Microstructure Evolution, Hot Deformation Behavior and Processing Maps of an FeCrAl Alloy.

The deteriorated plasticity arising from the insoluble precipitates may lead to cracks during the rolling of FeCrAl alloys. The microstructure evolution and hot deformation behavior of an FeCrAl alloy were investigated in the temperature range of 750-1200 °C and strain rate range of 0.01-10 s-1. The flow stress of the FeCrAl alloy decreased with an increasing deformation temperature and decreased strain rate during hot working. The thermal deformation activation energy was determined to be 329.49 kJ/mol based on the compression test. Then, the optimal hot working range was given based on the established hot processing maps. The hot processing map revealed four small instability zones. The optimal working range for the material was identified as follows: at a true strain of 0.69, the deformation temperature should be 1050-1200 °C, and the strain rate should be 0.01-0.4 s-1. The observation of key samples of thermally simulated compression showed that discontinuous dynamic recrystallization started to occur with the temperate above 1000 °C, leading to bended grain boundaries. When the temperature was increased to 1150 °C, the dynamic recrystallization resulted in a microstructure composed of fine and equiaxed grains.

[Analysis of the causes of cage subsidence after oblique lateral lumbar interbody fusion].

OBJECTIVE: To observe the cage subsidence after oblique lateral interbody fusion (OLIF) for lumbar spondylosis, summarize the characteristics of the cage subsidence, analyze causes, and propose preventive measures. METHODS: The data of 144 patients of lumbar spine lesions admitted to our hospital from October 2015 to December 2018 were retrospectively analyzed. There were 43 males and 101 females, and the age ranged from 20 to 81 years old, with an average of (60.90±10.06) years old. Disease types:17 patients of lumbar intervertebral disc degenerative disease, 12 patients of giant lumbar disc herniation, 5 patients of discogenic low back pain, 33 patients of lumbar spinal stenosis, 26 patients of lumbar degenerative spondylolisthesis, 28 patients of lumbar spondylolisthesis with spondylolisthesis, 11 patients of adjacent vertebral disease after lumbar internal fixation, 7 patients of primary spondylitis in the inflammatory outcome stage, and 5 patients of lumbar degenerative scoliosis. Preoperative dual-energy X-ray bone mineral density examination showed 57 patients of osteopenia or osteoporosis, and 87 patients of normal bone density. The number of fusion segments:124 patients of single-segment, 11 patients of two-segment, 8 patients of three-segment, four-segment 1 patient. There were 40 patients treated by stand-alone OLIF, and 104 patients by OLIF combined with posterior pedicle screw. Observed the occurrence of fusion cage settlement after operation, conducted monofactor analysis on possible risk factors, and observed the influence of fusion cage settlement on clinical results. RESULTS: All operations were successfully completed, the median operation time was 99 min, and the median intraoperative blood loss was 106 ml. Intraoperative endplate injury occurred in 30 patients and vertebral fracture occurred in 5 patients. The mean follow-up was (14.57±7.14) months from 6 to 30 months. During the follow-up, except for the patients of primary lumbar interstitial inflammation and some patients of lumbar spondylolisthesis with spondylolisthesis, the others all had different degrees of cage subsidence. Cage subsidence classification:119 patients were normal subsidence, and 25 patients were abnormal subsidence (23 patients were gradeⅠ, and 2 patients were gradeⅡ). There was no loosening or rupture of the pedicle screw system. The height of the intervertebral space recovered from the preoperative average (9.48±1.84) mm to the postoperative average (12.65±2.03) mm, and the average (10.51±1.81) mm at the last follow-up. There were statistical differences between postoperative and preoperative, and between the last follow-up and postoperative. The interbody fusion rate was 94.4%. The low back pain VAS decreased from the preoperative average (6.55±2.2 9) to the last follow-up (1.40±0.82), and there was statistically significant different. The leg pain VAS decreased from the preoperative average (4.72±1.49) to the final follow-up (0.60±0.03), and the difference was statistically significant (t=9.13, P<0.000 1). The ODI index recovered from the preoperative average (38.50±6.98)% to the latest follow-up (11.30±3.27)%, and there was statistically significant different. The complication rate was 31.3%(45/144), and the reoperation rate was 9.72%(14/144). Among them, 8 patients were reoperated due to fusion cage subsidence or displacement, accounting for 57.14%(8/14) of reoperation. The fusion cage subsidence in this group had obvious characteristics. The monofactor analysis showed that the number of abnormal subsidence patients in the osteopenia or osteoporosis group, Stand-alone OLIF group, 2 or more segments fusion group, and endplate injury group was higher than that in the normal bone mass group, OLIF combined with pedicle screw fixation group, single segment fusion group, and no endplate injury group, and the comparison had statistical differences. CONCLUSION: Cage subsidence is a common phenomenon after OLIF surgery. Preoperative osteopenia or osteoporosis, Stand-alone OLIF, 2 or more segments of fusion and intraoperative endplate injury may be important factors for postoperative fusion cage subsidence. Although there is no significant correlation between the degree of cage subsidence and clinical symptoms, there is a risk of cage migration, and prevention needs to be strengthened to reduce serious complications caused by fusion of cage subsidence, including reoperation.

CircRREB1 mediates lipid metabolism related senescent phenotypes in chondrocytes through FASN post-translational modifications.

Osteoarthritis is a prevalent age-related disease characterized by dysregulation of extracellular matrix metabolism, lipid metabolism, and upregulation of senescence-associated secretory phenotypes. Herein, we clarify that CircRREB1 is highly expressed in secondary generation chondrocytes and its deficiency can alleviate FASN related senescent phenotypes and osteoarthritis progression. CircRREB1 impedes proteasome-mediated degradation of FASN by inhibiting acetylation-mediated ubiquitination. Meanwhile, CircRREB1 induces RanBP2-mediated SUMOylation of FASN and enhances its protein stability. CircRREB1-FASN axis inhibits FGF18 and FGFR3 mediated PI3K-AKT signal transduction, then increased p21 expression. Intra-articular injection of adenovirus-CircRreb1 reverses the protective effects in CircRreb1 deficiency mice. Further therapeutic interventions could have beneficial effects in identifying CircRREB1 as a potential prognostic and therapeutic target for age-related OA.

Bioactive mineralized small intestinal submucosa acellular matrix/PMMA bone cement for vertebral bone regeneration.

Polymethylmethacrylate (PMMA) bone cement extensively utilized for the treatment of osteoporotic vertebral compression fractures due to its exceptional handleability and mechanical properties. Nevertheless, the clinical application of PMMA bone cement is restricted by its poor bioactivity and excessively high modulus of elasticity. Herein, mineralized small intestinal submucosa (mSIS) was incorporated into PMMA to prepare a partially degradable bone cement (mSIS-PMMA) that provided suitable compressive strength and reduced elastic modulus compared to pure PMMA. The ability of mSIS-PMMA bone cement to promote the attachment, proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells was shown through cellular experiments carried out in vitro, and an animal osteoporosis model validated its potential to improve osseointegration. Considering these benefits, mSIS-PMMA bone cement shows promising potential as an injectable biomaterial for orthopedic procedures that require bone augmentation.

[Comparison of clinical effect and muscle injury imaging between oblique lateral lumbar interbody fusion and transforaminal lumbar interbody fusion in the treatment of single-segment degenerative lumbar spinal stenosis].

OBJECTIVE: To compare the efficacy and muscle injury imaging between oblique lateral lumbar interbody fusion (OLIF) and transforaminal lumbar interbody fusion (TLIF) in the treatment of single-segment degenerative lumbar spinal stenosis. METHODS: The clinical data of 60 patients with single-segment degenerative lumbar spinal stenosis who underwent surgical treatment from January 2018 to October 2019 was retrospectively analyzed. The patients were divided into OLIF groups and TLIF group according to different surgical methods. The 30 patients in the OLIF group were treated with OLIF plus posterior intermuscular screw rod internal fixation. There were 13 males and 17 females, aged from 52 to 74 years old with an average of (62.6±8.3) years old. And 30 patients in the TLIF group were treated with TLIF via the left approach. There were 14 males and 16 females, aged from 50 to 81 years old with an average of (61.7±10.4) years old. General data including operative time, intraoperative blood loss, postoperative drainage volume, and complications were recorded for both groups. Radiologic data including disc height (DH), the left psoas major muscle, multifidus muscle, longissimus muscle area, T2-weighted image hyperintensity changes and interbody fusion or nonfusion were observed. Laboratory parameters including creatine kinase (CK) values on postoperative 1st and 5th days were analyzed. Visual analogue scale(VAS) and Oswestry disability index(ODI) were used to assess clinical efficacy. RESULTS: There was no significant difference in the operative time between two groups(P>0.05). The OLIF group had significantly less intraoperative blood loss and postoperative drainage volume compared to the TLIF group(P<0.01). The OLIF group also had DH better recovery compared to the TLIF group (P<0.05). There were no significant differences in left psoas major muscle area and the hyperintensity degree before and after the operation in the OLIF group (P>0.05). Postoperativly, the area of the left multifidus muscle and longissimus muscle, as well as the mean of the left multifidus muscle and longissimus muscle in the OLIF group, were lower than those in the TLIF group (P<0.05) .On the 1st day and the 5th day after operation, CK level in the OLIF group was lower than that in the TLIF group(P<0.05). On the 3rd day after operation, the VAS of low back pain and leg pain in the OLIF group were lower than those in the TLIF group (P<0.05). There were no significant differences in the ODI of postoperative 12 months, low back and leg pain VAS at 3, 6, 12 months between the two groups(P>0.05). In the OLIF group, 1 case of left lower extremity skin temperature increased after the operation, and the sympathetic chain was considered to be injured during the operation, and 2 cases of left thigh anterior numbness occurred, which was considered to be related to psoas major muscle stretch, resulting in a complication rate of 10% (3/30). In the TLIF group, one patient had limited ankle dorsiflexion, which was related to nerve root traction, two patients had cerebrospinal fluid leakage, and the dural sac was torn during the operation, and one patient had incision fat liquefaction, which was related to paraspinal muscle dissection injury, resulting in a complication rate of 13% (4/30). All patients achieved interbody fusion without cage collapse during the 6- month follow-up. CONCLUSION: Both OLIF and TLIF are effective in the treatment of single-segment degenerative lumbar spinal stenosis. However, OLIF surgery has obviously advantages, including less intraoperative blood loss, less postoperative pain, and good recovery of intervertebral space height. From the changes in laboratory indexes of CK and the comparison of the left psoas major muscle, multifidus muscle, longissimus muscle area, and high signal intensity of T2 image on imaging, it can be seen that the degree of muscle damage and interference of OLIF surgery is lower than that of TLIF.

Positive Feedback Regulation of Circular RNA Hsa_circ_0000566 and HIF-1α promotes Osteosarcoma Progression and Glycolysis Metabolism.

Hypoxia is an indispensable factor for cancer progression and is closely associated with the Warburg effect. Circular RNAs (CircRNA) have garnered considerable attention in molecular malignancy therapy as they are potentially important modulators. However, the roles of circRNAs and hypoxia in osteosarcoma (OS) progression have not yet been elucidated. This study reveals the hypoxia-sensitive circRNA, Hsa_circ_0000566, that plays a crucial role in OS progression and energy metabolism under hypoxic stress. Hsa_circ_0000566 is regulated by hypoxia-inducible factor-1α (HIF-1α) and directly binds to it as well as to the Von Hippel-Lindau (VHL) E3 ubiquitin ligase protein. Consequentially, binding between VHL and HIF-1α is impeded. Furthermore, Hsa_circ_0000566 contributes to OS progression by binding to HIF-1α (while competing with VHL) and by confers protection against HIF-1α against VHL-mediated ubiquitin degradation. These findings demonstrate the existence of a positive feedback loop formed by HIF-1α and Hsa_circ_0000566 and the key role they play in OS glycolysis. Taken together, these data indicate the significance of Hsa_circ_0000566 in the Warburg effect and suggest that Hsa_circ_0000566 could be a potential therapeutic target to combat OS progression.

A novel circular RNA circRBMS3 regulates proliferation and metastasis of osteosarcoma by targeting miR-424-eIF4B/YRDC axis.

Circular RNAs (circRNAs) have been demonstrated to have critical regulatory roles in tumorigenesis. However, the contribution of circRNAs to OS (osteosarcoma) remains largely unknown. circRNA deep sequencing was performed to the expression of circRNAs between OS and chondroma tissues. The regulatory and functional role of circRBMS3 (a circRNA derived from exons 7 to 10 of the RBMS3 gene, hsa_circ_0064644) upregulation was examined in OS and was validated in vitro and in vivo, upstream regulator and downstream target of circRBMS3 were both explored. RNA pull down, a luciferase reporter assay, biotin-coupled microRNA capture and fluorescence in situ hybridization were used to evaluate the interaction between circRBMS3 and micro (mi)-R-424-5p. For in vivo tumorigenesis experiments, Subcutaneous and Orthotopic xenograft OS mouse models were built. Expression of circRBMS3 was higher in OS tissues due to the regulation of adenosine deaminase 1-acting on RNA (ADAR1), an abundant RNA editing enzyme. Our in vitro data indicated that ShcircRBMS3 inhibits the proliferation and migration of osteosarcoma cells. Mechanistically, we showed that circRBMS3 could regulate eIF4B and YRDC, through 'sponging' miR-424-5p. Furthermore, knockdown of circRBMS3 inhibited malignant phenotypes and bone destruction of OS in vivo. Our results reveal an important role for a novel circRBMS3 in the growth and metastasis of malignant tumor cells and offer a fresh perspective on circRNAs in OS progression.

CircZSWIM6 mediates dysregulation of ECM and energy homeostasis in ageing chondrocytes through RPS14 post-translational modification.

BACKGROUND: Circular RNAs (CircRNAs) are important and have different roles in disease progression. Herein, we aim to elucidate the roles of a novel CircRNA (CircZSWIM6) which is upregulated in ageing chondrocytes. METHODS: We verified the roles of CircZSWIM6 in senescent and osteoarthritis (OA) development in vitro through CircZSWIM6 knockdown and overexpression. RNA pulldown assay and RNA binding protein immunoprecipitation were performed to identify the interaction between CircZSWIM6 and Ribosomal protein S14 (RPS14). The roles of CircZSWIM6 in ageing-related OA were also confirmed in non-traumatic and traumatic model respectively. RESULTS: CircZSWIM6 regulates extracellular matrix (ECM) and energy metabolism in ageing chondrocyte. Mechanistically, CircZSWIM6 competitively bound to the E3 ligase STUB1 binding site on RPS14 (K125) to inhibit proteasomal degradation of RPS14 to maintain RPS14 function. CircZSWIM6-RPS14 axis is highly associated with AMPK signaling transduction, which keeps energy metabolism in chondrocyte. Furthermore, CircZSWIM6 AAV infection leads to senescent and OA phenotypes in a non-traumatic model and accelerates OA progression in a traumatic model. CONCLUSION: Our results revealed a significant role of CircZSWIM6 in age-related OA by regulating ECM metabolism and AMPK-associated energy metabolism. We highlight the CircZSWIM6-RPS14-PCK1-AMPK axis is a potential biomarker for OA.

[Application of oblique lateral interbody fusion in the treatment of lumbar intervertebral disc degeneration in patients with Modic change and endplate sclerosis].

OBJECTIVE: To explore the feasibility and clinical effect of Stand-alone oblique lateral interbody fusion (OLIF) in the treatment of lumbar intervertebral disc degeneration with Modic changes and endplate sclerosis. METHODS: A retrospective analysis was performed on 16 cases with lumbar intervertebral disc degeneration with Modic changes and endplate sclerosis admitted to three medical centers from January 2015 to December 2018. There were 6 males and 10 females, the age ranged from 45 to 67 years old with an average of (55.48±8.07) years old, the medical history ranged from 36 to 240 months with an average of (82.40±47.68) months. The lesion sites included L2,3 in 2 cases, L3,4 in 5 cases, and L4,5 in 9 cases. All patients presented with chronic low back pain with lower limb neurological symptoms in 3 cases. All patients were treated by Stand-alone oblique lateral lumbar interbody fusion. Clinical and radiological findings and complications were observed. RESULTS: There was no vascular injury, endplate injury and vertebral fracture during the operation. The mean incision length, operation time, and intraoperative blood loss were(4.06±0.42) cm, (45.12±5.43) min, (33.40±7.29) ml, respectively. The mean visual analogue scale (VAS) of the incision pain was (1.14±0.47) at 72 hours after operation. There was no incision skin necrosis, poor incision healing or infection in patients. Sympathetic chain injury occurred in 1 case, anterolateral pain and numbness of the left thigh in 2 cases, and weakness of the left iliopsoas muscle in 1 case, all of which were transient injuries with a complication rate of 25%(4/16). All 16 patients were followed up from 12 to 36 months with an average of (20.80±5.46) months. The intervertebral space height was significantly recovered after operation, with slight lost during the follow-up. Coronal and sagittal balance of the lumbar spine showed good improvement at the final follow-up. There was no obvious subsidence or displacement of the cage, and the interbody fusion was obtained. At the final follow-up, Japanese Orthopaedic Association(JOA) score and Oswestry disability index(ODI) were significantly improved. CONCLUSION: As long as the selection of case is strict enough and the preoperative examination is sufficients, the use of Stand-alone OLIF in the treatment of lumbar intervertebral disc degeneration with Modic changes and endplate sclerosis has a good results, with obvious clinical advantages and is a better surgical choice.

In Situ Biomimetic Mineralization of Bone-Like Hydroxyapatite in Hydrogel for the Acceleration of Bone Regeneration.

A critical-sized bone defect, which cannot be repaired through self-healing, is a major challenge in clinical therapeutics. The combination of biomimetic hydrogels and nano-hydroxyapatite (nano-HAP) is a promising way to solve this problem by constructing an osteogenic microenvironment. However, it is challenging to generate nano-HAP with a similar morphology and structure to that of natural bone, which limits the improvement of bone regeneration hydrogels. Inspired by our previous works on organic-inorganic cocross-linking, here, we built a strong organic-inorganic interaction by cross-linking periosteum-decellularized extracellular matrix and calcium phosphate oligomers, which ensured the in situ mineralization of bone-like nano-HAP in hydrogels. The resulting biomimetic osteogenic hydrogel (BOH) promotes bone mineralization, construction of immune microenvironment, and angiogenesis improvement in vitro. The BOH exhibited acceleration of osteogenesis in vivo, achieving large-sized bone defect regeneration and remodeling within 8 weeks, which is superior to many previously reported hydrogels. This study demonstrates the important role of bone-like nano-HAP in osteogenesis, which deepens the understanding of the design of biomaterials for hard tissue repair. The in situ mineralization of bone-like nano-HAP emphasizes the advantages of inorganic ionic oligomers in the construction of organic-inorganic interaction, which provides an alternative method for the preparation of advanced biomimetic materials.

A plant-derived natural photosynthetic system for improving cell anabolism.

Insufficient intracellular anabolism is a crucial factor involved in many pathological processes in the body1,2. The anabolism of intracellular substances requires the consumption of sufficient intracellular energy and the production of reducing equivalents. ATP acts as an 'energy currency' for biological processes in cells3,4, and the reduced form of NADPH is a key electron donor that provides reducing power for anabolism5. Under pathological conditions, it is difficult to correct impaired anabolism and to increase insufficient levels of ATP and NADPH to optimum concentrations1,4,6-8. Here we develop an independent and controllable nanosized plant-derived photosynthetic system based on nanothylakoid units (NTUs). To enable cross-species applications, we use a specific mature cell membrane (the chondrocyte membrane (CM)) for camouflage encapsulation. As proof of concept, we demonstrate that these CM-NTUs enter chondrocytes through membrane fusion, avoid lysosome degradation and achieve rapid penetration. Moreover, the CM-NTUs increase intracellular ATP and NADPH levels in situ following exposure to light and improve anabolism in degenerated chondrocytes. They can also systemically correct energy imbalance and restore cellular metabolism to improve cartilage homeostasis and protect against pathological progression of osteoarthritis. Our therapeutic strategy for degenerative diseases is based on a natural photosynthetic system that can controllably enhance cell anabolism by independently providing key energy and metabolic carriers. This study also provides an enhanced understanding of the preparation and application of bioorganisms and composite biomaterials for the treatment of disease.

Delayed postoperative spinal epidural hematoma after anterior cervical discectomy and fusion: A case report.

Background: Postoperative spinal epidural hematoma (POSEH) causes rapid neurological deficits within 24 h following the operation and can be fatal. However, some POSEH symptoms manifest three days after the operation, also known as delayed POSEH (DPOSEH). Little attention has been provided upon DPOSEH owing to its rare incidence, resulting in serious consequences upon occurrence. To date, no cases of delayed POSEH after anterior cervical surgery have been reported. Case presentation: We describe a case of DPOSEH that presented with delayed neurological deficits on the fifth day after anterior cervical discectomy and fusion (ACDF) surgery. Methylprednisolone was administered but showed no efficacy. MR revealed low T1 and strip long T2 signals located behind discs. After emergency surgical decompression, the patient's muscle strength returned to the preoperative state. However, his muscle strength decreased again on the seventh postoperative day, and the patient's family refused further surgery. Nine months after ACDF, the patient died of septic shock and respiratory failure. Conclusions: DPOSEH can occur after three days or more following anterior cervical surgery; hence, monitoring of neurological function is suggested to be extended. Complete evaluation of risk factors, timely recognition, and differentiation of neurological symptoms are required for spine surgery. In the case of DPOSEH, methylprednisolone can be administered reasonably during the transition period. However, if there is no resolution of symptoms, emergency surgery should be performed as soon as possible.

[Case-control study on endplate injury of lumbar spine with two different intervertebral fusion methods].

OBJECTIVE: To summarize and compare the endplate injury occurrence characteristics and clinical results of transforaminal intervertebral fusion combined with pedicle screw fixation through intermuscular approach and oblique lateral intervertebral fusion combined with pedicle screw fixation in the treatment of lumbar disease. METHODS: A retrospective analysis of 213 cases of lumbar disease admitted from January 2016 to June 2019, including 73 males and 140 females. The age ranged from 24 to 81 years old, with an average of(54.9±10.5) years old. The courses of disease ranged from 6 to 180 months, with an average of (40.30±28.71) months. There were 35 cases of degenerative lumbar intervertebral disc disease, 22 cases of giant lumbar disc herniation, 15 cases of discogenic low back pain, 9 cases of primary lumbar intervertebral inflammation at the turn of inflammation, 52 cases of lumbar spinal stenosis, 47 cases of lumbar degenerative spondylolisthesis, 33 cases of lumbar spondylolysis with or without spondylolisthesis. There were 191 cases of single-segment lesions, including 5 cases on L2, 3, 24 cases on L3, 4, 162 cases on L4, 5. And there were 22 cases of two-segment lesions, including 3 cases on L2, 3 and L3, 4, and 19 cases on L3, 4 and L4, 5. One hundred and ten cases were taken by bilateral pedicle screw fixation and interbody fusion under the posterior muscle space approach (abbreviated as posterior fusion group), and 103 cases were taken by oblique lateral interbody fusion combined with bilateral pedicle screw fixation under the posterior muscle space approach (oblique lateral fusion group). Observed the characteristics of endplate injury in the two groups, and compared the clinical and imaging results and complications of the two groups. RESULTS: There were 8 cases of endplate injury occurred in 9 segments in the posterior fusion group. According to the number of cases, the incidence rate was 7.27%(8/110), 1 case was male, 7 cases were female, with an average age of (63.22±3.51) years old. Among the 8 cases, there were 7 cases of bone loss or osteoporosis before the operation, 5 cases using banana fusion cages, 3 cases using anatomical fusion cages. Three cases occurred in the upper endplate of the vertebral body and 6 cases in the inferior endplate of the vertebral body. In the oblique lateral fusion group, there were 21 cases of endplate injury in 24 segments, and the incidence rate was 20.39%(21/103). There were 4 males and 17 females, with an average age of (62.50±5.02) years old. Among the 21 cases, 16 cases were bone loss or osteoporosis before operation. There were 5 cases used large fusion cages, 4 cases had abnormal endplate anatomy, and 3 cases had iliac crest hypertrophy. It occurred in 20 segments of the upper endplate of the vertebral body, and 4 segments of the lower endplate of the vertebral body. Two of the 21 cases of endplate injury combined with vertebral body fractures. The incidence of endplate injury of the posterior fusion group was significantly lower than that of the oblique lateral fusion group. No incision infection occurred in the two groups, the follow-up time was ranged from 12 to 48 months, and the median follow-up period was 12 months. In the follow-up, 22 cases occurred fusion cage subsidence in the posterior fusion group, 43 cases in the oblique lateral fusion group, and 1 case in each group occurred fusion cage displacement. There was no loosening, displacement or breakage of the internal fixation. The incidence of complications in the oblique lateral fusion group 33.98%(35/103) was significantly higher than that in the posterior fusion group 23.64%(26/110), P=0.039. The height of the intervertebral space in both groups recovered well after the operation, but it was lost to varying degrees during follow-up. The fusion rate of the posterior fusion group was 94.5%(104/110), and 96.1%(99/103) in the oblique lateral fusion group(P=0.083). At the latest follow-up, the clinical symptoms of the two groups of patients were significantly improved. CONCLUSION: Two methods in treating single or two-segment lumbar spine lesions obtained good clinical effects. The characteristics of endplate injury in the two fusion methods are not completely the same. Although the endplate injury did not affect the final clinical results of the two fixed fusion methods, it still needs to be paid attention to and emphasize the prevention and effective treatment of endplate injury, especially for oblique lateral intervertebral fusion.

Injectable Dual-Dynamic-Bond Cross-Linked Hydrogel for Highly Efficient Infected Diabetic Wound Healing.

Diabetic wound is a significant challenge for clinical treatment with high morbidity and mortality. Plenty of hydrogels with good biocompatibility have been widely used in diabetic wound healing. However, most of them cannot be directly absorbed and utilized by the wounds, which prolongs the regeneration time. Here a new type of healing hydrogel is developed that is based on histidine, a natural dietary essential amino acid that is significant for tissue formation. The amino acid is cross-linked with zinc ions (Zn2+ ) and sodium alginate (SA) via dynamic coordinate and hydrogen bonds, respectively, forming a histidine-SA-Zn2+ (HSZH) hydrogel with good injectable, adhesive, biocompatible, and antibacterial properties. Application of this dual-dynamic-bond cross-linked HSZH hydrogel accelerates the migration and angiogenesis of skin-related cells in vitro. Furthermore, it significantly promotes the healing of infected diabetic wounds in vivo and uniquely allows a full repair of wounds within ≈13 days, while ≈27 days are required for the healing process of the control group. This work provides a new strategy for designing wound dressing materials, that weakly cross-linked material based on tissue-friendly micromolecules can heal the wounds more efficiently than highly cross-linked materials based on long-chain polymers.

A myogenic niche with a proper mechanical stress environment improves abdominal wall muscle repair by modulating immunity and preventing fibrosis.

Volumetric muscle loss (VML) healing is often complicated by fibrosis, which impairs muscle regeneration and function. Adjusting mechanical stress in the repair environment may modulate immunity and reduce fibrosis. In this study, we aimed to create a biomaterial with suitable tension conditions and bidirectional tissue-inducing abilities to prevent fibrosis thus promote muscle regeneration and induce aponeurosis-like structures to restore muscle force transmission. A protocol was developed to manufacture decellularized muscle aponeurosis (D-MA) patches with an intact extracellular matrix (ECM) and low cytotoxicity. D-MA optimized the mechanical stress distribution in muscle injury sites and decreased the number of proinflammatory macrophages and myofibroblasts, thereby attenuating muscle fibrosis. Muscle and aponeurosis ECM environments had different microstructures and mechanical properties, which specifically enhanced stem cell differentiation into muscle-like cells on muscle ECM and tenocyte-like cells on aponeurosis ECM in vitro. Four weeks after orthotopic implantation, the biphasic muscle-aponeurosis-like tissue was successfully regenerated by the D-MA scaffold. The regenerated muscle fibers in D-MA were more abundant than those in the fibrotic decellularized muscle (D-M) scaffold. D-MA can be used to repair abdominal defects, which significantly improves the repair outcomes. Our results suggest D-MA as a promising material for VML repair.

Oblique lateral interbody fusion combined with lateral plate fixation for the treatment of degenerative diseases of the lumbar spine: A retrospective study.

ABSTRACT: Oblique lateral interbody fusion (OLIF) is a minimally invasive decompression technique used in the treatment of lumbar degenerative diseases (LDDs). It is usually combined with posterior pedicle screw fixation to decrease perioperative complications. Few studies have reported the efficacy of OLIF combined with lateral plate instrumentation (OLIF-LP) for the treatment of LDDs.The purpose of this retrospective study was to evaluate the clinical efficacy of OLIF combined with lateral plate instrumentation for the treatment of LDDs.From May 2020 to September 2020, the clinical data of 52 patients who underwent OLIF-LP were analyzed. The operation time, blood loss, and complications were recorded. The radiological parameters, visual analog scale score, and Oswestry Disability Index were evaluated.The average operation time, blood loss, and length of hospital stay were 75.41 ±â€Š11.53 minutes, 39.57 ±â€Š9.22 mL, and 7.22 ±â€Š1.85 days, respectively. The visual analog scale score and Oswestry Disability Index both improved significantly after surgery (7.23 ±â€Š1.26 vs 2.15 ±â€Š0.87; 60.27 ±â€Š7.91 vs 21.80 ±â€Š6.32, P < .01). The postoperative disk height was 13.02 ±â€Š8.83 mm, which was much greater than the preoperative value. The postoperative foraminal height improved significantly (16.18 ±â€Š3.49 vs 21.54 ±â€Š2.12 mm, P < .01), and the cross-sectional area improved from 88.95 ±â€Š14.79 to 126.53 ±â€Š8.83 mm2 (P < .001). The radiological fusion rate was 88% at the last follow-up. No major complications, such as ureteral injury, vascular injury, or vertebral body fracture, occurred.Use of the OLIF-LP technique can help avoid lumbar posterior surgery and minimize the operative time and blood loss. OLIF-LP can achieve 1-stage intervertebral fusion and instrumentation through a single small incision.

Stem cell-homing hydrogel-based miR-29b-5p delivery promotes cartilage regeneration by suppressing senescence in an osteoarthritis rat model.

Osteoarthritis (OA) is a common joint disease characterized by progressive loss of cartilage and reduction in lubricating synovial fluid, which lacks effective treatments currently. Here, we propose a hydrogel-based miRNA delivery strategy to rejuvenate impaired cartilage by creating a regenerative microenvironment to mitigate chondrocyte senescence that mainly contributes to cartilage breakdown during OA development. An aging-related miRNA, miR-29b-5p, was first found to be markedly down-regulated in OA cartilage, and their up-regulation suppressed the expression of matrix metalloproteinases and senescence-associated genes (P16INK4a/P21) via ten-eleven-translocation enzyme 1 (TET1). An injectable bioactive self-assembling peptide nanofiber hydrogel was applied to deliver agomir-29b-5p, which was functionalized by conjugating a stem cell-homing peptide SKPPGTSS for endogenous synovial stem cell recruitment simultaneously. Sustained miR-29b-5p delivery and recruitment of synovial stem cells and their subsequent differentiation into chondrocytes led to successful cartilage repair and chondrocyte rejuvenation. This strategy enables miRNA-based therapeutic modality to become a viable alternative for surgery in OA treatment.

Mechanical force promotes dimethylarginine dimethylaminohydrolase 1-mediated hydrolysis of the metabolite asymmetric dimethylarginine to enhance bone formation.

Mechanical force is critical for the development and remodeling of bone. Here we report that mechanical force regulates the production of the metabolite asymmetric dimethylarginine (ADMA) via regulating the hydrolytic enzyme dimethylarginine dimethylaminohydrolase 1 (Ddah1) expression in osteoblasts. The presence of -394 4 N del/ins polymorphism of Ddah1 and higher serum ADMA concentration are negatively associated with bone mineral density. Global or osteoblast-specific deletion of Ddah1 leads to increased ADMA level but reduced bone formation. Further molecular study unveils that mechanical stimulation enhances TAZ/SMAD4-induced Ddah1 transcription. Deletion of Ddah1 in osteoblast-lineage cells fails to respond to mechanical stimulus-associated bone formation. Taken together, the study reveals mechanical force is capable of down-regulating ADMA to enhance bone formation.

Comparison of Oblique Lateral Interbody Fusion (OLIF) and Minimally Invasive Transforaminal Lumbar Interbody Fusion (MI-TLIF) for Treatment of Lumbar Degeneration Disease: A Prospective Cohort Study.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: To assess the differences in the clinical and radiological outcomes between oblique lateral interbody fusion (OLIF) and minimally invasive transforaminal lumbar interbody fusion (MI-TLIF). SUMMARY OF BACKGROUND DATA: Nowadays, there is still a controversy regarding whether OLIF is superior to MI-TLIF in the management of degenerative lumbar disease. METHODS: Between August 3, 2019 and February 3, 2020, 137 patients were assigned to OLIF or MI-TLIF at their request and the surgeon's discretion: 71 in the OLIF group and 66 in the MI-TLIF group. The perioperative data, patient-reported outcomes, radiographic outcomes, and complications were compared between the two groups. RESULTS: The OLIF group showed shorter operation time (110.5 vs.183.8 minutes, P < 0.001), lesser estimated blood loss (123.1 vs. 232.0 mL, P < 0.001), shorter length of hospital stay (5.5 vs. 6.7 days, P < 0.001), and lower serum creatine kinase (CK) (1 day postoperatively) (376.0 vs. 541.8 IU/L, P < 0.01) than that of MI-TLIF group. Both groups showed no significant differences in the visual analog scale (VAS) scores of lower back and leg pain and the Oswestry Disability Index (ODI) scores preoperatively and at 1, 3, and 12 months postoperatively, respectively (P > 0.05). Compared with the MI-TLIF group, the OLIF group showed better restoration of disc height (DH) (4.7/4.6/4.7 vs. 3.7/3.7/3.7 mm, P < 0.01) and lumbar lordosis angle (LLA) (10.5°/10.8°/11.1° vs. 5.8°/5.7°/5.3°, P < 0.001), but not the value of segmental lordosis angle (SLA) (P > 0.05) at 1 day, 1 month, and 1 year postoperatively, respectively. The complication rate of OLIF was higher than that of MI-TLIF (29.4% vs. 9.7%, P < 0.01). CONCLUSION: Compared with MI-TLIF, OLIF showed similar results in terms of patient-reported outcomes, restoration of SLA and fusion rate, and superior results with respect to restoration of DH and LLA, operation time, estimated blood loss, length of hospital stay, and serum CK levels (1 day postoperatively). Even though the complication rate of OLIF is higher than that of MI-TLIF, it does not bring persistent and substantial damage to the patients.Level of Evidence: 3.

Anteroinferior Psoas Technique for Oblique Lateral Lumbar Interbody Fusion.

Oblique lateral lumbar interbody fusion (OLIF) has been extensively used, with satisfactory outcomes for the treatment of degenerative lumbar disease. This article aims to demonstrate a modified lateral approach, also known as the anteroinferior psoas (AIP) technique for OLIF, which is expected to enhance security by operating under direct vision. The core procedures of our technique are as follows. First, a minimal skin incision is recommended 2 cm backward compared with the normal incision of OLIF, facilitating the oblique placement of the working channel and the orthogonal maneuver for the cage placement. Second, two special custom-made retractors, as an alternative to the index finger, are used to pull the psoas muscle to the dorsal side and pull the abdominal organs together with extraperitoneal fate to the ventral side under direct visualization, making the exposure of the working channel convenient and safe and avoiding radiation exposure. Third, the anterior border of the psoas is bluntly dissected and retracted backwards, obviously enlarging the retroperitoneal anatomic corridor and then expanding clinical indications of OLIF. The benefits of this technique include that it has a short learning curve, satisfactory clinical outcomes, and low risk of perioperative complications.