Biological and functional evaluation of a novel pyrolytic carbon implant for the treatment of focal osteochondral defects in the medial femoral condyle: assessment in a canine model.

Background: Osteochondral defects continue to be a clinical treatment challenge, and when left untreated, may cause pain and functional impairment. Pyrolytic carbon is a unique isotropic biomaterial used in heart valve and small joint replacements due to its excellent wear properties and biocompatibility with bone and articular cartilage. Therefore, a proposed solution is to utilize a focal pyrolytic carbon hemiarthroplasty implant as an alternative resurfacing treatment strategy for isolated cartilage lesions.

Methodological approaches to comparing information about bicycle accidents internationally: a case study involving Canada and Germany.

The use of bicycles as a mean of healthy and eco-friendly transportation is currently actively promoted in many industrialized countries. However, the number of severe bicycle accidents rose significantly in Germany and Canada in 2011. In order to identify risk factors for bicycle accidents and possible means of prevention, a study was initiated that analyses bicycle accidents from selected regions in both countries.

Correlation of computed tomography with histology in the assessment of periprosthetic defect healing.

Computed tomography (CT) may more accurately assess the healing of grafted osteolytic lesions around acetabular components compared with plain radiographs, although clinical validation is lacking. To determine whether clinical or micro-CT imaging could assess accurately the grafted lesion compared with histology, we therefore quantified bone healing and ingrowth to determine an effective rhBMP-2 dose and ratio to allograft bone when grafted adjacent to a cementless porous-coated component. We grafted surgically created acetabular defects in canines (n = 20) before uncemented total hip arthroplasty.

The effect of low-intensity pulsed ultrasound on autologous osteochondral plugs in a canine model.

Background: Low-intensity pulsed ultrasound promotes the enchondral portion of fracture healing, which has a direct stimulatory effect on cartilage formation and maturation.

Hypothesis: Daily ultrasound treatment positively affects the repair and incorporation of modified autologous osteochondral plugs in a canine model.

Study Design: Controlled laboratory study.

Bone defect healing with an osteogenic protein-1 device combined with carboxymethylcellulose.

One consideration for the practical use and application of osteogenic proteins is an effective method of delivery. This study evaluated a putty-type collagen carrier with recombinant human osteogenic protein-1 (rhOP-1) ability to heal canine critical sized (2.5 cm) ulna segmental defects compared to rhOP-1 with a particulate collagen carrier (OP device).

Osteogenic protein-1 in knee arthritis and arthroplasty.

The use of graft materials to restore bone stock and promote healing and implant stabilization is a crucial part of total knee arthroplasty, especially in revision surgery. Recent research has centered on the use of osteoinductive materials to promote bone formation. Osteogenic proteins are members of a superfamily of proteins called transforming growth factor-beta that, either alone or in combination with other regulatory molecules, induce new bone formation.

Biomechanical study of pedicle screw fixation in severely osteoporotic bone.

Background Context: Obtaining adequate purchase with standard pedicle screw techniques remains a challenge in poor quality bone. The development of alternate insertion techniques and screw designs was prompted by recognition of potential fixation complications. An expandable pedicle screw design has been shown to significantly improve fixation compared to a conventional screw in poor quality bone.

Osteoinductive agents in reconstructive hip surgery: a look forward.

The use of autograft and allograft material to restore bone stock and promote healing and implant stabilization is a crucial part of total hip arthroplasty, especially in the revision situation. Recent research has centered on the use of osteoinductive materials such as osteogenic proteins or bone morphogenetic proteins to promote bone formation. These proteins are members of the transforming growth factor-beta superfamily of proteins that either alone or in combination with other regulatory molecules induce new bone formation.

Induction of bone ingrowth from acetabular defects to a porous surface with OP-1.

Reliable ingrowth of bone into porous-coated cementless total hip components can be expected in primary surgery. In the revision scenario, however, bone deficiency frequently is encountered and the remaining bone may have less ingrowth potential. Allograft bone and bone graft substitutes may be successful in healing bone defects, but have virtually no capacity to induce bone growth from the defect into the porous surface.

Lumbosacral fixation using expandable pedicle screws. an alternative in reoperation and osteoporosis.

Background Context: Pedicle screw fixation in osteoporotic bone and in revision of previous pedicle screw fixation cases presents a significant challenge to spine surgeons. Biomechanical tests have shown that a pedicle screw that expands within the vertebrae body can substantially improve fixation in the presence of compromised bone.

Purpose: To review the clinical and radiographic results with the use of expandable pedicle screws.

Low-intensity pulsed ultrasound improves spinal fusion.

Background Context: Increasing the incidence of solid bony fusion is a primary goal in spine surgery. Daily low-intensity pulsed ultrasound therapy has been shown to improve and accelerate the bone healing process.

Purpose: The purpose of this study was to evaluate the efficacy of daily low-intensity pulsed ultrasound therapy to improve the rate and quality of spinal fusion.

Repair of articular cartilage defects with osteogenic protein-1 (BMP-7) in dogs.

Background: Articular cartilage injury has a poor prognosis for repair. Mesenchymal cells, when exposed to osteogenic proteins and other cytokines, can differentiate into cells that behave phenotypically as chondrocytes. In this study, we examined the ability of recombinant human osteogenic protein-1 (rhOP-1 or rhBMP-7) to elicit the repair of osteochondral defects in dogs.

The effect of demineralized bone matrix gel on bone ingrowth and fixation of porous implants.

The presence of demineralized bone matrix (DBM) gel did not enhance or accelerate attachment strength or bone ingrowth and resulted in a significant decrease in implant interface attachment strength at 3 weeks. Hydroxyapatite (HA) coating resulted in significant increases in interface shear strength and bone ingrowth compared with non-HA-coated porous implants at all time periods. The HA-coated implants achieved greater attachment strength and bone ingrowth at earlier time periods and maintained greater attachment strength at long-term periods.

Healing course of primate ulna segmental defects treated with osteogenic protein-1.

Twelve African green monkeys were implanted with recombinant human osteogenic protein-1 (rhOP-1) placed on a bovine bone-derived Type I collagen carrier to characterize healing in an ulna segmental bone defect model at 1, 3, 12, and 20 weeks postoperative. Defect healing was evaluated by plain film radiography, computed tomography (CT), magnetic resonance imaging (MRI), bone mineral density (BMD), and histologic analysis. Radiographically, new bone formation was observed as early as 3 weeks postoperative.

Improved cartilage repair after treatment with low-intensity pulsed ultrasound.

Low-intensity pulsed ultrasound accelerates bone healing via upregulation of cartilage formation and maturation phases of endchondral bone formation. The current authors evaluated the effect of ultrasound therapy on the repair of full-thickness osteochondral defects. Bilateral, 3.

The effect of osteogenic protein-1 on the healing of segmental bone defects treated with autograft or allograft bone.

Background: Large amounts of bone graft are frequently used to elicit the healing of bone defects resulting from reconstructive procedures. Autograft and allograft bone are often used, but each has its limitations. Bone morphogenetic proteins (BMPs) improve the healing of segmental bone defects treated with autograft or allograft.

Biomechanical testing and clinical experience with the OMEGA-21 spinal fixation system.

The role of spinal instrumentation is to provide mechanical stability, obtain and maintain anatomic alignment, and promote fusion. The American Society for Testing and Materials (ASTM) introduced guidelines and procedures so that biomechanical properties of different implant designs could be compared in a consistent manner. Combined with biomechanical analyses, clinical evaluation allows the safety and efficacy of a spinal implant system to be determined before construction.

Histologic analysis of implant sites after grafting with demineralized bone matrix putty and sheets.

Grafting to restore lost alveolar bone is frequently used to enable placement of endosseous implants and improve cosmesis. Conflicting reports concerning the osteoinductivity of demineralized bone matrix (DBM) and historical use of synthetic bone graft substitutes has limited the use of DBM in oral and maxillofacial applications. Implant placement after bone grafting provides the unique opportunity to biopsy and histologically evaluate new bone formation.

The Otto Aufranc Award. Strut allograft healing to the femur with recombinant human osteogenic protein-1.

Allograft struts are used to reinforce the deficient proximal femur in hip arthroplasty or for fixation of a periprosthetic fracture. Although the use of strut grafts wired or cabled to the proximal femur generally has been successful, the time for healing is slow. The purpose of the current study was to determine whether cortical strut graft healing to the femur could be enhanced by the addition of recombinant human osteogenic protein-1.

Biomechanical evaluation and preliminary clinical experience with an expansive pedicle screw design.

The advantages of pedicle screw fixation depend on their ability to retain bony purchase until the fusion mass is stable. Osteoporotic bone and removal and replacement of pedicle screws in revision procedures substantially reduce screw mechanical fixation strength and can lead to clinical failure. The objective of this study was to determine if an expansive pedicle screw design could be used to improve biomechanical fixation in bone of compromised quality.

Use of an osteoinductive biomaterial (rhOP-1) in healing large segmental bone defects.

Objective: To assess the radiographic, histologic, and mechanical characteristics of new bone formation in large segmental bone defects treated with a new osteoconductive material, recombinant human osteogenic protein-1 (rhOP-1).

Design: In vivo animal study.

Intervention: Sixteen dogs (thirty-two limbs) with an ulna segmental defect (2.

Simian immunodeficiency virus (human HIV-II) transmission in allograft bone procedures.

Study Design: Infection of rhesus monkeys (Macaca mulatta) with simian immunodeficiency virus (SIV, HIV-II) was used to study disease transmission in allograft bone. Four allograft bone processing techniques--fresh, fresh frozen, double freeze-thaw, and double freeze-thaw with chemical decontamination--were evaluated.

Objectives: To determine if SIV could be transmitted in allograft bone and if processing techniques could be used to eliminate the potential for disease transmission.

Effect of recombinant human osteogenic protein-1 on healing of segmental defects in non-human primates.

The effect of recombinant human osteogenic protein-1 on the healing of segmental bone defects was studied in twenty-eight African green monkeys (Cercopithecus aethiops). A 2.0-centimeter osteoperiosteal defect was created in the middle of the ulnar shaft in fourteen animals and in the diaphysis of the tibia in the other fourteen.

Evaluation of recombinant human osteogenic protein-1 (rhOP-1) placed with dental implants in fresh extraction sites.

This study used the canine mandibular model to evaluate the efficacy of recombinant human osteogenic protein-1 (rhOP-1) for accelerating the healing of fresh dental extraction defects and in encouraging osseointegration of dental implants. Eight implants, four hydroxylapatite (HA)-coated and four non-coated, were placed in each mandible of four adult male mongrel dogs immediately after extraction of the eight premolars. The rhOP-1 was placed in all extraction sites with and without implants on the left side of the mandible.

Bone ingrowth into a porous-coated total shoulder component retrieved postmortem.

An uncemented porous-coated humeral component, which functioned in vivo for over 2 1/2 years, was retrieved postmortem and examined histologically. Radiographs of the specimen revealed close approximation to the endosteal cortex medially and laterally. Apposition was limited or absent anteriorly and posteriorly.