The degree of mobility of a given linkage depends upon the order of its screw system, whereby a loop with six joint freedoms may be related to its reciprocal screw system, a single screw axis with an associated pitch. It has been postulated that this reciprocal screw can provide an alternative means of identifying its parent linkage, and an investigation in this respect has been recently carrie...

PURPOSE During the early postoperative period, the stability of the fixation of a hamstring graft to the bone tunnel is the primary factor in limiting rehabilitation. The aim of this study was to evaluate if the initial fixation strength of a new suspension screw is comparable to that of the biodegradable interference screw fixation technique in the hamstring reconstruction of the anterior cruc...

Fixation with a dynamic hip screw (DHS) is one of the most common methods for stabilizing intertrochanteric fractures, except for unstable and reverse oblique fracture types. However, failure is often observed in osteoporotic patients whereby the lag screw effectively 'cuts out' through the weak bone. Novel anti-migration blades have been developed to be used in combination with a lag screw ('B...

BACKGROUND Lag screw cut-out failure following fixation of unstable intertrochanteric fractures in osteoporotic bone remains an unsolved challenge. This study tested if resistance to cut-out failure can be improved by using a dual lag screw implant in place of a single lag screw implant. Migration behavior and cut-out resistance of a single and a dual lag screw implant were comparatively evalua...

a 16-year-old class ii female patient was treated without tooth extraction. the upper first molars were distalized by the pendulum appliance. after six months, the molars tipped significantly to the distal. to correct this side effect, we decided to upright the molars using skeletal anchorage. on each side, a mini-screw was inserted between first and second premolars in the buccal cortical plat...

conclusions the functional outcome 22 months post injury showed that although primary treatment method uses locked imn in humeral shaft fractures, unlocked imn can be used in appropriate cases. less injury risk to the axillary and radial nerve, short period of surgery, and less radiation can be considered as advantages of this technique. introduction although intramedullary nailing (imn) is use...

BACKGROUND Screw fixation of pelvic ring fractures is a common, but demanding procedure and navigation techniques were introduced to increase the precision of screw placement. The purpose of this case series was the evaluation of screw misplacement rate and functional outcome of percutaneous screw fixation of pelvic ring disruptions using a 2D navigation system. METHODS Between August 2004 an...

The intention of this study was to compare the biomechanical characteristics using 5 internal fixation methods used clinically to stabilize a pubic symphysis diastasis (PSD, Tile type B1).A 3-dimensional finite element model of PSD was simulated using 5 implants, including single superior plate (Single-Plate), superior and anterior plate (Dual-Plate), single cannulated screw (Single-Screw), cro...

A three-dimensional simulation of trabecular surface remodeling was performed to investigate the basic effects of a fixation screw on the trabecular structural changes in a vertebral body. Voxel-based finite elements were used to construct computational models of the bone and screw for an entire vertebral body with the screw and for the bone-screw interface. The remodeling simulation for the en...