Chronic plantar heel pain modifies associations of ankle plantarflexor strength and body mass index with calcaneal bone density and microarchitecture

Chronic plantar heel pain (CPHP) is associated with calcaneal bone spurs, but its associations with other calcaneal bone features are unknown. This study therefore aimed to determine associations between having CPHP and bone density and microarchitecture of the calcaneus. We assessed 220 participants with CPHP and 100 age- and sex-matched population-based controls. Trabecular bone density, thickness, separation and number, BV/TV, and cortical density, thickness and area were measured using a Scanco Xtreme1 HR-pQCT scanner at a plantar and mid-calcaneal site. Clinical, physical activity and disease history data were also collected. Associations with bone outcomes were assessed using multivariable linear regression adjusting for age, sex, physical activity, BMI and ankle plantarflexor strength. We assessed for potential effect modification of CPHP on these covariates using interaction terms. There were univariable associations at the plantar calcaneus where higher trabecular bone density, BV/TV and thickness and lower trabecular separation were associated with CPHP. In multivariable models, having CPHP was not independently associated with any bone outcome, but modified associations of BMI and ankle plantarflexor strength with mid-calcaneal and plantar bone outcomes respectively. Beneficial associations of BMI with mid-calcaneal trabecular density (BMI-case interaction standardised X/unstandardised Y beta -10.8(mgHA/cm3) (se 4.6), thickness -0.002(mm) (se 0.001) and BV/TV -0.009(%) (se 0.004) were reduced in people with CPHP. Beneficial associations of ankle plantarflexor strength with plantar trabecular density (ankle plantarflexor strength -case interaction -11.9(mgHA/cm3) (se 4.4)), thickness -0.003(mm) (se 0.001), separation -0.003(mm) (se 0.001) and BV/TV -0.010(%) (se 0.004) were also reduced. CPHP may have consequences for calcaneal bone density and microarchitecture by modifying associations of BMI and ankle plantarflexor strength with calcaneal bone outcomes. The reasons for these case-control differences are uncertain but could include a bone response to entheseal stress, altered loading habits and/or pain mechanisms. Confirmation with longitudinal study is required.

Methylsulfonylmethane Increases the Alveolar Bone Density of Mandibles in Aging Female Mice

Methylsulfonylmethane (MSM) is a naturally occurring anti-inflammatory compound that effectively treats multiple degenerative diseases such as osteoarthritis and acute pancreatitis. Our previous studies have demonstrated the ability of MSM to differentiate stem cells from human exfoliated deciduous (SHED) teeth into osteoblast-like cells. This study examined the systemic effect of MSM in 36-week-old aging C57BL/6 female mice in vivo by injecting MSM for 13 weeks. Serum analyses showed an increase in expression levels of bone formation markers [osteocalcin (OCN) and procollagen type 1 intact N-terminal propeptide (P1NP)] and a reduction in bone resorption markers [tartrate-resistant acid phosphatase (TRAP) and C-terminal telopeptide of type I collag (CTX-I)] in MSM-injected animals. Micro-computed tomographic images demonstrated an increase in trabecular bone density in mandibles. The trabecular bone density tended to be higher in the femur, although the increase was not significantly different between the MSM- and phosphate-buffered saline (PBS)-injected mice. In mandibles, an increase in bone density with a corresponding decrease in the marrow cavity was observed in the MSM-injected mice. Furthermore, immunohistochemical analyses of the mandibles for the osteoblast-specific marker – OCN, and the mesenchymal stem cell-specific marker – CD105 showed a significant increase and decrease in OCN and CD105 positive cells, respectively. Areas of bone loss were observed in the inter-radicular region of mandibles in control mice. However, this loss was considerably decreased due to stimulation of bone formation in response to MSM injection. In conclusion, our study has demonstrated the ability of MSM to induce osteoblast formation and function in vivo, resulting in increased bone formation in the mandible. Hence, the application of MSM and stem cells of interest may be the right combination in alveolar bone regeneration under periodontal or other related diseases that demonstrate bone loss.

PP2A in LepR+ mesenchymal stem cells contributes to embryonic and postnatal endochondral ossification through Runx2 dephosphorylation

It has not been well studied which cells and related mechanisms contribute to endochondral ossification. Here, we fate mapped the leptin receptor-expressing (LepR+) mesenchymal stem cells (MSCs) in different embryonic and adult extremities using Lepr-cre; tdTomato mice and investigated the underling mechanism using Lepr-cre; Ppp2r1afl/fl mice. Tomato+ cells appear in the primary and secondary ossification centers and express the hypertrophic markers. Ppp2r1a deletion in LepR+ MSCs reduces the expression of Runx2, Osterix, alkaline phosphatase, collagen X, and MMP13, but increases that of the mature adipocyte marker perilipin, thereby reducing trabecular bone density and enhancing fat content. Mechanistically, PP2A dephosphorylates Runx2 and BRD4, thereby playing a major role in positively and negatively regulating osteogenesis and adipogenesis, respectively. Our data identify LepR+ MSC as the cell origin of endochondral ossification during embryonic and postnatal bone growth and suggest that PP2A is a therapeutic target in the treatment of dysregulated bone formation.

POS1092 SUBCHONDRAL BONE NORMALIZATION AFTER KNEE JOINT DISTRACTION TREATMENT AS MEASURED WITH CT

Background:In addition to cartilage degeneration, knee osteoarthritis (OA) causes bone changes, including cortical bone thickening, subchondral bone density decrease, and bone shape changes as a result of widening and flattening condyles and osteophyte formation. Knee joint distraction (KJD) is a joint-preserving treatment for younger (<65 years) knee OA patients that has been shown to reverse OA cartilage degradation. On radiographs, KJD showed a decrease in subchondral bone density and an increase in osteophyte formation. However, these bone changes have never been evaluated with a 3D imaging technique.Objectives:To evaluate cortical bone thickness, subchondral trabecular bone density, and bone shape on CT scans before and one year after KJD treatment.Methods:19 KJD patients were included in an extended imaging protocol, undergoing a CT scan before and one year after treatment. Stradview v6.0 was used for semi-automatic tibia and femur segmentation from axial thin-slice (0.45mm) CT scans. Cortical bone thickness (mm) and trabecular bone density (Hounsfield units, HU) were measured with an automated algorithm. Osteophytes were excluded. Afterwards, wxRegSurf v18 was used for surface registration. Registration data was used for bone shape measurements. MATLAB R2020a and the SurfStat MATLAB package were used for data analysis and visualization. Two-tailed F-tests were used to calculate changes over time. Two separate linear regression models were used to show the influence of baseline Kellgren-Lawrence grade and sex on the changes over time. Statistical significance was calculated with statistical parametric mapping; a p-value <0.05 was considered statistically significant. Bone shape changes were explored visually using vertex by vertex displacements between baseline and follow-up. Patients were separated into two groups based on whether their most affected compartment (MAC) was medial or lateral. Only patients with axial CT scans at both time points available for analysis were included for evaluation.Results:3 Patients did not have complete CTs and in 1 patient the imaged femur was too short, leaving 16 patients for tibial analyses and 15 patients for femoral analyses. The MAC was predominantly the medial side (medial MAC n=14; lateral n=2). Before treatment, the MAC cortical bone was compared to the rest of the joint (Figure 1). One year after treatment, MAC cortical thickness decreased, although this decrease of up to approximately 0.25 mm was not statistically significant. The trabecular bone density was also higher before treatment in the MAC, and a decrease was seen throughout the entire joint, although statistically significant only for small areas on mostly the MAC where this decrease was up to approximately 80 HU (Figure 1). Female patients and patients with a higher Kellgren-Lawrence grade showed a somewhat larger decrease in cortical bone thickness. Trabecular density decreased less for patients with a higher Kellgren-Lawrence grade, and female patients showed a higher density decrease interiorly while male patients showed a higher decrease exteriorly. None of this was statistically significant. The central areas of both compartments showed an outward shape change, while the outer ring showed inward changes.Conclusion:MAC cortical bone thickness shows a partial decrease after KJD. Trabecular bone density decreased on both sides of the joint, likely as a direct result of the bicompartmental unloading. For both subchondral bone parameters, MAC values became more similar to the LAC, indicating (partial) subchondral bone normalization in the most affected parts of the joint. The bone shape changes may indicate a reversal of typical OA changes, although the inward difference that was seen on the outer edges may be a result of osteophyte-related changes that might have affected the bone segmentation. In conclusion, KJD treatment shows subchondral bone normalization in the first year after treatment, and longer follow-up might show whether these changes are a temporary result of joint unloading or indicate more prolonged bone changes.Disclosure of Interests:None declared.

Peptidomimetic inhibitor of L-plastin reduces osteoclastic bone resorption in aging female mice

L-plastin (LPL) was identified as a potential regulator of the actin-bundling process involved in forming nascent sealing zones (NSZs), which are precursor zones for mature sealing zones. TAT-fused cell-penetrating small molecular weight LPL peptide (TAT- MARGSVSDEE, denoted as an inhibitory LPL peptide) attenuated the formation of NSZs and impaired bone resorption in vitro in osteoclasts. Also, the genetic deletion of LPL in mice demonstrated decreased eroded perimeters and increased trabecular bone density. In the present study, we hypothesized that targeting LPL with the inhibitory LPL peptide in vivo could reduce osteoclast function and increase bone density in a mice model of low bone mass. We injected aging C57BL/6 female mice (36 weeks old) subcutaneously with the inhibitory and scrambled peptides of LPL for 14 weeks. Micro-CT and histomorphometry analyses demonstrated an increase in trabecular bone density of femoral and tibial bones with no change in cortical thickness in mice injected with the inhibitory LPL peptide. A reduction in the serum levels of CTX-1 peptide suggests that the increase in bone density is associated with a decrease in osteoclast function. No changes in bone formation rate and mineral apposition rate, and the serum levels of P1NP indicate that the inhibitory LPL peptide does not affect osteoblast function. Our study shows that the inhibitory LPL peptide can block osteoclast function without impairing the function of osteoblasts. LPL peptide could be developed as a prospective therapeutic agent to treat osteoporosis.

The effect of deer antler from East Kalimantan to increase trabecular bone density and calcium levels in serum on osteoporotic mice

Objectives Glucocorticoid-induced osteoporosis (dexamethasone) is a primary cause of secondary osteoporosis by the decreasing formation and increasing resorption activities. Previously, the in vitro study showed that 70% ethanol and aqueous extract of deer antler have increased alkaline phosphatase in osteoblast cell that known as marker of bone formation. The mind of this study is to analyze the effect of deer antlers in increasing the bone trabecular density of osteoporosis-induced male mice. Methods This study used a post-test control group design. A total of 54 healthy male mice were randomly divided to nine groups, i.e., healthy control, osteoporotic, positive control, 70% ethanol (4, 8, and 12 mg/kg BW), and aqueous extracts (4, 8, and 12 mg/kg BW) of deer antler groups. All of the interventions were given 1 mL of test sample for 4 weeks orally. The bone densities were determined using histomorphometry by Image J and Adobe Photoshop. The statistical data were performed using SPSS 23 and statistical significance was set at p<0.05. Results The results showed that alendronate group, 70% ethanol, and aqueous extract groups increased bone density and calcium levels in serum (p<0.05) compared to osteoporotic group in dose dependent manner. It indicated that 70% ethanol and aqueous extract of deer antler stimulating bone turnover and aqueous extract showed the highest. Conclusions Dexamethasone induction for 4 weeks caused osteoporotic mice and the administration of 70% ethanol and aqueous extracts of deer antler from East Kalimantan increased trabecular bone density and calcium levels in dose dependent manner.

The comparative Micro-CT analysis on trabecular bone density between hydroxyapatite gypsum puger scaffold application and bovine hydroxyapatite scaffold application

Background: Generally, after tooth extraction, trauma is caused by bone damage, which leads to a decreased bone density. Bone damage repair should be conducted using a bone graft containing hydroxyapatite (HA). HA can be synthesised from gypsum puger powder, which is abundant and easy to obtain. Hydroxyapatite gypsum puger (HAGP) was successful with 100% hydroxyapatite purity level. Purpose: To compare the ratio of trabecular bone density in Wistar rats between HAGP scaffold application and bovine hydroxyapatite (BHA) scaffold application. Methods: This study is a laboratory experiment using 6 treatment groups, namely K (-) polyethylene glycol (PEG) 7, K (-) PEG 28, HAGP + PEG 7, HAGP + PEG 28, BHA + PEG 7, and BHA + PEG 28. HAGP scaffold freeze-drying. The rats were anaesthetised intramuscularly, and their left mandibular incisor was removed. The scaffold was applied to the mouse socket, followed by tissue decapitation after 7 and 28 days. The examination was carried out with micro-computed tomography (Micro-CT). Next, statistical analysis using a one-way analysis of variance (ANOVA) test was conducted (p <0.05). Results: The ANOVA test result showed a difference in bone density between the treatment and control groups on days 7 and 28. The Least Significant Difference (LSD) test result revealed that there was no significant difference between K (-) PEG 28 and HAGP + PEG 7 (p=0.133). Nevertheless, there were significant differences between the other groups. Conclusion: Based on the Micro-CT analysis, the trabecular bone density in Wistar rats following HAGP scaffold application is higher than that of BHA scaffold application.

Korelasi usia kronologis dengan densitas tulang mandibula pada radiograf panoramik pada pasien perempuan usia 5-35 tahunCorellation between chronological age with mandibular bone density on panoramic radiographs of female patients aged 5-35 years

Pendahuluan: Tingkat perkembangan dan maturasi seorang pasien tidak dapat diketahui secara pasti dari usia kronologis, dikarenakan adanya variasi waktu percepatan pertumbuhan pubertas pada setiap individu, maka perlu ditentukan usia biologisnya. Usia biologis ini dapat ditentukan dari usia tulang berupa kualitas tulang yang dapat dilihat dari ukuran densitas tulang. Radiograf panoramik dapat menilai kualitas kepadatan (densitas) tulang secara makrostruktur dan mikrostruktur. Penelitian ini menggunakan sampel perempuan karena perempuan cenderung kehilangan densitas mineral tulang lebih cepat daripada laki-laki. Tujuan penelitian ini yaitu menganalisis korelasi usia kronologis dengan densitas tulang pada radiograf panoramik pada pasien perempuan. Metode: Jenis penelitian ini adalah cross-sectional, dengan menggunakan analisis korelasi. Populasi penelitian menggunakan data primer dari seluruh radiograf panoramik pasien perempuan usia 5-35 tahun pada bulan Desember 2016-Januari 2017 di Rumah Sakit Gigi dan Mulut (RSGM) Universitas Padjadjaran dengan jumlah sampel 64 orang. Analisis densitas tulang trabekula mandibula dilakukan dengan menggunakan software ImageJ dengan Region of Interest (ROI) 4x4mm pada tepi distal foramen mentale mandibula. Hasil: Rerata ukuran densitas tulang trabekula pada kelompok usia 5-11 tahun 17,54%, kelompok usia 12-16 tahun 21,06%, kelompok usia 18-25 tahun 24,01%, dan kelompok usia 26-35 tahun 25,96% dengan hasil korelasi Pearson r = 0,827, dan nilai p=0,0001. Simpulan: Terdapat korelasi antara usia kronologis dengan nilai densitas tulang trabekula pada radiograf panoramik pasien perempuan, yaitu semakin bertambahnya usia kronologis maka nilai densitas tulang juga akan semakin meningkat sesuai dengan rentang usia penelitian 5-35 tahun.Kata kunci: Usia kronologis, densitas tulang, radiograf panoramik, software imageJ. ABSTRACTIntroduction: The level of development and maturation of a patient can not be known with certainty from chronological age, due to variations in the time of pubertal growth spurt in each individual, it is necessary to determine the biological age. This biological age can be determined from bone age in bone quality, which can be seen from the bone density measurement. Panoramic radiographs can assess the quality of bone density macrostructure and microstructure. This study used a female sample because female tend to lose bone mineral density faster than male. This study was aimed to analyse the correlation between chronological age and bone density on female patients’ panoramic radiographs. Methods: This research was cross-sectional with correlation analysis. The study population used was the primary data from all panoramic radiographs of female patients aged 5-35 years in December 2016-January 2017 at Universitas Padjadjaran Dental Hospital (RSGM Unpad) with a total sample of 64 people. Mandibular trabecular bone density analysis was performed using ImageJ software with a 4x4mm Region of Interest (ROI) on the mandibular mental foramen’s distal edge. Results: The mean size of trabecular bone density in the 5-11 years age group was 17.54%, the 12-16 years age group was 21.06%, the 18-25 year age group was 24.01%, and the 26-35 years age group was 25.96%; with the results of Pearson correlation r=0.827, and the p-value = 0.0001. Conclusion: There is a correlation between chronological age and the value of trabecular bone density on the panoramic radiograph of female patients, that is, the increasing of chronological age will also increase the value of bone density, according to the age range of the study (5-35 years).Keywords: Chronological age, bone density, panoramic radiographs, image-J software.