BACKGROUND When performing arthroscopic ankle arthrodesis for end-stage ankle arthritis, internal fixation is performed using bone screws after appropriate preparation. However, optimal characteristics of bone screws have not been examined in terms of pressure force. Objective comparisons of bone-screw performance may provide information on procedures for arthroscopic ankle arthrodesis. The stu...

The purpose of this study was to analyze the relative biomechanical stability of three types of internal fixation with cancellous bone graft in a cadaveric, scaphoid nonunion model. A scaphoid nonunion model was created by removing a volar wedge of bone from the waist of the scaphoid in 18 fresh frozen human cadavers. Cancellous sawbone graft was inserted into the osteotomy site and three group...

The properties of shape memory alloys, specifically the equiatomic intermetallic NiTi, are unique and significant in that they offer simple and effective solutions for some of the biomechanical issues encountered in orthopedics. Pedicle screws, used as an anchoring point for the implantation of spinal instrumentations in the spinal fracture and deformity treatments, entail the major drawback of...

BACKGROUND Dynamic compression plate (DCP) constructs provide inadequate fixation in cases of poor bone quality and early weight-bearing. Screw locking elements (SLE) are flat locking nuts placed at the end of the screw to prevent screw stripping from the bone, improving fixation stability. The purpose of this work was to compare biomechanical and radiological evaluations of femoral ovine osteo...

OBJECTIVE We evaluated the validity of bone cement-augmented percutaneous screw fixation for treating malignant spinal metastases. METHODS Between 2011 and 2015, 14 patients (eight men and six women) who underwent bone cement-augmented percutaneous screw fixation for malignant spinal metastases were enrolled in this study. Their life expectancy was considered to be more than one month and les...

The purpose of this study was to histomorphometrically evaluate the bone-to-implant contact and bone area around a titanium implant retrieved from a human lower jaw. A screw-shaped titanium implant (sandblasted and acid-etched surface) was removed from a 68-year-old male after having been in function for 40 months because of a fracture of the abutment screw. Following the implant removal, an un...

Introduction Poor bone quality due to osteoporosis is an increasing problem in dorsal transpedicular instrumentation of the aging spine. As the number of patients and indications are increasing, complications as screw loosening, cut-out, migration and loss of reduction are more and more observed [1,2]. These complications can be avoided to a large degree by choosing appropriate implant design a...

Introduction Electromagnetic stimulation is a common therapy to support bone healing in cases of avascular necrosis or pseudarthrosis. An electrostimulative screw implant (Asnis III s-series screw in Figure 1) is used to stimulate bone regeneration in the treatment of femoral head avascular necrosis. To enable positive outcome of the treatment, optimal positioning of the electric implant is cri...

Bisphosphonates improve implant fixation in randomised clinical trials of knee prostheses, hip prostheses and dental implants. However, a limited amount of bone resorption is required for bisphosphonates to exert an effect. Anti-RANKL treatment does not have this limitation, and we therefore tested whether if they might be more effective for improvement of implant fixation. This is of interest,...

Background and purpose — Cancellous bone appears to heal by mechanisms different from shaft fracture healing. There is a paucity of animal models for fractures in cancellous bone, especially with mechanical evaluation. One proposed model consists of a screw in the proximal tibia of rodents, evaluated by pull-out testing. We evaluated this model in rats by comparing it to the healing of empty dr...