Bioglass ®45S5 Stimulates Osteoblast Turnover and Enhances Bone Formation In Vitro: Implications and Applications for Bone Tissue Engineering

We investigated the concept of using bioactive substrates as templates for in vitro synthesis of bone tissue for transplantation by assessing the osteogenic potential of a melt-derived bioactive glass ceramic (Bioglass 45S5) in vitro. Bioactive glass ceramic and bioinert (plastic) substrates were seeded with human primary osteoblasts and evaluated after 2, 6, and 12 days. Flow cytometric analysis of the cell cycle suggested that the bioactive glass-ceramic substrate induced osteoblast proliferation, as indicated by increased cell populations in both S (DNA synthesis) and G2/M (mitosis) phases of the cell cycle. Biochemical analysis of the osteoblast differentiation markers alkaline phosphatase (ALP) and osteocalcin indicated that the bioactive glass-ceramic substrate augmented osteoblast commitment and selection of a mature osteoblastic phenotype. Scanning electron microscopic observations of discrete bone nodules over the surface of the bioactive material, from day 6 onward, further supported this notion. A combination of fluorescence, confocal, transmission electron microscopy, and X-ray microprobe (SEM-EDAX) examinations revealed that the nodules were made of cell aggregates which produced mineralized collagenous matrix. Control substrates did not exhibit mineralized nodule formation at any point studied up to 12 days. In conclusion, this study shows that Bioglass 45S5 has the ability to stimulate the growth and osteogenic differentiation of human primary osteoblasts. These findings have potential applications for tissue engineering where this bioactive glass substrate could be used as a template for the formation of bioengineered bone tissue.     

A Comparative Study of Bone Tissue Morphology and Bone Turnover Markers in Different Stages of Kümmell's Disease

Although the incidence of Kümmell's disease (KD) has increased significantly in recent years, its pathological mechanism is still unclear. The aim of this study is to investigate the histomorphological characteristics and the kinetics of bone turnover markers following KD. This study involves 82 patients with KD, and fasting blood samples were collected to detect the serum concentration of bone turnover markers. A transpedicular bone biopsy was performed to collect bone biopsy specimens during vertebroplasty surgery. According to Li's staging system for KD, all cases were divided into 3 stages. Comparisons of the 3 stages and their kinetics were conducted. 19 (23.2%) patients were classified as Stage I, 39 (47.5%) as Stage II, 24 (29.2%) as Stage III. Bone histomorphological analysis showed that the ratios of WBV and FV reached a peak value (14.23 ± 0.62 and 54.63% ± 3.52%; p = 0.001 and 0.001) at Stage I. The ratios of NBV remained low (4.81% ± 2.61%) in Stage I, but reached a peak value (18.50% ± 2.77%; p = 0.001) in Stage III. Bone metabolism index level showed that the serum concentration of OST and β-CTX continued to rise after fracture, reaching a peak value of (38.15 ± 3.84 and 1.31 ± 0.16 ng/Ml; p = 0.073 and 0.026), while PINP reached its valley value (48.57 ± 7.25 ng/Ml; p = 0.069) in Stage III. A significant and negative correlation was found between the ratio of β-CTX and EBV/TV (p= 0.0194, r = -0.2037), and FV/TV (p= 0.0001, r = -0.5368). At the same time, β-CTX had a positive significant correlation with the NBV/TV (p= 0.0001, r = 0.6218). Bone histomorphometric analysis and bone turnover markers showed that KD has a possibility of healing in the early stage.     

Port Site Metastases: Where are we at the Beginning of the 21st Century ?

Following the introduction of minimal invasive surgery in the field of malignant disease, a number of reports have been published describing the occurence of tumour deposits in the abdominal or thoracic wall at the sites of trocar placement. These trocar site metastases have caused great concern among minimal invasive surgeons and have put an important restraint on the rapid development of these techniques in oncologic surgery.

The present review article focuses on the clinical facts and experimental studies that have been conducted on the problem of port site metastases, more specifically upon their occurence and pathogenesis.

Although most of the port site recurrences are due to technical surgical problems and can be avoided by adapting the same oncologic surgical principles as in open surgery, some features of the minimal invasive techniques facilitate tumour growth and should be kept in mind when performing minimum invasive surgery for malignancy.     

Is Quantitative Ultrasound Dependent on Bone Structure? A Reflection

Trabecular bone plays a significant role in maintaining bone structural integrity. Its density is a significant determinant of bone strength and fracture risk, but there is still unexplained variance. It has been suggested that the ability to measure structural information will improve the estimation of bone strength and fracture risk. Quantitative ultrasound (QUS) is a mechanical wave that can be influenced by bone structure, in addition to bone mineral density (BMD). This article reviews the evidence in the literature supporting or refuting this assumption. Theoretically, the propagation of QUS is influenced by both structure and density of the medium. QUS measurement in vivo shows weak but significant association with axial BMD. However, the association becomes stronger when measured in vitro. Broadband ultrasound attenuation (BUA) exhibits a nonlinear relationship with density over a large density range. When cubes of cancellous bone are measured in the three orthogonal directions, both BUA and speed of sound (SOS) show significant anisotropy which mirrors mechanical anisotropy. QUS has also been shown to correlate significantly with structural parameters measured by histomorphometry. However, structure remains a significant predictor after adjustment for BMD mainly in bovine samples. Other studies using phantoms of bone samples have also demonstrated that QUS is dependent on structure. There is preliminary indication that fractal dimensions are significantly associated with QUS. The ultimate usefulness of structural dependence of QUS will be in its ability to improve bone strength estimation above and beyond density. There is ample evidence documenting the ability of QUS to predict bone strength in vitro. BMD is a significant predictor of bone strength and the additive value of structure in estimating bone strength is variable. Clinically, ultrasound of the calcaneus is measured in one direction (medio-lateral) and the structural variation in this direction may be limited. Nevertheless, QUS can provide useful additional information to that provided by axial BMD due in part to different precision and accuracy errors and to biological discordance. On the whole one could conclude that ultrasound attenuation is due to structural parameters and these variables are also dependent on density.     

CORR Insights®: The Effect of Surgical Technique and Spacer Texture on Bone Regeneration: A Caprine Study Using the Masquelet Technique

Clinical Orthopaedics and Related Research® -     

Historical Review of Surgical Simulation—A Personal Perspective

Although simulation is relatively new to surgical education, there is a long history in many other disciplines, such as military, aviation, and nuclear power plant operations, among others. In the late 1980s these technologies began to be adapted to the surgical world, along with the new technology of virtual reality. This is a review of the introduction of manikins, computers, and virtual reality into education and training for surgical skills. Two concomitant revolutions occurred: objective assessment of surgical skills and converting training from the apprenticeship model to one of criterion-based training. A personal perspective on these developments adds information not previously published. Opinions or assertions contained herein are the private views of the author(s) and are not to be construed as official, or as reflecting the views of the Departments of the Army, Navy or Air Force, the Defense Advanced Research Projects Agency, or the Department of Defense. This is a declared work of the U. S. Government and as such is not subject to copyright protection in the United States.     

Evaluation of Partially Demineralized Osteoporotic Cancellous Bone Matrix Combined with Human Bone Marrow Stromal Cells for Tissue Engineering: An In Vitro and In Vivo Study

Allogenous demineralized bone matrix (DBM) represents a potential scaffold for bone tissue engineering due to its close relation in structure and function with autologous bone, but its supply is often restricted by donor availability. Thus, an expanded source of human bone is needed. The aim of this study was to evaluate the capacity of partially DBM scaffolds derived from allogenous cancellous bone of osteoporotic femurs to support osteogenesis of human bone marrow stromal cells (BMSCs) in vitro and in vivo in order to assess their potential use in bone tissue-engineering strategies. Human BMSCs of passage 2 were seeded either on osteoporotic bone–derived DBM scaffolds or on normal bone–derived scaffolds and cultured in osteogenic medium for 14 days. To assess the in vitro proliferation potential and osteogenic differentiation of BMSCs on scaffolds, scanning electronic microscopy observation, DNA content assays, and measurements of alkaline phosphatase activity and osteocalcin content were applied; the results displayed no significant differences between the osteoporotic DBM group and the normal DBM group. After 2 weeks of subculture in vitro, the BMSC/DBM composites were subcutaneously implanted into athymic mice for 8 weeks to evaluate their in vivo bone-forming ability. Histological examination showed tissue-engineered bone formation in the DBM pores in both groups, and no significant differences were observed in either the extent or frequency of new bone formation between these two groups. Based on these results, it can be concluded that osteoporotic bone–derived DBM may serve as a promising scaffold for bone tissue engineering.     

Outcome Scores Collected by Touchscreen: Medical Audit as it Should be in the 21st Century?

INTRODUCTION

Collecting outcome scores in paper form is fraught with difficulty. We have assessed the feasibility of, and patient''s attitude towards, entering scores using a touchscreen.

PATIENTS AND METHODS

A touchscreen was installed in the orthopaedic out-patient clinic. If relevant, patients were asked to complete either an Oswestry Disability Index (ODI) or Oxford Shoulder Score (OSS) using the screen. Patients were given written instructions and their hospital number by the receptionist who had no further input. Scores were completed with two identifiers. A paper questionnaire was used to assess computer experience and attitude towards the touchscreen.

RESULTS

A total of 1348 patients, average age 50 years, successfully completed a score in the first 12 months. One-third were over 60 years. Overall, 91% correctly entered their hospital number and date of birth, falling to 84% in patients over 70 years. All patients were identifiable. The average time to complete the scores was 4.7 min rising with age. Of 170 patients completing the paper assessment of the touchscreen, one-third had little or no experience of computers and a third were over 60 years. Of patients, 93% were willing to repeat the score using the touchscreen to monitor progress. Two-thirds found it easier to use than expected. Only 10% would prefer a paper score. These results were maintained among patients over 60 years. Only two were unable to complete the score and 80% of those potentially eligible did so. The remainder were called to clinic before the touchscreen was free.

CONCLUSIONS

Orthopaedic outcome scores can be collected in very large volumes using a touchscreen. Data are then in an immediately usable form. The method is acceptable to patients, independent of age and computer experience. Even in the oldest patients, the accuracy is higher than for paper versions of the score. Combined with operative data, this simple method has the potential to provide a very powerful audit tool indeed.     

Immune Components of Colostrum and Milk—A Historical Perspective

Key developments in the understanding of the immune functions of milk and colostrum are reviewed, focusing on their proteinaceous components. The topics covered include the immunoglobulins, immune cells, immunomodulatory substances, and antimicrobial proteins. The contributions of new technologies and the introduction of fresh approaches from other fields are highlighted, as are the contributions that mammary biology research has made to the development of other fields. Finally, a summary of some current outstanding questions and likely future directions of the field are given.