Objective: This study presents a method to determine the volumetric density of pelvic bone and cortical bone thickness along critical regions of the S2 alar-iliac (S2AI) screw trajectory using bi-planar multi-energy X-ray (BMEX). Methods: Simulated BMEXs were generated from CT data from eight patients, with coordinate matching linking pixels to voxel density values. This dataset included pixel attenuation values, coordinates as independent variables, and voxel attenuation values (Hounsfield Units, HU) as the dependent variable for training a random forest regressor model. Results: The trained model revealed adequate trabecular bone density prediction (root mean square error: 32.8 mg/cm³) and cortical thickness accuracy (error ≤1.2 mm). Trabecular bone showed a minor tendency for density overestimation with a maximum difference of 83 HU, while cortical bone exhibited an underestimation of up to 118 HU. Conclusions: The improved prediction of bone density and the capability to estimate cortical bone thickness signify a significant advancement towards a comprehensive modality for predicting bone quality in implant placement planning.

Objectives: Collegiate Track and Field and Cross-Country (TF-XC) athletes require high training volumes, potentially contributing to their elevated injury rates. But concurrent examination of musculoskeletal injury (MSKI), health, anatomical structure, and performance is rare. This study’s purpose was to compare training habits, MSKI history, bone health, body composition, muscle morphology, and neuromuscular characteristics between collegiate TF-XC athletes and controls. Methods: Thirty TF-XC athletes (n=21 females; n=9 males) and 30 physically active, sex-, age-, and body mass-matched controls completed training and MSKI history questionnaires, Dual-energy X-ray Absorptiometry scans, ultrasonography of the lower body musculature, and knee extensor isometric force testing with surface electromyography. Independent t-tests, analyses of covariance, and Cohen’s d effect sizes compared group differences, and α=0.050. Results: Athletes presented a 3-fold higher MSKI incidence than controls (p<0.001; d=0.96), despite greater total body bone mineral density (BMD) Z-Scores (p=0.008; d=0.81) and regional BMD (all p≤0.005; d≥0.78), and lower muscle echogenicity (better muscle quality) (all p≤0.002; d≥0.87). However, athletes’ muscle size and force production were similar to controls (both p≥0.200; d≤0.62). Conclusions: Though TF-XC demonstrated better bone health and muscle quality than non-athletes, their muscle size and force similarities may suggest potential sport-specific mechanical loading inadequacies, coinciding with high MSKI rates.

Objectives: Postmenopausal women develop estrogen deficiency which produces a pro-resorptive bone environment, leading to osteoporosis and increased fracture risk. Craniectomies are a common clinical procedure, especially in older populations, where calvarial bone is removed to relieve intracranial pressure (i.e., in the case of traumatic brain injury or stroke). Cranial reconstruction surgeries often result in failure due to infection or resorption of autograft material. Despite the need for calvarial bone graft alternatives for older patients, there is limited literature available on the effects of estrogen deficiency on skull bone metabolism and healing. Methods: The purpose of this work was to assess the effects of short-term ovariectomy (OVX) on calvarial bone properties and on the healing of 3.5 mm unilateral calvarial defects. Results: Surprisingly, the intact calvarial bone of OVX rats had higher bone volume, thickness, and number of remodeling cavities than intact calvaria of sham rats. Normalized measures of bone volume showed consistently more calvarial defect healing in OVX compared to sham rats at 4-, 8-, and 12-weeks post-surgery. Conclusion: These findings have implications for future investigations on therapies for treating calvarial bone defects in ovariectomy-induced osteoporotic rats.

Objectives: Force sense (FS) is a proprioceptive component related with functionality, but no specific tests have been developed for pelvic floor (PF). We aimed to evaluate the test-retest reliability of a novel pelvic proprioceptive test (PPT) to explore FS and its relationship with maximal voluntary contraction (MVC) in female athletes. Methods: A total of 42 female athletes (from 18 to 45 years old) were evaluated with digital intravaginal palpation and graded according to modified Oxford grading scale (MOGS) to ensure they had at least a grade 2 in MOGS and a correct PF contraction. All participants completed the PPT twice, 10 minutes apart, to obtain FS proprioceptive error (cmH₂O). MVC was also obtained with manometry during the PPT. A perineometer-manometer was used for evaluations. Results: The test-retest reliability was excellent for force sense (ICC = 0.94, p < 0.001), with an average of 6.2 ± 4.6 cmH₂O of proprioceptive error. A strong correlation was found between FS error and MVC (r = 0.82, p < 0.001). Conclusions: The novel PPT shows excellent test-retest reliability for assessing FS in terms of absolute proprioceptive error in female athletes and correlates with MVC: increased MVC strength is associated with reduced FS accuracy.

Objective: The aim of this study was to investigate the relationship between foot pressure, body mass index and balance in children aged 8-12 years. Methods: Ninety normal children aged from 8 to 12 years old participated in this study. Foot pressure was recorded by a pedograph, BMI was calculated by weight/height2 (CDC chart), and balance was assessed by Biodex balance system. Results: Subjects who were overweight or obese had significantly higher peak plantar pressure on both their right and left sides when compared to those who were normal weight (p < 0.05) and underweight (p < 0.001), and those who were normal weight had significantly higher peak plantar pressure on both sides when compared to those who were underweight (p < 0.05). Subjects who were overweight or obese had significantly higher anterior-posterior stability index, medial-lateral stability index, and overall stability index than those who were underweight or normal weight (p < 0.001). Conclusion: According to the results of our research, it includes positive association between plantar pressure, body mass index and balance in normal children with different weight characteristics. Our findings indicate that while obese and overweight children exhibit significantly higher peak plantar pressure, their higher stability indices suggest reduced postural stability compared to normal and underweight children with different weight characteristics. This implies that increased body mass in these children poses challenges to their balance control. Clinical Trial.gov ID: NCT06478836.

Objectives: Sarcopenia is a condition of the musculoskeletal system that has three distinctive dimensions: muscle strength, muscle mass and muscle performance. We need to accurately define it considering population particularities at national level. The aim of this study is measuring muscle mass variables in healthy young Greek population and set their reference values. Methods: Between June 2020 and June 2022, we recruited (convenience sampling) 185 healthy adults (103 males and 82 females) measured their body composition using two different methods. Bioelectrical Impedance Analysis (BIA) and Dual Energy X – Ray Absorptiometry (DXA). We calculated cut-off values as mean – 2 SDs. Results: Appendicular Lean Mass Index cut-off values for Greek males are 5.61 kg/m² and 4.06 kg/m² for females, Skeletal Muscle Mass Index cut-off values are 9.66 kg/m² for males and 7.83 kg/m² for females. Conclusions: We estimated cut-off values of normal skeletal muscle mass values in a rather selected sample of healthy Greek adult population. Since to our knowledge this is the first study of this type in Greece, these values are a useful tool towards better defining sarcopenia, but there is need to validate them in studies including rural and urban population and in sarcopenia studies in older people.ClinicalTrials.gov ID:NCT04584944

Objective: This study aimed to assess the prevalence of sarcopenia in adult patients with osteogenesis imperfecta (OI) and to identify its associated factors. Methods: Seventeen adult OI patients and 17 adult healthy controls matched for age, sex, and BMI were included. Assessments included handgrip strength (HGS), ultrasonographic muscle measurements, the International Physical Activity Questionnaire (IPAQ), Upper and Lower Extremity Functional Indices (UEFI & LEFI), the SARC-F questionnaire, and laboratory markers. Results: Left-handgrip strength was significantly lower in OI patients than in controls (21.8±4.9 kg vs. 25.3±4.2 kg, p = 0.034). Four OI patients had a SARC-F score ≥4, whereas none in the control group did. Handgrip strength was negatively correlated with thigh fat thickness (r = – 0.604, p = 0.010) and free T4 levels (p < 0.05) but positively correlated with gastrocnemius thickness, serum calcium, albumin, and triglycerides (p < 0.05). Conclusion: Routine muscle strength assessments should be considered an integral component of OI management to optimize patient outcomes. This work is a pilot, hypothesis‑generating study; its preliminary findings require confirmation in larger cohorts with formal power calculations.

Objective: To investigate the role of ALKBH5, a member of the AlkB family of Fe(II)/α-KG-dependent dioxygenases that functions as an RNA demethylase removing N6-methyladenosine (m6A), in regulating apoptosis of rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS), with a focus on miR-181b-5p maturation. Methods: RA-FLS were isolated and analyzed for ALKBH5, pre-miR-181b-1, and miR-181b-5p expression using qRT-PCR. ALKBH5 protein levels were assessed by Western blotting. Cell proliferation and apoptosis were evaluated using MTT assay and flow cytometry, respectively. m6A modification on pre-miR-181b-1 was measured via MeRIP, and its binding to DGCR8 was assessed using co-immunoprecipitation. Results: ALKBH5 expression was significantly downregulated in RA-FLS. ALKBH5 overexpression inhibited proliferation and promoted apoptosis, while its knockdown had the opposite effect. ALKBH5 decreased m6A modification of pre-miR-181b-1, thereby increasing levels of pre-miR-181b-1 and mature miR-181b-5p. Inhibition of miR-181b-5p attenuated the effects of ALKBH5. Conclusion: Overexpression of ALKBH5 promotes apoptosis and inhibits proliferation in RA-FLS by demethylating m6A on pre-miR-181b-1, thereby enhancing miR-181b-5p maturation. These findings suggest a novel therapeutic target for rheumatoid arthritis.

Objectives: To investigate differences in body composition (fat mass, lean body mass [LBM] and bone mineral content [BMC]) between the paretic and non-paretic sides in patients with chronic stroke, and to identify predictive factors for paretic LBM and BMC. Methods: This cross-sectional study included 84 patients (58 men, 26 women; age 58.3 ± 9.5 years). Body composition was assessed using dual-energy X-ray absorptiometry to measure fat mass, LBM and BMC of the paretic and non-paretic limbs. Results: LBM and BMC of both the upper and lower extremities were significantly lower on the paretic side. Fat mass in the paretic lower limb was significantly higher. The greatest percentage differences were found in upper limb BMC (-16.8 %), lower limb LBM (-7.9 %) and lower limb BMC (-7.3 %). Predictors of paretic LBM included age, body mass, motor strength (Motricity Index), and body fat percentage. For paretic BMC, sex and height were significant predictors in both limbs: paretic arm LBM predicted arm BMC, while body mass and age predicted paretic leg BMC. Conclusions: Significant differences in body composition exist between the paretic and non-paretic sides in chronic stroke. This study identified key predictors of paretic LBM and BMC.

Objective: To analyze the effectiveness of a modified knee joint functional exercise method combined with a goniometer in patients after joint replacement. Methods: Sixty patients who underwent orthopedic knee replacement were divided into two groups: a control group (n = 30, conventional intervention) and an intervention group (n = 30, modified knee functional exercise method combined with a goniometer). Postoperative knee function (Knee Society Score, KSS), compliance with functional exercises, and quality of life were evaluated and compared between the two groups. Results: Before the intervention, as well as two days post-operation and on the day of discharge, there were no significant differences in KSS scores between the two groups. However, at 2 weeks, 3 weeks, 1 month, 3 months, and 6 months post-operation, the intervention group showed significantly higher KSS scores compared to the control group (P < 0.05). The compliance rate of knee joint function exercise in the intervention group was significantly higher (P<0.05). After intervention, the PF, GH, VT, and MH dimensions of quality-of-life scores in the intervention group were higher than those before intervention and higher than those in the control group (P<0.05). Conclusion: The modified knee functional exercise method combined with an goniometer effectively improves knee function, enhances training compliance, and improves the quality of life in patients following joint replacement.

Objectives: Reduced weight-loading on the lower extremities during growth induces abnormal bone morphology and malalignment, but the effects of reloading on these abnormalities remain unknown. We aimed to determine the specific timeframes in which hindlimb suspension (HS) during growth induces abnormal femoral morphologies and knee malalignments present at skeletal maturity in rats. Methods: Four-week-old female rats were subjected to HS for one, two, or four weeks using the tail suspension method, followed by reloading. Age-matched rats were used as controls. At 12 weeks of age, femoral morphology and knee joint alignment were assessed using X-ray computed tomography. Results: Femoral anteversion angle, medial/lateral condylar height ratio (MC/LC), and patellar tilt angle were significantly larger, while trochlear angle, lateral condylar height (LC), and lateral trochlear inclination (LTI) were smaller in the groups that underwent HS for two or four weeks prior to reloading, compared with the control group. There were significant correlations between LTI and LC (r = 0.57), MC/LC (r = -0.42), and patellar tilt angle (r = -0.49). In the 4-week HS group, lateral patellar dislocation was observed in 3 of 8 animals. Conclusion: Insufficient weight-loading more than two weeks during growth may induce knee joint instability even after reloading.

Objectives: Osteoporosis (OP) is a major public health concern characterized by increased bone fragility. This study aimed to investigate the causal relationship between circulating metabolites, particularly lipid-related metabolites, and OP using Mendelian Randomization (MR). Methods: A bidirectional two-sample MR approach was applied using summary statistics from large-scale Genome-Wide Association Studies (GWAS) comprising 484,598 individuals of European ancestry. Genetic variants associated with circulating metabolites were selected as instrumental variables. Causal effects were estimated using inverse variance weighting (IVW), weighted median, and MR-Egger methods. Sensitivity analyses were conducted to assess heterogeneity and pleiotropy. Results: MR analyses indicated a potential causal relationship between higher levels of monounsaturated fatty acids (MUFA) and a reduced risk of OP (OR = 0.997; 95% CI: 0.994–0.999; P = 0.013). Conversely, increased total lipids in lipoprotein particles were associated with a higher OP risk (OR = 1.002; 95% CI: 1.000–1.004; P = 0.031). In addition, OP was inversely associated with total lipids (OR = 0.269; 95% CI: 0.095–0.759; P = 0.013) and triglycerides (OR = 0.259; 95% CI: 0.090–0.745; P = 0.012) in chylomicrons and extremely large very-low-density lipoproteins. No evidence of pleiotropy or heterogeneity was detected. Conclusion: This study provides genetic evidence for causal links between lipid metabolism and OP, suggesting that circulating lipid metabolites may serve as potential biomarkers for risk stratification and prevention.

Primary Hyperparathyroidism (PHPT) is a common endocrine disorder characterized by autonomous secretion of parathyroid hormone (PTH) leading to hypercalcemia. Whereas bone mineral density (BMD) is generally preserved at skeletal sites rich in trabecular bone, such as the lumbar spine (LS), studies, using peripheral quantitative computed tomography (pQCΤ) and high-resolution peripheral quantitative computed tomography (HR-pQCΤ), have revealed disruption of both cortical and trabecular bone microarchitecture, even in the contemporary ‘asymptomatic’ form of the disease, highlighting the catabolic effect of PHPT on bone. Moreover, epidemiological studies reported increased fracture risk in patients with PHPT, even in those with BMD T-score within normal or osteopenic range, suggesting that there is a discrepancy between BMD and fracture risk in patients with PHPT and that new diagnostic methods are needed for assessing bone fragility in this population. Surgery is the only definitive treatment for PHPT. Non-surgical treatment is recommended in patients who do not meet the criteria for surgical management, in patients who deny surgical treatment or are high-risk surgical patients. The most frequently used agents are bisphosphonates, denosumab, cinacalcet and vitamin D supplementation.