A modified cementing technique using BoneSource to augment fixation of the acetabulum in a sheep model

Abstract

Background and purposeOur aim was to assess in an animal model whether the use of HA paste at the cement-bone interface in the acetabulum improves fixation. We examined, in sheep, the effect of interposing a layer of hydroxyapatite cement around the periphery of a polyethylene socket prior to fixing it using polymethylmethacrylate (PMMA).MethodsWe performed a randomized study involving 22 sheep that had BoneSource hydroxyapatite material applied to the surface of the acetabulum before cementing a polyethylene cup at arthroplasty. We studied the gross radiographic appearance of the implant-bone interface and the histological appearance at the interface.ResultsThere were more radiolucencies evident in the control group. Histologically, only sheep randomized into the BoneSource group exhibited a fully osseointegrated interface. Use of the hydroxyapatite material did not give any detrimental effects. In some cases, the material appeared to have been fully resorbed. When the material was evident in histological sections, it was incorporated into an osseointegrated interface. There was no giant cell reaction present. There was no evidence of migration of BoneSource to the articulation.InterpretationThe application of HA material prior to cementation of a socket produced an improved interface. The technique may be useful in humans, to extend the longevity of the cemented implant by protecting the socket interface from the effect of hydrodynamic fluid flow and particulate debris.

Can bone apposition predict the retention force of a femoral stem? An experimental weight-bearing hip-implant model in goats

“…This strain can partly explain the large percentage of animals excluded in this study. In one study [ 14 ], the fact that sheep has little spongy bone in the acetabular socket was used as a model for an augment of fixation of an acetabular component in sclerotic bone. This notion was not observed in our goat model, but we cannot eliminate the possibility that the spongy bone is of poorer quality than in humans.…”