RETRIEVAL ANALYSIS OF LORD MADREPORIQUE STEMS IMPLANTED FOR UP TO 13 YEARS

Retrieval analysis of two autopsy and two revision Lord Madreporique f emoral components (range 3.2 to 13 years) was performed to determine q uantitatively the percentage of bone ingrowth in the madreporique surf ace. The mean percentage of bone ingrowth for all specimens was 48%. Q ualitatively, there were extensive amounts of bone along the length of the implant, and no differences were observed in the type or quality of bone between the revision and autopsy specimens. Osseointegration o f the implant was evidenced in all specimens with bone seen adjacent t o the substrate surface. Strain gage analysis also was done on the 13- year autopsy specimen. Results showed a distal increase in cortical me dial principal strains, consistent with the histologic and radiographi c evaluations.