scholarly journals Local bone quality measure and construct failure prediction: a biomechanical study on distal femur fractures

Author(s):  
Dominic Gehweiler ◽  
Ursula Styger ◽  
Boyko Gueorguiev ◽  
Christian Colcuc ◽  
Thomas Vordemvenne ◽  
...  

Abstract Introduction The aim of this investigation was to better understand the differences in local bone quality at the distal femur and their correlation with biomechanical construct failure, with the intention to identify regions of importance to optimize implant anchorage. Materials and methods Seven fresh–frozen female femurs underwent high-resolution peripheral quantitative computed tomography (HR-pQCT) to determine bone mineral density (BMD) within three different regions of interest (distal, intermedium, and proximal) at the distal femur. In addition, local bone quality was assessed by measuring the peak torque necessary to break out the trabecular bone along each separate hole of a locking compression plate (LCP) during its instrumentation. Finally, biomechanical testing was performed using cyclic axial loading until failure in an AO/OTA 33 A3 fracture model. Results Local BMD was highest in the distal region. This was confirmed by the measurement of local bone quality using DensiProbe™. The most distal holes represented locations with the highest breakaway torque resistance, with the holes on the posterior side of the plate indicating higher values than those on its anterior side. We demonstrated strong correlation between the cycles to failure and local bone strength (measured with DensiProbe™) in the most distal posterior screw hole, having the highest peak torque. Conclusion The local bone quality at the distal femur indicates that in plated distal femur fractures the distal posterior screw holes seem to be the key ones and should be occupied. Measurement of the local bone strength with DensiProbe™ is one possibility to determine the risk of construct failure, therefore, thresholds need to be defined.

2013 ◽  
Vol 5 (2) ◽  
pp. 16 ◽  
Author(s):  
Stefan Grote ◽  
Tatjana Noeldeke ◽  
Michael Blauth ◽  
Wolf Mutschler ◽  
Dominik Bürklein

Knowledge of local bone quality is essential for surgeons to determine operation techniques. A device for intraoperative measurement of local bone quality has been developed by the AO-Research Foundation (DensiProbe®). We used this device to experimentally measure peak breakaway torque of trabecular bone in the proximal femur and correlated this with local bone mineral density (BMD) and failure load. Bone mineral density of 160 cadaver femurs was measured by <em>ex situ </em>dual-energy X-ray absorptiometry. The failure load of all femurs was analyzed by side-impact analysis. Femur fractures were fixed and mechanical peak torque was measured with the DensiProbe® device. Correlation was calculated whereas correlation coefficient and significance was calculated by Fisher’s Z-transformation. Moreover, linear regression analysis was carried out. The unpaired Student’s t-test was used to assess the significance of differences. The Ward triangle region had the lowest BMD with 0.511 g/cm2 (±0.17 g/cm2), followed by the upper neck region with 0.546 g/cm2 (±0.16 g/cm2), trochanteric region with 0.685 g/cm2 (±0.19 g/cm2) and the femoral neck with 0.813 g/cm2 (±0.2 g/cm2). Peak torque of DensiProbe® in the femoral head was 3.48 Nm (±2.34 Nm). Load to failure was 4050.2 N (±1586.7 N). The highest correlation of peak torque measured by Densi Probe® and load to failure was found in the femoral neck (r=0.64, P&lt;0.001). The overall correlation of mechanical peak torque with T-score was r=0.60 (P&lt;0.001). A correlation was found between mechanical peak torque, load to failure of bone and BMD <em>in vitro</em>. Trabecular strength of bone and bone mineral density are different aspects of bone strength, but a correlation was found between them. Mechanical peak torque as measured may contribute additional information about bone strength, especially in the perioperative testing.


Endocrinology ◽  
2007 ◽  
Vol 148 (9) ◽  
pp. 4466-4474 ◽  
Author(s):  
Sara Johnston ◽  
Sharon Andrews ◽  
Victor Shen ◽  
Felicia Cosman ◽  
Robert Lindsay ◽  
...  

A cyclic PTH regimen is as effective as a daily regimen on bone density gain in humans and in improving bone quality in mice. Our previous murine study evaluated the effects of a cyclic PTH regimen in the absence of a bisphosphonate, whereas our human study addressed the effects of a cyclic PTH regimen in the presence of ongoing alendronate (ALN) treatment. Accordingly, the current study examined the effects of cyclic or daily PTH regimens in combination with ALN on bone quality and bone density in mice. Twenty-week-old, female C57BL/6J mice were treated with the following sc injections (n = 10): 1) vehicle for 5 d/wk (control); 2) ALN (20 μg/kg·d) 3 d/wk (ALN); 3) human PTH(1–34) (40 μg/kg·d) 5 d/wk (daily PTH); 4) daily PTH in addition to ALN (daily PTH plus ALN); 5) PTH 5 d/wk and vehicle 5 d/wk alternating weekly (cyclic PTH); 6) cyclic PTH in addition to ALN (cyclic PTH plus ALN); and 7) PTH and ALN alternating weekly (alt PTH and ALN). Bone mineral density was measured weekly by dual-energy x-ray absorptiometry, and at 7 wk, bone markers, bone structure, and bone strength were evaluated by biochemical assays, peripheral quantitative computed tomography and mechanical testing, respectively. At 7 wk, all treatments significantly increased femoral and vertebral bone mineral density. ALN slightly decreased endosteal circumference, whereas PTH increased periosteal circumference, resulting in significant increases in femoral cortical thickness in all groups. PTH and ALN enhanced bone strength synergistically in the lumbar vertebrae and additively in the femur. Combined therapy, however, had no effects on bone markers. The results show that combinations of ALN and PTH, in both daily and cyclic regimens, produce more beneficial effects than treatment with either agent alone, suggesting that the mechanisms of actions of ALN and PTH on bone quality may be complementary.


Medicina ◽  
2021 ◽  
Vol 57 (11) ◽  
pp. 1224
Author(s):  
Katharina Jäckle ◽  
Friederike Klockner ◽  
Daniel Bernd Hoffmann ◽  
Paul Jonathan Roch ◽  
Maximilian Reinhold ◽  
...  

Background and Objectives: Hyponatremia is the most common electrolyte disorder in elderly and associated with increased risk of falls. Clinical studies as well as small animal experiments suggested an association between chronic hyponatremia and osteoporosis. Furthermore, it has been assumed that subtle hyponatremia may be an independent fracture risk in the elderly. Therefore, this study was designed to evaluate the possible influence of chronic hyponatremia on osteoporosis and low-energy fractures of the spine. Materials and Methods: 144 patients with a vertebral body fracture (mean age: 69.15 ± 16.08; 73 females and 71 males) due to low-energy trauma were treated in a level one trauma center within one year and were included in the study. Chronic hyponatremia was defined as serum sodium < 135 mmol/L at admission. Bone mineral density (BMD) of the spine was measured using quantitative computed tomography in each patient. Results: Overall, 19.44% (n = 28) of patients in the low-energy trauma group had hyponatremia. In the group with fractures caused by low-energy trauma, the proportion of hyponatremia of patients older than 65 years was significantly increased as compared to younger patients (p** = 0.0016). Furthermore, there was no significant gender difference in the hyponatremia group. Of 28 patients with chronic hyponatremia, all patients had decreased bone quality. Four patients showed osteopenia and the other 24 patients even showed osteoporosis. In the low-energy trauma group, the BMD correlated significantly with serum sodium (r = 0.396; p*** < 0.001). Conclusions: The results suggest that chronic hyponatremia affects bone quality. Patients with chronic hyponatremia have an increased prevalence of fractures after low-energy trauma due to a decreased bone quality. Therefore, physicians from different specialties should focus on the treatment of chronic hyponatremia to reduce the fracture rate after low-energy trauma, particularly with elderly patients.


2021 ◽  
Vol 7 ◽  
Author(s):  
Fabio Massimo Ulivieri ◽  
Luca Rinaudo

For a proper assessment of osteoporotic fragility fracture prediction, all aspects regarding bone mineral density, bone texture, geometry and information about strength are necessary, particularly in endocrinological and rheumatological diseases, where bone quality impairment is relevant. Data regarding bone quantity (density) and, partially, bone quality (structure and geometry) are obtained by the gold standard method of dual X-ray absorptiometry (DXA). Data about bone strength are not yet readily available. To evaluate bone resistance to strain, a new DXA-derived index based on the Finite Element Analysis (FEA) of a greyscale of density distribution measured on spine and femoral scan, namely Bone Strain Index (BSI), has recently been developed. Bone Strain Index includes local information on density distribution, bone geometry and loadings and it differs from bone mineral density (BMD) and other variables of bone quality like trabecular bone score (TBS), which are all based on the quantification of bone mass and distribution averaged over the scanned region. This state of the art review illustrates the methodology of BSI calculation, the findings of its in reproducibility and the preliminary data about its capability to predict fragility fracture and to monitor the follow up of the pharmacological treatment for osteoporosis.


Author(s):  
Kate D. Liddle ◽  
Michael A. Tufaga ◽  
Glenn Diekmann ◽  
Jenni M. Buckley ◽  
Viva Tai ◽  
...  

Failure of the pedicle screw at the screw-bone interface is a common clinical problem, particularly in the setting of osteoporosis, and poses reconstructive challenges for all orthopaedic surgeons. Pedicle screw failure through screw loosing and pull-out is highly correlated with bone mineral density (BMD) and local bone quality [1]. Pre-operative assessment of BMD via dual x-ray absorptiometry (DEXA) has been shown to help determine the need for screw augmentation. However, patients frequently present without pre-operative DEXA scans. Furthermore, DEXA scans provide a measure of general bone quality, but do not necessarily reflect segmental and local variation in the spine [2]. The ability to assess BMD on a per-vertebrae basis intra-operatively would assist with surgical decisions regarding screw sizing, placement and augmentation.


2014 ◽  
Vol 37 (1) ◽  
pp. E4 ◽  
Author(s):  
Joseph J. Schreiber ◽  
Paul A. Anderson ◽  
Wellington K. Hsu

Assessing local bone quality on CT scans with Hounsfield unit (HU) quantification is being used with increasing frequency. Correlations between HU and bone mineral density have been established, and normative data have been defined throughout the spine. Recent investigations have explored the utility of HU values in assessing fracture risk, implant stability, and spinal fusion success. The information provided by a simple HU measurement can alert the treating physician to decreased bone quality, which can be useful in both medically and surgically managing these patients.


2006 ◽  
Vol 50 (4) ◽  
pp. 579-585 ◽  
Author(s):  
Juliet Compston

Bone quality describes aspects of bone composition and structure that contribute to bone strength independently of bone mineral density. These include bone turnover, microarchitecture, mineralisation, microdamage and the composition of bone matrix and mineral. New techniques to assess these components of bone quality are being developed and should produce important insights into determinants of fracture risk in untreated and treated disease.


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