The Effect of Radial Preload on the Implant-Bone Interface

Biliouris, T.; Schneider, Erich; Rahn, B. A.; Gasser, B.; Perren, Stephan M.

doi:10.1097/00005131-198912000-00012

Cited by 34 publications

(29 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Histological studies indicate that a misfit of 0.5 mm between the loaded screw and the drilling hole, as previously described, as well as mechanical loading of the screw–bone interface, are critical to the screw's cortical integration. This conclusion is in accordance with examinations of Biliouris et al,38 who found structural damage in terms of lamellar deformation, osteonal compression, and microfractures in the bone with a misfit of 0.5 mm.…”

Section: Discussionsupporting

confidence: 93%

Poly(D,L‐lactide) coating is capable of enhancing osseous integration of Schanz screws in the absence of infection

Partale

Klein²,

Schell³

et al. 2005

J Biomed Mater Res

View full text Add to dashboard Cite

Pin loosening is a major complication in external fixation. Biological and mechanical conditions play an important role in the maintenance and enhancement of the implant-bone interface in fracture fixation. It is thought that biodegradable coatings may be capable of preventing pin track infection and pin loosening. The goal of this study was therefore to analyze the influence of a biodegradeable coating on the osseous integration of Schanz' screws during fracture treatment. Standardized osteotomies (3-mm fracture gap) of the right tibiae were performed on 16 sheep and stabilized by an AO mono-lateral external fixator. Additional, mechanically less loaded Schanz' screws were also mounted. All screws were randomly coated with biodegradable poly(D,L-lactide). The sheep were sacrificed after 9 weeks. All screws were removed and rolled on blood agar plates for microbiological analysis. Histological sections of the pin tracks were histochemically and morphometrically analyzed. Clinically, no signs of severe infection were visible. Microbiological analysis revealed 14.8% colonization by Staphylococcus aureus in the coated and 29% in the uncoated screws. Histomorphometry of the bone surrounding the Schanz' screws revealed that significantly more osseous integration had occurred on poly(D,L-lactide)-coated screws in the absence of bacterial colonization. Significantly more bone remodeling and a higher osteoclastic activity was seen near the screw-bone interface in the uncoated screw group. Up to a threefold increase in new bone formation and more severe remodeling was observed around the screw entry compared to the pin exit in all groups. Loaded screws showed significantly more callus formation around the exit sites than their less loaded counterparts. In the present study, poly(D,L-lactide) coating of Schanz' screws was found to enhance osseous integration in the absence of bacterial colonization in sheep by causing less cortical remodeling and less osteoclastic activity in the cortices compared to uncoated screws. Additionally, the coating appeared to reduce the instances of pin track infections. Mechanical loading showed an adverse effect on bone formation and remodeling. It has been shown that both biological and mechanical factors play an important role in the maintenance of osseous integrity of the pin-bone interface. Poly(D,L-lactide) coating of Schanz' screws does not prevent osseous destruction and severe bacterial colonization along the pin tracts, but can improve osseous integration of Schanz' screws in the absence of infection.

show abstract

Section: Discussionsupporting

confidence: 93%

Poly(D,L‐lactide) coating is capable of enhancing osseous integration of Schanz screws in the absence of infection

Partale

Klein²,

Schell³

et al. 2005

J Biomed Mater Res

View full text Add to dashboard Cite

show abstract

“…The pilot hole approximates or equals the core diameter of the pin, or screw, leaving the remaining diameter of the threads to subsequently tap and then engage the cortex to provide purchase. It has been shown that pilot holes that are smaller than the core diameter of pins can cause an increase in microstructural damage 12,13 and surrounding cortical stress concentration. 14 However, in cancellous bone, a small core diameter and large thread diameter were advantageous.…”

Section: Discussionmentioning

confidence: 99%

Predrilling Does Not Improve the Pullout Strength of External Fixator Pins

Oliphant

Kim

Osgood

et al. 2013

Journal of Orthopaedic Trauma

View full text Add to dashboard Cite

“…A standard Coulomb friction coefficient of 0.3 was employed based on some of the recent studies (Eser et al, 2010;Pessoa et al, 2010). Additionally, condition (c) considered insertion of the screw into an undersized pilot hole in the bone, which results in a tighter fit (Biliouris et al, 1989;Kuhn et al, 1995). A simple yet novel artifice in which a thermal expansion was applied to the screw after insertion was employed to simulate this condition within the FE analysis.…”

Section: Methodsmentioning

confidence: 99%