Osteoporosis Research Articles

The Coraco-Gleno-Scapular Line: A Simple Novel Tool for Assessing Glenoid Bone Defects.

Treatment decisions for shoulder instability often necessitate surgical intervention, with glenoid bone loss being a key factor. Currently, various techniques exist to identify glenoid bone loss, each with its own advantages and disadvantages. This study introduces the Coraco-Gleno-Scapular (CGS) line as a tool for assessing critical glenoid bone defects. The objective is to define the CGS line and evaluate its utility in guiding clinical decisions regarding bone loss, proposing that defects extending posterior to this line indicate critical bone involvement requiring surgical intervention. The study analyzed 50 normal right shoulders from individuals aged 18-40 years. Using 3D en face views of the glenoid, the CGS line was defined from the anteroinferior base of the coracoid process, crossing the anterior glenoid, to the anteroinferior pole of the scapula. The Best fit circle area method and the Glenoid index linear method were used to calculate the percentage of the bone area located anterior to the CGS line. The Best Fit Circle Area Method revealed a mean glenoid surface area anterior to the CGS line of 22.19%, while the Glenoid Index Linear Method indicated a mean area of 27.2% anterior to the CGS line. Of the 50 shoulders, 14 had a glenoid surface area <20% anterior to the CGS line using the Best Fit Circle Method, with no cases below 17.5%, while 36 individuals had a glenoid surface area >20%. The Coraco-Gleno-Scapular line is a reliable and simple tool for assessing glenoid bone loss, providing valuable guidance in managing shoulder instability. Its ease of use makes it a promising candidate for standard application in clinical practice. Prospective observational study, Level III.

Inhibition of osteocyte apoptosis does not prevent iron overload-induced bone resorption and bone loss

Inhibition of osteocyte apoptosis does not prevent iron overload-induced bone resorption and bone loss

Improvement of antioxidant capability by dietary N-acetyl cysteine supplementation alleviates bone loss induced by chronic heat stress in finisher broilers

BackgroundHeat stress (HS) incidence is associated with the accumulation of reactive substances, which might be associated with bone loss. N-Acetylcysteine (NAC) exhibits strong antioxidants due to its sulfhydryl group and being as the precursor for endogenous glutathione synthesis. Therefore, interplay between oxidative stress and bone turnover of broilers and the effects of dietary NAC inclusion on antioxidant capability and “gut-bone” axis were evaluated during chronic HS.ResultsImplementing cyclic chronic HS (34 °C for 7 h/d) evoked reactive oxygen species excessive production and oxidant stress, which was accompanied by compromised tibia mass. The RNA-seq of proximal tibia also revealed the enrichment of oxidation–reduction process and inflammatory outbursts during HS. Although no notable alterations in the growth performance and cecal microbiota were found, the diet contained 2 g/kg NAC enhanced the antioxidant capability of heat-stressed broiler chickens by upregulating the expression of Nrf2 in the ileum, tibia, and bone marrow. Simultaneously, NAC tended to hinder NF-κB pathway activation and decreased the mRNA levels of the proinflammatory cytokines in both the ileum and bone marrow. As a result, NAC suppressed osteoclastogenesis and osteoclast activity, thereby increasing osteocyte-related gene expression. Furthermore, the inclusion of NAC tended to increase the ash content and density of the whole tibia, as well as improve cortical thickness and bone volume of the diaphysis.ConclusionsThese findings HS-mediated outburst of oxidant stress accelerates bone resorption and negatively regulates the bone quality of tibia, which is inhibited by NAC in broilers.Graphical abstract

Bone Erosions and Systemic Bone Loss on HR-pQCT in Men With Tophaceous Gout.

Gout, a prevalent inflammatory arthropathy, predominantly affects males and arises from persistent hyperuricemia, resulting in monosodium urate crystal deposition. Hyperuricemia is associated with comorbidities, exacerbating patient morbidity. Conflicting literature exists regarding uric acid's impact on bone mineral density (BMD), with potential proinflammatory effects in gout patients. Localized bone destruction (erosions) is a hallmark of gout, necessitating early detection due to its predictive role in musculoskeletal disability. This cross-sectional study included 26 tophaceous gout patients. Clinical and densitometric parameters were assessed, and high-resolution peripheral quantitative computed tomography (HR-pQCT) was used for bone microarchitecture evaluation, as well as bone erosions in metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints. A healthy control group of 52 age and BMI-matched individuals was included. Despite normal areal bone mineral density (BMD), tophaceous gout patients exhibited impaired HR-pQCT parameters, including lower cortical volumetric BMD (Ct.vBMD) and higher cortical porosity at the distal radius. Similar trends were observed at the tibia. Bone erosions were prevalent (96%), with distribution across MCP and PIP joints. Patients with ≥ 4 erosions displayed increased tophi prevalence and longer uricosuric use. Erosions correlated with compromised microarchitecture, emphasizing their association with disease activity. Despite normal BMD, tophaceous gout patients manifest systemic bone loss, with bone microarchitectural deterioration and localized bone erosions, underscoring the need for detailed clinical approaches to prevent musculoskeletal disabilities, including fragility fractures, in this population.

Photobiomodulation therapy at 650 nm enhances osteogenic differentiation of osteoporotic bone marrow mesenchymal stem cells through modulating autophagy

BackgroundPhotobiomodulatiom therapy (PBMT) has biostimulatory effects on bone marrow mesenchymal stem cells (BMSCs), which takes a pivotal role in maintaining bone mass and avoiding osteoporosis (OP). Autophagy is an important regulator for cell survival and homeostasis. Previous researchers found that BMSCs derived from osteoporotic rats (OP-BMSCs) were with the feature of reduced osteogenic differentiation and autophagy dysfunction. However, the potential regulation of PBMT in osteogenic differentiation of OP-BMSCs and its underling relationship with autophagy remain unclear. Methods650 nm red light-emitting diode (LED) was selected to initiate PBMT effects. The isolation and culture of OP-BMSCs were implemented after the establishment of the OP rat model. Firstly, the optimal dose of LED was screened on OP-BMSCs by CCK-8. Meanwhile, the osteogenic and mineralization activities were studied through the detection of Alkaline phosphatase (ALP) and alizarin red S (ARS). Then, the levels of osteogenesis and autophagy were investigated via western blot and immunofluorescence staining. Finally, the autophagy inhibitor 3-MA was applied to illustrate the underlying mechanism of the osteogenic effect of PBMT on OP-BMSCs. ResultsFirstly, the optimal dose of 6 J/cm2 LED was selected in the subsequent experiments according to CCK-8. Then, the ALP activity and the mineralization ability of OP-BMSCs were obviously increased by PBMT. Meanwhile, Runx-2, OCN and OPN were significantly upregulated in LED group. Furthermore, the expressions of autophagic proteins were significantly increased in LED group by immunofluorescence staining and western blot assay. At last, the promoted effects of PBMT on osteogenic differentiation in OP-BMSCs were distinctly reversed via inhibiting autophagy. ConclusionOur research illustrated that 650 nm LED could improve osteogenic differentiation of OP-BMSCs, suggesting a potential correlation between PBMT-mediated activation of autophagy and promotion of osteogenic differentiation.

Total Hip Arthroplasty in Patients with Hip Osteoporosis: A Narrative Review.

Osteoporosis and osteopenia can affect patients undergoing arthroplasty of the hip, which is typically recommended for patients with severe osteoarthritis or elderly patients with a femoral neck fracture. Preoperative screening for this type of bone loss could be helpful to patients and prevent poor outcomes due to the rate of underdiagnosis of osteoporosis, which can reach 73% in patients undergoing hip arthroplasty. Complications associated with low bone mineral density include periprosthetic fractures as well as an increased revision rate. Although the benefit of antiresorptive medications postoperatively has been demonstrated, when administered preoperatively, worse outcomes were reported compared to its non-usage. Surgical management is as important as pre-medication. According to general recommendations, cemented implants provide greater benefit in osteoporotic patients. However, when using cementless implants, ribbed stems, straight tapered stems, stems with medial calcar contact, and titanium-composed stems can be used to prevent periprosthetic loss of bone mineral density; however, they should not be placed in a varus position. These stems can also be coated with zoledronate and other products.

The identification of low-pathogenic bacteria on removed spinal implants and implications for antimicrobial prophylaxis

IntroductionThe role of low-pathogenic bacteria cultured from removed spinal implants is unclear and the efficacy of perioperative single-dose antibiotics against such bacteria remains underexplored. Research questionThis study aims to investigate whether pedicle screw loosening is associated with pathogens and if the choice of perioperative antibiotics can prevent these bacteria. MethodsA retrospective analysis was conducted on 93 patients with implants removed between 01/01/2018 and 03/31/2020. Patients with both loosened and non-loosened implants were included. The latter group was subdivided into cases where implants were exchanged due to adjacent segment degeneration (ASD) and those with elective implant removal after fracture healing. Bacterial cultures from removed implants were analyzed for resistance profiles against the prophylactic single-shot antibiotics administered during implantation. Patients with acute infection, spondylodiscitis, deep wound infection, empyema, and carbon/polyetheretherketone spinal implants were excluded. ResultsBacterial isolates were detected in both loosened (41%) and non-loosened (27%) implants (p=0.23). The most frequently cultivated bacteria were Cutibacterium acnes and Staphylococcus epidermidis. Sensitivity to the administered antibiotics was 75%. While Cutibacterium acnes was entirely sensitive, Staphylococcus epidermidis was completely resistant. Patients with loosened implants without bacteria had a significantly lower bone mineral density (BMD) than patients with implants removed due to ASD. However, patients with loosened implants and positive bacterial cultures had comparable BMD to ASD patients. ConclusionsThe high rate of sensitive Cutibacterium acnes and resistant Staphylococcus epidermidis on removed spinal implants suggests a need to revisit current antimicrobial prophylaxis. Further research is required to determine the clinical significance of low-virulence bacteria, especially on non-loosened implants.

The difference in bone mineral density between femur and tibia is related to tibia deformation in endstage knee osteoarthritis

BackgroundThis study investigated bone mineral density (BMD) around the knee joint to clarify the mechanism by which tibia deformation exceeds that of the femur in patients with end-stage knee osteoarthritis (KOA). MethodsWe retrospectively analyzed 193 patients who underwent total knee arthroplasty for end-stage KOA with varus alignment. Preoperative T-score of the femur neck and femur total using dual-energy X-ray absorptiometry (DXA) and hounsfield units (HU) of the distal femur and proximal tibia using computed tomography (CT) were measured to asess the BMD. HU was measured by dividing the femur and tibia into medial, lateral, and total parts, respectively. Patients with medial proximal tibial angle (MPTA) ≥ 85° were considered ‘group 1′, and MPTA < 85° were ‘group 2′. The HU between femur and tibia were compared in group 1. T-score, HU, and HU difference between group 1 and group 2 were compared. ResultsThe HU of the proximal tibia was lower than that of the distal femur (femur lateral > femur medial > tibia medial > tibia lateral). T-score (femur neck, femur total) and HU (femur lateral, femur total, tibia lateral) were lower in group 2 than in group 1. There was no difference in femur-tibia HU difference between groups. ConclusionThe medial tibia collapse more than the medial femur in varus endstage KOA was associated with the lower BMD of the proximal tibia than that of the distal femur, and the MPTA collapse was affected by the absolute value of BMD rather than by the femur-tibia BMD difference.

Oyster Mantle-Derived Exosomes Alleviate Osteoporosis by Regulating Bone Homeostasis

Osteoporosis is a major public health problem with an urgent need for safe and effective therapeutic interventions. The process of shell formation in oysters is similar to that of bone formation in mammals, and oyster extracts have been proven to exert osteoprotective effects. Oyster mantle is the most crucial organ regulating shell formation, in which exosomes play an important role. However, the effects of oyster mantle-derived exosomes (OMEs) on mammalian osteoporosis and the underlying mechanisms remain unknown. The OMEs investigated herein was found to carry abundant osteogenic cargos. They could also survive hostile gastrointestinal conditions and accumulate in the bones following oral administration. Moreover, they promoted osteoblastic differentiation and inhibited osteoclastic differentiation simultaneously. Further mechanistic examination revealed that OMEs likely promoted osteogenic activity by activating PI3K/Akt/β-catenin pathway in osteoblasts and blunted osteoclastic activity by inhibiting NF-κB pathway in osteoclasts. These favorable pro-osteogenic effects of OMEs were also corroborated in a rat femur defect model. Importantly, oral administration of OMEs effectively attenuated bone loss and improved the bone microstructure in ovariectomy-induced osteoporotic mice, and demonstrating excellent biosafety. The mechanistic insights from our data support that OMEs possess promising therapeutic potential against osteoporosis.

Erythropoietin treatment and osteoporotic fracture risk in hemodialysis patients: A nationwide population-based study

ObjectivesConcerns about erythropoietin (EPO) therapy for anemia in patients with end-stage renal disease (ESRD) contributing to potential bone loss and increased fracture risks are growing. This study investigated the impact of EPO administration on the risk of common osteoporotic fractures in ESRD patients. MethodsThis population-based retrospective cohort study compared EPO users and non-EPO users among ESRD patients undergoing hemodialysis, diagnosed with ESRD between 2000 and 2014 identified from the National Health Insurance Research Database of Taiwan. The cohorts were matched at a propensity score ratio of 1:1, resulting in equal sample sizes of 2839. Variables related to comorbidities were considered. ResultsEPO users exhibited higher cumulative incidences of major osteoporotic fractures, hip fractures, spine fractures, and wrist fractures compared with the non-EPO user (all P < 0.001). In adjusted Cox regression models, higher adjusted subdistribution hazard ratios (aSHRs) were observed for major osteoporotic fractures (2.41, 95% confidence interval [CI] = 2.01–2.89), osteoporotic hip fractures (2.19, 95% CI = 1.69–2.85), spine fractures (2.50, 95% CI = 1.87–3.34), and wrist fractures (2.34, 95% CI = 1.44–3.78) in EPO users than in non-EPO users. The risk of major osteoporotic fractures significantly increased with increasing EPO doses (P for trend < 0.0001), and a similar trend was observed for the risks of osteoporotic spine and wrist fractures. ConclusionsOur findings suggest that EPO treatment in patients with ESRD undergoing hemodialysis is associated with an increased risk of osteoporotic fractures.

Evaluation of Panoramic Radiography Diagnostic Accuracy in the Assessment of Interdental Alveolar Bone Loss Using CBCT.

Alveolar bone loss (ABL) and periodontal lesions are common diseases that have an undeniable effect on teeth maintenance and health. Current diagnostic methods include probing, intraoral radiography, and panoramic radiography; each has its limitations. In this study, we aimed to assess the diagnostic accuracy of panoramic radiography in the diagnosis of interdental ABL. In this cross-sectional study, panoramic and cone-beam computed tomography (CBCT) images from 80 patients were collected from the archives of an oral and maxillofacial radiology center. The amount of ABL was obtained by measuring the distance from the Cemento-Enamel Junction (CEJ) to the alveolar bone crest on both panoramic and CBCT images. Patients were divided into healthy (ABL ≤ 2 mm) and diseased (2 mm < ABL) groups in terms of periodontal disease. There was no statistically significant difference in the average ABL in the premolar, maxillary molar, and mandibular molar areas between the two techniques. However, in other areas, the ABL size was significantly lower in the panoramic view (p < 0.05). Also, the panoramic technique correctly recognized 89.1% of normal and 88.4% of ABL cases. The overall accuracy of panoramic radiography in the diagnosis of ABL was 85%, indicating the good accuracy of this technique. In maxilla, the highest diagnostic accuracy of the panoramic technique was in the molars, and the lowest was in the incisors. In the mandible, the highest and lowest diagnostic accuracy of the panoramic technique was related to molars and premolars, respectively. According to the kappa statistic, there was a significant good to very good agreement between the two types of techniques in all maxillary areas (p < 0.001). Panoramic radiography is accurate in showing ABL. Measuring ABL in the posterior mandibular areas in panoramic radiographs is quite reliable; however, in general, digital panoramic radiography shows less ABL than the actual amount.

Electronic Cigarettes and Peri-Implantitis: An Umbrella Review.

Electronic cigarettes (e-cigarettes) are offered to consumers as a healthier option than traditional tobacco. However, the long-term effect of non-heat-burning tobacco and e-cigarettes on periodontal and peri-implantitis is unknown. The present review evaluates the impact of electronic cigarettes on peri-implantitis and compares the results with traditional cigarettes and nonsmokers. Systematic/meta-analysis studies were searched in PubMed, MEDLINE, EMBASE, Cochrane Library, and Google Scholar until December 30, 2022. Five systematic/meta-analysis studies were identified based on the search strategy in the selected databases. The overall quality assessment of the studies showed acceptable evidence with high quality. All systematic review studies showed that compared with traditional tobacco smoke, electronic cigarettes might reduce or not change the clinical inflammatory symptoms of periodontitis and peri-implantitis, such as bleeding on probing, probing depth, peri-implant bone loss, and response to treatments. Electronic cigarettes contain nicotine, which can harm periodontal and implant health. On the other hand, a wide range of oral health consequences may be associated with using e-cigarettes. E-cigarette is a potential risk factor for the healing process and the results of implant treatment.

Periodontitis Continuum: Antecedents, Triggers, Mediators, and Treatment Strategies.

Periodontitis (PD) is a chronic inflammatory disease of the periodontium characterized by the formation of gingival pockets and gingival recession. The local inflammatory environment can lead to the destruction of the extracellular matrix and subsequent bone loss. The pathophysiology of PD involves interactions between genetic predisposition, lifestyle, environmental factors, the oral microbiota condition, systemic health disorders, innate and adaptive immune responses, and various host defenses. The review highlighted the importance of the oral cavity condition in systemic health. Thus, a correlation between harmful oral microbiota and cardiovascular disease (CVD)/diabetes/ arthritis, etc, progressions through inflammation and bacterial translocation was highlighted. Antecedents increase an individual's risk of developing PD, trigger initiate microbe-host immunologic responses, and mediators sustain inflammatory interactions. Generally, this review explores the antecedents, triggers, and mediators along the pathophysiological continuum of PD. An analysis of modern approaches to treating periodontitis, including antibiotics for systemic and local use, was carried out. The potential role of natural ingredients such as herbal extracts, phytoconstituents, propolis, and probiotics in preventing and treating PD was highlighted.

Lipoteichoic Acid Rescued Age-Related Bone Loss by Enhancing Neuroendocrine and Growth Hormone Secretion Through TLR2/COX2/PGE2 Signalling Pathway.

The phenomenon of brain-bone crosstalk pertains to the intricate interaction and communication pathways between the central nervous system and the skeletal system. Disruption in brain-bone crosstalk, particularly in disorders such as osteoporosis, can result in skeletal irregularities. Consequently, investigating and comprehending this communication network holds paramount importance in the realm of bone disease prevention and management. In this study, we found that Staphylococcus aureus lipoteichoic acid promoted the conversion of arachidonic acid to PGE2 by interacting with TLR2 receptors acting on the surface of microglial cells in the pituitary gland, leading to the upregulation of COX-2 expression. Subsequently, PGE2 bound to the EP4 receptor of growth hormone-secreting cells and activated the intracellular CREB signalling pathway, promoting GH secretion and ameliorating age-related bone loss.

Stephanine Protects Against Osteoporosis by Suppressing Osteoclastogenesis via Inhibition of the RANKL-RANK Interaction.

The interaction between the receptor activator of nuclear factor-κB ligand (RANKL) and its receptor RANK is known to regulate osteoclastogenesis in bone remodelling and has become an important therapeutic target for the treatment of osteoporosis. Stephanine (SA), an isoquinoline aporphine-type alkaloid isolated from Stephania plants, possesses excellent anti-inflammatory effects and can be used for rheumatoid arthritis treatment. However, its specific role in osteoclastogenesis and osteoporosis remains unknown. In this study, we investigated the influence of SA on osteoclastogenesis in RANKL-stimulated RAW 264.7 cells and osteoporosis in an ovariectomised (OVX) mouse model and elucidated the underlying molecular mechanism. Invitro, SA can bind to RANK and RANKL with the KD values of 3.7 and 76.47 μM, respectively, and disrupt the RANKL-RANK interaction, which inhibits RANKL-stimulated RANK-tumour necrosis factor receptor associated factor 6 (TRAF6) binding and RANK signalling pathways activation, downregulates the expression of key osteoclastogenesis-related regulatory factors in osteoclast precursors, ultimately suppresses osteoclast differentiation and activation. Invivo, SA significantly ameliorated bone loss through inhibiting osteoclastogenesis in OVX mice because of the decreased number of osteoclasts and the increased trabecular bone area. SA markedly inhibited the serum levels of tartrate-resistant acid phosphatase 5b (TRACP-5b), c-telopeptide of type I collagen (CTX-I), and RANKL, whereas it increased that of osteoprotegerin (OPG) in OVX mice. Additionally, SA strikingly downregulated the OVX-induced expression of osteoclast-specific genes and proteins. Taken together, this study elucidated that SA can effectively protect against osteoporosis by suppressing osteoclastogenesis via inhibition of the RANKL-RANK interaction, which supports the potential application of SA as a natural therapeutic agent for osteoporosis.

Biochemical investigation and in silico analysis of the therapeutic efficacy of Ipriflavone through Tet-1 Surface-Modified-PLGA nanoparticles in Streptozotocin-Induced Alzheimer’s like Disease: Reduced oxidative damage and etiological Descriptors

Ipriflavone (IPRI), an isoflavone derivative, is clinically used to prevent postmenopausal bone loss in addition to its antioxidant and cognitive benefits. However, its poor aqueous solubility retained its bioavailability. New strategies have been developed to improve the bioavailability and solubility of neurological medications to enhance their potency and limit adverse effects. This study aimed to prepare targeted IPRI-poly-lactic-co-glycolic acid (PLGA) nanoparticles coupled with Tet-1 peptide to increase the therapeutic potency of IPRI in a rat model of Alzheimer’s disease (AD). Streptozotocin (STZ) exacerbates Alzheimer-related alterations by promoting central insulin resistance resulted from defective signaling pathways related to neuroinflammation and neurotoxicity. Bilateral intracerebroventricular (icv) injection of STZ was used to introduce the AD model. Icv-STZ injection significantly affected brain insulin, oxidative stress, inflammatory, and apoptotic indicators and caused behavioral abnormalities. STZ promoted the formation of amyloid β42 (Aβ42) by increasing BACE1 and reducing ADAM10 and ADAM17 expression levels. STZ also triggered the accumulation of neurofibrillary tangles and synaptic dysfunction, which are crucial for neurological impairments. Icv-STZ injection showed evident degenerative changes in the pyramidal cell layer and significantly reduced the count of viable cells in both CA1 and prefrontal cortex, indicating increased neuronal cell death. IPRI successfully ameliorated cognitive dysfunction by improving the phosphorylated forms of cAMP-response element-binding protein (pCREB) and extracellular signal-regulated kinase 1/2 (pERK1/2) related to synaptic plasticity. Targeted IPRI nanoparticles exceeded free IPRI potential in reducing oxidative stress, acetylcholinesterase/monoamine oxidase activities, Tau phosphorylation, and Aβ42 levels revealing less degenerative changes and increased viable neuron counts. IPRI-targeted nanoparticles improved the neuroprotective potential of free IPRI, making this strategy applicable to treat many neurodegenerative diseases. Finally, the in silico study predicted its ability to cross the BBB and to bind various protein targets in the brain.

Survival Rate and Esthetic Outcomes of 2-Piece Zirconia Dental Implants: A 1-Year Single Clinical Trial of Partially Edentulous Patients.

Titanium dental implants, traditionally used for tooth replacement, face certain biological and esthetic limitations. Recently, zirconia has become a notable alternative, valued for its esthetics and biocompatibility. This study evaluated the efficacy of 2-piece zirconia dental implants, particularly their impact on inflammatory cytokines and their survival rate over 1 year. This study was a single-center, prospective trial and included adults aged 18 and above. From 2021 to 2022, 9 2-piece, tissue-level zirconia implants were placed in 8 patients. Following a 3-month osseointegration phase, crowns were cemented. Over a year, we assessed plaque and gingival indices, pocket depth, and tissue color and texture. Peri-apical radiographs measured bone levels, and IL-1β in peri-implant crevicular fluid was quantified using the enzyme-linked immunosorbent assay. Eight subjects (ages 31-63) participated. One implant failed after 6 months, resulting in a 1-year survival rate of 88.8%. Plaque and gingival indices rose, but peri-implant soft tissue remained stable in color and texture. At 12 months, average bone loss was minimal and insignificant compared with the baseline, and IL-1β levels were similar to those at contralateral teeth with no correlation between IL-1β, pocket depth, and bleeding on probing. Two-piece zirconia implants emerged as a viable tooth replacement option with an 88.8% 1-year survival rate. They maintained stable soft tissue and bone levels, indicating their potential as effective dental restoratives.

Posterior Shoulder Stability Depends on Acromial Anatomy: A Cadaveric, Biomechanical Study

Failure rates in the management of recurrent posterior shoulder instability remain a concern. Cadaveric studies have established that posterior capsulolabral tears, glenoid retroversion, and posterior glenoid bone loss result in increased posterior humeral head translation in the setting of a posteriorly directed force. A high and flat acromion has recently been associated with posterior instability. Therefore, the purpose of this study was to evaluate a potential stabilizing effect of the acromion against posterior humeral head displacement. Eight fresh-frozen human cadaveric shoulders were biomechanically tested in a shoulder simulator in the load-and-shift and Jerk test positions. Prior to testing, CT scans were performed to measure native glenoid width, glenoid retroversion, posterior acromial coverage (PAC), sagittal acromial tilt (SAT) and posterior acromial height (PAH). Each specimen underwent four testing conditions using pre-planned and 3D printed cutting and reduction guides: (1) Intact joint, native acromion; (2) Intact joint, severe acromial malalignment (SAT 69°, PAC 47°, PAH 26mm); (3) Intact joint, moderate acromial malalignment (SAT 59°, PAC 57°, PAH 20mm); (4) Intact joint, corrected acromial alignment (SAT 48°, PAC 70°, PAH 11mm). The degree of acromial malalignment and acromial reorientation was chosen based on a previous study that defined acromial anatomy in patients with posterior instability. The humeral head was translated posteriorly until reaching either (1) a peak force of 150N or (2) a maximum posterior displacement of 50% of the glenoid width. Forces (N), displacement (mm) and acromiohumeral contact pressures (kPA) were simultaneously recorded. The force needed to displace the humeral head by 50% of the glenoid width decreased between 23% and 60% in moderate to severe acromial malalignment (high and flat acromion) and increased up to 122% following surgical correction of acromial alignment (low and steep acromion) when compared to the native condition. Correction of acromial alignment significantly increased stability compared to all other scenarios after ≥5% of displacement (p<0.05 for all comparisons). Furthermore, it increased acromiohumeral contact pressures compared with severe malalignment in 30° flexion and with moderate and severe acromial malalignment in 60° flexion (p<0.05 for all comparisons). The acromion acts as a mechanical buttress to posterior humeral head displacement. Surgical correction of acromial malalignment cannot only effectively restore but increase glenohumeral joint stability. Future studies are needed to define the quantitative relevance of the different factors contributing to posterior shoulder instability and assist in defining the optimal amount of correction needed in an individual situation.

Influence of Bisphosphonates on Alveolar Bone Loss around Osseointegrated Implants

ABSTRACT Context: Bisphosphonates are extensively used drugs for the management of osteoporosis and other disorders affecting the bones. The stability and lifetime of osseointegrated dental implants may be influenced by their impact on bone metabolism. Materials and Methods: A randomized controlled trial was undertaken with a sample size of 60 individuals who were implanted with orally integrated dental implants. Study participants were split into two groups: Group A (n = 30) had bisphosphonate therapy for a minimum of 1 year before implant placement, while Group B (n = 30) did not have any bisphosphonate treatment. Cone beam computed tomography images were performed to quantify the alveolar bone levels surrounding the implants at three time points: baseline, 6 months, and 12 months after implantation. Findings: At the 6-month mark, Group A had an average bone loss of 0.8 mm with a standard deviation of 0.3 mm, but Group B had a bone loss of 1.2 mm with a standard deviation of 0.4 mm. At the 12-month mark, Group A experienced an average bone loss of 1.1 mm ± 0.5 mm, while Group B had a loss of 1.6 mm ± 0.6 mm. The substantial differences in bone loss between the groups were observed at both the 6-month (P &lt; 0.05) and 12-month (P &lt; 0.01) time points. Conclusion: Bisphosphonate treatment seems to decrease the atrophy of the alveolar bone surrounding osseointegrated dental implants, indicating a possible advantage in improving the durability and lifespan of the implants.

Age- and Sex-Related Volumetric Density Differences in Trabecular and Cortical Bone of the Proximal Femur in Healthy Population

Background: There are age- and sex-related increases in the prevalence of osteoporosis. Bone densitometry based on dual energy X-ray absorptiometry (DXA) is the gold standard for the assessment of bone mineral density (BMD). Three-dimensional (3D) analysis of the proximal femur (3D-DXA) allows discrimination between cortical and trabecular compartments, and it has shown a good correlation with computed tomography. We aimed to assess age- and sex-related volumetric density differences in trabecular and cortical bone using 3D-DXA and determine the reference intervals for integral volumetric (v)BMD within the Argentine population.Methods: Healthy female and male adult subjects (N=1,354) from Argentina were included. Hip BMD was measured using DXA, and 3D analysis was performed using 3D-Shaper software. The integral vBMD, cortical surface BMD, and trabecular vBMD (trab vBMD) were measured.Results: The study population included 73.9% women (N=1,001) and 26.13% men (N=353). We found a significant decrease in integral vBMD between 20 and 90 years in both sexes (women, -23.1%; men, -16.6%). Bone loss indicated in the integral vBMD results was mainly due to a decrease in trabecular bone in both sexes (women, -33.4%; men, -27.7%). The age-related loss of cortical bone density was less and was limited to the female population, without no age-related differences in men. Moreover, 3D-DXA allowed us to propose reference intervals for integral vBMD.Conclusions: We found age- and sex-related bone loss between 20 and 90 years in an Argentine cohort via integral vBMD measurements using 3D-DXA, mainly due to decreases in trabecular bone in both sexes. The age-related loss of cortical bone density was less and was limited to the female population.