Die nachspannende Balgrist-Hüftpfanne für zementlose Fixation - Entwicklungsgeschichte und bisherige klinische Erfahrungen

Abstract

In March, 1981, development of a hip socket for implantation without the use of bone cement was begun in the Biomechanics Research Laboratory of the Department of Orthopaedic Surgery of the University of Zurich, Balgrist. Already in March, 1982, the first artificial socket with selflocking action, the Balgrist Hip Socket, was successfully implanted in a patient. Following some design modifications, a series of 287 hip sockets were implanted before April, 1986; all of them being made entirely of high density polyethylene. In an attempt to improve the anchoring of the prosthesis within the bone, the outer surface of polyethylene that faced the bone was furnished with a thin coating of titanium and in this form the socket was used 63 times. In the meantime, a model with the outer split shell made of titanium was designed so that in this presently used form, from November, 1987, up to August, 1989, 133 of these hip sockets have been implanted. With the removal or replacement of only 29 sockets, which amounts to 6% (2.7% aseptic and 0.8% septic loosenings, 1.3% removed because of technical mistakes made in the early stages, and 1.3% removed because of suspected low grade infection) the results up to now might well be considered most encouraging.

Langzeitergebnisse der zementfreien konischen Balgrist-Spreizpfanne – Vergleichsanalyse zur Alloclassic-Schraubpfanne

“…Bei späterer Belastung durch den Patienten kann sich der Einsatz weiter in den Spreizring setzen, um so die Vorlast nachträglich zu erhöhen. Die Idee, die hinter dieser Vorlasterhöhung (auch "Nachspannen" genannt) stand, war, gerade während der kritischen Remodelling-Phase des Knochens in den ersten 3 Monaten postoperativ zu einer besseren Sekundärverankerung beizutragen [5]. Trotz guter kurz-bis mittelfristiger Ergebnismitteilungen konnte sich dieses Pfannenkonzept einer breiteren Aufmerksamkeit nicht erfreuen und ist inzwischen vom Markt verschwunden.…”