Development and First Experience with an Uncemented Press-Fit Cup

Should We Worry About Periacetabular Interference Gaps in Hip Resurfacing?

“…It has been suggested apical gaps indicate a strong peripheral interference fit, which reduces micromotion and allows osteointegration to occur [16,18]. In support of this view, apical interference gaps have been associated with less component migration and 100% gap healing [18].…”

“…Concerns exist about incomplete seating leading to reduced bony ingrowth and acetabular failure [12]. Recommendations for the size of underream in acetabular press-fit fixation range from 1 to 3 mm [1,3,15,16,24]. A 2-mm underream has been recommended for use in Birmingham Hip TM Resurfacing (BHR TM ; Smith & Nephew Inc, Memphis, TN, USA) [21].…”

“…A 2-mm underream has been recommended for use in Birmingham Hip TM Resurfacing (BHR TM ; Smith & Nephew Inc, Memphis, TN, USA) [21]. While a 2-mm underream reportedly increases the torque-out force required in implanted press-fit acetabular cups [8], several authors have suggested an undersized reamed cavity of less than 2 mm may provide adequate press-fit fixation, while reducing the risk of acetabular fracture during impaction [1,16,24]. Currently, the ideal underream for uncemented, press-fit acetabular fixation is uncertain and little is known about the effect of underream size and the incidence of incomplete acetabular component seating in hip resurfacing.…”

Reconstruction of Large Acetabular Defects Using Trabecular Metal Augments

“…In der Literatur werden bipolare Pfannen, ovaläre oder andere lang gestreckte Implantate, zementierte Pfannen unter Verwendung des "impaction bone grafting", die Kombination mit strukturierten Allografts, die Verwendung von Stützringen, die Sockelpfanne sowie die Individualprothese genannt [4,9,11].…”

R�sultats � long terme de deux composants cotylo�diens non ciment�s dans les proth�ses totales de hanche

“…Cette approche mEcanique de la stabilitE ?~ long terme ne laisse place qu'~ deux alternatives, une stabilitE mEcanique initiale parfaite et un effet de surface autorisant une fixation biologique secondaire 6tant des principes fondamentaux: -L'emploi d'un implant isodlastique qui se dEforme sous l'effet de la charge et suit la ddformation du cotyle osseux [ 19,20]; cette proposition faite par certains auteurs utilisant un matdriau plus 61as-tique que le chrome-cobalt avec un anneau fendu ?~ sa pattie infdrieure au niveau de l'6chancrure et mis en press-fit, est une vole intdressante de recherche; deux objections peuvent atre toutefois soulevdes: l'absence de neutralisation des forces tangentielles ?~ l'interface laissant ainsi ?a la seule rdhabitation le r61e de force de cohdsion et l'inconnue que reprdsente le devenir de l'insert de polydthyRne dans un anneau ddformable.…”