Bone Metabolic Activity Research Articles

The effects of all-trans retinoic acid on prednisolone-induced osteoporosis in zebrafish larvae

Glucocorticoids (GCs) are extensively used as anti-inflammatory and immunosuppressive medications in the long-term treatment of rheumatic disorders, respiratory diseases, renal diseases, and organ transplantation. Prolonged use of GCs can reduce bone mineral density, leading to osteoporosis (Glucocorticoid Induced Osteoporosis, GIOP) and fracture. All-trans retinoic acid (ATRA) is an active vitamin A metabolite that regulates embryonic development and adult organ function. ATRA has been found in studies to enhance osteogenesis. To examine the interventional effects of ATRA on GIOP and the mechanisms of ATRA activities, we first performed bioinformatic analysis to identify potential gene targets of ATRA. Zebrafish larvae were recruited as experimental animals, and the frequently used GC, prednisolone, was administered to larvae to construct a GIOP model. We evaluated the influence of exogenous ATRA on the activities of bone metabolic enzymes, the expression of genes linked to osteoblasts and osteoclasts, and the restoration of bone mineral density and bone mass in GIOP zebrafish larvae. Furthermore, we studied the influence of RBM14, a transcriptional coactivator and negative reciprocal factor of ATRA, on the regulation of osteoblastic gene expression during the anti-GIOP process of ATRA using the morpholino knockdown approach. The findings of bone metabolic enzyme activity (alkaline phosphatase, ALP and tartrate-resistant acid phosphatase, TRAP) and expression assays of osteoblastic marker genes (Runx2a, Runx2b, SP7, Csf1a, RANKL, and CTSK) indicated that ATRA had bidirectional effects on osteogenesis. However, in the GIOP model, ATRA reversed the GIOP-induced osteoporosis phenotype by inhibiting the GIOP-induced suppression of osteoblastic metabolic enzyme (ALP) activities and osteoblastic marker gene expression (Runx2a, Runx2b, and SP7), and this antagonism was concentration-dependent. We also observed that ATRA inhibited RBM14 expression in zebrafish larvae, while ATRA alone and RBM14 knockdown showed a consistent induction of osteoblast marker gene expression, implying that ATRA's inhibitory effect on RBM14 expression may underlie ATRA's osteogenic effects. Based on these data, we postulated that ATRA may ameliorate GIOP by decreasing RBM14 expression, thereby enhancing osteoblastic marker gene expression.

Volumetric differences in the temporomandibular joint in patients with condylar hyperplasia in active and passive state, SPECT/CT study.

Condylar hyperplasia (CH) is a progressive and deforming disease that modifies anatomy of the temporomandibular joint (TMJ) structures. This study aims to correlate the metabolic bone activity of the condyle measured by SPECT with the volumetry anatomic information from the condyle, fossa and joint space provided by CT images, in patients with CH in active and inactive forms. A cross-sectional comparative study was performed with a set of 116 images from healthy and diagnosed CH patients to compare volumetric measures of the TMJ. Images were acquired through a bone tissue mask using a three-dimensional DICOM reconstruction for SPECT/CT and CBCT images and the Threshold option for segmentation with standardized values for each tissue on the HU scale. there are differences (p<0.01), with greater condylar volume on the affected side in patients with active CH compared to passive CH. The volume of the glenoid cavity shows no differences in either form of CH (p>0.05), however, there were differences for the volume of the joint space on the affected right side of hemimandibular elongation (HE) in the active form. The volume of the mandibular condyle on the affected side in CH cases were larger in HE cases in active and inactive form (p<0.01) compared to healthy patients. Similar results were presented for the glenoid cavity and joint space. Volumetric anatomical evaluation of TMJ structures, as well as information on condylar metabolic activity, can be obtained from SPECT/CT. The study shows a greater condylar volume on the affected side of the CH compared to the contralateral side, but there are more significant differences in the active than in the inactive form.

Dynamics of blood osteomarkers in the treatment of generalized periodontitis

AIM. Study of the dynamics of bone metabolism in the treatment of generalized periodontitis.MATERIALS AND METHODS. 60 patients with chronic generalized periodontitis of moderate to severe severity were examined and treated. A group of 15 healthy individuals without periodontal disease served as a control group. To assess the dynamics of bone formation, blood parameters were measured for bone metabolism: osteocalcin levels, alkaline phosphatase levels, and β-CrossLaps levels. Densitometry of the proximal femoral and lumbar spine regions was also performed.RESULTS. The study revealed increased bone metabolism compared with the control group, an increase in bone metabolism activity was found 3 months after treatment of patients with chronic generalized periodontitis, and after 12 months the values of the studied parameters did not differ from the control group.CONCLUSIONS. Thus, when treating generalized periodontitis, it is necessary to use a treatment regimen that takes into account the individual mineral metabolism of the patient’s bone tissue.

Assessment of regional and total skeletal metabolism using 18F-NaF PET/CT in patients with chronic kidney disease.

The study aims to assess regional and total bone metabolic activity in patients with chronic kidney disease using Na[18F]F PET and correlation between semi-quantitative indices and blood parameters. Seventy-two subjects (mean age 61.8 ± 13.8years) were included. Of these 24/72 patients had end-stage renal disease (ESRD) (GFR < 15mL/min/1.73 m2), 38/72 had chronic kidney disease (CKD) (GFR between 60 and 15mL/min/1.73 m2), and 10/72 were controls with normal renal function. All subjects underwent Na[18F]F PET-CT with a dose activity of 0.06mCi/Kg. Regional and total skeletal metabolism were assessed with mean SUVs in a skeletal volume of interest (VOI), bone to soft tissue index (B/S), global SUV mean (GSUV mean) of the whole bone, and uptake in the femoral neck. Statistically significant differences were observed in a number of 18F-NaF metrics like femoral neck metabolism in CKD and ERSD groups in comparison to control in right (P = 0.003) and left femur (P = 0.006), bone to soft tissue index in the femur (P = 0.016) and GSUV5 (P = 0.006). There is also a significant difference in SUV mean in lumbar vertebrae (L1-L4) among CKD, ESRD, and controls. There was a moderate correlation between 18F-NaF PET scan uptake and blood parameters such as ALP and PTH. Na[18F]F uptake parameters were significantly different in low versus high bone turnover state. The assessment of total skeleton and regional metabolism and bone turnover in CKD patients is feasible with Na[18F]F PET. Na[18F]F can help to detect early changes in bone metabolism and assess the progression of bone disease in this complex condition. Quantification with Na[18F]F PET might provide better assessment of the bone turnover. The difference in Na[18F]F uptake in CKD compared to controls is likely related to a change in bone turnover which, however, requires further validation.

DOES BONE TURNOVER EXPLAIN HIGH BONE DENSITY IN FEMOROACETABULAR IMPINGEMENT? AN ANALYSIS OF PET AND CT IMAGING

Femoroacetabular impingement (FAI) results from a morphological deformity of the hip and is associated with osteoarthritis (OA). Increased bone mineral density (BMD) is observed in the antero-superior acetabulum rim where impingement occurs. It is hypothesized that the repeated abnormal contact leads to damage of the cartilage layer, but could also cause a bone remodelling response according to Wolff's Law. Thus the goal of this study was to assess the relationship between bone metabolic activity measured by PET and BMD measured in CT scans.Five participants with asymptomatic cam deformity, three patients with uni-lateral symptomatic cam FAI and three healthy controls were scanned in a 3T PET-MRI scanner following injection with [18F]NaF. Bone remodelling activity was quantified with Standard Uptake Values (SUVs). SUVmax was analyzed in the antero-superior acetabular rim, femoral head and head-neck junction. In these same regions, BMD was calculated from CT scans using the calibration phantom included in the scan. The relationship between SUVmax and BMD from corresponding regions was assessed using the coefficient of determination (R2) from linear regression.High bone activity was seen in the cam deformity and acetabular rim. SUVmax was negatively correlated with BMD in the antero-superior region of the acetabulum (R2=0.30, p=0.08). SUVmax was positively correlated with BMD in the antero-superior head-neck junction of the femur (R2=0.359, p=0.067). Correlations were weak in other regions.Elevated bone turnover was seen in patients with a cam deformity but the relationship to BMD was moderate. This study demonstrates a pathomechanism of hip degeneration associated with FAI deformities, consistent with Wolff's law and the proposed mechanical cause of hip degeneration in FAI. [18F]-NaF PET SUV may be a biomarker of degeneration, especially in early stages of degeneration, when joint preservation surgery is likely to be the most successful.

Clinical Images: Increased bone metabolism in secondary hyperparathyroidism.

The patient, a 47-year-old man, was diagnosed as having severe hyperparathyroidism secondary to end-stage kidney disease (ESKD), the underlying cause being leukocytoclastic vasculitis with IgA nephritis and minimal-change glomerulonephritis, which was confirmed by kidney biopsy in 2008. The patient had been receiving hemodialysis since 2014 and had a history of multiple fractures. His treatment included azathioprine, low-dose prednisolone, calcium carbonate, vitamin D, sevelamer, cinacalcet, torasemide, carvedilol, amlodipine, moxonidine, simvastatin, low molecular weight heparin, and erythropoietin. After a sudden transitory episode of vision loss with increased C-reactive protein (18.1 mg/liter) and response to glucocorticoids, 18F–positron emission tomography/computed tomography (18F-PET/CT) evaluation was performed to rule out systemic vasculitis. Ophthalmologic examination was negative for arteritic ischemic optic neuropathy, ophthalmoparesis, loss of visual field, and diplopia. Imaging with 18F-PET/CT revealed enhanced fluorodeoxyglucose uptake in the skeleton (A and B) and thickening of cortical bone such as in the femurs (C). Bone loss as osteolytic lesions in the calvaria, increased uptake in the setting of diffuse skull thickening with loss of distinction between the inner and outer table (D), and increased uptake in mandible bones (E) could be seen. There was no evidence for vasculitis. ESKD is associated with a complex remodeling of bone, summarized as renal osteopathy (1). This might include bone resorption, periosteal reaction, brown tumors, osteoporosis, osteosclerosis, osteomalacia, and soft tissue/vascular calcifications. Imaging may reveal any number of these conditions (2, 3). In our patient, 18F-PET/CT revealed osteolytic lesions, which were considered brown tumors and interpreted as osteitis fibrosa cystica. The patient was hypocalcemic (adjusted serum calcium 1.90 mmoles/liter), with elevated alkaline phosphatase (758 IU/liter) and massively elevated parathyroid hormone levels (1,872 pmoles/liter), indicating severe secondary hyperparathyroidism. These 18F-PET/CT images reflect the widespread, strongly induced metabolic activity of bone in secondary hyperparathyroidism during ESKD. Disclosure Form Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

The human microbiota key role in the bone metabolism activity.

Data collection has suggested a complex correlation between the gut microbiota (GM) and bone homeostasis involving host-microbiota crosstalk. Although the GM is known to affect bone metabolism, the mechanisms linked with these effects remain unclear. The aim of this review is to current insight advances regarding how gut-derived hormones regulate bone homeostasis in humans, emphasizing gut-bone axis and bone regeneration. The GM may be engaged in bone metabolism and fracture risk. Additional investigations of the fundamental microbiota-related pathways in bone metabolism may uncover treatment strategies and enable the prevention of osteoporosis. A better knowledge of gut hormones' action on bone homeostasis may lead to new strategies for preventing and treating skeletal frailty related to age.

EVALUATION OF METABOLIC RESPONSE IN BONE MARROW LESIONS AFTER EXERCISE IN RELATION TO CHANGES IN ADJACENT CARTILAGE T2 VALUES

Patellofemoral pain syndrome (PFPS) is one of the most common causes of anterior knee pain in active populations. Due to its multifactorial nature, patellofemoral pain is hard to diagnose and treat. Increased stress in the subchondral bone is associated with PFPS and is correlated to elevated bone remodelling. [18F]NaF PET-MR imaging can localize regions of elevated bone remodelling and provide information about the metabolic processes involved (1, 2). Further, [18F]NaF uptake changes after exercise, thus showing that it is sensitive to changes in bone physiology resulting from acute bone loading (3, 4). For cartilage, T2 relaxation times have been used to study cartilage hydration and microstructure changes after exercise. While some studies have observed a decrease in T2 times after exercise, changes are usually transient and have largely been evaluated in the context of healthy subjects (5). An early sign of persistent abnormal mechanical stress is Bone Marrow Lesions (BMLs), which are strongly associated with pain and structural disease progression. We aimed to reproduce prior work which has shown that acute loading results in a large physiological response in bone regions with BMLs. Further, we wanted to explore if there is breakdown of the cartilage microstructure, either at baseline or in response to loading in cartilage regions adjacent to BMLs. The purpose of this study is to detect changes in the functional response of the knee joint to loading using [18F]NaF PET-MR imaging after a stair-climbing exercise in subjects with unilateral patellofemoral pain. The aims of this feasibility study are 1) to detect acute loading-induced changes in [18F]NaF uptake in bone regions with BMLs and 2) compare consequent T2 values in the cartilage adjacent to BMLs at baseline and in response to loading. 4 subjects (3 F, aged 39.5±15.0 years, BMI 26.1±5.9 kg/m2) with unilateral knee pain and BMLs (3 in patella, 1 in femur) underwent two consecutive 30-min [18F]NaF PET/MRI scans of both knees, at baseline and then repeated after a stair-climbing exercise [112 stairs, up and down]. Bone metabolic activity was quantified by calculating maximum standardized uptake values (SUVmax) in areas of BMLs in the painful leg and the corresponding region in the contralateral leg. T2 maps were calculated from quantitative DESS images [TE(1,2)=6.04, 30.44 ms] in the cartilage regions adjacent to the BMLs and in the same regions in the contralateral leg. Segmentations of cartilage were done manually in MATLAB, while SUVmax in BMLs was calculated using ROIs drawn in Horos. Pre- and post-exercise changes in SUVmax and T2 values were compared to account for loading-induced response in both metabolic and structural parameters in painful vs healthy knees. Increased [18F]NaF uptake was observed post-exercise in areas with BMLs (as compared to contralateral leg regions), confirming that PET findings correspond to structural changes observed in MRI (Fig-1). The average SUVmax values increased from 6.35±3.98 to 10.49±5.42 in the painful leg and from 1.71±1.96 to 4.04±3.21 in the contralateral leg after exercise. The average T2 relaxation times increased from 30.61±1.87 ms to 31.61±1.55 ms in the painful leg and from 27.17±2.73 ms to 27.65±2.29 ms in the contralateral leg (Fig-2). The mean change in SUVmax due to exercise was 4.15±2.42 in the BML vs 2.34±2.06 in the contralateral leg. In adjacent cartilage, a mean change in T2 values of 1.01±1.45 ms in the BML region of the painful leg and 0.47±0.48 ms in the contralateral leg was observed. In this feasibility study, [18F]NaF PET-MR showed acute loading-induced changes in BMLs, with a 2-fold increase in SUVmax in the painful leg vs the contralateral leg. While there seemed to be a higher cartilage T2 in regions adjacent to BMLs compared to the contralateral leg, the change induced by exercise was small.

Quantification of bone metabolic activity in the natural course of fractural lesions measured by quantitative SPECT/CT.

While increased uptake at the bone fractural site gradually decreases over time on bone scans, the rate of change has not been quantitatively evaluated. The purpose of this study was to quantify the extent of bone metabolic changes in fractural lesions on bone SPECT/CT. We reviewed bone scans acquired by dedicated SPECT/CT and chose those scans in which quantitative SPECT/CT of the same range was acquired twice or more. We set the region of interest on lesions of bone fracture and degeneration, and measured the maximum standardized uptake value (SUVmax). From the SUVmax of lesions and the interval between scans, a value for 30-day change in SUVmax was calculated as ∆SUVmax30d. The relationship between preSUVmax, SUVmax for the first scan of the comparison, and ∆SUVmax30d was evaluated utilizing a linear least-squares method. Furthermore, we assessed the ability to differentiate between fracture and degeneration using receiver operating characteristics (ROC) analysis and the Mann-Whitney U test. All cases were then categorized into five groups according to preSUVmax. Values of p <0.05 were considered statistically significant. We investigated 175 scans from 60 patients and analyzed scan combinations for 157 fractural lesions and 266 degenerative lesions. The relationship between preSUVmax of fractural lesions and ∆SUVmax30d was approximated as ∆SUVmax30d =-0.15×preSUVmax +1.35 (R 2=0.60, p<0.0001). Area under the curves for all cases, 30≤ preSUVmax, 20≤ preSUVmax <30, 15≤ preSUVmax <20, 10≤ preSUVmax <15, and preSUVmax <10 were 0.73, 0.89, 0.86, 0.80, 0.91, and 0.59, respectively. Median ∆SUVmax30d was significantly lower at fractural lesions than at degenerative lesions (-0.62 vs -0.04; p <0.0001). As for analyses of groups divided by preSUVmax, all median ∆SUVmax30d for fractural lesions were significantly lower than those of degenerative lesions except for the group with preSUVmax <10. The increased uptake at the fractural bone lesion observed in the quantitative bone SPECT/CT gradually decreased at the rate of SUV 0.15 per month, which showed a different trend with degenerative change.

Recent protocol of the sendai surgery-first (SSF) approach: Clinical and scientific perspectives

The treatment protocol of Surgery-First has gradually evolved, since our team employed it for the first time twenty-years ago. In this article, we describe every step of the current Sendai Surgery-First (SSF) approach protocol, in detail. Two major differences between the recent and old protocol, exists, which are (1) In the recent protocol, placement of brackets and passive surgical wires is no longer required before jaw surgery, and (2) only surgical hooks are needed to be bonded to the lateral teeth. Further, the duration of surgical splint use has been significantly shortened. Instead of a surgical splint, a posterior build-up in the maxillary dentition is used to secure a vertical stop. These considerations allow patients to undergo treatment in a more comfortable manner. However, the skeletal anchorage system (SAS) using the orthodontic miniplate for postoperative orthodontics remains unchanged. Based on many SSF approach cases, we have confirmed that the SAS can predictably improve unstable and complicated occlusion immediately after surgery, and reliably achieve treatment goals. Therefore, our SSF approach has the distinguishing feature of having a wider range of indications than other Surgery-First approaches. Furthermore, in regard to scientific perspectives, dynamic systemic changes in bone metabolic activity of the SSF approach is also discussed. The C-reactive protein levels increase immediately after surgery, followed by an increase in the C-terminal telopeptide type I collagen levels, which is associated with osteoclastic activity, indicating bone resorption. After this, alkaline phosphatase, and bone-specific alkaline phosphatase levels, which are associated with osteoblastic activity, increase with a peak at 1 month and then decrease gradually to preoperative levels by 6 months. During the early postoperative period, osteocalcin-positive cells, such as osteogenic precursors, appear in the peripheral blood and are involved in the bone healing process after surgery through the systemic acceleration phenomenon. Therefore, orthognathic surgery induces regional and systemic accelerated phenomena, which, in turn, causes rapid orthodontic tooth movement, resulting in reduced treatment duration with the SSF approach.

After Total Ankle Arthroplasty, When Does Bone Perfusion and Metabolic Activity at the Bone-Implant Interface Normalize? A PET/CT Study

Category: Ankle Arthritis Introduction/Purpose: Radionuclide bone scintigraphy in combination with computed tomography (CT) has been used to evaluate painful total hip and knee arthroplasties, and has also been used in the evaluation of the painful total ankle arthroplasty (TAA). Increased tracer uptake around implants may indicate loosening, but uptake characteristics of bone-seeking radiopharmaceuticals in asymptomatic total ankle patients have not been clarified. While findings of increased metabolic activity may prompt surgical intervention, there has been no work performed to define when postoperatively periprosthetic activity normalizes, if at all. In this study, we plan to establish normative data on 18F sodium fluoride (18F-NaF) positron emission tomography/CT (PET/CT) uptake ratios around TAA implants at various time intervals after surgery in asymptomatic TAA patients. Methods: The majority of the arthroplasty literature has investigated use of SPECT/CT performed with 99mTc-labeled bisphosphonates. However, data suggest that 18F-NaF PET/CT may be superior for this indication, with more favorable pharmacokinetics and similar sensitivity to detect aseptic loosening. In the present study, asymptomatic patients who underwent TAA with a modern fixed-bearing TAA prosthesis (either the Wright Infinity Adaptis or Exactech Vantage prosthesis) for posttraumatic arthritis were eligible for inclusion. Patients with ipsilateral hindfoot fusion and with any periprosthetic lucencies or cysts were excluded. Patients were enrolled at one of four time intervals following TAA: 6, 12, 18, or 24 months. Standard uptake values were measured at the bone-implant interface for the tibial and talar components on static PET, in regions of interest defined on axial CT scan slices. Periprosthetic bone blood flow (K1) and bone turnover (flux) were assessed at each time interval in each periprosthetic region using dynamic PET. Results: Sixteen asymptomatic patients underwent PET/CT: 4 patients at 6 months postoperatively, 6 at 12 months, and 6 at 24 months. We are currently still in data collection and at this time only 2 patients at 18 months have completed the scan, therefore their data were excluded. The average age was 65 years (range, 55 to 80) and 6 patients were female (38%), with individual patient data shown in the Table. Talar K1 and flux both appeared to increase from 6 to 12 months, and decrease between 12 and 24 months, although there was no statistically significant difference between timepoints. Overall tibial K1 and flux appeared to decrease slightly from 6 to 12 months, and stayed relatively stable between 12 and 24 months, again with no significant difference between timepoints (Figure). Conclusion: There is currently no normative data to help guide interpretation of radionuclide bone scintigraphy for the painful TAA. The present study utilizing 18F-NaF PET/CT scans demonstrates that even in asymptomatic patients, periprosthetic bone blood flow and bone turnover remain elevated up to 24 months following modern fixed-bearing TAA. Not only do these values remain elevated at 24 months, but we found that there does not appear to be any significant decrease in either measurement over time from 6 to 24 months postoperatively. Our findings suggest that radionuclide bone scintigraphy should be cautiously interpreted when performed within 2 years of TAA.

Changes of metabolic parameters in patients with primary hyperparathyroidism of different age groups

BACKGROUND: Studies have shown a high incidence of metabolic disorders and cardiovascular diseases in patients with primary hyperparathyroidism (PHPT). PHPT is usually diagnosed in people of age over 50 years and therefore age-associated changes of metabolism should be excluded. Researching predictors of cardiovascular pathology contributes to choosing optimal approaches to personalized patient management.AIM: To determine the features of metabolic disorders in patients of various age groups with confirmed active stage of PHPT.MATERIALS AND METHODS: A single-center observational retrospective comparative study of patients with active PHPT at the age of 18-49 years (Group 1, n=66) and over 50 years (Group 2, n=290) was carried out. The exclusion criteria for both groups were: persistent PHPT or recurrence after surgical treatment of the disease in history; clinical/genetically confirmed multiple endocrine neoplasia syndrome; for Group 1 — pregnancy, lactation. The assessment of laboratory parameters of mineral, carbohydrate, fat and purine metabolism obtained during a hospital examination was carried out, the frequencies of various metabolic disorders were determined and compared between age groups.RESULTS: There were no significant differences in parathyroid hormone and serum calcium levels between age groups, however, there were more severe hypercalciuria, a tendency to active bone metabolism and lower vitamin D level in Group 1. Patients of Group 2 had statistically significantly lower glomerular filtration rate and a higher frequency of bone complications. In the same group glycaemia and triglycerides levels were higher (the latter difference has the level of a statistical tendency). These patients also had a higher body mass index and, as a result, a higher incidence of obesity (37% vs 20%, p=0.006) and diabetes mellitus type 2 (12.5% vs 3%, p=0.013). At the same time, patients did not significantly differ in the rates of hypercholesterolemia (62% in Group 1 vs 70% in Group 2, p=0.228), hypertriglyceridemia (27% vs 32%, p=0.433) and hyperuricemia (42% vs 50%, p=0.302), significantly exceeding similar indicators in the general Russian population.CONCLUSION: Carbohydrate disorders are more often observed in patients older than 50 years, providing an increased prevalence of diabetes mellitus type 2 among patients with PHPT compared with the general population. The high incidence of various types of dyslipidemia and hyperuricemia in the primary parathyroid pathology has no age specific features. Thereby these disorders are significant risk factors of cardiovascular diseases, even in young people with PHPT.

(Digital Presentation) Formation Mechanism and Defects of Electrodeposited Ca-P Coating on Biodegradable Mg-Zn-Ca Alloy

Biodegradable implants are a new concept to substitute current nondegradable medical materials. The biodegradable implant can decompose in the patients’ body when the treatment is finished and be discharged through metabolism. Mg alloys, with their biocompatibility and high reactivity, meet the requirements of a biodegradable material. Also, Mg has a similar density to the human bones and the lowest elastic modulus among the structural metallic biomaterials, which can mitigate the stress shielding effect. For Mg-Zn-Ca alloys, besides the merits of Mg, Zn is related to bone metabolism and osteopathic phosphate activity, while Ca is the main element of bones that is essential for the synthesis of bone compounds. However, the degradation rate of Mg alloy implants needs to be controlled, or the implant may corrode too fast, causing local hydrogen accumulation and alkalization that hurts the patients. One of the effective ways to improve the alloy corrosion resistance is by coating. Ca-P coatings, such as brushite (dicalcium phosphate dihydrate, DCPD) and hydroxyapatite (HA), can mitigate the degradation rate of Mg alloys and show good biocompatibility and osseointegration. Electrodeposition is a simple way to synthesize coatings on metallic materials with an easy experimental set-up, and the process parameters are highly controllable.Even though there are plenty of reports about the fabrication of Ca-P coatings on Mg alloys through electrodeposition, few of them focus on the film formation mechanism. Issues related to coating defect formation and inhomogeneity are rarely discussed. Therefore, this report focuses on the film formation mechanism and the relationship to the defects of the electrodeposited DCPD coating on a Mg-2.5wt%Zn-1wt%Ca alloy. By altering the deposition potential, the reduction reactions that proceed on the substrate are different. The involvement of H2O reduction affects the formation of DCPD and changes the microstructure of the coating. Combining electrochemical tests and microstructure analysis, the corrosion properties of the coatings are measured, and the results are linked to the difference in film microstructure and defects. With SEM/FIB cross-sectional observations, the formation mechanism of the coatings and the relationship to the process condition will be discussed. The degradation rate of Mg alloys can be tuned by understanding the DCPD film formation mechanism and the cause of the defects.

Effects of Knee Debridement with Flurbiprofen on Knee Function, Inflammatory Levels, and Bone Metabolism Activity in Patients with Knee Osteoarthritis.

Objective The objective of this study is to explore the effects of knee debridement with flurbiprofen on the knee function, inflammatory levels, and bone metabolism activity in patients with knee osteoarthritis. Methods 110 patients with knee osteoarthritis who underwent arthroscopic debridement in our hospital from 2020.01 to 2022.01 were selected for retrospective analysis. Based on whether or not flurbiprofen was used in combination during the perioperative phase, the patients were divided into the control group (only arthroscopic debridement of the knee) and the research group (flurbiprofen with arthroscopic debridement of the knee), with 55 cases in each group. The indexes such as knee function, inflammatory levels, and bone metabolism activity of the two groups were analyzed. Results According to hospital for special surgery (HSS) evaluation for knee function, most patients in the control group were assessed as “moderate,” while patients in the research group were mainly focused on “excellent” and “good,” and their excellent and good rates were remarkably higher than those in the control group (P < 0.05). There were no significant variations in bone metabolism indices such as osteoprotegerin levels (OPG), insulin-like growth factor-1 (IGF-1), β-isomerized C-terminal telopeptide (β-CTX), and receptor activator of nuclear factor-κB ligand (RANKL) before treatment between both groups (P > 0.05), with higher OPG, IGF-1 levels, and remarkably lower β-CTX, RANKL levels in the research group than those in the control group after treatment (P < 0.05). There were no remarkable differences in pain between both groups before treatment (P > 0.05), while at 24 h and 48 h after surgery, the VAS scores in the research group were remarkably lower than those in the control group (P < 0.05). In terms of inflammatory factors, the levels of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and cyclooxygenase-2 (COX-2) in the research group were remarkably lower than those in the control group after treatment (P < 0.05). Conclusion Arthroscopy coupled with flurbiprofen provides a good analgesic effect in the therapeutic treatment of patients with knee osteoarthritis, which contributes to the recovery of knee function with definite results. Its mechanism may be associated with the control of inflammatory response and the regulation of bone metabolism disorder.

Prevalence of Abnormal Bone-Specific Alkaline Phosphatase in Orthopaedic Trauma Patients: A Cross-Sectional Study From a Tertiary Trauma Centre.

Introduction: Bone-specific alkaline phosphatase (BALP) has been a sensitive and reliable marker of bone metabolic activity. The study aimed to study the epidemiology of orthopaedic trauma patients and estimate the level of BALP in these patients.Material and methods: This hospital-based observational cross-sectional study was conducted on over 300 patients admitted to the orthopaedic trauma unit in the level I trauma centre of North India during the study period from January 2020 to January 2021. The level of BALP was assessed in serum samples of 258 patients.Result: A total of 300 patients were included in this study, with an average age of 33.52±17.16 years. Road traffic accidents were the most common mode of injury among admitted patients. We found a significant linear correlation between age and mean BALP levels (P-value < 0.005). The mean age of patients having abnormal BALP is 63.0±16.61 years. Females (22.61±16.23) had greater mean BALP levels than males (13.15±5.86). Among different fractures, fractures around the hip had a higher mean BALP level (23.17±15.07). Patients with diabetes mellitus have higher mean BALP levels.Conclusion: BALP is a cost-effective, readily available bone marker to assess the metabolic activity of orthopaedic trauma patients. Old age patients should undergo routine BALP estimation at admission to rule out metabolic disorders, and timely intervention will prevent complications associated with metabolic disorders.

Bone Remodeling Changes in an Individual with Tuberculosis-Induced, Left-Sided Femoroacetabular Joint Destruction, from Nineteenth-Century Milton, New Zealand

Bone is dynamic, undergoing metabolic changes in response to behavioral and pathological stimuli. This information can be reconstructed in bioarchaeology using histological methods, providing another avenue to explore the experiences of past peoples. We report histological findings from midshaft femoral cortical bone of an identified individual from nineteenth-century New Zealand, who suffered from tuberculosis and had a historically documented period of invalidism. Materials: Burial 21 (B21) is a middle-aged male excavated from the nineteenth-century site of St. John’s burial ground, Milton. B21’s left proximal femur and acetabulum exhibited lytic lesions associated with tuberculosis-induced destruction of bone. Documentation, including a cause of death of “pneumonic phthisis haemorrhage,” and various biographic details exist for this burial. These suggest that B21’s left and right midshaft femur were under asymmetric biomechanical and pathological conditions and should show differences in the underlying bone remodeling. Methods: We collected data on Haversian bone microstructure geometric properties and densities from a total of 148 secondary osteons and 481 Haversian canals. Results: The left femur, from the tuberculosis-inflicted hip joint, had fewer, larger, and more irregularly shaped canals and osteons than the right femur. Discussion and Conclusion: These findings may indicate the left femur received less biomechanical stimulation than the right femur due to decreased weightbearing. It is also possible that the tuberculosis infection in this individual impacted his bone metabolic activity, leading to increased experiences of bone loss. The presented histological approach may enhance interpretations in bioarchaeology by identifying whether bone remodeling changes occur as a result of long-or short-term disuse.

Efficacy of treating segmental bone defects through endochondral ossification: 3D printed designs and bone metabolic activities.

Three-dimensional printing (3D printing) is a promising technique for producing scaffolds for bone tissue engineering applications. Porous scaffolds can be printed directly, and the design, shape and porosity can be controlled. 3D synthetic biodegradable polymeric scaffolds intended for in situ bone regeneration must meet stringent criteria, primarily appropriate mechanical properties, good 3D design, adequate biocompatibility and the ability to enhance bone formation. In this study, healing of critical-sized (5 ​mm) femur defects of rats was enhanced by implanting two different designs of 3D printed poly(l-lactide-co-ε-caprolactone) (poly(LA-co-CL)) scaffolds seeded with rat bone marrow mesenchymal stem cells (rBMSC), which had been pre-differentiated in vitro into cartilage-forming chondrocytes. Depending on the design, the scaffolds had an interconnected porous structure of 300–500 ​μm and porosity of 50–65%. According to a computational simulation, the internal force distribution was consistent with scaffold designs and comparable between the two designs. Moreover, the defects treated with 3D-printed scaffolds seeded with chondrocyte-like cells exhibited significantly increased bone formation up to 15 weeks compared with empty defects. In all experimental animals, bone metabolic activity was monitored by positron emission tomography 1, 3, 5, 7, 11 and 14 weeks after surgery. This demonstrated a time-dependent relationship between scaffold design and metabolic activity. This confirmed that successful regeneration was highly reproducible. The in vitro and in vivo data indicated that the experimental setups had promising outcomes and could facilitate new bone formation through endochondral ossification.

Dual nuclear magnetic resonance for probing intrinsic bone structure and a potential gut-bone axis in ovariectomized rats.

Currently, the existence of a gut-bone axis receives massive attention, and while sound premises and indirect proofs exist for the gut-bone axis concept, few studies have provided actual data linking the gut and bone physically. This study aimed to exploit the versatile nature of nuclear magnetic resonance (NMR) to link NMR relaxometry data on bone mineralization with NMR spectroscopic profiling of gut metabolites. For this purpose, sample material was obtained from a 6-week intervention study with ovariectomized (OVX) rats (n = 49) fed with seven different diets varying in calcium content (0.2-6.0 mg/kg) and prebiotic fiber content (0-5.0% w/w). This design ensured a span in (i) calcium available for bone mineralization and (ii) metabolic activity in the gut. After termination of the intervention, longitudinal (T1 ), transverse (T2 ) relaxation, and mechanical bone strength were measured on the excised femur bones. A PLS model with high predictability (Q2 = 0.86, R2 = 0.997) was demonstrated between T2 decay curves and femur mechanical strength. Correlations were established between bone T2 populations and gut short-chain fatty acids. In conclusion, the present dual NMR approach showed strong correlation between T2 relaxation and mechanical strength of the bone, and when metabolic activity in the gut was modulated by inulin, the potential existence of a gut-bone axis was demonstrated.

APPLICATION OF SPECT EXAMINATION WITH 99MTC MDP IN DENTAL IMPLANTOLOGY

Treatment with intraosseous osteointegrable dental implants is a modern therapeutic method that achieves complete rehabilitation by fully restoring the patient's masticatory function and aesthetics. The success of their application is closely related to the process of osseointegration. Osteointegration is the process of bone formation between the alloplastic material and the surrounding biological environment. The quality and quantity of bone available is a major prognostic factor for the success of dental implants. Some authors evaluate metabolic activity of bone after placement of dental implants or bone grafts using conventional scintigraphy and singlephoton emission computed tomography (SPECT). The aim of the publication is to present the application of the SPECT study with 99mTc MDP in dental implantology.

Increase in Bone Mass Before Onset of Type 1 Diabetes Mellitus in Rats.

The typical insulin deficiency in type 1 diabetes mellitus has general effects on metabolism and also affects bone quality. Two diabetic rat lines (BB/OK; BB.6KWR) and two non-diabetic rat strains (KWR and BB.14+18KWR), as control group, were included in the study. Bone mineral density, bone mineral content and body structure measurements were performed. The measurements took place before the onset of diabetes mellitus Results: A comparison of the groups showed increased bone density values of the diabetic rats in relation to the control groups. A new finding of increased bone density in the diabetic rats occurs. Diabetic rats showed no osteoporotic bone metabolism before the onset of clinically relevant type 1 diabetes mellitus, but rather increased bone metabolic activity.