On the basis of a FE-model for bone modeling which takes into account bone apposition and resorption as well as revascularization, the ossification process of the repair zone around a dental implant in the mandible is studied for two alternatives. The conventional two-stage implantation method consists of a healing phase (no direct loading of the implant) and a functional phase (direct loading). In the recently applied one-stage method the healing phase is omitted (early loading). The presented simulations show that both processes finally lead to the same degree of ossification of the repair zone. However, the relative displacements and rotations of the implant are considerably larger in the one-stage process and might therefore possibly lead to a violation of the bond between implant and bone.
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http://dx.doi.org/10.1515/bmte.2002.47.s1a.298 | DOI Listing |
J Bone Joint Surg Am
November 2024
Department of Orthopedic Surgery, Columbia University Irving Medical Center, New York, NY.
Background: An accurate knowledge of a patient's risk of cord-level intraoperative neuromonitoring (IONM) data loss is important for an informed decision-making process prior to deformity correction, but no prediction tool currently exists.
Methods: A total of 1,106 patients with spinal deformity and 205 perioperative variables were included. A stepwise machine-learning (ML) approach using random forest (RF) analysis and multivariable logistic regression was performed.
J Appl Oral Sci
January 2025
Universidade Federal de Uberlândia, Faculdade de Odontologia, Departamento de Periodontia e Implantodontia, Uberlândia, Brasil.
Objective: This study aimed to assess the effects of a single-dose radiation therapy (15 Gy) on grafted and non-grafted defects, bone microarchitecture, and collagen maturity.
Methodology: Bone defects were surgically created in rat femurs. The right femur defect was filled with blood clot (group "Clot") and the left femur defect by deproteinized bovine bone mineral graft (group "Xenograft").
Purpose: To create tridimensional (3D) anatomical models of diaphyseal fractures in dogs (3D AMDFD) and to evaluate the models from their radiographs.
Methods: The study consisted of six stages: preparation of femur from a healthy dog cadaver; digitalization of the bone through a 3D scanner and creation of the base model; creation of a 3D AMDFD based on the image of the base model, 3D modeling carried out to reproduce five different types of diaphyseal fractures; printing the models produced on a 3D printer with a thermoplastic material; insertion of neodymium magnets in the fracture line to allow the assembly and disassembly of the parts; and radiography of 3D AMDFD in lateromedial and craniocaudal positions.
Results: The base model and 3D AMDFD had high precision in the replication of bone structures, like the bone in natura.
J Bone Joint Surg Am
November 2024
Department of Orthopaedic Surgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
Background: Fractures of the thoracic and lumbar spine are increasingly common. Although it is known that such fractures may elevate the risk of near-term morbidity, the natural history of patients who sustain such injuries remains poorly described. We sought to characterize the natural history of patients treated for thoracolumbar fractures and to understand clinical and sociodemographic factors associated with survival.
View Article and Find Full Text PDFJ Bone Joint Surg Am
November 2024
Department of Orthopaedic Surgery, Harvard Medical School, Boston Shoulder Institute, Massachusetts General Hospital, Boston, Massachusetts.
Background: Rotator cuff repair (RCR) is a frequently performed outpatient orthopaedic surgery, with substantial financial implications for health-care systems. Time-driven activity-based costing (TDABC) is a method for nuanced cost analysis and is a valuable tool for strategic health-care decision-making. The aim of this study was to apply the TDABC methodology to RCR procedures to identify specific avenues to optimize cost-efficiency within the health-care system in 2 critical areas: (1) the reduction of variability in the episode duration, and (2) the standardization of suture anchor acquisition costs.
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