Ectopic Ossification Research Articles

Understanding the Action of RARγ Agonists on Human Osteochondroma Explants.

Osteochondromas are cartilage-capped growths located proximate to the physis that can cause skeletal deformities, pain, limited motion, and neurovascular impingement. Previous studies have demonstrated retinoic acid receptor gamma (RARγ) agonists to inhibit ectopic endochondral ossification, therefore we hypothesize that RARγ agonists can target on established osteochondromas. The purpose of this study was to examine the action of RARγ agonist in human osteochondromas. Osteochondroma specimens were obtained during surgery, subjected to explant culture and were treated with RARγ agonists or vehicles. Gene expression analysis confirmed the up-regulation of RARγ target genes in the explants treated with NRX 204647 and Palovarotene and revealed strong inhibition of cartilage matrix and increased extracellular matrix proteases gene expression. In addition, immunohistochemical staining for the neoepitope of protease-cleaved aggrecan indicated that RARγ agonist treatment stimulated cartilage matrix degradation. Interestingly, cell survival studies demonstrated that RARγ agonist treatment stimulated cell death. Moreover, RNA sequencing analysis indicates changes in multiple molecular pathways due to RARγ agonists treatment, showing similarly to human growth plate chondrocytes. Together, these findings suggest that RARγ agonist may exert anti-tumor function on osteochondromas by inhibiting matrix synthesis, promoting cartilage matrix degradation and stimulating cell death.

Operative effect and treatment strategies for the low distal humerus fracture

Objective: To explore the operative effect and treatment strategies for the low distal humerus fracture. Methods: A retrospective analysis was conducted on the clinical data of 16 patients with the low distal humerus fracture between January 2016 and January 2018 at Department of Orthopaedics, Shanghai Tongji Hospital Affiliated to Tongji University.All fractures were coronal fractures of humeral head, partly combined fractures of humeral trochlea or posterior part. Fractures were classified according to Dubberley classification as 9 cases in type Ⅰ, 3 cases in typeⅡ and 4 cases in type Ⅲ.Selection of the kind of operative approach and internal fixation was made according to the fracture type and shape. For simple coronal fractures of humeral head or combining humeral trochlea fractures, which were relatively stable, single or multiple countersunk screws fixation by the lateral approach were chosen.For humeral head coronal fractures, which combining obviously displaced comminuted humeral trochlea factures, posterolateral locking plates and countersunk screws internal fixation by the olecranon osteotomy approach were chosen. The incision and elbow soft tissues were observed within 2 weeks after operation.The radiographic evaluation of fracture reduction, bone healing, internal fixation, arthritis and elbow range of motion were made at 3, 6, 12 months after operation. The Mayo elbow functional scores were documented for analysis of elbow joint function, and compared between different surgery groups by Kruskal-Wallis H test. Results: The follow-up time was (22.1±9.2)months(range: 15 to 39 months). The incisions healed well in 2 weeks after operation without soft tissue infection, necrosis or vascular complications. There was no fracture reduction loss or internal fixation loosening according to radiographic evaluation 3 months after operation. One case of ectopic ossification was observed 6 months after operation and inhibited by the treatment of non steroidal anti-inflammatory drugs.One case of ulnar neuritis occurred after operation and released after removing the long screw and loosing the ulnar.Osteoarthritis images were observed at the end of follow-up.Arc of motion was (120.4±11.2) ° in flexion and (5.5±1.9) ° in extension. The Mayo score was 88.7±9.1, including 11 excellent, 4 good, and 1 fair.The Mayo score was 90.1±3.7 in Dubberley classification type Ⅰcases, 89.7±4.6 in type Ⅱ cases and 84.5±5.8 in type Ⅲ cases. There were no significant differences in Mayo scores between 3 types cases according to Kruskal-Wallis H test. Conclusion: Choosing the appropriate surgical approach and composite internal fixation according to the fracture types and shapes of low distal humerus fracture, anatomic reduction of the articular surface and early functional exercise are the keys to obtain ideal curative effect.

Tag-Free Site-Specific BMP-2 Immobilization with Long-Acting Bioactivities via a Simple Sugar-Lectin Interaction.

The construction of a biomaterial matrix with biological properties is of great importance to developing functional materials for clinical use. However, the site-specific immobilization of growth factors to endow materials with bioactivities has been a challenge to date. Considering the wide existence of glycosylation in mammalian proteins or recombinant proteins, we establish a bioaffinity-based protein immobilization strategy (bioanchoring method) utilizing the native sugar-lectin interaction between concanavalin A (Con A) and the oligosaccharide chain on glycosylated bone morphogenetic protein-2 (GBMP-2). The interaction realizes the site-specific immobilization of GBMP-2 to a substrate modified with Con A while preserving its bioactivity in a sustained and highly efficient way, as evidenced by its enhanced ability to induce osteodifferentiation compared with that of the soluble GBMP-2. Moreover, the surface with Con A-bioanchored GBMP-2 can be reused to stimulate multiple batches of C2C12 cells to differentiate almost to the same degree. Even after 4 month storage at 4 °C in phosphate-buffered saline (PBS), the Con A-bioanchored GBMP-2 still maintains the bioactivity to stimulate the differentiation of C2C12 cells. Furthermore, the ectopic ossification test proves the in vivo bioactivity of bioanchored GBMP-2. Overall, our results demonstrate that the tag-free and site (i.e., sugar chain)-specific protein immobilization strategy represents a simple and generic alternative, which is promising to apply for other glycoprotein immobilization and application. It should be noted that although the lectin we utilized can only bind to d-mannose/d-glucose, the diversity of the lectin family assures that a specific lectin could be offered for other sugar types, thus expanding the applicable scope further.

Role of Signal Transduction Pathways and Transcription Factors in Cartilage and Joint Diseases.

Osteoarthritis and rheumatoid arthritis are common cartilage and joint diseases that globally affect more than 200 million and 20 million people, respectively. Several transcription factors have been implicated in the onset and progression of osteoarthritis, including Runx2, C/EBPβ, HIF2α, Sox4, and Sox11. Interleukin-1 β (IL-1β) leads to osteoarthritis through NF-ĸB, IκBζ, and the Zn2+-ZIP8-MTF1 axis. IL-1, IL-6, and tumor necrosis factor α (TNFα) play a major pathological role in rheumatoid arthritis through NF-ĸB and JAK/STAT pathways. Indeed, inhibitory reagents for IL-1, IL-6, and TNFα provide clinical benefits for rheumatoid arthritis patients. Several growth factors, such as bone morphogenetic protein (BMP), fibroblast growth factor (FGF), parathyroid hormone-related protein (PTHrP), and Indian hedgehog, play roles in regulating chondrocyte proliferation and differentiation. Disruption and excess of these signaling pathways cause genetic disorders in cartilage and skeletal tissues. Fibrodysplasia ossificans progressive, an autosomal genetic disorder characterized by ectopic ossification, is induced by mutant ACVR1. Mechanistic target of rapamycin kinase (mTOR) inhibitors can prevent ectopic ossification induced by ACVR1 mutations. C-type natriuretic peptide is currently the most promising therapy for achondroplasia and related autosomal genetic diseases that manifest severe dwarfism. In these ways, investigation of cartilage and chondrocyte diseases at molecular and cellular levels has enlightened the development of effective therapies. Thus, identification of signaling pathways and transcription factors implicated in these diseases is important.

Adipose-derived stem cells improve tendon repair and prevent ectopic ossification in tendinopathy by inhibiting inflammation and inducing neovascularization in the early stage of tendon healing.

IntroductionAchilles tendinopathy is characterized by scar formation or ectopic ossification, both of which result in pain and worsened physical function in athletes and older people. Although cell therapy using adipose-derived stem cells (ASCs) has been shown to be effective for tendinopathy, the underlying mechanisms by which ASCs result in tendon healing in vivo have not yet been fully clarified.MethodsASCs were obtained from the fat pads of EGFP transgenic mice by collagenase digestion. C57BL/6 mice were used in a collagenase-induced injury model. ASCs were transplanted into injury sites at 1 week after injury. Tendons were harvested at 9 days, 2 weeks, and 4 weeks after transplantation, and analyzed by histological examination and μCT scanning.ResultsHistological analysis and μCT scanning revealed greater recovery of collagen fibers and suppression of ectopic ossification in the ASC-treated group than in the control group at 2 and 4 weeks after injury. Immunohistochemical analysis identified transplanted ASCs in the tendon core close to peritenon and connective tissue at 2 days and 1 week after transplantation, but not at 3 weeks. Furthermore, while the expression levels of IL-1β, GLUT1, and CA9 were significantly reduced in the ASC group compared to the control group at 9 days after injury, those of VEGF and the number of CD31 positive vessels were significantly increased.ConclusionThe efficacy of ASCs for tendon repair and the prevention of ectopic ossification in Achilles tendinopathy were demonstrated. Our data suggest that ASCs can modulate inflammation and induce neovascularization in the early stage of tendon injury.

A case of traumatic elbow joint contracture with massive ectopic ossification operated using ultrasonic cutting-coagulation device

A case of traumatic elbow joint contracture with massive ectopic ossification operated using ultrasonic cutting-coagulation device

Arthroscopic bone resection for non-traumatic ectopic ossification of the coracoclavicular ligament: a case report

Arthroscopic bone resection for non-traumatic ectopic ossification of the coracoclavicular ligament: a case report

Clinical and Molecular Characteristics of GNAS Inactivation Disorders Observed in 18 Korean Patients.

The GNAS gene on chromosome 20q13.3 is a complex, imprinted locus regulated in a tissue-specific manner. GNAS inactivation disorders are a heterogeneous group of rare disorders caused by mutations and methylation defects. These are divided into pseudohypoparathyroidism (PHP) types 1A and 1B, pseudo-pseudohypoparathyroidism (PPHP), and progressive osseous heteroplasia (POH), depending on the presence or absence of hormone resistance, Albright's hereditary osteodystrophy (AHO), and ectopic ossification. This study analyzed the clinical characteristics and molecular genetic backgrounds of 18 Korean patients from 16 families with a genetically confirmed GNAS defect. Auxological parameters, AHO phenotypes, types of hormonal resistance, family history, and molecular genetic disturbances were reviewed retrospectively. Nine (90%) patients with PHP1A showed resistance to parathyroid hormone (PTH) and all patients showed elevated thyroid-stimulating hormone (TSH) levels at diagnosis. Eight (80%) patients were managed with levothyroxine supplementation. Three of six patients with PHP1B had elevated TSH levels, but none of whom needed levothyroxine medication. AHO features were absent in PHP1B. Patients with PPHP and POH did not show any hormone resistance, and both of them were born as small for gestational age. Among the 11 families with PHP1A, PPHP, and POH, eight different (three novel) mutations in the GNAS gene were identified. Among the six patients with PHP1B, two were sporadic cases and four showed isolated loss of methylation at GNAS A/B:TSS-DMR. Clinical and molecular characteristics of Korean patients with GNAS inactivation disorders were described in this study. Also, we reaffirmed heterogeneity of PHP, contributing to further accumulation and expansion of current knowledge of this complex disease.

Treatment of complex acetabular fractures involving the posterior column by anterograde lag screws via the ilioinguinal approach

Objective To evaluate the treatment of complex acetabular fractures involving the posterior column by anterograde lag screws via the ilioinguinal approach. Methods A retrospective study was conducted of the 8 patients with complex acetabular fracture involving the posterior column who had been treated at Department of Orthopaedics, The Second Affiliated Hospital to Inner Mongolia Medical University from January 2017 to June 2018. They were 5 males and 3 females, aged from 35 to 62 years (average, 43.5 years). According to the Letournel-Judet classification, 3 cases were T-shaped fractures, 4 anterior column plus posterior hemitransverse fractures and one both column fracture. The interval from injury to operation averaged 8 days (from 7 to 17 days). The anterior acetabulum was fixated by a reconstruction plate and the posterior column by antegrade lag screws, all through the ilioinguinal approach. The quality of fracture reduction, fracture union time, function of the affected hip and complications were recorded. Results By the Matta imaging criteria, the quality of fracture reduction was rated as excellent in 7 cases and as fine in one. Intraoperative major hemorrhage or injury to sciatic nerve occurred in none of the patients. This cohort obtained an average follow-up of 8 months (from 6 to 18 months). All fractures united well after an average of 10 weeks (from 8 to 12 weeks). The function of affected hip evaluated by the improved Merle d’Aubigne & Postel criteria at the last follow-up was excellent in 7 cases and fine in one. Follow-ups revealed no incidence of deep vein thrombosis or heterotopic ossification. Conclusions For patients with complex acetabular fracture involving the posterior column, internal fixation of the anterior acetabulum with a reconstruction plate through the ilioinguinal approach and fixation of the posterior column with antegrade lag screws also through the ilioinguinal approach can result in fine therapeutic effects, because complications like ectopic ossification and sciatic nerve injury related to the Kocher-Langenbeck approach can be prevented. This treatment is particularly suitable for the patients whose condition of the soft tissues at the posterior pelvis is poor. Key words: Acetabulum; Fractures, bone; Fracture fixation, internal; Bone nails; Surgical approach

Self-made one-fourth tubular hook plate for fixation of comminuted fractures of acetabular posterior wall

Objective To observe the clinical efficacy of self-made one-fourth tubular hook plate used in the fixation of comminuted fractures of acetabular posterior wall. Methods The clinical data of 21 patients with comminuted fracture of acetabular posterior wall were retrospectively analyzed who had been treated by fixation with our self-made one-fourth tubular hook plate from June 2015 to September 2017 at Deparment I of Orhthopaedics, The Second People's Hospital of Anhui Province. They were 12 males and 9 females, aged from 20 to 59 years (mean, 38.5 years). The time from injury to surgery ranged from 3 to 6 days (average, 4.5 days). All the fractures were fixated with our self-made one-fourth tubular hook plate via the Kocher-langenbeck approach. Depending on the fracture fragments, the hook plate was cut out obliquely through the 3rd or 4th hole and the sharp end of the plate was bent into a small hook to hold the fragments. Only the hook plate was used in 6 cases and an additional construction plate in the other 15 cases. The postoperative reduction, functional recovery of the affected hip and complications were recorded. Results The follow-up averaged 13 months (from 8 to 32 months). Intermuscular venous thrombosis occurred in one patient and sciatic nerve contusion was observed intraoperatively in one patient with sciatic nerve injury. According to the improved Matta criteria, the fracture reduction was rated as excellent in 16 cases, as good in 4 and as poor in one, giving a good to excellent rate of 95.2%. The fractures united after an average of 7.5 months (from 6 to 12 months). According to the improved Merle d'Aubigne and Postel scoring system, the hip function at the final follow-up was excellent in 14 cases, good in 3, fair in 2 and poor in 2, giving a good to excellent rate of 81.0%. Follow-ups revealed traumatic arthritis in 3 cases, femoral head necrosis in 2 cases and ectopic ossification in one. Conclusion Our self-made one-fourth tubular hook plate is simple, economical and effective because it can provide easy and rigid fixation of the comminuted fractures of acetabular posterior wall, leading to fine therapeutic effects. Key words: Acetabulum; Fractures, comminuted; Fracture fixation, internal; Bone plates

Cytokine-Induced and Stretch-Induced Sphingosine 1-Phosphate Production by Enthesis Cells Could Favor Abnormal Ossification in Spondyloarthritis.

Spondyloarthritis (SpA) is a common rheumatic disease characterized by enthesis inflammation (enthesitis) and ectopic ossification (enthesophytes). The current pathogenesis model suggests that inflammation and mechanical stress are both strongly involved in SpA pathophysiology. We have previously observed that the levels of sphingosine 1-phosphate (S1P), a bone anabolic molecule, were particularly high in SpA patients' serum compared to healthy donors. Therefore, we wondered how this deregulation was related to SpA molecular mechanisms. Mouse primary osteoblasts, chondrocytes, and tenocytes were used as cell culture models. The sphingosine kinase 1 (Sphk1) gene expression and S1P secretion were significantly enhanced by cyclic stretch in osteoblasts and chondrocytes. Further, TNF-α and IL-17, cytokines implicated in enthesitis, increased Sphk1 mRNA in chondrocytes in an additive manner when combined to stretch. The immunochemistry on mouse ankles showed that sphingosine kinase 1 (SK1) was localized in some chondrocytes; the addition of a pro-inflammatory cocktail augmented Sphk1 expression in cultured ankles. Subsequently, fingolimod was used to block S1P metabolism in cell cultures. It inhibited S1P receptors (S1PRs) signaling and SK1 and SK2 activity in both osteoblasts and chondrocytes. Fingolimod also reduced S1PR-induced activation by SpA patients' synovial fluid (SF), demonstrating that the stimulation of chondrocytes by SFs from SpA patients involves S1P. In addition, when the osteogenic culture medium was supplemented with fingolimod, alkaline phosphatase activity, matrix mineralization, and bone formation markers were significantly reduced in osteoblasts and hypertrophic chondrocytes. Osteogenic differentiation was accompanied by an increase in S1prs mRNA, especially S1P1/3 , but their contribution to S1P-impact on mineralization seemed limited. Our results suggest that S1P might be overproduced in SpA enthesis in response to cytokines and mechanical stress, most likely by chondrocytes. Moreover, S1P could locally favor the abnormal ossification of the enthesis; therefore, blocking the S1P metabolic pathway could be a potential therapeutic approach for the treatment of SpA. © 2019 American Society for Bone and Mineral Research.

S9B-05 SESSION 9B: FACE RESEARCH - PART II INHIBITION OF VASCULARIZED CARTILAGE REGENERATION BY LOADED CURCUMIN SCAFFOLD.

Introduction: Autologous chondrocytes are important cells for cartilage regeneration. But chondrocytes had limited sources. BMSCs are known for their strong proliferative ability and multi-directional differentiation. At present, ectopic ossification of cartilage constructed by BMSCs in subcutaneous environment is an internationally recognized problem. It is generally believed that ectopic ossification is mainly related to vascularization. The key to solve this problem might be vascularization inhibition.Curcumin has anti-angiogenesis effect.The aims of this study were to investigate the regeneration of chondrocytes in the presence of curcumin in-vivo and clarify how to regulate curcumin loading materials to inhibit angiogenesis without affecting the BMSCs proliferation. Methods: The curcumin loaded materials were set 2groups (serum-free medium and PBS) and treated at 3 different time-point stages(24h,48h,72h).For the PBS group, the absorbance rate was measured at the beginning of each stage to detect the curcumin concentration standard line.For the serum-free medium group, the loaded materials were given to vascular endothelial cells and BMSCs at the beginning of each stage.The tests for concentrations of curcumin solution, cell scratch test, cell cycle, and apoptosis tests were carried.The curcumin loaded materials were implanted subcutaneously into nude mice. After 3,6,12weeks tests HE,S/Ostaining, CD31 immunohistochemical, CD31 immunofluorescence were performed. Seed cells from rabbit ear cartilage were cultured 4weeks in vitro and 3,6weeks in vivo.Constructs were implanted subcutaneously into the nude mice. Results: The results of CCK8 showed that the levels of curcumin released after the first 24 hours were higher than those after 48 and 72 hours. However, the effects on BMSCs growth were not obvious. The cell scratch test showed that the apoptosis of vascular endothelial cells began at the curcumin concentration of 30um while BMSCs apoptosis began at 40um. Therefore, the curcumin concentration of 30um can be considered as appropriate since it can inhibit the growth of vascular endothelial cells without affecting the proliferation of BMSCs. The results of gross view images, CD31 immunohistochemistry and immunofluorescence showed that scaffolds loaded with curcumin could significantly inhibit the vascularization (compared to the control group). After 4 weeks of in-vitro and 3,6weeks of in-vivo, both constructs were able to form cartilaginous tissues. Conclusion: With the appropriate concentration, curcumin loaded scaffolds can inhibit the vascular endothelial cells without any obvious effects on bone marrow stem cells proliferation. Therefore, they could be successfully used in the construction and tissue engineering of cartilages in subcutaneous animal models. That gives curcumin loaded scaffolds a great potential application prospect.

Aging-associated microstructural deterioration of vertebra in zebrafish

Zebrafish, a small teleost fish, is currently emerging as an animal model of local and systemic aging. In this study, we assessed age-related degenerative changes in the vertebral bone of zebrafish (3–12 month-post-fertilisation [mpf]) using micro-CT scanning. The bone volume (BV) of the trabecular bone in the male and female fish peaked at 6 mpf and reduced with age. In contrast to BV, bone mineral density and tissue volume did not change after 6 mpf, implying that the total mineral volume in the trabecular area remains unchanged, retaining the strength of vertebra. In addition, we performed micro-structural analysis of the trabecular thickness, trabecular number, and star volume of the tissue space and trabeculae, and found that the size of the trabecular bone reduced with age. Furthermore, aged zebrafish (45 mpf) exhibited ectopic ossification inside or outside of their vertebrae.In summary, we analysed bone structural parameters in adult zebrafish vertebra, which are also used in humans, and demonstrated that aged zebrafish have deteriorated microarchitecture (trabecular thickness and number, tissue space star volume and trabecular star volume) with reduction of trabecular bones, similar to that observed during aging in humans. Zebrafish can be utilised as an animal model to understand the pathology of human bone aging, and the discovery of new therapeutic agents against age-related osteoporosis.

Metallic Press-fit Radial Head Replacement for Radial Head Fractures.

This study evaluated the clinical and radiographic results of patients who sustained nonreconstructible radial head fractures that subsequently were treated with a metallic press-fit radial head prosthesis (RHP). Nine patients with comminuted radial head fractures were treated with a metallic press-fit RHP; mean follow-up was 38.7 months. The radial head fracture was acute in 6 patients (group A) and chronic in 3 patients (group B). Functional evaluation was assessed using the Mayo Elbow Performance Score (MEPS) and Disabilities of the Arm, Shoulder and Hand (DASH) Questionnaire. Radiographs were assessed for loosening, radiocapitellar alignment, osteolysis of the radial neck, lucency, periarticular ossifications, and ulnohumeral degeneration. Average flexion and flexion contracture were 133° and 5°, respectively. Average supination and pronation angles were 70° and 73°, respectively. Mean MEPS was 90 (range, 70-100), and elbow performance was excellent in 4 patients, good in 4 patients, and fair in 1 patient. Mean DASH score was 21.9 (range, 0-61). Flexion contracture, forearm rotation arc, and MEPS score were better and the complication rate was lower in group A compared with group B. Centering of the stem was observed on both anteroposterior and lateral radiographs in 6 patients. Lucent lines around the prostheses, stress shielding under the neck of the radius, and ectopic ossification occurred in 5 patients. Three patients had osteoarthritis. Elbow stiffness and ulnar impaction syndrome occurred in 2 patients but only after placement of a secondary RHP. Satisfactory outcomes were obtained using a metallic press-fit RHP for nonreconstructible radial head fractures. [Orthopedics. 2019; 42(6):e545-e551.].

Application of customized variable-angle locking acetabular wing plates in treatment of acetabular fractures in the elderly via the lateral-rectus approach

Objective To evaluate clinical efficacy and surgical techniques of customized variable-angle locking acetabular wing plates in treatment of complex acetabular fractures in the elderly through the lateral-rectus approach. Methods Data of 11 elder patients of complex acetabular fractures (mean age 75 y, range: 60-93 y; 8 males, 3 females) admitted to our department from March 2016 to March 2017 were retrospectively analyzed. According to Judet-Letournel classification of acetabular fractures, there were 2 cases of anterior column and posterior hemitransverse fractures, 9 cases of both-column fractures. The customized variable-angle locking acetabular wing plates were designed by mimics software and then produced before surgery. During the operation, the customized variable-angle locking acetabular wing plate was applied to reduction and fixation via the anterior lataral-rectus approach. The effect of fracture reduction was assessed by Matta's criteria. The clinical effect was assessed by Harris Hip score and the modified Merle d' Aubigne-Postal score at the 6th month of postoperative follow-up. Results The average time of designing and producing customized variable-angle locking acetabular wing plates was 4 d (3-5 d), the average operation time was 95 min (45-150 min), and the average intraoperative bleeding was 600 ml (250-1 400 ml). All patients were followed up, with an average follow-up of 18 m (6-24 m). All fractures were healed, with an average healing time of 8 weeks (6-12 weeks). Reduction quality: excellent in 8 cases, good in 2 cases, poor in 1 case, with an overall excellent and good rate of 90.9%. The result of Harris Hip scoring: excellent in 7 cases, good in 3 cases, and acceptable in 1 case, with a total excellent and good rate of 90.9%; Modified Merle d' Aubigne-Postal soring: excellent in 6 cases, good in 3 cases, and acceptable in 2 cases, with an overall excellent and good rate of 81.8%. There were 2 cases of obturator nerve injury, 1 case of fat liquefaction of incision, 3 cases of traumatic hip arthritis. During the follow-up, no complications such as ectopic ossification, plate fracture and screw loosening were found. Conclusion The customized variable-angle locking acetabular wing plates in treatment of complex acetabular fractures in the elderly via the lateral-rectus approach can achieve satisfactory reduction and firm fixtation. Key words: Acetabulum; Fracture; Aged; Fracture fixation, internal

Overexpression of mechanical sensitive miR-337-3p alleviates ectopic ossification in rat tendinopathy model via targeting IRS1 and Nox4 of tendon-derived stem cells.

Tendinopathy, which is characterized by the ectopic ossification of tendon, is a common disease occurring in certain population, such as athletes that suffer from repetitive tendon strains. However, the molecular mechanism underlying the pathogenesis of tendinopathy caused by the overuse of tendon is still lacking. Here, we found that the mechanosensitive miRNA, miR-337-3p, had lower expression under uniaxial cyclical mechanical loading in tendon-derived stem cells (TDSCs) and negatively controlled chondro-osteogenic differentiation of TDSCs. Importantly, downregulation of miR-337-3p expression was also observed in both rat and human calcified tendons, and overexpressing miR-337-3p in patellar tendons of rat tendinopathy model displayed a robust therapeutic efficiency. Mechanistically, we found that the proinflammatory cytokine interleukin-1β was the upstream factor of miR-337-3p that bridges the mechanical loading with its downregulation. Furthermore, the target genes of miR-337-3p, NADPH oxidase 4, and insulin receptor substrate 1, activated chondro-osteogenic differentiation of TDSCs through JNK and ERK signaling, respectively. Thus, these findings not only provide novel insight into the molecular mechanisms underlying ectopic ossification in tendinopathy but also highlight the significance of miR-337-3p as a putative therapeutic target for clinic treatment of tendinopathy.

Molecular Pathophysiology of Ossification of the Posterior Longitudinal Ligament (OPLL).

Ossification of the posterior longitudinal ligament (OPLL) can be defined as an ectopic ossification in the tissues of spinal ligament showing a hyperostotic condition. OPLL is developed mostly in the cervical spine and clinical presentations of OPLL are majorly myelopathy and/or radiculopathy, with serious neurological pathology resulting in paralysis of extremities and disturbances of motility lowering the quality of life. OPLL is known to be an idiopathic and multifactorial disease, which genetic factors and non-genetic factors including diet, obesity, physical strain on the posterior longitudinal ligament, age, and diabetes mellitus, are involved into the pathogenesis. Up to now, surgical management by decompressing the spinal cord is regarded as standard treatment for OPLL, although there might be the risk of development of reprogression of ossification. The molecular pathogenesis and efficient therapeutic strategy, especially pharmacotherapy and/or preventive intervention, of OPLL has not been clearly elucidated and suggested. Therefore, in this review, we tried to give an overview to the present research results on OPLL, in order to shed light on the potential pharmacotherapy based on molecular pathophysiologic aspect of OPLL, especially on the genetic/genomic factors involved into the etiology of OPLL.

Anatomical Assessment of the Adult Skeleton of Zebrafish Reared Under Different Thyroid Hormone Profiles.

Thyroid hormone (TH) directs the growth and maintenance of tissues throughout the body during development and into adulthood, and plays a particularly important role in proper ossification and homeostasis of the skeleton. To better understand the roles of TH in the skeletogenesis of a vertebrate model, and to define areas of the skeleton that are particularly sensitive to developmental TH, we examined the effects of hypo- and hyperthyroidism on skeletal development in zebrafish. Performing a bone-by-bone anatomical assessment on the entire skeleton of adult fish, we found that TH is required for proper ossification, growth, morphogenesis, and fusion of numerous bones. We showed that the pectoral girdle, dermatocranium, Weberian apparatus, and dentary are particularly sensitive to TH, and that TH affects development of skeletal element regardless of bone type and developmental origin. Indeed, the hormone does not universally promote ossification: we found that developmental TH prevents ectopic ossification in multiple thin bones and within connective tissue of the jaw. In all, we found that TH regulates proper morphogenesis and ossification in the majority of zebrafish bones, and that the requirement for the hormone extends across bone types and developmental profiles. Anat Rec, 302:1754-1769, 2019. © 2019 American Association for Anatomy.

Propranolol and ascorbic acid in control of fibrodysplasia ossificans progressiva flare-ups due to accidental falls.

Fibrodysplasia ossificans progressiva (FOP) is a rare, intractable and devastating genetic connective tissue disorder characterized by progressive ectopic ossification in the soft tissues and skeleton. Three patients, one teenage girl (P1), one male adult (P2) and one male child (P3), were studied and treated with FOPCON (combined formulation of 14 mg of propranolol and 250 mg of ascorbic acid), given three times per day. P1 started treatment in March 2012, P2 in October 2012 and P3 in July 2015. The clinical follow-up of these three patients, before initiating treatment with FOPCON, showed that FOP flare-ups used to occur frequently and that under FOPCON therapy, none of these patients had flare-ups. The striking feature of this treatment with FOPCON, is that, all three cases suffered accidental falls with documented injures until complete healing and that where major flare-ups should occur, injures or sequels, there was none. The present clinical observation shows that ascorbic acid plus the nonspecific beta blocker propranolol can be effectively useful, when administered previously and continually, in the prophylaxis of FOP flare-ups, especially for accidental falls. In this regard, FOPCON could be a prophylactic aid in cases of surgery of patients with FOP, hoping that it may benefit patients from having the severe sequels, characteristic of heterotopic bone formation. All three patients reported, to date, they no longer had flare-ups nor heterotopic ossification and showed normal scar healing.

Magnolol prevents ossified tendinopathy by inhibiting PGE2-induced osteogenic differentiation of TDSCs

Magnolol is a compound that is extracted from magnolia, is used in Chinese medicine and is a type of lignan. Magnolol has various anti-inflammation, anti-proliferation and pro-autophagy effects. Ossified tendinopathy affects many athletes and people with repetitive tendon injuries. Ossified tendinopathy is a tremendous economic burden, and no effective and safe drugs are available to prevent the pathogenesis of ectopic ossification. In this study, we aimed to study how magnolol affects ossified tendinopathy by evaluating its effects on osteogenic differentiation of tendon-derived stem cells (TDSCs). Our data suggested that magnolol attenuated ectopic ossification in the Achilles tendon caused by Achilles tenotomy. Magnolol inhibited PGE2-induced ALP activity and prevented calcium deposits in TDSCs in vitro. Magnolol also exerted inhibitory effects on expression of osteogenic factors, such as Runx2, OCN, and BMP2 in vivo. Further investigation revealed the underlying mechanism by which magnolol prevents PGE2-induced ectopic ossification. Specifically, magnolol inhibits PGE2-induced PI3K/AKT/β-catenin pathway activation in TDSCs. Our findings demonstrated that magnolol inhibited ossified tendinopathy through preventing osteogenic differentiation of TDSCs via downregulation PGE2-induced PI3K/AKT/β-catenin pathways.