Absorbance or organization into ankylosis: a microarray analysis of haemarthrosis in a sheep model of temporomandibular joint trauma

Background Traumatic haemarthrosis was hypothesized to be the etiology of temporomandibular (TMJ) ankylosis. Here, taking haematoma absorbance as a control, we aimed to reveal the molecular mechanisms involved in haematoma organizing into ankylosis using transcriptome microarray profiles. Material/methods Disk removal was performed to building haematoma absorbance (HA) in one side of TMJ, while removal of disk and articular fibrous layers was performed to induced TMJ ankylosis through haematoma organization (HO) in the contralateral side in a sheep model. Haematoma tissues harvested at days 1, 4 and 7 postoperatively were examined by histology, and analyzed by Affymetrix OviGene-1_0-ST microarrays. The DAVID were recruited to perform the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis for the different expression genes (DEGs). The DEGs were also typed into protein–protein interaction (PPI) networks to get the interaction data. Six significant genes screened from PPI analysis, were confirmed by real-time PCR. Results We found 268, 223 and 17 DEGs at least twofold at days 1, 4 and 7, respectively. At day 1, genes promoting collagen ossification (POSTN, BGN, LUM, SPARC), cell proliferation (TGF-β), and osteogenic differentiation of mesenchymal stem cells (BMP-2) were up-regulated in the HO side. At day 4, several genes involved in angiogenesis (KDR, FIT1, TEK) shower higher expression in the HO side. While HA was characterized by a continuous immune and inflammatory reaction. Conclusions Our results provide a comprehensive understanding of the role of haematoma in the onset and progress of TMJ ankylosis. The study will contribute to explaining why few injured TMJs ankylose and most do not from the molecular level.

788. Enterobacter cloacae Infection Characteristics and Outcomes in Military Personnel who Sustained Trauma in Iraq and Afghanistan

Background Enterobacter cloacae is a Gram-negative rod with chromosomally-induced Amp-C β-lactamase with multidrug-resistant potential. Joint Trauma System guidelines for treating combat wounds include prophylaxis with cefazolin and ertapenem, potent inducers of Amp-C. We evaluated clinical characteristics, antibiotic utilization, and outcomes associated with battlefield-related E. cloacae infections. Methods All initial solitary (those with single isolates) and serial E. cloacae isolates (≥24 hours from initial isolate from any site) were collected from the Trauma Infectious Disease Outcomes Study (6/2009-12/2014). Inclusion required E. cloacae isolation from a clinical infection. Amp-C-inducing β-lactams were classified based on induction potential and lability to the Amp-C β-lactamase as Amp-C induction levels. Results Of 653 E. cloacae isolates, 253 met inclusion criteria – 64 patients had only initial isolates, 54 patients had serial isolates. Patients were largely male (99%), median age 23 years (IQR 21-27), with injury severity score of 34 (IQR 24-45). Initial isolates were wound (70%), respiratory (22%), blood (7%), urine (1%), and other (1%). Patients commonly had blast injuries (89%), required ICU admission (95%), and had a median hospital stay of 57 days (IQR 39-82). Patients with serial isolates showed a trend towards earlier clinical infection (5 vs 8 days, P = 0.07). They were also less likely to receive carbapenems prior to E. cloacae isolation compared to those with only initial isolates (4% vs 38%) and more likely to receive 1st generation cephalosporins (79% vs 58%, P = 0.01). The serial isolate group received more days of 1st generation cephalosporins (median 6 days vs 2.5 days, P = 0.01). Cumulative antimicrobial therapy trended towards significance and was greater with the serial isolates (median 100 days vs 74 days, P = 0.08). There was no difference in number of surgical interventions between those with and without serial isolates (P = 0.54). Overall, 6 patients died. Conclusion E. cloacae infections after battlefield trauma were frequently encountered and associated with exposure to 1st generation cephalosporins. Serial infections did not correlate to worse patient outcomes but displayed a trend towards an overall greater duration of antibiotic use. Disclosures William N. Bennett, V, MD, Abbvie (Shareholder)Amgen (Shareholder)Nabriva (Shareholder)

Acromioclavicular Joint Pseudo-dislocations with Lateral end Clavicle Fracture: A Rare Injury and Proposed Technique of Fixation

Introduction: Lateral end clavicle fractures are rare injuries in pediatric and adolescent population. Most of these injuries can be managed conservatively. However, in patients with acromioclavicular joint (ACJ) “pseudo-dislocations” associated with significant clinical deformity, some patients will benefit from operative intervention. Case Report:Our reported case is a young adolescent with a Type IV Dameron and Rockwood distal clavicle fracture and ACJ pseudo-dislocation, who underwent surgical fixation for this injury. We propose a novel technique of fixation with a suture anchor and endo button with temporary K wire stabilization. These are rare injuries and there are no standardized techniques for reconstruction and fixation. Stabilization with a suture anchor can provide a minimally invasive method of fixation for such injuries without the traditional plating and can lead to excellent final outcomes. Conclusion:ACJ pseudo-dislocations are rare injuries. There is limited evidence in guiding the management of such injuries. Our proposed technique of fixation with suture anchor, endo button and temporary stabilisation with K-wire can provide promising results. Keywords:Clavicle fracture, paediatrics, suture anchors, acromioclavicular joint, trauma.

Analysis of Clinical Effect of Arthroscopic Minimally Invasive Surgery on Patients with Knee Joint Bone Trauma

To study and analyze the clinical effect of arthroscopic minimally invasive surgery in the treatment of knee joint trauma. Methods: A total of 80 patients with knee joint bone trauma who were treated in our hospital from July 2018 to July 2019 were selected as the research objects, and randomly divided into observation group and control group. Patients in the control group were treated in the conventional way, patients in the observation group were treated with arthroscopic minimally invasive surgery, and the treatment effect, neer score and complications of the two groups were compared. Result: The treatment efficiency of the observation group was significantly higher than that of the control group (P < 0.05); the neer score of the observation group was significantly higher than that of the control group (P < 0.05); the number of complications in the observation group was significantly lower than that of the control group (P < 0.05), the difference was statistically significant. Conclusion: The application of arthroscopic minimally invasive surgery in the treatment of knee joint trauma patients has significant effect, improve the treatment effect, the number of patients with complications is lower, with higher safety, which is worth promoting in clinical treatment.

Hyaluronic Acid-Binding, Anionic, Nanoparticles Inhibit ECM Degradation and Restore Compressive Stiffness in Aggrecan-Depleted Articular Cartilage Explants

Joint trauma results in the production of inflammatory cytokines that stimulate the secretion of catabolic enzymes, which degrade articular cartilage. Molecular fragments of the degraded articular cartilage further stimulate inflammatory cytokine production, with this process eventually resulting in post-traumatic osteoarthritis (PTOA). The loss of matrix component aggrecan occurs early in the progression of PTOA and results in the loss of compressive stiffness in articular cartilage. Aggrecan is highly sulfated, associates with hyaluronic acid (HA), and supports the compressive stiffness in cartilage. Presented here, we conjugated the HA-binding peptide GAHWQFNALTVRGSG (GAH) to anionic nanoparticles (hNPs). Nanoparticles conjugated with roughly 19 GAH peptides, termed 19 GAH-hNP, bound to HA in solution and increased the dynamic viscosity by 94.1% compared to an HA solution treated with unconjugated hNPs. Moreover, treating aggrecan-depleted (AD) cartilage explants with 0.10 mg of 19 GAH-hNP restored the cartilage compressive stiffness to healthy levels six days after a single nanoparticle treatment. Treatment of AD cartilage with 0.10 mg of 19 GAH-hNP inhibited the degradation of articular cartilage. Treated AD cartilage had 409% more collagen type II and 598% more GAG content than untreated-AD explants. The 19 GAH-hNP therapeutic slowed ECM degradation in AD cartilage explants, restored the compressive stiffness of damaged cartilage, and showed promise as a localized treatment for PTOA.

Absorbance or Organization into Ankylosis: A Microarray Analysis of Haemarthrosis in a Sheep Model of Temporomandibular Joint Trauma

Background: Traumatic haemarthrosis was hypothesized to be the etiology of temporomandibular joint (TMJ) ankylosis. Here, taking haematoma absorbance as a control, we aimed to reveal the molecular mechanisms involved in haematoma organizing into ankylosis using transcriptome microarray profiles.Material/Methods: Disk removal was performed to building haematoma absorbance (HA) in one side of TMJ, while removal of disk and articular fibrous layers was performed to induced TMJ ankylosis through haematoma organization (HO) in the contralateral side in a sheep model. Haematoma tissues harvested at days 1, 4 and 7 postoperatively were examined by histology, and analyzed by Affymetrix OviGene-1_0-ST microarrays. The DAVID were recruited to perform the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis for the different expression genes (DEGs). The DEGs were also typed into protein–protein interaction (PPI) networks to get the interaction data. Six significant genes screened from PPI analysis, were confirmed by real-time PCR.Results: We found 268, 223 and 17 DEGs at least 2-fold at days 1, 4 and 7, respectively. At day 1, genes promoting collagen ossification (POSTN, BGN, LUM, SPARC), cell proliferation (TGF-β), and osteogenic differentiation of mesenchymal stem cells (BMP-2) were up-regulated in the HO side. At day 4, several genes involved in angiogenesis (KDR, FIT1, TEK) shower higher expression in the HO side. While HA was characterized by a continuous immune and inflammatory reaction.Conclusions: Our results provide a comprehensive understanding of the role of haematoma in the onset and progress of TMJ ankylosis. Further study of key genes may provide new ideas for future treatment of the disease.

An Exploration of the Method for Repairing Knee Joint Trauma-Induced Skin Defects with a Saphenous Flap

The present study aimed to explore the methods and clinical outcomes of repairing skin defects caused by knee joint trauma with a saphenous flap. Fifteen patients with skin and soft tissue defects after knee joint trauma received saphenous flap transposition, and the rotation axis point of the pedicle and transposition method were modified. The flap was transposed through a “semi-open tunnel” using a subcutaneous tissue pedicle and by parallel “bilobed” flap transposition through an “open tunnel.” The whole flap survived after the surgery in all patients. The pedicle was not bulging, had no “cat’s ear” deformity, and was flattened. The donor site was sutured directly, and the wound healed by primary intention without postoperative complications. When a saphenous flap is applied to repair the knee joint trauma skin defects with small and medium size, by modifying the pedicle transposition method, the flap rotation angle is more flexible, surgery is safer and more reliable, and flap appearance is more optimized.

Genetic Deletion of Interleukin-15 Is Not Associated with Major Structural Changes Following Experimental Post-Traumatic Knee Osteoarthritis in Rats

Post-traumatic osteoarthritis (PTOA) is a degenerative joint disease, leading to articular cartilage breakdown, osteophyte formation, and synovitis, caused by an initial joint trauma. Pro-inflammatory cytokines increase catabolic activity and may perpetuate inflammation following joint trauma. Interleukin-15 (IL-15), a pro-inflammatory cytokine, is increased in OA patients, although its roles in PTOA pathophysiology are not well characterized. Here, we utilized Il15 deficient rats to examine the role of IL-15 in PTOA pathogenesis in an injury-induced model. OA was surgically induced in Il15 deficient Holtzman Sprague-Dawley rats and control wild-type rats to compare PTOA progression. Semi-quantitative scoring of the articular cartilage, subchondral bone, osteophyte size, and synovium was performed by two blinded observers. There was no significant difference between Il15 deficient rats and wild-type rats following PTOA-induction across articular cartilage damage, subchondral bone damage, and osteophyte scoring. Similarly, synovitis scoring across six parameters found no significant difference between genetic variants. Overall, IL-15 does not appear to play a key role in the development of structural changes in this surgically-induced rat model of PTOA.