Yuehuei H. An

Concise review of mechanisms of bacterial adhesion to biomaterial surfaces

This article reviews the mechanisms of bacterial adhesion to biomaterial surfaces and the factors affecting the adhesion. The process of bacterial adhesion includes an initial physicochemical interaction phase (phase one) and a late molecular and cellular interaction phase (phase two), which is a complicated process affected by many factors, including the characteristics of the bacteria themselves, the target material surface, and the environmental factors, such as the presence of serum proteins or bactericidal substances.

Mechanical testing of bone and the bone-implant interface

GENERAL CONSIDERATIONS Basic Composition and Structure of Bone -E. Bonucci Basic Concepts of Mechanical Property Measurement and Bone Biomechanics -Y. H. An and W. R. Barfield and R. A. Draughn Mechanical Properties of Bone -Y.H. An Factors Affecting Mechanical Properties of Bone -P. Zioupos, C. W. Smith, and Y. H. An Basic Facilities and Instruments for Mechanical Testing of Bone -C.V. Bensen and Y.H. An Methods of Evaluation for Bone Dimensions, Densities, , Morphology, and Structures -Y.H. An, W. R. Barfield and I. Knets General Considerations of Mechanical Testing -Y.H. An and C.V. Bensen A Hierarchical Approach to Exploring Bone Mechanical Properties -C. E. Hoffler, B. R. McCreadie, E. A. Smith, and S. A. Goldstein Nondestructive Mechanical Testing of Cancellous Bone -F. Linde and I. Hvid Synthetic Materials and Structures Used as Models for Bone -J. A. Szivek METHODS OF MECHANICAL TESTING OF BONE Tensile and Compression Testing of Bone -T. S. Keller and M. A. Liebschner Bending Tests of Bone -M. J. Lopez and M. D. Markel Torsional Testing of Bone -B. Furman and S. Saha Indentation Testing of Bone -B. E. McKoy, Q. Kang and Y. H. An Penetration Testing of Bone Using an Osteopenetrometer -I. Hvid and F. Linde Microhardness Testing of Bone -S. S. Huja, T. R. Katona, and W. E. Roberts Nanoindentation Testing of Bone -J. Y. Rho and G. M. Pharr Single Osteon Micromechanical Testing -M. G. Ascenzi, A. Benvenuti, and A. Ascenzi Micromechanical Testing of Single Trabeculae -P. L. Mente Strain Gauge Measurements from Bone Surfaces -J. A. Szivek and V. M. Gharpuray Screw Pullout Test for Evaluating Mechanical Properties of Bone -M. S. Crum, F. A. Young, Jr., and Y. H. An Viscoelastic Properties of Bone and Testing Methods -N. Sasaki Observation of Material Failure Mode Using a SEM with a Built-in Mechanical Testing Device -R. M. Wang and Y. H. An Ultrasonic Methods for Evaluating Mechanical Properties of Bone -J. Y. Rho Evaluating Mechanical Properties of Bone Using Scanning Acoustic Microscopy -C. H. Turner and J. L. Katz Peripheral Quantitative Computed Tomography for Evaluating Structural and Mechanical Properties of Small Bone -J. L. Ferretti Computer Modeling for Evaluating Trabecular Bone Mechanics -R. Saxena and T. S. Keller METHODS OF MECHANICAL TESTING OF THE BONE-IMPLANT INTERFACE Factors Affecting the Strength of the Bone-Implant Interface -B. E. McKoy, Y. H. An and R. J. Friedman Implant Pushout and Pullout Test -A. Berzins and D. R. Sumner The Validity of a Single Pushout Test -W. J. A. Dhert and J. A. Jansen Tensile Testing of Bone-Implant Interface -T. Nakamura and S. Nishiguchi Fracture Toughness Tests of the Bone-Implant Interface -X. Wang, K. A. Athanasiou, and C. M. Agrawal In Vitro Measurements of Implant Stability -A. Berzins and D. Sumner In Vitro Testing of the Stability of Acetabular Components -J. R. Davis, R. A. Lofthouse, and R. H. Jinnah In Vitro Testing of the Stability of Femoral Components -S. H. Naidu, F. M. Khoury and J. M. Cuckler Screw Pullout Test -L. A. Ferrara and T. C. Ryken Finite Element Analysis for Evaluating Mechanical Properties of the Bone-Implant Interface -K. R. Williams Fatigue Testing of Bioabsorbable Screws in a Synthetic Bone Substrate -W. S. Pietrzak, D. R. Sarver, and D. H. Kohn Testing Intervertebral Stability after Spinal Fixation -K. S. James and A. U. Daniels

Pre-clinical in vivo evaluation of orthopaedic bioabsorbable devices

The presence of bioabsorbable materials in orthopaedics has grown significantly over the past two decades with applications in fracture fixation, bone replacement, cartilage repair, meniscal repair, fixation of ligaments, and drug delivery. Numerous biocompatible, biodegradable polymers are now available for both experimental and clinical use. Not surprisingly, there have been a wealth of studies investigating the biomechanical properties, biocompatibility, degradation characteristics, osteoconductivity, potential toxicity, and histologic effects of various materials. Promising results have been reported in the areas of fracture fixation, ligament repair, and drug delivery. In this article we review the pre-clinical in vivo testing of bioabsorbable devices with particular emphasis on implants used for these applications.

Laboratory methods for studies of bacterial adhesion

Abstract Prosthetic infection following total joint replacement can have catastrophic results both physically and psychologically for the patients, leading to complete failure of the arthroplasty, possible amputation, prolonged hospitalization, and even death. Bacterial adherence to biomaterial surfaces is an important step in the pathogenesis of prosthetic infection. The exact mechanism of prosthetic infection remains unclear. It is thought that certain bacteria, particularly coagulase-negative staphylococci, after adhering to biomaterial surfaces, secrete a layer polysaccharide, an extracellular substance (slime) and then form a biofilm (a biomass of bacteria and slime). The biofilm makes the embedded bacteria less accessible to the human defense system and significantly decreases antibiotic susceptibility. Before effective preventive or therapeutic measures can be achieved, the process, characteristics, or mechanism of bacterial adhesion to biomaterials have to be studied. In this review, the in-vitro experimental methods for bacterial adhesion will be discussed, which concentrates on (1) how to design a new in-vitro model of bacterial adhesion or biofilm formation, including the selection of bacteria, sample surface preparation, conducting bacterial adhesion or biofilm formation experiments, and the sample preparation for evaluation; and (2) methods for examining adhered bacteria and biofilm, which include microscopy for counting and morphological observation of adhered bacteria, viable bacterial counting methods, other direct or indirect bacterial counting methods, and the methods for evaluating biofilm.

Handbook of histology methods for bone and cartilage

Part I. Introduction Introduction to Experimental Bone and Cartilage Histology Yuehuei H. An and Helen E. Gruber Part II. Structure and Function of Bone and Cartilage Cell Structure and Biology of Bone and Cartilage William R. Walsh, Mark Walton, Warwick Bruce, Yan Yu, Ronald M. Gillies, and Martin Svehla Normal Structure and Function of Bone Torben Steiniche and Ellen M. Hauge Structure and Function of Articular Cartilage Jerry C. Y. Hu and Kyriacos A. Athanasiou Part III. Tissue Harvesting, Fixation, and Preparation Bone-Labeling Techniques Reinhold G. Erben Human Bone Biopsy Robert S. Weinstein Biopsy Issues for Bone and Cartilage Tumors John L. Eady Tissue Harvesting and Fixation Linda L. Jenkins and Karen J. L. Burg Common Fixatives in Hard-Tissue Histology Antonio Scarano, Giovanna Iezzi, and Adriano Piattelli Decalcification of Bone Tissue Robert A. Skinner Principles of Embedding and Common Protocols Yuehuei H. An, Patricia L. Moreira, Qian K. Kang, and Helen E. Gruber Infiltration Techniques and Results in Different Types of Resin Antonio Scarano, Giovanna Orsini, and Adriano Piattelli Part IV. Sectioning Techniques Histological Techniques for Decalcified Bone and Cartilage Qian K. Kang, Jackie C. LaBreck, Helen E. Gruber, and Yuehuei H. An Techniques for Sectioning Undecalcified Bone Tissue Using Microtomes William L. Ries Cutting and Grinding Methods for Hard-Tissue Histology Thomas W. Bauer and Diane Mahovlic Bone Sectioning Using the Exakt System Karl Donath and Michael Rohrer Bone Sectioning Using a Modified Inner Diamond Saw Joop G. C. Wolke, Jan-Paul C. M. van der Waerden, Christel P. A. T. Klein, and John A. Jansen Bone Sectioning Using the Precise 1 Automated Cutting System Antonio Scarano, Manlio Quaranta, and Adriano Piattelli Bone, Cement, and Metal Implant Interface Preparation with a High-Pressure Water Cutter Jian-Sheng Wang and Lars Lidgren Part V. Staining Techniques Basic Staining and Histochemical Techniques and Immunohistochemical Localizations Using Bone Sections Helen E. Gruber and Jane A. Ingram Basic Staining Techniques for Cartilage Sections Helen E. Gruber and Jane A. Ingram Histochemical and Immunohistochemical Staining of Cartilage Sections Andreas G. Nerlich Staining Techniques for Plastic-Embedded Specimens Antonio Scarano, Giovanna Petrone, and Adriano Piattelli In Situ Hybridization of Bone and Cartilage Shintaro Nomura and Seiichi Hirota Part VI. Analysis Techniques Bone Histomorphometry: Concepts and Common Techniques Jean E. Aaron and Patricia A. Shore Histological Analysis of Bone-Implant Interface John A. Jansen Histomorphometric Analysis of Bone-Cement and Cement-Metal Interface Jian-Sheng Wang, Gonzalo G. Valdivia, Michael J. Dunbar, Cecil H. Rorabeck, Robert B. Bourne, and Suzanne Maher Histologic Analysis of Bone Healing Ryland B. Edwards, III, Mandi J. Lopez, and Mark D. Markel Histomorphometry of Metabolic Bone Conditions Ellen M. Hauge, Torben Steiniche, and Troels T. Andreassen Histology of Articular Cartilage Repair Stefan Nehrer and Myron Spector Histological Analysis of Cartilage Conditions Theodore R. Oegema, Jr., Cathy S. Carlson, and Ada A. Cole Histological Analysis of Soft-Tissues Biomaterial Interface: Relevance to Dental Implants Antonio Scarano, Gian Antonio Favero, Elisabetta Fiera, and Adriano Piattelli Pathological Diagnosis of Common Tumors of Bone and Cartilage Jasvir S. Khurana and Kri

Rapid quantification of staphylococci adhered to titanium surfaces using image analyzed epifluorescence microscopy

Abstract A method for rapid enumeration of S. epidermidis adhered to the surface of commercially pure titanium samples was developed using image analyzed epifluorescence microscopy. The method was used to determine the effects of different surface roughnesses of titanium samples and the influence of adsorbed human serum proteins on bacterial adherence. Bacterial suspension of S. epidermidis (VAS-11, concentration: 10 7 cfu/ml) were incubated with titanium samples (with different surface roughnesses and coated with human serum albumin or fibronectin) for 1 h at 37°C with agitation. Thereafter they were washed, stained with propidium iodide, air dried, mounted onto microslides, and counted by using image analyzed epifluorescence microscopy. The results showed that: (1) this direct counting method is quick, simple, accurate, reproducible, and suitable for counting bacteria adhered to opaque surfaces such as netal, (2) the different roughnesses of the titanium surfaces (roughness: 1.25 to 0.44 Ra) had no effect on the S. epidermidis adherence, and (3) adsorbed human serum albumin reduced the S. epidermidis adherence by more than 90%, suggesting that precoating biomaterials with albumin may reduce the possibility of prosthesis or implant colonization by staphylococci. Conversely, human serum fibronection had no effect on S. epidermidis adherence to a titanium surface.

MULTIDIRECTIONAL INSTABILITY OF THE GLENOHUMERAL JOINT

The concept of multidirectional instability (MDI) was introduced as an important clinical entity in 1980. Previously, it had received little mention in the literature and was not considered to be clinically relevant. MDI is a symptomatic glenohumeral subluxation or dislocation occurring in more than one direction. The basic pathology of this condition is a loose and redundant joint capsule. Most patients with MDI can be treated successfully by conservative methods, such as patient education, a shoulder girdle strengthening program, or modification of the patients routine activity.

Animal Models of Orthopedic Implant Infection

Prosthetic infection following total joint replacement can have catastrophic results both physically and psychologically for patients, leading to complete failure of the arthroplasty, possible amputation, prolonged hospitalization, and even death. Although with the use of prophylactic antibiotics and greatly improved operating room techniques the infection rate has decreased markedly during the years, challenges still remain for better preventive and therapeutic measures. In this review the in vivo experimental methods for studies of prosthetic infection are discussed, concentrating on (1) the animal models that have been established and the use of these animal models for studies of pathogenesis of bacteria, behavior of biofilm, effect of biomaterials on prosthetic infection rate, and the effect of infection on biomaterial surfaces, and (2) how to design and conduct an animal model of orthopedic prosthetic infection including animal selection, implant fabrication, bacterial inoculation, surgical technique, and the methods for evaluating the results.

An injectable cementing screw for fixation in osteoporotic bone

With the aging population, osteoporosis and osteoporotic fractures are becoming more prevalent. Adequate screw fixation in this type of bone is difficult. Screws are often cemented in bone to help obtain purchase. However, current cementing techniques do not ensure implant stability. Here we present a new cannulated screw with side ports that can be injected with polymethylmethacylate (PMMA) for fixation in osteoporotic bone. We compared the ultimate holding power of this cannulated screw injected with PMMA to a solid screw with the same dimensions secured with PMMA by the standard technique. Both screws were placed into embalmed and fresh frozen lumbar vertebral bodies and pulled out using a mechanical testing system. The cannulated screw had a 278% greater holding power compared to the standard screw (p < 0.006). The cannulated screw provided a significant increase in holding power in osteoporotic bone. This novel screw is promising for fixation in osteoporotic bone and warrants clinical evaluation.

THE PREVENTION OF PROSTHETIC INFECTION USING A CROSS-LINKED ALBUMIN COATING IN A RABBIT MODEL

We evaluated the effects of a serum protein coating on prosthetic infection in 29 adult male rabbits divided into three groups: control, albumin-coated and uncoated. We used 34 grit-blasted, commercially pure titanium implants. Eleven were coated with cross-linked albumin. All the implants were exposed to a suspension of Staphylococcus epidermidis before implantation. Our findings showed that albumin-coated implants had a much lower infection rate (27%) than the uncoated implants (62%). This may be a useful method of reducing the infection of prostheses.