Fragile bone syndrome associated with craniognathic fibro-osseous lesions and abnormal modeling of the tubular bones: report of two cases and review of the literature

 Objective. To report examples of disorders characterized by bone fragility, calvarial and/or gnathic fibro-osseous lesions, and metadiaphyseal undermodeling of the tubular bones. Design. The clinical, radiological, and pathological features of two patients are described and the literature reviewed. Patients. The patients comprised a 10-year-old boy and a 48-year-old woman. The former exhibited multiple fractures starting in early childhood and calvarial masses which developed in late childhood; the latter showed a mandibular mass. Results. Calvarial doughnut lesions, osteopenia with coarse bony trabeculae, and undermodeling of the lower limbs were radiologically demonstrated in the first patient, while multiple sclerotic foci in the maxilla and mandible, spontaneous bowing of the right femur, and minimal undermodeling of the tibiae were demonstrated in the second. Bone biopsy of the iliac crest in the first patient revealed histologically normal bony trabeculae. Bone histomorphometry suggested an increased osteoid surface. Osteoid volume was also slightly increased. The pathological findings of the mass in the jaw in the latter patient were consistent with it being a fibro-osseous lesion. The literature review revealed several patients whose features overlapped with those of our patients. Conclusion. These patients may represent a group of fragile bone syndromes which differ from osteogenesis imperfecta.     

遗传性成骨不全临床及X线诊断探讨(附一家系42例报告)

目的探讨遗传性成骨不全诊断要点。方法对一家系健在的３５例遗传性成骨不全患者的临床和Ｘ线资料及死亡的７例的临床资料进行回顾性分析。结果（１）一家系五代４２例（男１８例，女２４例）患病，年龄１０个月至６７岁。（２）同时具有两种不同遗传方式（显性３５例，隐性７例）。（３）４２例均有深浅不同蓝色巩膜。（４）健在３５例的骨骼Ｘ线改变：２９例为普遍性骨密度减低，皮质薄，长管状骨细长，６例正常。２２例合并骨折。（５）进行性耳聋２４例（含死亡３例）。（６）蓝巩膜、骨脆、耳聋三联症２１例（含死亡３例）。（７）碱性磷酸酶升高（１７例）为本组实验室检查的特殊表现。结论蓝巩膜、骨脆、进行性耳聋为遗传性成骨不全的特征性表现，尤其蓝巩膜为本病首现及易显体征，为诊断必备条件。     

A scanning electron microscopic investigation of in vitro osteogenesis

Summary Chick limb mesenchymal cells differentiate into muscle, cartilage, fibrous, and bone tissue. Previous reports show that when stage 24 limb mesenchymal cells are cultured in vitro, chondrocytes, myocytes, fibrocytes, and osteoblasts can be identified on the basis of morphological and biochemical parameters. The study reported here demonstrates that phenotypic expression in culture seems to be dependent on the initial plating density, Scanning electron microscopic observations indicate that when stage 24 limb mesenchymal cells are initially seeded at high densities (5 × 10⁶ cells per 35 mm culture dish), mounds of cells appear in culture. These mounds represent cartilage nodules composed of a fine fibrous matrix and chondrocytes, surrounded by a loose fibrous connective tissue matrix. Cultures initially plated at intermediate densities (2.0–2.5 × 10⁶ cells/35 mm culture dish) produce a flattened layer of fibrocytes overlying a matrix of collagen fibers and calcium phosphate deposits as determined by electron-microprobe analysis; these observations are indicative of osteoblast expression. Cells seeded at this intermediate density appear larger and possess greater surface area than cells seeded at high density. It is suggested that conditions that permit such increased cell surface area coupled with a relative compaction due to cell crowding may provide conditions permissive for osteogenesis. Based on morphological criteria, it appears that chick limb mesenchymal cell osteogenesis in vitro is not associated with chondrogenesis but represents a separate route of phenotypic expression.     

Osteogenesis imperfecta in childhood: cardiac and renal manifestations

We examined 58 children aged 1–16 years with various forms of osteogenesis imperfecta (OI). Congenital cardiac malformations were diagnosed in 4 children (valvular aortic stenosis, 2 with atrial septal defect II, Fallot Tetralogy). Two additional children developed holosystolic mitral valve prolapse and regurgitation. Children suffering from a severe clinical course (type III according to the Sillence classification) showed aortic root dilatation (28%) and increased septal (40%) and posterior left ventricular wall thickening (68%) on initial evaluation. All three parameters were significantly correlated to body surface area.Kidney stones and renal papillary calcifications were detected in 4 children. Cardiovascular abnormalities and nephrolithiasis may be important extraskeletal manifestations of childhood OI.     

Decrease in outpatient department visits and operative interventions due to bisphosphonates in children with osteogenesis imperfecta

Introduction  

Bisphosphonates are currently the medical treatment most often used in children with osteogenesis imperfecta (OI). The purpose of this retrospective pre–post study was to evaluate the efficacy of treatment with bisphosphonates. We measured the effect by evaluating the number of outpatient department consultations and operative interventions before and after treatment with bisphosphonates in children with OI.     

Distinct osteogenic mechanisms of bones of distinct origins

Mammalian bones have three distinct origins (paraxial mesoderm, lateral plate mesoderm, and neural crest) and undergo two different modes of formation (intra-membranous and endochondral). Bones derived from the paraxial mesoderm and lateral plate mesoderm mainly form through the endochondral process. During this process, hypertrophic chondrocytes play a vital role in inducing both osteogenesis and angiogenesis. One of the essential osteogenic factors secreted from hypertrophic chondrocytes is Indian hedgehog (Ihh). In contrast, bones derived from the neural crest mainly form through the intramembranous pro-cess and do not require Ihh. Thus, depending on their origin, bones have distinct signaling properties, which need to be considered in the research and application of bone biology.Presented at the 18th Annual Research Meeting of the Japanese Orthopaedic Association, Kitakyushu, Japan, October 17, 2003     

神经植入对大段组织工程骨成骨效果的一年观察

目的 观察在组织工程骨内植入神经束后大段组织工程骨的长期成骨效果.方法 新西兰大白兔64只,随机分为四组:A组,单纯组织工程骨组;B组,运动神经束植入组(股神经肌支);C组,感觉神经束植入组(隐神经);D组,感觉、运动神经束联合植入组.每只动物均在左侧股骨制作长1.5 cm的段缺性骨与骨膜缺损,钢板固定后在骨缺损处分别植入四种方法制备的组织工程骨.术后1、3、6、12个月行大体观察、X线和组织学定量观察成骨情况. 结果 术后1、3、6个月时,在组织工程骨内植入感觉神经或联合植入两种神经后,比单纯组织工程骨和运动神经束植入的修复效果均有明显提高.术后12个月时,各组骨再生情况基本一致,但新生骨组织出现一定程度的吸收,其外观较正常股骨细,新生骨组织与兔股骨牢固愈合,并开始塑形且出现髓腔再通. 结论 在组织工程骨内植入感觉神经可促进成骨,而植入运动神经未见促进作用;组织工程骨可以修复兔大段骨缺损;该实验新生骨组织的吸收可能与模型的制作方法有关.     

The sagittal balance of the spine in children and adolescents with osteogenesis imperfecta

In severe forms of osteogenesis imperfecta, multiple compression fractures of the spine, as well as vertebral height shortening could be responsible for an increased thoracic kyphosis or a diminished lumbar lordosis. Theses progressive changes in sagittal shapes of the trunk could be responsible for a global sagittal trunk imbalance. We compare the parameters of sagittal spinopelvic balance in young patients with OI to those parameters in a control group of healthy volunteers. Eighteen patients with osteogenesis imperfecta were compared to a cohort of 300 healthy volunteers. A standing lateral radiograph of the spine was obtained in a standardized fashion. The sacral slope, pelvic tilt, pelvic incidence, lumbar lordosis, thoracic kyphosis, T1 and T9 sagittal offset were measured using a computer-assisted method. The variations and reciprocal correlations of all parameters in both groups according to each other were studied. Comparison of angular parameters between OI patients and control group showed an increased T1T12 kyphosis in OI patients. T1 and T9 sagittal offset was positive in OI patients and negative in control group. This statistically significant difference among sagittal offsets in both groups indicated that OI patients had a global sagittal balance of the trunk displaced anteriorly when compared to the normal population. Reciprocal correlations between angular parameters in OI patients showed a strong correlation between lumbar lordosis (L1L5 and L1S1) and sacral slope. The T9 sagittal offset was also strongly correlated with pelvic tilt. Pelvic incidence was correlated with L1S1 lordosis, T1 sagittal offset and pelvic tilt. In OI patients, the T1T12 thoracic kyphosis was statistically higher than in control group and was not correlated with other shape (LL) or pelvic (SS, PT or PI) parameters. Because isolated T1T12 kyphosis increase without T4T12 significant modification, we suggest that vertebral deformations worsen in OI patients at the upper part of thoracic spine. Further studies are needed to precise the exact location of most frequent vertebral deformities.     

冲击波诱导人骨髓基质细胞成骨分化及机制的研究

目的 观察出生后人骨髓基质细胞(hIMSCs)在体外培养条件下增殖与分化的特点；研究适宜能量冲击波对出生后hMSCs成骨分化的作用及机制。方法 抽取健康自愿者髂骨骨髓，采用密度梯度离心法进行hMSCs体外培养。设冲击波组(SW组)与对照组，应用不同能量级冲击波对SW组原代细胞进行处理，根据细胞活力测定与集落形成数量确定适宜的冲击波能量值。应用适宜的冲击波能量处理hMSCs原代细胞并传代培养，采用倒置显微镜观察、细胞增殖活力测定、ELISA法检测细胞分泌TGF-81、茜素红染色、钙钴法染色、四环素荧光标记、细胞分泌碱性磷酸酶测定和逆转录一聚合酶链反应(RT-PCR)检测骨钙素mRNA表达等方法，对SW组和对照组的各代细胞形态、增殖与分化及其机制进行探讨。结果冲击波处理体外原代培养hMSCs的适宜能量为10kV(500)。SW组细胞在冲击波处理后早期分泌TGF-B1显著高于对照组(P＜0．001)。SW组与对照组细胞在形态学方面第3代前无明显差别；SW组各代细胞分泌碱性磷酸酶显著高于对照组(P＜0．01)；茜素红染色、钙钴法染色、四环素荧光标记等显示SW组细胞的成骨作用明显优于对照组；SW组细胞经冲击波处理后第10天应用RT-PCR方法可以检测到骨钙素mRNA的表达，与对照组比较差异有统计学意义(P＜0．001)。结论 冲击波对体外培养的出生后人骨髓基质细胞具有促进成骨分化的作用，适宜能量为10kv(500)，其机制之一为TGF-B1介导的促hMSCs成骨分化作用。10kV(500)能量级的冲击波对体外培养的hMSCs增殖无影响，大于该能量的冲击波具有抑制细胞增殖的作用。