Aims. Despite the interest in the association of gut microbiota with bone health, limited population-based studies of gut microbiota and bone mineral density (BMD) have been made. Our aim is to explore the possible association between gut microbiota and BMD. Methods. A total of 3,321 independent loci of gut microbiota were used to calculate the individual polygenic risk score (PRS) for 114 gut microbiota-related traits. The individual genotype data were obtained from UK Biobank cohort. Linear regressions were then conducted to evaluate the possible association of gut microbiota with L1-L4 BMD (n = 4,070), total BMD (n = 4,056), and femur total BMD (n = 4,054), respectively. PLINK 2.0 was used to detect the single-nucleotide polymorphism (SNP) × gut microbiota interaction effect on the risks of L1-L4 BMD, total BMD, and femur total BMD, respectively. Results. We detected five, three, and seven candidate gut microbiota-related traits for L1-L4 BMD, total BMD, and femur BMD, respectively, such as genus Dialister (p = 0.004) for L1-L4 BMD, and genus Eisenbergiella (p = 0.046) for total BMD. We also detected two common gut microbiota-related traits shared by L1-L4 BMD, total BMD, and femur total BMD, including genus Escherichia Shigella and genus Lactococcus. Interaction analysis of BMD detected several genes that interacted with gut microbiota, such as phospholipase D1 (PLD1) and endomucin (EMCN) interacting with genus Dialister in total BMD, and COL12A1 and Discs Large MAGUK Scaffold Protein 2 (DLG2) interacting with genus Lactococcus in femur BMD. Conclusion. Our results suggest associations between gut microbiota and BMD, which will be helpful to further explore the regulation mechanism and intervention gut microbiota of BMD. Cite this article: Bone Joint Res 2021;10(11):734–741

Objectives. The goal of this study is to investigate the relation between indicators of osteoporosis (i.e., bone mineral density (BMD), and Cortical Index (CI)) and the complexity of a fracture of the proximal humerus as a result of a low-energy trauma. Methods. A retrospective chart review of 168 patients (mean age 67.2 years, range 51 to 88.7) with a fracture of the proximal humerus between 2007 and 2011, whose BMD was assessed at the Fracture Liaison Service with Dual Energy X-ray Absorptiometry (DXA) measurements of the hip, femoral neck (FN) and/or lumbar spine (LS), and whose CI and complexity of fracture were assessed on plain anteroposterior radiographs of the proximal humerus. Results. No significant differences were found between simple and complex fractures of the proximal humerus in the BMD of the hip, FN or LS (all p > 0.3) or in the CI (p = 0.14). Only the body mass index was significantly higher in patients with a complex fracture compared with those with a simple fracture (26.9 vs 25.2; p = 0.05). Conclusion. There was no difference in BMD of the hip, FN, LS or CI of the proximal humerus in simple compared with complex fractures of the proximal humerus after a low-energy trauma. Factors other than the BMD and CI, for example body mass index, may play a more important role in the complexity of this fracture. Cite this article: J.W.A.M. den Teuling, B.S. Pauwels, L. Janssen, C.E. Wyers, H. M. J. Janzing, J.P.W. van den Bergh, J. W. Morrenhof. The Influence of bone mineral density and cortical index on the complexity of fractures of the proximal humerus. Bone Joint Res 2017;6:584–589. DOI: 10.1302/2046-3758.610.BJR-2017-0080

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 bone mineral density (BMD) and bone turnover in patients about to undergo arthroplasty of the hip and knee. Methods. We prospectively measured bone mineral density of the hip and lumbar spine using dual-energy X-ray absorptiometry (DEXA) scans in a cohort of 194 patients awaiting hip or knee arthroplasty. We also assessed bone turnover using urinary deoxypyridinoline (DPD), a type I collagen crosslink, normalised to creatinine. Results. The prevalence of DEXA proven hip osteoporosis (T-score ≤ -2.5) among hip and knee arthroplasty patients was found to be low at 2.8% (4 of 143). Spinal osteoporosis prevalence was higher at 6.9% (12 of 175). Sixty patients (42% (60 of 143)) had osteopenia or osteoporosis of either the hip or spine. The mean T-score for the hip was -0.34 (. sd. 1.23), which is within normal limits, and the mean hip Z-score was positive at 0.87 (. sd. 1.17), signifying higher-than-average BMD for age. The median urinary DPD/creatinine was raised in both female patients at 8.1 (interquartile range (IQR) 6.6 to 9.9) and male patients at 6.2 (IQR 4.8 to 7.5). Conclusions. Our results indicate hip and knee arthroplasty patients have higher BMD of the hip and spine compared with an age-matched general population, and a lower prevalence of osteoporosis. However, untreated osteoporotic patients are undergoing arthroplasty, which may negatively impact their outcome. Raised DPD levels suggest abnormal bone turnover, requiring further investigation. Cite this article: Bone Joint Res 2014;3:14–19

Purpose. The purpose of this study was to evaluate periprosthetic bone mineral density (BMD) changes around a cementless short tapered-wedge stem and determine correlations between BMD changes and various clinical factors, including daily activity, after total hip arthroplasty (THA) with a short tapered-wedge stem. Methods. The study included 65 patients (65 joints) who underwent THA with a TriLock stem. At baseline, and 6, 12, and 24 months postoperatively, BMDs of the seven Gruen zones were evaluated using dual-energy X-ray absorptiometry. Correlations were determined between BMD changes and clinical factors, including the Harris hip score, body mass index, University of California at Los Angeles (UCLA) activity rating score, age at surgery, and initial lumbar BMD. Results. Minimal BMD changes were noted in the distal femur (Gruen zones 3, 4, and 5). However, significant BMD loss was noted in zone 7 at each time point. BMD loss was also noted in zone 1 at 6 and 12 months postoperatively, but BMD recovered after 18 months. Significant positive correlations were noted between BMD changes and the UCLA activity rating score in zones 1, 6, and 7. Additionally, negative correlations were noted between BMD changes and initial spine BMD in zones 2 and 3. Table legends. Table 1 Background of the patients. Table 2 Bone mineral density changes (%) at 6, 12, and 24 months postoperatively in the seven Gruen zones. Columns represent mean ± standard deviation. ※indicates P < 0.05 compared with baseline bone mineral density. Table 3 Correlations between periprosthetic bone mineral density changes and clinical factors (the Harris hip score, body mass index, University of California at Los Angeles activity rating score, age at surgery, and initial lumbar bone mineral density) in the seven Gruen zones at 24 months postoperatively. Correlation coefficients and P-values are presented. Boldface indicates P < 0.05. Conclusion. Periprosthetic BMD was maintained in the proximal femur, especially Gruen zone 1, with a short tapered stem. Daily activity may reflect improvements in periprosthetic bone quality after THA with a short tapered stem; however, this stem is not recommended in patients with low bone quality. To view tables, please contact authors directly

We studied the bone mineral density (BMD) and the bone mineral content (BMC) of the proximal tibia in patients with a well-functioning uncemented Oxford medial compartment arthroplasty using the Lunar iDXA bone densitometer. Our hypothesis was that there would be decreased BMD and BMC adjacent to the tibial base plate and increased BMD and BMC at the tip of the keel. There were 79 consecutive patients (33 men, 46 women) with a mean age of 65 years (44 to 84) with a minimum two-year follow-up (mean 2.6 years (2.0 to 5.0)) after unilateral arthroplasty, who were scanned using a validated standard protocol where seven regions of interest (ROI) were examined and compared with the contralateral normal knee. All had well-functioning knees with a mean Oxford knee score of 43 (14 to 48) and mean Knee Society function score of 90 (20 to 100), showing a correlation with the increasing scores and higher BMC and BMD values in ROI 2 in the non-implanted knee relative to the implanted knee (p = 0.013 and p = 0.015, respectively). The absolute and percentage changes in BMD and BMC were decreased in all ROIs in the implanted knee compared with the non-implanted knee, but this did not reach statistical significance. Bone loss was markedly less than reported losses with total knee replacement. There was no significant association with side, although there was a tendency for the BMC to decrease with age in men. The BMC was less in the implanted side relative to the non-implanted side in men compared with women in ROI 2 (p = 0.027), ROI 3 (p = 0.049) and ROI 4 (p = 0.029). The uncemented Oxford medial compartment arthroplasty appears to allow relative preservation of the BMC and BMD of the proximal tibia, suggesting that the implant acts more physiologically than total knee replacement. Peri-prosthetic bone loss is an important factor in assessing long-term implant stability and survival, and the results of this study are encouraging for the long-term outcome of this arthroplasty. Cite this article: Bone Joint J 2013;95-B:1480–3

In patients with osteoporosis there is always a strong possibility that pedicle screws will loosen. This makes it difficult to select the appropriate osteoporotic patient for a spinal fusion. The purpose of this study was to determine the correlation between bone mineral density (BMD) and the magnitude of torque required to insert a pedicle screw. To accomplish this, 181 patients with degenerative disease of the lumbar spine were studied prospectively. Each underwent dual-energy x-ray absorptiometry (DEXA) and intra-operative measurement of the torque required to insert each pedicle screw. The levels of torque generated in patients with osteoporosis and osteopenia were significantly lower than those achieved in normal patients. Positive correlations were observed between BMD and T-value at the instrumented lumbar vertebrae, mean BMD and mean T-value of the lumbar vertebrae, and mean BMD and mean T-value of the proximal femur. The predictive torque (Nm) generated during pedicle screw insertion was [-0.127 + 1.62 × (BMD at the corresponding lumbar vertebrae)], as measured by linear regression analysis. The positive correlation between BMD and the maximum torque required to insert a pedicle screw suggests that pre-operative assessment of BMD may be useful in determining the ultimate strength of fixation of a device, as well as the number of levels that need to be fixed with pedicle screws in patients who are suspected of having osteoporosis

We compared peri-prosthetic bone mineral density between identical cemented and cementless LCS rotating platform total knee arthroplasties. Two matched cohorts had dual energy x-ray absorptiometry scans two years post-operatively using a modified validated densitometric analysis protocol, to assess peri-prosthetic bone mineral density. The knee that was not operated on was also scanned to enable the calculation of a relative bone mineral density difference. Oxford Knee and American Knee Society scores were comparable in the two cohorts. Statistical analysis revealed no significant difference in absolute, or relative peri-prosthetic bone mineral density with respect to the method of fixation. However, the femoral peri-prosthetic bone mineral density and relative bone mineral density difference were significantly decreased, irrespective of the method of fixation, particularly in the anterior distal portion of the femur, with a mean reduction in relative bone mineral density difference of 27%. There was no difference in clinical outcome between the cemented and cementless LCS total knee arthroplasty. However, both produce stress-shielding around the femoral implants. This leads us to question the use of more expensive cementless total knee components

The major advantage of hip resurfacing is the decreased amount of bone resection compared with a standard total hip replacement. Fracture of the femoral neck is the most common early complication and poor bone quality is a major risk factor. We undertook a prospective consecutive case control study examining the effect of bone mineral density changes in patients undergoing hip resurfacing surgery. A total of 423 patients were recruited with a mean age of 54 years (24 to 87). Recruitment for this study was dependent on pre-operative bilateral femoral bone mineral density results not being osteoporotic. The operated and non-operated hips were assessed. Bone mineral density studies were repeated over a two-year period. The results showed no significant deterioration in the bone mineral density in the superolateral region in the femoral neck, during that period. These findings were in the presence of a markedly increased level of physical activity, as measured by the short-form 36 health survey physical function score

Low-energy fractures of the proximal humerus indicate osteoporosis and it is important to direct treatment to this group of patients who are at high risk of further fracture. Data were prospectively collected from 79 patients (11 men, 68 women) with a mean age of 69 years (55 to 86) with fractures of the proximal humerus in order to determine if current guidelines on the measurement of the bone mineral density at the hip and lumbar spine were adequate to stratify the risk and to guide the treatment of osteoporosis. Bone mineral density measurements were made by dual-energy x-ray absorptiometry at the proximal femur, lumbar spine (L2-4) and contralateral distal radius, and the T-scores were generated for comparison. Data were also collected on the use of steroids, smoking, the use of alcohol, hand dominance and comorbidity. The mean T-score for the distal radius was −2.97 (. sd. 1.56) compared with −1.61 (. sd. 1.62) for the lumbar spine and −1.78 (. sd. 1.33) for the femur. There was a significant difference between the mean lumbar and radial T scores (1.36 (1.03 to 1.68); p < 0.001) and between the mean femoral and radial T-scores (1.18 (0.92 to 1.44); p < 0.001). The inclusion of all three sites in the determination of the T-score increased the sensitivity to 66% compared with that of 46% when only the proximal femur and lumbar spine were used. This difference between measurements in the upper limb compared with the axial skeleton and lower limb suggests that basing risk assessment and treatment on only the bone mineral density taken at the hip or lumbar spine may misrepresent the extent of osteoporosis in the upper limb and the subsequent risk of fracture at this site. The assessment of osteoporosis must include measurement of the bone mineral density at the distal radius to avoid underestimation of osteoporosis in the upper limb

Low bone mass and osteopenia have been described in the axial and peripheral skeleton of patients with adolescent idiopathic scoliosis (AIS). Recently, many studies have shown that gene polymorphism is related to osteoporosis. However, no studies have linked the association between IL6 gene polymorphism and bone mass in AIS. This study examined the association between bone mass and IL6 gene polymorphism in 198 girls with AIS. The polymorphisms of IL6-597 G→A, IL6-572 G→C and IL6-174 G→A and the bone mineral density in the lumbar spine and femoral neck were analysed and compared with their levels in healthy controls. The mean bone mineral density at both sites in patients with AIS was decreased compared with controls (p = 0.0022 and p = 0.0013, respectively). Comparison of genotype frequencies between AIS and healthy controls revealed a statistically significant difference in IL6-572 G→C polymorphism (p = 0.0305). There was a significant association between the IL6-572 G→C polymorphism and bone mineral density in the lumbar spine, with the CC genotype significantly higher with the GC (p = 0.0124) or GG (p = 0.0066) genotypes. These results suggest that the IL6-572 G→C polymorphism is associated with bone mineral density in the lumbar spine in Korean girls with AIS

Transient osteoporosis of the hip is a disorder characterised by pain, and associated with temporary osteopaenia. Although osteopaenia is the essence of the condition, data do not exist about the local bone density of the femoral neck if no medication is administered. We describe three patients who were treated with limitation of weight-bearing only. Repeated bone mineral density measurements were obtained, and that at the femoral neck was lowest two months after the onset of the condition. The mean reduction in bone mineral density when compared with an age-matched control group was 13% (3% to 24%). Spontaneous recovery was observed in all patients

There is limited literature available looking into circumstances surrounding the development of stress fracture of the medial and lateral malleoli after ankle replacement. We present the preliminary results of a prospective study examining the effect of ankle replacement upon local bone mineral density and the phenomenon of stress shielding. We aimed to assess the effect of ankle replacement loading of the medial and lateral malleoli, by analysing the Bone Mineral Density (BMD) of the medial and lateral malleoli before and after Mobility total ankle replacement. Ten consecutive patients undergoing Mobility total ankle replacement for osteoarthritis had pre-operative bone densitometry scans of the ankle, repeated at 6 months after surgery. The bone mineral density of a 2 cm square area within the medial malleolus and lateral malleolus was measured. The pre-operative and postoperative bone densitometry scans were compared. The relation between the alignment of the tibial component and the bone mineral density of the malleoli was also analysed. The mean preoperative BMD within the medial malleolus improved from 0.57g/cm2 to mean 6 months postoperative BMD of 0.62g/cm2. The mean preoperative BMD within the lateral malleolus decreased from 0.39g/cm2 to a mean 6 months postoperative of 0.33g/cm2. The mean alignment of the tibial component was 88.50 varus (range 850 varus to 940 valgus). However, there was no correlation between the alignment of the tibial component and the bone mineral density on the medial malleolus (r = 0.09, p = 0.865). The absence of stress shielding around the medial malleolus indicates that ankle replacements implanted within the accepted limits for implant alignment, load the medial malleolus. However, there was stress shielding over the lateral malleolus resulting in decreased BMD in the lateral malleolus

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

Aims. Assessment of bone mineral density (BMD) with dual-energy X-ray absorptiometry (DXA) is a well-established clinical technique, but it is not available in the acute trauma setting. Thus, it cannot provide a preoperative estimation of BMD to help guide the technique of fracture fixation. Alternative methods that have been suggested for assessing BMD include: 1) cortical measures, such as cortical ratios and combined cortical scores; and 2) aluminium grading systems from preoperative digital radiographs. However, limited research has been performed in this area to validate the different methods. The aim of this study was to investigate the evaluation of BMD from digital radiographs by comparing various methods against DXA scanning. Methods. A total of 54 patients with distal radial fractures were included in the study. Each underwent posteroanterior (PA) and lateral radiographs of the injured wrist with an aluminium step wedge. Overall 27 patients underwent routine DXA scanning of the hip and lumbar spine, with 13 undergoing additional DXA scanning of the uninjured forearm. Analysis of radiographs was performed on ImageJ and Matlab with calculations of cortical measures, cortical indices, combined cortical scores, and aluminium equivalent grading. Results. Cortical measures showed varying correlations with the forearm DXA results (range: Pearson correlation coefficient (r) = 0.343 (p = 0.251) to r = 0.521 (p = 0.068)), with none showing statistically significant correlations. Aluminium equivalent grading showed statistically significant correlations with the forearm DXA of the corresponding region of interest (p < 0.017). Conclusion. Cortical measures, cortical indices, and combined cortical scores did not show a statistically significant correlation to forearm DXA measures. Aluminium-equivalent is an easily applicable method for estimation of BMD from digital radiographs in the preoperative setting. Cite this article: Bone Joint Res 2021;10(12):830–839

To analyze the effect of tooth extraction site preservation on bone mineral density 6 months after surgery. From 2020 to 2021, two adjacent teeth (37, 38) of the same patient were extracted at the same time, and then 37 were selected for site preservation, implanted with Bio-oss bone powder, covered with double Bio-gide membrane, reduce tension and sutured. After 6 months of self-healing, 38 was taken CBCT, and the gray value measurement tool in the software was used to measure the bone mineral density of 37 bone graft areas and 38 extraction sockets. Bone density was high in the center of the bone graft area after the extraction site, and the density decreased in the adjacent alveolar socket, but the gray value was still higher than 38 for natural healing. Extraction site surgery can improve bone mass and quality at the extraction site. It is good for implanting

Introduction: Osteoporosis is one of the major diseases worldwide, affecting millions of elderly people, with severe economical and medical consequences. The most commonly used method for the determination of decreased bone quality is the assessment of Bone Mineral Density, measured by dual X-ray absorptiometry (DXA). However DXA is quantitative and not qualitative index of the bone structure. The purpose of this study was to correlate the bone mineral density measured by DXA with the mechanical properties of the femoral neck. Materials and Methods: Bone mineral density of the proximal femur of 30 patients (27 women, 3 men) undergoing total hip displacement was estimated by DXA. The average age of these patients was 63.7 years. Patients with sort femoral neck or previous surgeries in proximal femur were excluded from the study. After hip replacement bone samples (femoral head and neck) were frozen and stored at −60 °C. A plane bone slice with 6mm thickness was sawed of femoral neck using a double cutting saw. The exact specimen dimensions were measured using a sliding calliper with high accuracy. All bone specimens were destructively tested on a material testing machine, in order to determine the material properties (Young’s modulus and yield stress) of the samples. The maximum available compression load was 100 kN with a load rate of 10 kN/min. The operational parameters and experimental data were fully controlled and handled by a graphical software package. Finally all data were evaluated and statistically analyzed. Results: A strong linear correlation of bone mineral density (T-score) with maximum failure load of samples was noted (R2=0.852). No significant differences in Young’s modulus values, was found between bone samples. Conclusions: Bone mineral density measured by DXA, although has limitations, remain a strong predictor of bone strength in the femoral neck region

Introduction: There is limited literature available looking into circumstances surrounding the development of stress fracture of the medial and lateral malleoli after ankle replacement. We present the preliminary results of a prospective study examining the effect of ankle replacement upon local bone mineral density and the phenomenon of stress shielding. Aim: To assess the effect of ankle replacement loading of the medial and lateral malleoli, by analysing the BMD of the medial and lateral malleoli before and after Mobility total ankle replacement. Methodology: Ten consecutive patients undergoing Mobility total ankle replacement for osteoarthritis had pre-operative bone densitometry scans of the ankle, repeated at 6 months after surgery. The bone mineral density of a 2 cm square area within the medial malleolus and lateral malleolus was measured. The pre-operative and post-operative bone densitometry scans were compared. The relation between the alignment of the tibial component and the bone mineral density of the malleoli was also analysed. Results: The mean preoperative BMD within the medial malleolus improved from 0.57g/cm2 to mean 6 months postoperative BMD of 0.62g/cm2. The mean preoperative BMD within the lateral malleolus decreased from 0.39g/cm2 to a mean 6 months postoperative BMD of 0.33g/cm2. The mean alignment of the tibial component was 88.50 varus (range 850 varus to 940 valgus). However, there was no correlation between the alignment of the tibial component and the bone mineral density on the medial malleolus (r = 0.09, p = 0.865). Conclusion: The absence of stress shielding around the medial malleolus indicates that ankle replacements implanted within the accepted limits for implant alignment, load the medial malleolus. However, there was stress shielding over the lateral malleolus resulting in decreased BMD in the lateral malleolus

Introduction: There is limited literature looking into the circumstances surrounding the development of stress fractures of the medial and lateral malleoli after ankle replacement. We present the preliminary results of a prospective study examining the effect of total ankle replacement (TAR) upon local bone mineral density (BMD) and the phenomenon of stress shielding. Aim: To assess the effect of TAR loading othe medial and lateral malleoli, by analysing the BMD of the medial and lateral malleoli before and after Mobility TAR. Methodology: Ten consecutive patients undergoing Mobility total ankle replacement for osteoarthritis had pre-operative bone densitometry scans of the ankle, repeated at 6 and 12 months after surgery. The bone mineral density of a 2 cm square area within the medial and lateral malleoli was measured. The pre-operative and post-operative bone densitometry scans were compared. The relation between the alignment of the tibial component and the bone mineral density of the malleoli was also analysed. Results: The mean preoperative BMD within the medial malleolus increased from a mean of 0.57g/cm2 to 0.58g/cm2 at six months and 0.60g/cm2 at 12 months postoperatively. The mean preoperative BMD within the lateral malleolus decreased from 0.39g/cm2 to 0.34g/cm2 at six months postoperatively. However the BMD over the lateral malleolus increased to 0.356g/cm2 at 12 months. The mean alignment of the tibial component was 88.50 varus (range 850 varus to 940 valgus). There was no correlation between the alignment of the tibial component and the bone mineral density on the medial malleolus (r = 0.09, p = 0.865). Conclusion: The absence of stress shielding around the medial malleolus indicates that ankle replacements implanted within the accepted limits for implant alignment, load the medial malleolus. However, there was stress shielding over the lateral malleolus resulting in decreased BMD in the lateral malleolus

Background. Reduced bone mineral density is recognised as a risk factor for hip fractures and fragility fractures in general. Vitamin D is important in maintaining healthy bone mineral levels and can therefore affect risk of hip fracture. We investigated the correlation between vitamin D levels and bone mineral density, as well as fracture type, in neck of femur fractures and also assessed the relationship of vitamin D and social deprivation. Method. We included all patients admitted to our department, with a neck of femur fracture over one year (October 2013 to October 2014). We analysed vitamin D levels for all patients during admission and compared these to bone mineral density scores, based on DEXA scan results; hip fracture type & comminution, based on admission radiographs; and levels of social deprivation, based on the patient's address. Results. In total 360 patients were admitted over the study period, with a neck of femur fracture, of which 298 had vitamin D assessed and 76 had DEXA scans. Of these cohorts, 71% were found to be vitamin D deficient and 7% had osteoporosis. No significant correlation was found between vitamin D scores and bone density, or with level of vitamin D deficiency and fracture type or comminution. A significant correlation was however identified, between low vitamin D levels and decreasing levels of social deprivation (R=0.11, p=0.04). Conclusion. No relationship was identified between vitamin D levels and hip fracture type, suggesting that vitamin D cannot be used to predict patients at risk of more comminuted fractures. Although no relationship was also identified for bone mineral density and vitamin D, this may be because the sample size of DEXA scans was relatively small. Interestingly the relationship between vitamin D and social deprivation was the reverse of what was expected and suggests that affluent individuals may be at greater risk of low vitamin D

Varus deformity is found in 90% of patients with knee OA. Axis deviation of lower extremity influences joint biomechanics and produce alteration in bone mineral density. Structure and density of subchondral bone of the knee was previously examined by X-ray. Densitometry gives us a new method of bone mineral content measurement in the interesting regions of the skeleton. The aim of this study was the assessment of effect of varus deformity on bone mineral density in tibial epiphysis. Bone mineral densities (BMD) were estimated in 46 patients at a mean age of 62 years (15 to 78) who were operated on in Department of Orthopaedics. All of them represented osteoarthritis of the knee with varus deviation. BMD of the proximal tibia was evaluated on the Lunar DPX-IQ densitometer and analyzed in three regions of interest: medial, lateral and central. Lower extremity axis deviation was measured using the Metrecom devise (Faro). Results were compared to a control group of 20 patients without osteoarthritis of the knee and without deviation of lower extremity axis. Increased BMD was found on the overweighed compartment of the knee in comparison to the underweight one. These differences were not observed in the control group. We developed a coefficient, which is the ratio of BMD in the overweighed compartment compared to BMD in underweight one. In our patients the mean value of this coefficient was 3.3, and it ranged from 1,2 to 24,5 (SD 5,7). Significant correlation between varus axis deviation of the lower extremity and increased BMD coefficient was found

Femoral stem design affects periprosthetic bone mineral density (BMD), which may impact long term survival of cementless implants in total hip arthroplasty (THA). The aim of this study was to examine proximal femoral BMD in three morphologically different uncemented femoral stems designs to investigate whether one particular design resulted in improved preservation of BMDMethods: 119 patients were randomised to receive either a proximally coated dual taper wedge stem, a proximally coated anatomic stem or a fully coated collarless triple tapered stem. All surgeries were performed via the posterior approach with mobilization on the day of surgery. Dual energy x-ray absorptiometry scans (Lunar iDXA, GE Healthcare, Madison, WI) assessed BMD across the seven Gruen zones pre-operatively, and post-operatively at 6-weeks, 1-year, and 2-years and compared to the unoperated contralateral femur as a control. Patient reported outcome measures of pain, function and health were also included at these corresponding follow-ups. BMD increased in zones one (2.5%), two (17.1%), three (13.0%), five (10%) and six (17.9%) for all stems. Greater preservation of BMD was measured on the lateral cortex (zone 2) for both the dual taper wedge and anatomic stems (p = 0.019). The dual taper wedge stem also demonstrated preservation of BMD in the medial calcar (zone 7) whilst the anatomic and triple taper stem declined in this region, however this was not statistically significant (p = 0.059). BMD decreased on average by 2.1% inthe mid-diaphysis region, distal to the stem tip (zone 4) for all implants. All stems performed equivalently at final follow-up in all patient reported outcome measures. This study demonstrated maintenance of femoral BMD in three different cementless femoral stem designs, with all achieving excellent improvements in patient reported outcomes. There was no significant stress shielding observed, however longer follow-up is required to elucidate the impact of this finding on implant survivorship

Aims. To examine the relationship of sex steroid hormones with osteopenia in a nationally representative sample of men in the USA. Methods. Data on bone mineral density (BMD), serum sex hormones, dairy consumption, smoking status, and body composition were available for 806 adult male participants of the cross-sectional National Health and Nutrition Examination Survey (NHANES, 1999-2004). We estimated associations between quartiles of total and estimated free oestradiol (E2) and testosterone (T) and osteopenia (defined as 1 to 2.5 SD below the mean BMD for healthy 20- to 29-year-old men) by applying sampling weights and using multivariate-adjusted logistic regression. We then estimated the association between serum hormone concentrations and osteopenia by percentage of body fat, frequency of dairy intake, cigarette smoking status, age, and race/ethnicity. Results. Men in the lowest quartile of total E2 concentrations (< 21.52 pg/ml) had greater odds of osteopenia compared with men in the highest quartile (odds ratio (OR) 2.29, 95% confidence interval (CI) 1.11 to 4.73; p-trend = 0.030). Total and free T were not associated with osteopenia. Low total E2 concentrations were associated with greater odds of osteopenia among non-daily dairy consumers (p-trend = 0.046), current or former smokers (p-trend = 0.032), and younger men (p-trend = 0.031). No differences were observed by race/ethnicity and obesity. Conclusion. In this nationally representative study of the USA, men with lower total E2 were more likely to have osteopenia, which was particularly evident among younger men, men with less-than-daily dairy consumption, and current or former smokers. Cite this article:Bone Joint Res. 2020;9(3):139–145

To ascertain whether patients with Colles’ fracture should be investigated for osteoporosis and the risk of future fractures, we measured the bone mineral density of the distal radius of the other arm in 31 women patients and compared the results with those of a control group of 289 normal women. We divided the patients into two groups, those younger than 66 years and those older. In 25 patients we found values for bone mineral density which were lower than one standard deviation below the mean value for their age. Younger patients had a deficit greater than that expected for their ages. We believe that women with Colles’ fracture should be evaluated routinely for osteoporosis, particularly if they are under 66 years of age

It is accepted that resurfacing hip replacement preserves the bone mineral density (BMD) of the femur better than total hip replacement (THR). However, no studies have investigated any possible difference on the acetabular side. Between April 2007 and March 2009, 39 patients were randomised into two groups to receive either a resurfacing or a THR and were followed for two years. One patient’s resurfacing subsequently failed, leaving 19 patients in each group. Resurfaced replacements maintained proximal femoral BMD and, compared with THR, had an increased bone mineral density in Gruen zones 2, 3, 6, and particularly zone 7, with a gain of 7.5% (95% confidence interval (CI) 2.6 to 12.5) compared with a loss of 14.6% (95% CI 7.6 to 21.6). Resurfacing replacements maintained the BMD of the medial femoral neck and increased that in the lateral zones between 12.8% (95% CI 4.3 to 21.4) and 25.9% (95% CI 7.1 to 44.6). On the acetabular side, BMD was similar in every zone at each point in time. The mean BMD of all acetabular regions in the resurfaced group was reduced to 96.2% (95% CI 93.7 to 98.6) and for the total hip replacement group to 97.6% (95% CI 93.7 to 101.5) (p = 0.4863). A mean total loss of 3.7% (95% CI 1.0 to 6.5) and 4.9% (95% CI 0.8 to 9.0) of BMD was found above the acetabular component in W1 and 10.2% (95% CI 0.9 to 19.4) and 9.1% (95% CI 3.8 to 14.4) medial to the implant in W2 for resurfaced replacements and THRs respectively. Resurfacing resulted in a mean loss of BMD of 6.7% (95% CI 0.7 to 12.7) in W3 but the BMD inferior to the acetabular component was maintained in both groups. These results suggest that the ability of a resurfacing hip replacement to preserve BMD only applies to the femoral side

Aims. The aim of this study was to compare the pattern of initial fixation and changes in periprosthetic bone mineral density (BMD) between patients who underwent total hip arthroplasty (THA) using a traditional fully hydroxyapatite (HA)-coated stem (T-HA group) and those with a newly introduced fully HA-coated stem (N-HA group). Methods. The study included 36 patients with T-HA stems and 30 with N-HA stems. Dual-energy X-ray absorptiometry was used to measure the change in periprosthetic BMD, one and two years postoperatively. The 3D contact between the stem and femoral cortical bone was evaluated using a density-mapping system, and clinical assessment, including patient-reported outcome measurements, was recorded. Results. There were significantly larger contact areas in Gruen zones 3, 5, and 6 in the N-HA group than in the T-HA group. At two years postoperatively, there was a significant decrease in BMD around the proximal-medial femur (zone 6) in the N-HA group and a significant increase in the T-HA group. BMD changes in both groups correlated with BMI or preoperative lumbar BMD rather than with the extent of contact with the femoral cortical bone. Conclusion. The N-HA-coated stem showed a significantly larger contact area, indicating a distal fixation pattern, compared with the traditional fully HA-coated stem. The T-HA-coated stem showed better preservation of periprosthetic BMD, two years postoperatively. Surgeons should consider these patterns of fixation and differences in BMD when selecting fully HA-coated stems for THA, to improve the long-term outcomes. Cite this article: Bone Joint J 2024;106-B(6):548–554

Femoral stem design affects periprosthetic bone mineral density (BMD), which may impact long term survival of cementless implants in total hip arthroplasty (THA). The aim of this study was to examine proximal femoral BMD in three morphologically different uncemented femoral stems designs to investigate whether one particular design resulted in improved preservation of BMD. 119 patients were randomized to receive either a proximally coated dual taper wedge stem, a proximally coated anatomic stem or a fully coated collarless triple tapered stem. Dual energy x-ray absorptiometry scans (Lunar iDXA, GE Healthcare, Madison, WI) assessed BMD across the seven Gruen zones pre-operatively, and post-operatively at 6-weeks, 1-year, and 2-years comparing the unoperated contralateral femur as a control. BMD increased in zones one (2.5%), two (17.1%), three (13.0%), five (10%) and six (17.9%) for all stems. Greater preservation of BMD was measured on the lateral cortex (zone 2) for both the dual taper wedge and anatomic stems (p = 0.019). The dual taper wedge stem also demonstrated preservation of BMD in the medial calcar (zone 7) whilst the anatomic and triple taper stem declined in this region, however this was not statistically significant (p = 0.059). BMD decreased on average by 2.1% in the mid-diaphysis region, distal to the stem tip (zone 4) for all implants. All stems performed equivalently at final follow-up in all patient reported outcome measures. Implant design was shown to impact BMD changes. All stems preserved bone at the metaphyseal level in early follow-up, which theoretically indicates favorable implant fixation. There was no significant stress shielding observed, however longer follow-up is required to elucidate the impact of this finding on implant survivorship

The measurement of bone mineral density in defined areas around metal implants has improved with the development of dual-energy X-ray absorptiometry. We used this technique to compare the bone mineral density adjacent to metal cementless femoral implants with that of identical regions of bone in normal proximal femora. We studied the anteroposterior views only of 72 femora which contained total hip implants and 34 non-operated femora. We compared the regional bone mineral density of bone adjacent to proximally porous-coated and distally porous-coated implants of one design, to measure the relative differences in the remodelling changes induced by different amounts of porous coating. We also measured differences in bone density with time and with variations in implant size (and therefore stiffness). The greatest decrease in bone mineral density (34.8%) occurred in the most proximal 1 cm of the medial femoral cortex around relatively stiff, extensively porous-coated implants. The next most severe decrease (20% to 25%) was in the next most proximal 6 cm of the medial femoral cortex. Small, progressive decreases in bone mineral density continued for five to seven years after implantation

Objectives. Several genome-wide association studies (GWAS) of bone mineral density (BMD) have successfully identified multiple susceptibility genes, yet isolated susceptibility genes are often difficult to interpret biologically. The aim of this study was to unravel the genetic background of BMD at pathway level, by integrating BMD GWAS data with genome-wide expression quantitative trait loci (eQTLs) and methylation quantitative trait loci (meQTLs) data. Method. We employed the GWAS datasets of BMD from the Genetic Factors for Osteoporosis Consortium (GEFOS), analysing patients’ BMD. The areas studied included 32 735 femoral necks, 28 498 lumbar spines, and 8143 forearms. Genome-wide eQTLs (containing 923 021 eQTLs) and meQTLs (containing 683 152 unique methylation sites with local meQTLs) data sets were collected from recently published studies. Gene scores were first calculated by summary data-based Mendelian randomisation (SMR) software and meQTL-aligned GWAS results. Gene set enrichment analysis (GSEA) was then applied to identify BMD-associated gene sets with a predefined significance level of 0.05. Results. We identified multiple gene sets associated with BMD in one or more regions, including relevant known biological gene sets such as the Reactome Circadian Clock (GSEA p-value = 1.0 × 10. -4. for LS and 2.7 × 10. -2. for femoral necks BMD in eQTLs-based GSEA) and insulin-like growth factor receptor binding (GSEA p-value = 5.0 × 10. -4. for femoral necks and 2.6 × 10. -2. for lumbar spines BMD in meQTLs-based GSEA). Conclusion. Our results provided novel clues for subsequent functional analysis of bone metabolism, and illustrated the benefit of integrating eQTLs and meQTLs data into pathway association analysis for genetic studies of complex human diseases. Cite this article: W. Wang, S. Huang, W. Hou, Y. Liu, Q. Fan, A. He, Y. Wen, J. Hao, X. Guo, F. Zhang. Integrative analysis of GWAS, eQTLs and meQTLs data suggests that multiple gene sets are associated with bone mineral density. Bone Joint Res 2017;6:572–576

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 bone mineral density (BMD) scores, RANKL and OPG levels of plasma and RANKL and OPG immunoreactivities of tissue in rats. In this study, totally 36 Swiss Albino rats (70±10 g) were used in three groups. Whereas normal drinking water was given for the control group (n:12), 0.4 mg/kg/day and 6.0 mg/kg/day nicotine was added to drinking water for low-dose nicotine (LDN) group (n:12) and high-dose nicotine (HDN) group (n:12), respectively for 12 months. At the end of 12. th. month, BMD scores were measured via X-ray absorptiometry and then bone turnover was assessed via measuring both RANKL, OPG levels in plasma and RANKL, OPG immunoreactivities in tail vertebrae of all rats. Lumbar spine and femoral regions BMD scores of the control group and the nicotine groups were not significantly difference. In HDN group, OPG levels of plasma were found significantly higher when compared with the control and LDN groups (p=0.001) unlike RANKL levels of plasma. RANKL and OPG immunoreactivities of tissue were found significantly lower in both LDN and HDN groups (p<0.001, p=0.004, respectively) in comparison to control group. No correlation was found between plasma levels and tissue immunoreactivities of RANKL and OPG. As a result, this study indicates that nicotine is not primarily responsible for the decline of BMD frequently seen in smokers

Introduction. There is no published series described change in bone mineral density (BMD) after ankle replacement. We present the results of a prospective study examining the effect of total ankle replacement (TAR) upon local bone mineral density (BMD). Aim. To design a method and assess the effect of TAR loading on local ankle bones, by analysing the BMD of different area around ankle before and after Mobility TAR. Methods. 23 patients undergoing Mobility ankle arthroplasty for osteoarthritis had preoperative bone densitometry scans of the ankle, repeated at 1 and 2 years after surgery. BMD of 2 cm. 2. areas around ankle were measured. Pre- and postoperative data were compared. Results: Mean BMD within the lateral malleolus decreased significantly from 0.5g/cm. 2. to 0.42g/cm. 2. (17%, P > 0.01), at 1 & 2 years postoperatively. Mean BMD within medial malleolus decreased slightly from 0.67g/cm. 2. to 0.64 g/cm. 2. at the same period. However BMD at medial side metaphysic of tibia increased by 7%. There was little increase in BMD in tibia just proximal to implant and at talus. Discussion and Conclusion. Absence of stress shielding around distal tibia, just proximal to tibial component and talus indicates that ankle replacements implanted within the accepted limits for implant alignment, load distal tibia and talus. However, there was stress shielding over the lateral malleolus resulting in decreased BMD in lateral malleolus. Increase BMD at tibial metaphysis, proximal to medial malleolus indicates an increase in mechanical stress which may explain occasional postoperative stress fracture of medial malleolus or medial side ankle pain

To investigate whether children with fractures have a low bone mineral density, 109 children (46 female and 63 male) aged 10.5 ± 2.9 years (range 5–16) sustaining either a single fracture (n=60 patients) or multiple fractures (n=49 patients) had Bone Mineral Density measurements [BMD] (Hologic QDR4500A) of L2 to L4. The Z score {(Patient’s BMD – mean aged related BMD)/ standard deviation of that age group)} was calculated using two previously published data from Shropshire children and American children. A z score of zero indicates that the patients’ BMD is exactly on the mean. The proportion above and below zero and was compared using the binomial theorem. Comparison of frequencies between the groups was undertaken using the Chi 2 test. In a scatter plot of z score against age, low z scores were frequent in girls under 8yrs using both reference data. In this group BMD z score was more likely to be below zero (p< 0.05). A low z score was more frequent in boys less than 8 years using American reference data but not Shropshire data. Girls and boys above 8 years did not show any evidence of low BMD. There was no difference in the frequency of low BMD in patients with multiple compared with single fracture. Girls and possibly boys below 8 years who have sustained a fracture show evidence of low BMD. Boys at any age and girls over 8 years did not show any evidence of having low bone density. Further work is needed to establish whether this risk continues into later life. Multiple fractures do not appear to confer additional risk of low bone density

We undertook a randomised prospective follow-up study of changes in peri-prosthetic bone mineral density (BMD) after hip resurfacing and compared them with the results after total hip replacement. A total of 59 patients were allocated to receive a hip resurfacing (n = 29) or an uncemented distally fixed total hip replacement (n = 30). The BMD was prospectively determined in four separate regions of interest of the femoral neck and in the calcar region corresponding to Gruen zone 7 for the hip resurfacing group and compared only to the calcar region in the total hip replacement group. Standardised measurements were performed pre-operatively and after three, six and 12 months. The groups were well matched in terms of gender distribution and mean age. The mean BMD in the calcar region increased after one year to 105.2% of baseline levels in the resurfaced group compared with a significant decrease to 82.1% in the total hip replacement group (p < 0.001) by 12 months. For the resurfaced group, there was a decrease in bone density in all four regions of the femoral neck at three months which did not reach statistical significance and was followed by recovery to baseline levels after 12 months. Hip resurfacing did indeed preserve BMD in the inferior femoral neck. In contrast, a decrease in the mean BMD in Gruen zone 7 followed uncemented distally fixed total hip replacement. Long term follow-up studies are necessary to see whether this benefit in preservation of BMD will be clinically relevant at future revision surgery

To evaluate the effects of 6 and 18 months of abaloparatide (ABL) compared with placebo (PBO) on bone mineral density (BMD) in the acetabular regions of postmenopausal women with osteoporosis (OP). Acetabular bone loss, as may occur in OP, increases risk of acetabular fragility fractures. a. In total hip arthroplasty (THA), low acetabular BMD adversely affects primary stability, osseointegration, and migration of acetabular cups. c. ABL is an osteoanabolic agent for the treatment of men and postmenopausal women with OP at high risk for fracture. Effects of ABL on acetabular BMD are unknown. Hip DXA scans were obtained at baseline, 6, and 18 months from a random subgroup of postmenopausal women (aged 49–86 y) from the phase 3 ACTIVE trial randomized to either ABL 80 µg/d or PBO (n=250/group). Anatomical landmarks were identified in each DXA scan to virtually place a hemispherical shell model of an acetabular cup and define regions of interest corresponding to DeLee & Charnley zones 1 (R1), 2 (R2), and 3 (R3). BMD changes compared to baseline were calculated for each zone. Statistical P values were based on a repeated mixed measures model. BMD in all zones were similar at baseline in the ABL and PBO groups. BMD significantly increased in the ABL group at 6 and 18 months compared with PBO (all P<0.0001 vs PBO). BMD in the PBO group was relatively stable over time. ABL treatment resulted in rapid and progressive increases in BMD of all 3 acetabular zones. Increasing acetabular BMD has the potential to improve acetabular strength, which may reduce risk of acetabular fragility fractures. In bone health optimization prior to THA, increased acetabular BMD via ABL may provide better primary stability and longevity of acetabular cups in postmenopausal women with OP

Our aim in this prospective study was to compare the bone mineral density (BMD) around cementless acetabular and femoral components which were identical in geometry and had the same alumina modular femoral head, but differed in regard to the material of the acetabular liners (alumina ceramic or polyethylene) in 50 patients (100 hips) who had undergone bilateral simultaneous primary total hip replacement. Dual energy X-ray absorptiometry scans of the pelvis and proximal femur were obtained at one week, at one year, and annually thereafter during the five-year period of the study. At the final follow-up, the mean BMD had increased significantly in each group in acetabular zone I of DeLee and Charnley (20% (15% to 26%), p = 0.003), but had decreased in acetabular zone II (24% (18% to 36%) in the alumina group and 25% (17% to 31%) in the polyethylene group, p = 0.001). There was an increase in the mean BMD in zone III of 2% (0.8% to 3.2%) in the alumina group and 1% (0.6% to 2.2%) in the polyethylene group (p = 0.315). There was a decrease in the mean BMD in the calcar region (femoral zone 7) of 15% (8% to 24%) in the alumina group and 14% (6% to 23%) in the polyethylene group (p < 0.001). The mean bone loss in femoral zone 1 of Gruen et al was 2% (1.1% to 3.1%) in the alumina group and 3% (1.3% to 4.3%) in the polyethylene group (p = 0.03), and in femoral zone 6, the mean bone loss was 15% (9% to 27%) in the alumina group and 14% (11% to 29%) in the polyethylene group compared with baseline values. There was an increase in the mean BMD on the final scans in femoral zones 2 (p = 0.04), 3 (p = 0.04), 4 (p = 0.12) and 5 (p = 0.049) in both groups. There was thus no significant difference in the bone remodelling of the acetabulum and femur five years after total hip replacement in those two groups where the only difference was in the acetabular liner

Bone mineral density (BMD) around the femoral component has been reported to decrease after total knee replacement (TKR) because of stress shielding. Our aim was to determine whether a cemented mobile-bearing component reduced the post-operative loss of BMD. In our study 28 knees receiving a cemented fixed-bearing TKR were matched with 28 receiving a cemented mobile-bearing TKR. They underwent dual-energy x-ray absorptiometry, pre-operatively and at three weeks and at three, six, 12, 18 and 24 months post-operatively. The patients were not taking medication to improve the BMD. The pre-operative differences in the BMD of the femoral neck, wrist, lumbar spine and knee in the two groups were not significant. The BMD of the femur decreased postoperatively in the fixed-bearing group, but not the mobile-bearing group. The difference in the post-operative change in the BMD in the two groups was statistically significant (p < 0.05) at 18 and 24 months. Our findings show that a cemented mobile-bearing TKR has a favourable effect on the BMD of the distal femur after TKR in the short term. Further study is required to determine the long-term effects

We used dual-energy X-ray absorptiometry (DEXA) to compare the bone mineral density (BMD) of nine children aged from 2 years 7 months to 13 years 5 months who had mild osteogenesis imperfecta with an age- and sex-matched control group. The patients had only mild clinical symptoms but DEXA detected highly significant differences in BMD between them and the controls. The mean BMD in the children with osteogenesis imperfecta was 76.7% of normal in the lumbar spine (p < 0.001) and 71.2% of normal in the femoral neck (p < 0.001). DEXA is an objective, reproducible and sensitive method of measurement of BMD in children. It may help to establish the diagnosis, to assess prognosis and possibly to monitor the response to different types of treatment

Introduction:. Significant proximal femoral remodeling occurs after total hip arthroplasty (THA), with regions of bone loss, and regions of hypertrophy. This study compared three implants for changes in femoral bone mineral density over 2 years following primary uncemented hip arthroplasty with a conventional stem (THA), a novel femoral neck-sparing short hip stem (NS-THA), and resurfacing hip arthroplasty (RHA). Methods:. Seventy-one patients participated in this non-randomized, prospective study. All patients had a diagnosis of osteoarthritis and underwent primary uncemented hip arthroplasty. Dual Energy XRay Absorptomitry (DXA) scans were performed at preoperative, 3–7 days post-op, 6 weeks, 6 months, one, and two years post-op. Using custom 2 cm zones, 19 zones were observed for percent changes in bone mineral density (BMD). Radiographs and Harris Hip scores were obtained at each visit. Results:. Age, gender, and BMI were found to be statistically different with fewer females and lower age in the RHA group, and a lower age in the NS-THA group. In all three groups, regions that were located proximally were shown to be the most susceptible to bone loss. Combined 2 cm zones 1C/7C, 2A/6A, and 2B/6B showed statistical significance (p < 0.05). Bone loss in the proximal regions was 8–10% lower with the femoral neck-sparing short stem, and least in the RHA group, causing little to no BMD loss in proximal regions. Radiographic outcomes and clinical results including Harris Hip scores were equal between the groups. Conclusion:. Consistent with our hypothesis, it was found that hip arthroplasty with a conventional stem resulted in the highest proximal femoral bone loss, and resurfacing arthroplasty was associated with the least bone loss. The femoral neck-sparing short stem ameliorated the bone loss seen with traditional hip arthroplasty, and approximated the bone preservation seen with hip resurfacing. The short stem neck-sparing device may provide some of the benefits of hip resurfacing, but could potentially have wider indications for use

Introduction: This study prospectively measured fifty consecutive patients who had the preoperative diagnosis of osteoarthritis undergoing total knee arthroplasty (TKA) to evaluate the change of the bone mineral density (BMD) of the calcaneus. Materials & Methods: Broadband ultrasound attenuation through the calcaneus was measured to assess the BMD of patients. The BMD was measured preoperatively and 1 month (M), 3M, 6M, 1 year, and 2 years after TKA. Results: The mean BUA at each stage was 47.1, 45.8, 46.7, 46.7, 47.8 and 53.1, respectively. During the first 6 months, the BUA declined inconsistently in most patients, but by 1 year, the BUA recovered to the initial BUA before surgery and by 2 years, the BUA increased than the initial BUA, although there ware not satisfactory different. Despite a predicted age-related loss of 4% during 2 years, 78% of the calcaneus on the operative side had BMD higher than preoperative levels and 85% had BMD that was within the expected 4% age-related loss. Discussion: These results indicated that TKA might contribute to decrease the age-related BMD loss. The increase with TKA in patient mobility and the increased heel loading may be a mechanism whereby the calcaneus BMD increases. Conclusion: It is very important for surgeons to recognize the objection beneficial effects of TKA in addition to pain relief

Purpose of study:. The purpose of the study is to evaluate the changes in peri-prosthetic bone mineral density following cemented and cementless total hip arthroplasty over a follow up period of 1 year. Description of methods:. Ethics approval was sought and granted by the South African Medical Association Research Ethics Committee (SAMAREC). Patient consent for participation was obtained. Recruitment of the cohort took place over 2 years. Patients received an uncemented (Synergy) or cemented (Spectron) prosthesis as clinically appropriate. Functional status according to the University of California Los Angeles activity scale (UCLA scale) and bone mineral density as measured by Dual Energy X-ray Absorptiometry (DEXA) was assessed pre-operatively and at 3 months, 6 months and 12 months post-operatively. An independent Contract Research Organisation was used to monitor the site. Summary of results:. As at August 2010, 59 unique patients had undergone 59 hip replacements, and 7 patients (8.5%) were still due their 12 month evaluation. The mean UCLA scored showed a marked and steady improvement post-operatively, with most of the gain demonstrated by 3 months. When evaluating all patients, the mean pre-operative values for Gruen Zones 2, 4, and Net were significantly lower than the mean 12 month values. When evaluating patients who received the uncemented prosthesis (n=40), the mean pre-operative values for Gruen Zones 2 and Net were significantly lower than the mean 12 month values, and the mean pre-operative values for Gruen Zones 1 and 3 were significantly higher than the mean 12 month values. When evaluating patients who received the cemented prosthesis (n=19), the median pre-operative values for Gruen Zones 1, 2, 3, 4, 7 and Net were significantly lower than the median 12 month values. Conclusion:. At 1 year post surgery overall bone density showed a significant increase in both the cemented and uncemented cohort

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 bone mineral density in L1 to L4 (aBMD) using a stepwise linear regression model. A significant relationship was found between aBMD and vertebral shape that suggests that the method may be useful for correcting artefacts such as osteophytes

The bone mineral density (BMD) can be measured by dual energy X-ray absorptiometry (DEXA) accurately and precisely. BMD measurements of proximal tibia, where the structure is dominantly trabecular bone, were made on 45 normal women, aged 24–91 (52.0±14.2) years, and on 46 normal men, aged 20–71 (53.7±15.5) years. The precision of BMD measurements of proximal tibia, expressed as the coefficient of variation, was smaller than 4%. Throughout this cross-sectional study, the following results were acquired. The mean BMD in male is higher than that in female. The BMD show a decrease with age at different rates in women and men. The BMD in both genders is found to increase with body weight. A positive correlation is found between the BMD and body height in women, not in men. In right proximal tibia, the BMD of medial regions are higher than that of lateral regions significantly. Our study also demonstrates that the excellent symmetry of the BMD of the bilateral proximal tibias in both genders, but not in men with age less than 50 years old. Through the study of BMD in proximal tibias using the DEXA, it may reflect the bone reactions to many factors, such as age, sex, body weight & height, and weight bearing etc. Such a kind of study might be an useful adjuvant tool to assess the bone remodelling around the knee joint following the different surgical procedures such as total knee arthroplasty or high tibial osteotomy and might predict the future surgical outcomes

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 bone mineral density (BMD) measurements and assessments was developed 1) to estimate the periprosthetic fracture risk (FR) while press-fitting cementless stem; 2) to evaluate post-operative bone remodeling in terms of BMD changes after primary THR. Data for 5 out of over 70 patients (already involved in a previous study. 1. ) that underwent primary THA in Iceland were selected for developing novel methods to assess intra-operative FR and bone mineral density (BMD) changes after the operation. For each patient three CT images were acquired (Philips Brilliance 64 Spiral-CT, 120 kVp, slice thickness: 1 mm, slice increment: 0.5 mm): pre-op, 24 hours and 1 year post-operative. Pre-op CT scan was used to create 3D finite element model (Materialise Mimics) of the proximal femur. The material properties were assigned based on Hounsfield Units. Different strategies were analyzed for simulating the press-fitting operation, developing what has already been done in prior study. 1. In the finite element simulation (Ansys Workbench), a pressure (related to the implant hammering force of 9.25 kN. 2. ) was applied around the femur's hollow for the stem and the distribution of maximum principal elastic strain over the bone was calculated. Assuming a critical failure value. 3. of 7300 με, the percentage of fractured elements was calculated (i.e. FR). Post 24 hours and Post 1 year CT images were co-registrated and compared (Materialise Mimics) in order to assess BMD changes. Successively, volumes of bone lost and bone gained were calculated and represented in a 3D model. Age and gender should not be taken as unique indicators to choose between implants typologies, since also three dimensional BMD distribution along with volume of cortical bone influence the risk of periprosthetic fractures. Highest FR values were experienced in the calcar-femorale zone and in similar location on the posterior side. BMD loss volume fractions after 1 year were usually higher than BMD gain ones. Consistently with prior studies. 4. , BMD loss was mainly concentrated around the proximal end (lesser trochanter area, outer bone). If present, BMD gain occurred at the distal end (below stem's tip) or proximally (lesser trochanter area, interface contact with the stem). The use of clinical data for BMD assessments serves as an important tool to develop a quantitative method which will support surgeons in their decisions, guiding them to the optimal implant for the patient. Knowing the risk of fracture if choosing a cementless stem and being aware of how the bone will remodel around the stem in one year's time can eventually lead to reduction in revisions and increased quality of life for the patient. Further work will target analysis of a larger cohort of patients and validate FE models

Cementless implants have gained popularity in modern orthopaedic practice. The type implants and surface characteristics on fixation has been extensively investigated, however there is insufficient data on the effect of the host bone bed status on implant fixation. This study aims to determine if there is a correlation between the fixation strength of cementless press-fit implants and bone mineral density (BMD) of the host bone bed. Implants coated with pure titanium, Hydroxyapatite (HA) with or without Hyaluronic Acid (HY) and implants coated with bone growth factors – Bone Morphogenetic Protein 2 (BMP-2) were inserted into tibiae and femora of 32 skeletally mature ewes (109 implants) for a period of 1, 2 and 4 weeks. Mechanical pull-out testing was performed after each time interval to evaluate the ultimate load of failure (Nmm. −2. ). The BMD (gcm. −3. ) surrounding the implant site was measured using a CT scanner. The mean BMD (S.D.) was 1.515gcm. −3. (0.147gcm. −3. ). The mean (S.D.) mechanical pull-out strength at 1, 2 and 4 weeks was 0.37 (0.31), 3.14 (0.17) and 9.74 (2.31) Nmm. −2. respectively. The overall correlation co-efficient between BMD and pull out strength is 0.31. Early fixation strength of implants is independent of BMD, however, the strength of fixation increases with time in a ‘normal’ sheep population. This suggests that the fixation of implants is dependent on the type of implant and surface coating used rather than the density of the host bone bed

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 bone mineral density of 124.3 mg/cm. 3. over the local saline group (analysis of variance, p < 0.05) without any adverse effect on the left control tibiae. The findings indicate that the administration of local low-dose alendronate could be an effective pharmacological means of improving bone formation in distraction osteogenesis

Introduction: Selective COX-2 (Cyclooxygenase-2) inhibitors have been found to impede fracture healing. The effect of selective COX-2 inhibitors on tendon healing in a bone tunnel, however, is unknown. Methods: The authors performed bilateral anterior cruciate ligament reconstructions in 32 rabbits and used peripheral quantitative computed tomography (pQCT) to compare tendon-to-bone healing between tunnel aperture and midtunnel regarding bone mineral density (BMD) and ingrowth of new bone. Each animal was assigned to one of four groups. Two groups received selective COX-2 inhibitors orally for 3 weeks (Cele-coxib; 10 mg/kg/d), the two other groups received no COX-2 inhibitors (controls). The animals were sacrificed 3 and 6 weeks after surgery. In biomechanical testing maximum load to failure and stiffness of the tendon grafts were calculated from the load displacement curve and failure modes were recorded. To assess indirectly the effect on local COX-2 activity the synovial content of Prostaglandin E2 (PGE2), the major metabolite of arachnidonic acid metabolism and catalyzed by COX-2, was measured by Enzyme-linked Immunosorbent Assay (ELISA). Results: Animals treated with selective COX-2 inhibitors had significantly lower BMD at the tunnel aperture (P=.02). In all groups the BMD at the tunnel aperture was significantly higher in comparison with the midtunnel (P< .05). In the controls ingrowth of new bone was greater at the tunnel aperture at 3 weeks (P=.028). After 3 weeks of COX-2 inhibitor administration synovial fluid concentrations of PGE2 were significantly lowered (P=.018) and increased more than threefold by 6 weeks after surgery and 3 weeks after last drug administration (P=.022), while in the controls there was a decrease in PGE2 between week 3 and 6. At 6 weeks the controls exhibited a twofold increase in maximum load to failure (3 weeeks: 28.2±20.9 N; 6 weeks: 59.6±53.6 N; P=.394), whereas the COX-2 inhibitor treated specimens decreased 1.9fold (3 weeks: 69.3±50.5 N; 6 weeks: 37.4±16.8 N; P=.24). Maximum load to failure values correlated with PGE2 changes, but not statistically significant (r. 2. = −0,502; p=0,056). Failure modes at 3 and 6 weeks were rupture and degloving, respectively, of the tendon graft. Discussion: This study revealed decreased bone mineral density at the tunnel aperture at 3 weeks, an increase of the inflammatory mediator PGE2 and decreased graft stability with time after treatment with selective COX-2 inhibitors. Untreated controls appeared to have a more physiological healing course with a continuous decrease in PGE2 and an increase in graft stability. Our results suggest, that selective COX-2 inhibitors may delay tendon healing in a bone tunnel

To achieve desirable outcomes in cementless total knee replacement (TKR), sufficient primary stability is essential. The primary stability inhibits excessive motions at the bone-implant interface, hence providing the necessary condition for osseointegration [1]. Primary stability for cementless TKR is provided by press-fit forces between the bone and implant. The press-fit forces depend on several factors including interference fit, friction between bone and implant surface, and the bone material properties. It is expected that bone mineral density (BMD) will affect the stability of cementless TKR [2]. However, the effect of BMD on the primary stability of cementless femoral knee component has not been investigated in vitro. Phantom calibrated CT-scans of 9 distal femora were obtained after the surgical cuts were made by an experienced surgeon. Since the press-fit forces of the femoral component mainly occur in the Anteroposterior (AP) direction, the BMD was measured in the anterior and posterior faces for a depth of 5 mm; this depth was based on stress distributions from a Finite Element Analysis of the same implant design. In addition, four strain gauges were connected to different locations on the implant's outer surface and implant strain measured throughout as an indication of underlying bone strain. A cementless Sigma CR femoral component (DePuy Synthes Joint Reconstruction, Leeds, UK) was then implanted using an MTS machine. In order to simulate a ‘normal’ bone condition, the implanted bone was preconditioned for one hour at a cyclic load of 250–1500 N, and a rate of 1 Hz. Finally, the implants were pushed-off from the bone in a high-flex position. Forces and displacements were recorded both during insertion and push-off tests. Strong correlations were found for insertion and push-off forces with BMD, R. 2. = 0.88 and R. 2. = 0.88, respectively (p < 0.001), so although implantation may be harder in patients with higher BMD, initial stability is also improved. A correlation was also found between final strain and push-off forces (R. 2. = 0.89, p < 0.01) and BMD also showed a strong reverse correlation with total bone relaxation (R. 2. = 0.76, p = 0.023). These results indicate that higher BMD induces higher bone strain, which can lead to improved fixation strength. There is no consensus on the best fixation method for the TKR but some surgeons prefer a cementless design for young and active patients. The results of our study showed that the primary stability of a cementless femoral knee component is directly correlated with the bone mineral density. Therefore, patient selection based on bone quality may increase the likelihood of good osseointegration and adequate long-term fixation for cementless femoral knee components

Fractures of the distal forearm are widely regarded as the result of “fragility”. We have examined the extent to which patients with Colles’ fractures have osteopenia. We measured the bone mineral density (BMD) in the contralateral radius of 235 women presenting with Colles’ fractures over a period of two years. While women of all ages had low values for ultra-distal BMD, the values, in age-matched terms, were particularly low among premenopausal women aged less than 45 years. This result was not due to the presence of women with an early menopause. This large survey confirms and extends the findings from earlier small studies. We consider that it is particularly important to investigate young patients with fractures of the distal forearm to identify those with osteoporosis, to seek an underlying cause and to consider treatment

We studied the bone mineral density (BMD) of 48 long-term survivors of highly malignant osteosarcoma who had been treated according to the chemotherapy protocols of the German- Swiss-Austrian Co-operative Osteosarcoma Study Group which include high-dose methotrexate. The mean age of the patients was 31 ± 4.2 years and the mean follow-up 16 ± 2.2 years. The BMD of the lumbar spine and of the proximal femur of the non-operated side was measured by dual- energy x-ray absorptiometry. A questionnaire was given to determine life-style factors, medical history and medication. Ten patients were osteoporotic, 21 osteopenic and 17 normal according to the WHO definition. Eighteen patients suffered fractures after receiving chemotherapy and all had significantly lower levels of BMD for all the sites measured

Dual-energy X-ray absorptiometry (DEXA) is increasingly used to measure changes in bone mineral density (BMD) around femoral prostheses after total hip arthroplasty. We have studied the factors which affect the accuracy of these measurements. The coefficient of variation was < 2% using a hydroxyapatite phantom, 2.7% in an anthropomorphic phantom specimen, and < 1% in repeated measurements on implanted cadaver femora. The precision did not vary with different implant materials or designs. In patients we found a mean precision error of 2.7% to 3.4%. The most significant factor affecting reproducibility was rotation of the femur. We conclude that DEXA is a precise method of measurement for small changes in BMD around femoral implants, but that correct and careful positioning of patients is essential to obtain reliable results

We investigated prospectively the bone mineral density (BMD) of the proximal femur after implantation of a tapered rectangular cementless stem in 100 patients with a mean age of 60 years (16 to 87). It was determined using dual energy x-ray absorptiometry, performed one week after surgery and then every six months until the end-point of five years. The BMD increased significantly in Gruen zones 2, 4 and 5 by 11%, 3% and 11% respectively, and decreased significantly in Gruen zones 1, 6 and 7 by 3%, 6% and 14% respectively, over the five-year period. The net mean BMD did not change over this time period. The changes in the BMD were not confined to the first 12 months after surgery. This investigation revealed no change in the overall periprosthetic BMD, but demonstrated a regional redistribution of bone mass from the proximal to distal zones