Comparison of the effects of two screw insertion patterns on bone fragment translocation in a 3.5 mm dynamic compression plate and a 3.5 mm limited-contact dynamic compression plate.

Objective: To compare the effects of screw insertion pattern, plate type, application of bone reduction forceps, and additional load screw insertion in an 8-hole 3.5 mm dynamic compression plate (DCP) and limited-contact dynamic compression plate (LC-DCP) on bone fragment translocation (BFT) in a fracture gap model.

Study Design: In vitro mechanical study.

An animal model for interface tissue formation in cemented hip replacements.

Objective: To create a model in sheep for investigation of early changes related to the formation of an interface membrane in hip prosthesis.

Study Design: Experimental study.

Animals: Twenty-four female adult Swiss Alpine sheep.

An experimental animal model of aseptic loosening of hip prostheses in sheep to study early biochemical changes at the interface membrane.

Background: Aseptic loosening of hip prosthesis as it occurs in clinical cases in human patients was attributed to wear particles of the implants, the response of the tissue dominated by macrophages and the production of inflammatory mediators and matrix degrading enzymes; however, the cascade of events initiating the process and their interaction regarding the time course is still open and discussed controversially. Therefore, the goal of this study was to establish an experimental animal model in sheep allowing to follow the cascade of early mechanical and biochemical events within the interface membrane and study the sequence of how they contribute to the pathological bone resorption necessary for aseptic loosening of the implant.

Methods: A cemented modular system (Biomedtrix) was used as a hip replacement in 24 adult Swiss Alpine sheep, with one group receiving a complete cement mantle as controls (n = 12), and the other group a cement mantle with a standardized, lateral, primary defect in the cement mantle (n = 12).

Extraosseous cement granuloma associated with total hip replacement in 6 dogs.

Objective: To report the clinical, radiographic, and pathologic features of extraosseous cement granuloma (ECG), a low occurrence, long-term complication of total hip replacement (THR).

Study Design: Retrospective clinical study. Sample Population-Six client-owned dogs.

Removal of infected canine cemented total hip prostheses using a femoral window technique.

Objective: To evaluate a femoral window technique for retrieval of cemented total hip prostheses.

Study Design: Retrospective clinical study.

Animals: Twelve dogs with infection of a cemented modular total hip prosthesis.