Evaluation of matrix metalloproteases as early biomarkers for bone regeneration during the applied Masquelet therapy for non-unions

IntroductionIn the current study, we sought to determine if serum concentrations of MMPs correlate with bone regeneration occurring during the course of the Masquelet-therapy and to identify if MMPs may serve as early biomarkers reflecting successful bone regeneration and tissue remodeling.Material and methodsThis study was designed as a prospective clinical observer study. We compared serum samples over the time of treatment, as a matched-pair analysis, from 10 patients who were treated successfully with the Masquelet-therapy (Responder) with 10 patients who did not respond to the Masquelet-therapy (Non-Responder). The quantitative measurement was performed with Luminex Performance Human High Sensitivity Assays according to manufacturer’s instructions. The lab technician performing the Luminex assays was blinded to both patient data and clinical outcome.ResultsAnalysis of the expression pattern of MMP-2, -8 and -9 showed significant differences between groups. Two days after the first step of the Masquelet therapy Responder showed peak values of MMP-8 and MMP-9 that where significantly higher (p = 0.003 and p = 0.042, respectively) than in Non-Responder. In contrast serum levels of MMP-2 were lower after the first step of the Masquelet therapy in the Non-Responder group. The ratio of MMP-9 and MMP-2 was significantly higher in the Responder group two days after step I (p = 0.031) as well as 4 weeks after step II (p = 0.030).ConclusionThe findings of the current study emphasize the potential role of MMPs as biomarkers in bone remodeling. In particular, a distinct expression of MMP-2 correlates with successful bone regeneration, whereas initial overexpression of MMP-2 serum levels might identify patients that have a higher risk for a poor outcome of the Masquelet-therapy. Furthermore, we were able to introduce the serum analysis of the ratio of MMP-9 and MMP-2 as promising novel modality for early prediction of the outcome of the Masquelet therapy. Further analysis of this ratio over time subsequent to the second step might serve as an early indicator of a favorable response to the induced membrane technique.     

Evaluation of the presence of VEGF,BMP2 and CBFA1 proteins in autogenous bone graft: Histometric and immunohistochemical analysis

AimsThe purpose of this study was to evaluate the expression of proteins that participate in the osteoinduction stage (VEGF, BMP2 and CBFA1) of the process of bone regeneration of defects created in rat calvariae and filled with autogenous bone block grafts.Materials and methods10 adult male rats (Rattus norvegicus albinus, Wistar) were used, who received two bone defects measuring 5 mm each in the calvariae. The bone defects constituted two experimental groups (n = 10): Control Group (CONT) (defects filled with a coagulum); Graft Group (GR) (defects filled with autogenous bone removed from the contralateral defect). The animals were submitted to euthanasia at 7 and 30 days post-operatively.ResultsQuantitative analysis demonstrated significantly greater bone formation in Group GR, but the presence of the studied proteins was significantly greater in the CONT Group in both time intervals of observation.ConclusionIt was not possible in this study in cortical bone block groups to detect the osteoinductive proteins in a significant amount during the repair process.     

Using Speed of Sound Imaging to Characterize Breast Density

A population of 165 women with negative mammographic screens also received an ultrasound tomography (UST) examination at the Karmanos Cancer Institute in Detroit, MI. Standard statistical techniques were employed to measure the associations between the various mammographic- and UST-related density measures and various participant characteristics such as age, weight and height. The mammographic percent density (MPD) was found to have similar strength associations with UST mean sound speed (Spearman coefficient, r_s = 0.722, p < 0.001) and UST median sound speed (r_s = 0.737, p < 0.001). Both were stronger than the associations between MPD with two separate measures of UST percent density, a k-means (r_s = 0.568, p < 0.001) or a threshold (r_s = 0.715, p < 0.001) measure. Segmentation of the UST sound speed images into dense and non-dense volumes showed weak to moderate associations with the mammographically equivalent measures. Relationships were found to be inversely and weakly associated between age and the UST mean sound speed (r_s = ?0.239, p = 0.002), UST median sound speed (r_s = ?0.226, p = 0.004) and MPD (r_s = ?0.204, p = 0.008). Relationships were found to be inversely and moderately associated between body mass index (BMI) and the UST mean sound speed (r_s = ?0.429, p < 0.001), UST median sound speed (r_s = ?0.447, p < 0.001) and MPD (r_s = ?0.489, p < 0.001). The results confirm and strengthen findings presented in previous work indicating that UST sound speed imaging yields viable markers of breast density in a manner consistent with mammography, the current clinical standard. These results lay the groundwork for further studies to assess the role of sound speed imaging in risk prediction.     

FRAX and mandibular sparse trabeculation as fracture predictors: a longitudinal study from 1980 to 2002

The fracture assessment tool (FRAX) is widely used for predicting fractures, but better methods are needed. The aim of this study was to determine whether visual assessments of mandibular trabecular bone could improve FRAX predictions. Three age‐cohorts of women were examined twice – 499 women in 1980/1981 and 412 women in 1992/1993; 397 participated in both examinations. Information on 10‐yr fracture events was available, and bone trabeculation was assessed in radiographs as ‘dense’, ‘mixed’, or ‘sparse’. Fracture assessment tool values, without bone mineral density (BMD), were calculated twice. Both sparse trabeculation and FRAX >15% were associated with a twofold higher risk for future fracture in the younger group and with a three‐ to fourfold higher risk for future fracture in the older group. For those with both FRAX >15% and sparse trabeculation, the relative risk (RR) for a fracture in the next 10 yr was 5.9 (95% CI: 3.5–9.8) in the younger group and 22.7 (95% CI: 5.6–92) in the older group. If either FRAX >15% or sparse trabeculation was present, the RR was 2.6 (95% CI: 1.7–4.1) in the younger group and 15.7 (95% CI: 3.9–6.4) in the older group. We concluded that FRAX >15%, without BMD measurements, was an effective fracture predictor, and mandibular sparse trabeculation had a substantial additive effect. Together, FRAX plus mandibular sparse trabeculation predicts major osteoporotic fractures to approximately the same extent as does FRAX with BMD measurements.     

荧光标记法比较4种表面处理方式种植体骨矿化沉积率的研究

目的荧光标记法观察比较4种表面处理方式种植体周围骨矿化沉积率的差异。方法微创拔除4只Beagle犬双侧下颌4颗前磨牙,待拔牙创愈合3个月后,植入奥齿泰种植体40颗,其中机械形态表面(ma-chined morphology,MM)组4颗,喷砂加酸蚀(sand blasted with alumina and acid etched,SA)组、可吸收性研磨介质(resorbable blasting media,RBM)组和生物化学喷砂酸蚀组(biochemistry sand blasted with alumina and acid etched,Bio-SA)组各12颗,愈合3个月,处死前13、14 d和3、4 d分别注射盐酸四环素和钙黄绿素,制取标本并置于70%酒精固定,采用塑料包埋技术制作骨磨片,荧光显微镜下观察,测量骨矿化沉积率。结果螺纹间及远离螺纹区域新骨矿化沉积率在4组间的差异均没有统计学意义(P>0.05);单独比较每组种植体螺纹间及远离区域骨矿化沉积率的差异性,RBM组及SA组组内差异没有统计学意义(P>0.05),而MM组和Bio-SA组组内差异具有统计学意义(P<0.05)。结论采用塑料包埋技术,通过荧光标记法能成功观察到新骨矿化沉积的情况;种植体植入3个月后,4种不同粗糙程度的种植体螺纹间及远离螺纹区域骨矿化沉积率没有差异性,而经机械形态表面处理的种植体和生物化学喷砂酸蚀处理的种植体,螺纹间骨矿化沉积比远离螺纹区域快。     

包头地区人群骨密度影响因素研究

目的 研究影响包头地区人群骨密度的相关因素。方法 采用病例-对照研究方法。收集来自包头医学院第一附属医院进行健康体检的596例女性和230例男性流行病学资料，用双能X线吸收仪对研究对象进行骨扫描，按骨密度检测值分为正常对照组和骨质疏松及骨量流失组。采用 Logistic回归法分析影响骨密度的相关因素。结果 经Logistic回归分析，饮酒是女性发生骨质疏松的危险因素，吸烟、饮酒是男性发生骨质疏松的危险因素。补钙是人群保护因素。结论 包头地区 男、女性通过补钙均可预防骨质疏松；饮酒与女性骨量流失及骨质疏松显著相关，吸烟、饮酒与男性骨量流失及骨质疏松显著相关。     

湖北孝感2950例健康人群桡骨超声骨密度 调查分析

目的调查湖北孝感部分企事业单位健康体检人群的骨密度变化规律及骨质疏松（OP)患病 情况，为OP的诊断和防治提供科学依据。方法应用定量超声骨密度仪对本地区四50例健康体检 人群进行骨定量超声检测和分析。结果女性桡骨超声速率（SOS)峰值出现在46~50岁，50岁以后 缓慢下降，60岁以后下降趋势明显。男性桡骨SOS峰值出现在51~ 55岁，之后呈缓慢下降。50岁以 上，OP患病率男性为14.0%，女性为41.6%，女性显著高于男性(P<0. 01)，并且，各年龄段女性OP 发生率明显高于男性（P<0.01 )。结论随着年龄的增加，男女性骨质疏松发生率均逐渐增加，定量 超声适用于普查，可用于骨质疏松的早期诊断，并进行早期预防。     

Articular Ultrasound in Asymptomatic Volunteers: Identification of the Worst Measures of Synovial Hypertrophy,Synovial Blood Flow and Joint Damage Among Small-, Medium- and Large-Sized Joints

Articular ultrasound of 6500 joint recesses was performed for the purpose of identifying which joint had the highest measurements among small-sized (SSJ), medium-sized (MSJ) and large-sized (LSJ) joints. Quantitative measurements of synovial hypertrophy (QSR) and semiquantitative measurements of synovial hypertrophy (SSH), power Doppler (SPD) and bone erosion (SBE) (score: 0–3) were made. Higher measurements (p < 0.01) of QSR were obtained in the second metatarsophalangeal joint (MTP), talonavicular joint, and hip. The highest SSH scores (2/3) were obtained in the second MTP, talonavicular joint, hip and knee; the highest SPD scores (1/2/3) in the first MTP, second MTP, dorsal second metacarpophalangeal (MCP) and radiocarpal recesses; and the highest SBE scores (2/3) in the radiocarpal, ulnocarpal and posterior recesses of the glenohumeral joint. In conclusion, higher measurements of synovial hypertrophy were found in the first and second MTPs (SSJ), talonavicular recess (MSJ) and hip (LSJ). Synovial blood flow was frequent in the first MTP and radiocarpal recess. Bone erosion stood out only in the glenohumeral joint.     

Retrospective Evaluation of Crestal Bone Changes Around Implants With Reduced Abutment Diameter Placed Non‐Submerged and at Subcrestal Positions: The Effect of Bone Grafting at Implant Placement

Background: There is limited information regarding the effect of grafting of the osteotomy after subcrestal implant placement. The primary aim of this study is to retrospectively evaluate the effect of bone grafting of the defect between the bone crest and the coronal aspect of implants with reduced abutment diameter placed non‐submerged and at subcrestal positions. Methods: Records of 50 consecutive patients treated with subcrestally placed dental implants grafted with a xenograft (Group A) and 50 consecutive patients with subcrestally placed dental implants without any grafting material (Group B) were reviewed. For each implant, the radiographs after placement were compared to images from the last follow‐up visit and evaluated regarding the following: 1) degree of subcrestal positioning of the implant, 2) changes of marginal hard‐tissue height over time, and 3) whether marginal hard‐tissue could be detected on the implant platform at the follow‐up visit. Results: The mean marginal loss of hard tissues was 0.11 ± 0.30 mm for Group A and 0.08 ± 0.22 mm for Group B. Sixty‐nine percent of the implants in Group A and 77% of the implants in Group B demonstrated hard tissue on the implant platform. There were no statistically significant differences between the groups regarding marginal peri‐implant hard‐tissue loss. Conclusion: The present study fails to demonstrate that grafting of the remaining osseous wound defect between the bone crest and the coronal aspect of the implant has a positive effect on marginal peri‐implant hard‐tissue changes.