable and poor outcomes provided by open reduction and internal fixation and by hemiarthroplasty. Inferior results with plate osteosynthesis are often a result of complications of humeral head osteonecrosis, loss of fixation, and screw penetration through the humeral head, whereas major concerns with hemiarthroplasty are tuberosity resorption, malunion, and nonunion resulting in pseudoparalysis. Comparative studies support the use of reverse shoulder arthroplasty in elderly patients with complex proximal humerus fractures because the functional outcomes and relief of pain are reliably improved. Repair and union of the greater tuberosity fragment during reverse shoulder arthroplasty demonstrates improved external rotation, clinical outcomes, and patient satisfaction compared with outcomes after tuberosity resection, nonunion, or resorption. Satisfactory results can be obtained with careful preoperative planning and attention to technical details.