Aims. Osteoporosis and abnormal bone metabolism may prove to be significant
factors influencing the outcome of arthroplasty surgery, predisposing
to complications of aseptic loosening and peri-prosthetic fracture.
We aimed to investigate baseline
To analyze the effect of tooth extraction site preservation on
Background. Reduced
Objectives. Several genome-wide association studies (GWAS) of
To prevent bone loss, OPG/RANK/RANKL signalling pathway is a key in keeping the balance between the action of osteoblasts and osteoclasts. Aim of this study is to assess the influence of long-term nicotine exposure on
The shape of the vertebral bodies from L1 to L4 was assessed from lateral dual-energy x-ray absorptiometry (DXA) images using an active shape model. The output from the model was compared to measurements of areal
Total Hip Replacement (THR) is one of the most successful operations in all of medicine, however surgeons just rely on their experience and expertise when choosing between cemented or cementless stem, without having any quantitative guidelines. The aim of this project is to provide clinicians with some tools to support in their decision making. A novel method based on
We investigated the effect of locally administered bisphosphonate on distraction osteogenesis in a rabbit model and evaluated its systemic effect. An osteotomy on the right tibia followed by distraction for four weeks was performed on 47 immature rabbits. They were divided into seven equal groups, with each group receiving a different treatment regime. Saline and three types of dosage of alendronate (low, 0.75 μg/kg; mid, 7.5 μg/kg and high 75 μg/kg) were given by systemic injection in four groups, and saline and two dosages (low and mild) were delivered by local injection to the distraction gap in the remaining three groups. The injections were performed five times weekly during the period of distraction. After nine weeks the animals were killed and image analysis and mechanical testing were performed on the distracted right tibiae and the left tibiae which served as a control group. The local low-dose alendronate group showed a mean increase in
Fragility fractures are an increasing cause of morbidity and mortality in the elderly population. Their association with reduced
Locking plate fixation in proximal humeral fractures has demonstrated good results tempered by a significant rate of loss of fixation. Reported rates of failure are typically around 10% of cases but can be 20% or higher. In addition large series are often made up of a diverse patient population, so we have chosen to focus solely on patients confirmed to have significantly reduced BMD who can be considered a subset at high risk of fixation failure. Twenty-three patients (5 male, 18 female) with a proximal humeral fracture treated by locking plate fixation were confirmed on DEXA scanning to be osteopaenic (17), osteoporotic (4) or severely osteoporotic (2). Patients early in the series were reviewed retrospectively and recalled for an updated assessment where appropriate, and the remainder were followed prospectively. The average age was 66 years (range 49 to 82). Follow up was for an average of nine months following surgery (range 2 and a half to 28 months). 17 patients underwent surgery for acute injuries and 6 for established surgical neck non-unions. Seven injuries were 2-part fractures, 12 3-part, 3 were 4-part and one a 2-part surgical neck non-union.1 plate failed due to complete loss of fixation within 2 months in a patient with severe osteoporosis and was treated with removal of metalwork. This was the only injury that failed to unite. Avascular necrosis occurred in three patients with two revised to a hemiarthroplasty. 1 patient had ongoing pain and underwent removal of the plate. Our series demonstrated that locking plate fixation of proximal humeral fractures is associated with a low rate of fixation failure and satisfactory outcomes in patients with significantly reduced
Stand-alone anterior lumbar interbody fusion (ALIF) provides the opportunity to avoid supplemental posterior fixation. This may reduce morbidity and complication rate, which is of special interest in patients with reduced
We aimed to evaluate the precision and longitudinal sensitivity of measurement of
Our aim was to determine the precision of the measurements of
The operative treatment of fractures of the proximal humerus can be complicated by poor bone quality. Our aim was to evaluate a new method which allows prediction of the bone quality of the proximal humerus from radiographs. Anteroposterior radiographs were taken of 19 human cadaver humeri. The cortical thickness was measured at two levels of the proximal humeral diaphysis. The
Weight-bearing is a known stimulus for bone remodelling and a reduction in weight-bearing is associated with reduced
Background and objectives. Local bone-related adverse events occur more frequently following metal-on metal hip resurfacing (MOMHR) versus convention total hip arthroplasty (THA). High local tissue levels of cobalt and chromium may contribute to impaired bone health, however the systemic effects on bone of exposure to elevated metal levels after MOMHR are unknown. Methods. In this cross-sectional study we compared whole body
While knee osteoarthritis (OA) is now recognized as a complex disease affecting the whole joint, not just the cartilages, there remains a paucity of data regarding the interactions between knee components. One relationship of particular interest is between the spatial variations in cartilage thickness (CTh) and subchondral bone mineral density (BMD). Indeed, bone and cartilage are two mechanosensitive tissues that interact as a functional unit and there is evidence of a biomechanical coupling between both tissues. Particularly, a recent in vivo study has shown a positive relationship in non-OA knees with thicker cartilage where bone is denser, and an alteration of this relationship in OA knees. These observations support the concept of an osteochondral unit and warrant additional research to assess the influence of bone depth. Therefore, this study aimed to characterize the relationship between spatial variations in CTh and BMD measured at various depths below the bone surface. CT-arthrography of 20 non-OA tibias and 20 severe medial-compartment OA tibias were segmented to build 3D mesh models of the bones and cartilages. Each individual tibia model was registered to a reference tibia, allowing to calculate BMD maps at 1, 3, 5 and 10mm below the bone-cartilage interface in the medial compartment. Pearson correlations between CTh maps and the four BMD maps were then calculated for each knee. Lastly, differences in correlation coefficients between successive bone layers were assessed using Wilcoxon signed-rank tests. In both OA and non-OA tibias, the correlation coefficients were higher with the BMD measured in the 1mm layer, and followed a pattern of statistically significant decrease with bone layers of increasing depth (p < 0.021). In non-OA tibias, the median relationship was positive with a strong effect size in the 1, 3 and 5mm layers, while in OA tibias the median relationship was positive only in the 1mm layer and with a medium effect size. In the OA tibias, the median relationship was negative with a weak effect size in the 3 and 5mm layers, and it was negative with a medium effect size in the 10mm layer. In conclusion, the results of the present study support the value of considering bone and cartilage as a unit, and more generally support OA pathophysiology models based on relationships among knee properties.
Although knee osteoarthritis (OA) has first been thought to be a wear-and-tear disease of the articular cartilage, it is now established that it is a disease of the entire joint. Unfortunately, its complex physiopathology is still incompletely understood, limiting the design of efficient therapeutic options. Recently, it has been suggested that OA could be related to the breakdown of the relationships among knee tissues rather than to isolated alterations of one or more tissues. However, there is a paucity of data regarding relationships among knee tissues. Better understanding the bone and cartilage relationships is thus of particular interest as both tissues contribute to the transfer of the mechanical loads through the joint and altered loading is known to be a main factor of OA onset and progression. Specifically, there is an interest to determine if cartilage thickness (CTh) and subchondral bone mineral density (sBMD), two properties related to loading, are adapted in healthy femurs. CT-arthrography of the knee was performed unilaterally on 16 healthy subjects (8 males; 61.8± 2.8 years old). Bone and cartilage boundaries were segmented on the CT images in order to calculate 3D CTh and sBMD maps. sBMD was calculated as the average intensity of the CT-arthrography in the superficial 3mm of bone. The 3D CTh and sBMD maps were transformed into 2D anatomically-standardized maps to allow comparison among individuals. According to literature, relationships between CTh and sBMD were assessed both in terms of magnitude and spatial distribution. The magnitude of CTh and sBMD was quantified using the ratio between the (CTh and sBMD) values in the load-bearing region of the medial and lateral condyles. The spatial distribution was quantified using the location of thickest cartilage or densest bone in the load-bearing region of the medial condyle. Pearson correlations were performed between CTh and sBMD metrics, using an alpha-level at 5%.Background
Method
Osteoporosis is a common disorder characterized by low bone mass and reduced bone quality that affects the bone strength negatively and leads to increased risk of fracture.
To assess the sensitivity and specificity of self-reported osteoporosis
compared with dual energy X-ray absorptiometry (DXA) defined osteoporosis,
and to describe medication use among participants with the condition. Data were obtained from a population-based longitudinal study
and assessed for the prevalence of osteoporosis, falls, fractures
and medication use. DXA scans were also undertaken.Objectives
Methods