Effects of particulate high‐density polyethylene and titanium alloy on tissue ingrowth into bone harvest chamber in rabbits

Abstract

The purpose of this study was to determine whether small, phagocytosable particles of titanium alloy (Ti) and high-density polyethylene (HDPE) have an adverse effect on bone ingrowth. The bone harvest chamber (BHC) was implanted bilaterally in the proximal tibial metaphysis of six mature rabbits. The BHC has a transverse 1-mm wide pore providing a continuous canal through the chamber for tissue ingrowth. After an initial 6-week period for osseointegration of the BHC, the contents of the canal were harvested repeatedly at 3 weekly intervals. This could be done with the chamber in place, without disturbing its exterior surface or the surrounding bone. The carrier solution, 1% sodium hyaluronate (Healon) was implanted first. In subsequent implantations, Healon was mixed with particles of HDPE or Ti averaging 4.7 +/- 2.1 and 3.0 +/- 2.6 microns, respectively. The contralateral chamber was left empty and served as a control. The chambers were harvested repeatedly, alternating experimental and control sides. The sections from the control side, and those containing Healon alone demonstrated extensive trabecular bone in a fibrovascular stroma. The sections containing Ti alloy particles were qualitatively and quantitatively similar to the control sections and those containing Healon, except for the presence of small black granules of Ti alloy, dispersed in the fibrovascular stroma or phagocytosed by scattered macrophages. The sections containing HDPE particles were infiltrated and engulfed by mononuclear and multinuclear histiocytic cells in a highly fibrous stroma. The majority of the multinucleated cells present were interpreted as being foreign body giant cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Inflammatory Response to Metals and Ceramics

“…Instead, using the "bone harvest chamber" implanted in rabbits, titanium particles small enough to be phagocytosed by macrophages were shown not to hamper bone ingrowth (Goodman et al, 1995). The same authors injected low and high doses of phagocytosable (< 10 micron) particles of Ti-6Al-4V, and HDPE for comparison, in the rabbit bone and found that after 16 weeks a histiocytic reaction without extensive fibrosis, necrosis, or granuloma had been evoked (Goodman et al, 1996a).…”

Spectroscopic characterization of passivated titanium in a physiologic solution

“…A primary reason for using Ti relates to its biocompatibility 1,1-2]. Titanium ions, when released from implants, have generally been considered to be compatible with adjacent tissues I- [3][4][5].…”

No effect of hydroxyapatite particles in phagocytosable sizes on implant fixation: An experimental study in dogs

“…The initial concentration of particles in the gap was ∼1 × 10 9 particles/mL. This was based on a bone harvest chamber study in which an inhibitory effect of 1 × 10 8 PE particles/mL was found in cortical bone 26. However, we did not find any effects on bone ongrowth in our study.…”

“…HA and PE particles have in vitro been shown to stimulate myoblasts,19 fibroblasts,19, 20 monocytes,21, 22 macrophages,23, 24 and osteoclasts25 to the secretion of osteolytic cytokines. Negative effects on bone formation have been shown for PE particles tested in a bone harvest chamber study,26 but a similar in vivo study has not been able to detect any adverse effects on bone formation by HA particles in phagocytosable sizes,27 although inhibitory effects on osteoblasts have been shown in vitro 28…”