The effect of radial head implant shape on radiocapitellar kinematics during in vitro forearm rotation

Mason type 3 radial head fractures: proposal of a synthesis technique using bioabsorbable thread

“…Conversely, young patients have a high risk of revision surgery after prosthetic head implantation (13). Many artificial radial head designs have been developed, making it possible to choose between monopolar and bipolar versions (14); however, the ideal model for guaranteeing optimal tracking during movement on the capitellum remains to be established (15). Given these considerations, anatomical features of the radius are unique and very difficult to reproduce; moreover, even were a perfect prosthesis available, this should, crucially, be inserted in the correct position (6).…”

Die Passgenauigkeit monopolarer Radiuskopfprothesen im proximalen Radioulnargelenk

“…Folgerichtig reproduzieren die vorhandenen Radiuskopfprothesen die Kinematik des Ellenbogengelenks lediglich bedingt [12,19,20]. Dies führt nicht nur zu einer veränderten Biomechanik hinsichtlich der Stabilität, der Kontaktflä-chen und der Druckverteilung im Radiokapitellargelenk [12,19,20], sondern wirkt sich auch auf die Anatomie des proximalen Radioulnargelenks (PRUG) aus [21].…”

“…Dies führt nicht nur zu einer veränderten Biomechanik hinsichtlich der Stabilität, der Kontaktflä-chen und der Druckverteilung im Radiokapitellargelenk [12,19,20], sondern wirkt sich auch auf die Anatomie des proximalen Radioulnargelenks (PRUG) aus [21]. Im PRUG artikuliert der Radiuskopf mit der Incisura radialis der Ulna, um Umwendbewegungen im Unterarm zu ermöglichen.…”

Arthroplasty in Elbow Fracture Treatment

“…Usually both concepts have a built-in angle between the stem and neck as with the native proximal radius of approximately 15°. Anatomical studies have been made on mono-polar and bi-polar implants, and none is able to replicate the physiological kinematics of the radial head (Wegmann et al 2014, Shannon et al 2015.…”

“…Prosthetic loosening is a frequent indication for secondary surgery. In in-vitro studies have shown that perfect restoration of the normal anatomy is not possible using implants available today, and the incongruence produced leads to eccentric loads on the implant and that may cause loosening (Yian et al 2008, Wegmann et al 2014, Shannon et al 2015.…”