Chemical modification of extracellular matrix by cold atmospheric plasma‐generated reactive species affects chondrogenesis and bone formation

The goal of this study was to investigate whether cold plasma generated by dielectric barrier discharge (DBD) modifies extracellular matrices (ECM) to influence chondrogenesis and endochondral ossification. Replacement of cartilage by bone during endochondral ossification is essential in fetal skeletal development, bone growth and fracture healing. Regulation of this process by the ECM occurs through matrix remodelling, involving a variety of cell attachment molecules and growth factors, which influence cell morphology and protein expression. The commercially available ECM, Matrigel, was treated with microsecond or nanosecond pulsed (μsp or nsp, respectively) DBD frequencies conditions at the equivalent frequencies (1 kHz) or power (~1 W). Recombinant human bone morphogenetic protein‐2 was added and the mixture subcutaneously injected into mice to simulate ectopic endochondral ossification. Two weeks later, the masses were extracted and analysed by microcomputed tomography. A significant increase in bone formation was observed in Matrigel treated with μsp DBD compared with control, while a significant decrease in bone formation was observed for both nsp treatments. Histological and immunohistochemical analysis showed Matrigel treated with μsp plasma increased the number of invading cells, the amount of vascular endothelial growth factor and chondrogenesis while the opposite was true for Matrigel treated with nsp plasma. In support of the in vivo Matrigel study, 10 T1/2 cells cultured in vitro on μsp DBD‐treated type I collagen showed increased expression of adhesion proteins and activation of survival pathways, which decreased with nsp plasma treatments. These results indicate DBD modification of ECM can influence cellular behaviours to accelerate or inhibit chondrogenesis and endochondral ossification. Copyright © 2016 John Wiley & Sons, Ltd.     

Pituitary prolactin producing adenoma with ossification: A rare histological variant and review of literature

Pituitary adenoma with ossification is a rare histological variant. Previously there have been four cases reported in the literature. Here a case of pituitary prolactin‐producing adenoma with bone formation in a 21‐year‐old woman is described. The patient had irregular menstruation for three years. MRI revealed an unusual 1.5 cm³ ovoid nodule with partial shell‐like structure showing heterogeneous signals. The pre‐operative prolactin serum level was 258.78 ng/mL. The patient was operated through the trans‐sphenoidal pathway under general anesthesia. Histologically, the tumor was parenchymal and mostly replaced by the well‐differentiated lamellar bony tissue. Sheets of tumor cells interweaved with the mature lamellar bone trabeculae showing no cellular atypia. The cytoplasm of the adenoma cells was slightly eosinophilic and the myelo‐adipose metaplastic foci were also found within the parenchyma. Immunohistochemical staining of tumor cells showed positive expressions of prolactin, synaptophysin and chromogranin A in the cytoplasm of the tumor cells. Meanwhile, negative expressions of S‐100, epithelial membrane antigen, GFAP and other pituitary hormones were also demonstrated. As a rare histological variant of pituitary adenoma, the current case of pituitary prolactin producing adenoma with ossification is reported. It is speculated that the ossification may be derived from the osteo‐metaplasia of mesenchymal fibroblasts resulting from the effects of both secondary ischemia by the outgrowth of the tumor and/or the autocrine effect of prolactin in this case. The bony shell structure may limit the growth of pituitary adenoma.     

Vessel formation is induced prior to the appearance of cartilage in BMP‐2‐mediated heterotopic ossification

Heterotopic ossification (HO), or endochondral bone formation at nonskeletal sites, often results from traumatic injury and can lead to devastating consequences. Alternatively, the ability to harness this phenomenon would greatly enhance current orthopedic tools for treating segmental bone defects. Thus, understanding the earliest events in this process potentially would allow us to design more targeted therapies to either block or enhance this process. Using a murine model of HO induced by delivery of adenovirus‐transduced cells expressing bone morphogenetic protein 2 (BMP‐2), we show here that one of the earliest stages in this process is the establishment of new vessels prior to the appearance of cartilage. As early as 48 hours after induction of HO, we observed the appearance of brown adipocytes expressing vascular endothelial growth factors (VEGFs) simultaneous with endothelial progenitor replication. This was determined by using a murine model that possesses the VEGF receptor 2 (Flk1) promoter containing an endothelial cell enhancer driving the expression of nuclear‐localized yellow fluorescent protein (YFP). Expression of this marker has been shown previously to correlate with the establishment of new vasculature, and the nuclear localization of YFP expression allowed us to quantify changes in endothelial cell numbers. We found a significant increase in Flk1‐H2B::YFP cells in BMP‐2‐treated animals compared with controls. The increase in endothelial progenitors occurred 3 days prior to the appearance of early cartilage. The data collectively suggest that vascular remodeling and growth may be essential to modify the microenvironment and enable engraftment of the necessary progenitors to form endochondral bone. © 2010 American Society for Bone and Mineral Research     

Choice of surgical approach for ossification of the posterior longitudinal ligament in combination with cervical disc hernia

Ossification of the posterior longitudinal ligament (OPLL) is a common spinal disorder that presents with or without cervical myelopathy. Furthermore, there is evidence suggesting that OPLL often coexists with cervical disc hernia (CDH), and that the latter is the more important compression factor. To raise the awareness of CDH in OPLL for spinal surgeons, we performed a retrospective study on 142 patients with radiologically proven OPLL who had received surgery between January 2004 and January 2008 in our hospital. Plain radiograph, three-dimensional computed tomography construction (3D CT), and magnetic resonance imaging (MRI) of the cervical spine were all performed. Twenty-six patients with obvious CDH (15 of segmental-type, nine of mixed-type, two of continuous-type) were selected via clinical and radiographic features, and intraoperative findings. By MRI, the most commonly involved level was C5/6, followed by C3/4, C4/5, and C6/7. The areas of greatest spinal cord compression were at the disc levels because of herniated cervical discs. Eight patients were decompressed via anterior cervical discectomy and fusion (ACDF), 13 patients via anterior cervical corpectomy and fusion (ACCF), and five patients via ACDF combined with posterior laminectomy and fusion. The outcomes were all favorable. In conclusion, surgeons should consider the potential for CDH when performing spinal cord decompression and deciding the surgical approach in patients presenting with OPLL.     

胸椎黄韧带骨化症的手术方法选择

目的 探讨不同类型胸椎黄韧带骨化症的手术方法.方法 1994年1月至2008年6月,手术治疗56例胸椎黄韧带骨化症患者,男40例,女16例;年龄43～76岁,平均58.1岁;病程3个月至5年,平均13.4个月.通过CT及MR检查观察骨化累及节段、分布特点、骨化巢形态、椎管狭窄程度以及脊髓压迫程度等.患者均采用全椎板整块或分解切除加后外侧融合术进行治疗.术后手术疗效采用日本骨科协会(Japanese Orthopaedic Association,JOA)评分进行评价.结果 术后患者均获得随访,随访时间18～70个月,平均25个月.JOA评分由术前平均(6.25±2.47)分(0～10分)改善至末次随访时(7.53±3.20)分(0～11分).术后恢复率为-116.7%～100%;56例中优25例,良20例,可6例,差5例,优良率80.4%.CT扫描显示根据骨化巢形态胸椎黄韧带骨化分为外侧型6例,弥漫型17例,厚结节型33例.6例外侧型患者采用整块全椎板切除法,手术优良率为83.3%(5/6);弥漫型患者中,采用整块全椎板切除法11例、椎板分解切除法6例,手术优良率分别为81.8%(9/11)、83.3%(5/6);厚结节型患者中,采用整块全椎板切除法4例、椎板分解切除法29例,手术优良率分别为50%(2/4)、82.8%(24/29),并各有2例术后疗效差.结论 全椎板整块切除加后外侧融合适用于治疗外侧型、弥漫型胸椎黄韧带骨化,而全椎板分解切除法加后外侧融合适用于厚结节型胸椎黄韧带骨化.     

伴或不伴黄韧带骨化的胸椎和胸腰段椎间盘突出症的术式选择

目的 探讨伴或不伴黄韧带骨化的胸椎和胸腰段椎间盘突出症的术式选择.方法 2004年6月至2009年12月,手术治疗伴或不伴黄韧带骨化的胸椎和胸腰段椎间盘突出症患者31例,男22例,女9例;年龄24～71岁,平均54岁;病变节段T4～L2.根据Anand和Regan临床分类:2度1例,3a度2例,3b度3例,4度6例,5度19例;Frankel分级:B级2例,C级6例,D级11例,E级12例.18例不伴黄韧带骨化者行前路手术,采用椎体后缘切除、椎体后侧开槽或椎体次全切除减压并植骨内固定.13例伴有明显黄韧带骨化者行后路半关节突和全椎板切除减压术,未切除前侧突出的椎间盘.结果 前路术后发生硬膜囊撕裂1例,神经根袖损伤1例,肋间神经痛3例,肺不张1例,取髂骨区麻木2例.后路术后发生椎管内血肿1例,脑脊液漏2例,切口感染1例,肺部感染1例.随访6～48个月,平均18个月.末次随访时Frankel分级:C级3例,D级7例,E级21例;Anand和Regan分类:1度2例,2度1例,3a度1例,4度2例,5度10例,15例无明显症状.X线片示内固定均无失败,植骨融合良好.结论 胸椎和胸腰段椎间盘突出以脊髓前侧压迫为主者可选择前路椎体后侧开槽或椎体次全切除减压植骨融合术,伴黄韧带骨化导致脊髓前后侧压迫者可行后路半关节突和全椎板切除减压术.     

Altered gene expression in early osteochondrosis lesions

Osteochondrosis is a condition involving defective endochondral ossification and retention of cartilage in subchondral bone. The pathophysiology of this condition is poorly characterized, but it has been proposed that the fundamental defect is failure of chondrocyte hypertrophy. The aim of the current study was to characterize phenotypic changes in chondrocytes associated with the initiation of osteochondrosis. Early lesions were induced in an equine model of osteochondrosis by feeding foals a high energy diet for 8 or 15 weeks. Lesions in articular‐epiphyseal growth cartilage were examined histologically and by quantitative PCR analysis of expression of a number of genes representative of pathways that regulate chondrocyte behavior during endochondral ossification. There were more cells present in clusters in the lesions compared to normal articular cartilage. Expression of matrix metalloproteinase‐13, type I collagen, type X collagen, and Runx2 mRNA was significantly greater in the lesions compared to normal cartilage from the same joint. Expression of vascular endothelial growth factor, type II collagen, connective tissue growth factor, aggrecan, Sox9, and fibroblast growth factor receptor 3 mRNA was not significantly different in lesions than in control cartilage. These observations suggest that osteochondrosis does not result from failure of chondrocytes to undergo hypertrophy. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 452–457, 2009     

The impact of fusion on adjacent levels in cervical spine injuries: Is it really important?

Objective

Although the literature on degenerative disease of the cervical spine contains numerous articles studying the changes on levels adjacent to a fusion, there exist very few such studies concerning cervical spine stabilization for trauma.

Methods

Over a 16-year period (1989–2005), one hundred and twelve patients underwent stabilization of the lower cervical spine (C3–T1) for subaxial cervical spine injuries, either with an anterior or posterior procedure, or both. Eighty-one patients with adequate follow-up were included in the study and 3 groups were identified: Group A, consisting of 8 patients who underwent anterior stabilization and developed Adjacent Level Ossification Development (ALOD), Group B, comprising 53 patients who were anteriorly plated but who did not develop ALOD and Group C, comprising 20 patients who received posterior stabilization.

Results

Eight out of 61 patients (13.1%) who were anteriorly operated developed ALOD in 11 adjacent levels (Group A). Severe (grade 3) ossification was noted in 6/8 patients at the cranial adjacent level, and in 2/8 patients at the caudal one. Three out of 8 patients presented with early ALOD at 3, 4 and 18 months respectively. Despite the radiographic abnormalities showing ossification, all the patients had an uncomplicated course without symptoms. All the radiographs of Group B and Group C patients demonstrated grade 0 ossification for both the cranial and caudal adjacent levels.

Conclusion

Adjacent-level ossification in cervical spine injuries may appear very early in the postoperative period and it can have a different course than in the degenerative disc disease population, at least in some patients. The first cephalad level adjacent to a fusion appears to be at greater risk. However, even when ALOD is evident radiographically, it very rarely produces any symptoms.     

内窥镜下保留大部分黄韧带治疗腰椎间盘突出症

目的：探讨内窥镜下保留大部分黄韧带治疗腰椎间盘突出症的手术技巧和近期临床效果。方法：52例腰椎间盘突出症患者,男31例,女21例;年龄28～45岁,平均36岁;其中L4,524例,L5S128例。在内窥镜操作下,咬除上位椎板下缘1/4～1/3骨组织,纵向扩大骨窗,角度小刮匙在下位椎板上缘外侧分离出浅层黄韧带,用咬骨钳沿椎板上缘横行咬除浅层黄韧带成一小凹槽,用髓核钳在凹槽处钳夹黄韧带浅层向近端牵拉剥离并切除,保留深层黄韧带,然后用椎板咬骨钳在黄韧带外侧咬除小关节内侧1/4～1/3,扩大侧隐窝,游离黄韧带外缘,椎板咬骨钳咬除黄韧带外侧1/3入椎管,保留内侧2/3,神经根钩仔细分离突出椎间盘周围的组织,尽可能保留神经根周围及硬膜外脂肪,将硬脊膜及神经根牵向内侧,摘除突出的髓核。结果：52例中46例获得随访,随访时间5～51个月,平均34.5个月。疗效评定按Nakai标准,优34例,良9例,可3例。手术时间45～75min,出血40～80ml,均无神经根损伤和硬脊膜撕裂等并发症。结论：内窥镜下保留大部分黄韧带,技术上操作可行且尽可能的保留了人体的自然解剖结构,最大限度地维持了脊柱的稳定性,临床效果好。