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REVISION OF UNCEMENTED HYDROXY APATITE COATED TOTAL HIP REPLACEMENTS-SERIES OF 21 HIPS

Introduction: The use of H A coated implants for Total Hip Replacement is now well established. We are entering an era where some of these implants are requiring revision. This presentation reviews our experience of revising H A coated THR, considers the failure pattern and attempts to produce a rational method of treatment.

Methods: This is a retrospective study of all HAC coated implants revised by a single surgeon (senior author) covering last five years. It includes 20patients (21 Hips) eleven male and 9 female. The mean age at revision was 62 years (26–82 yrs). The mode of failure suggested three failure patterns hence we have divided them in three groups.

Results: 





Early Failure: The cause for early revision in most cases was technical problems with the primary procedure with improper seating of liner, cup or femoral stem. Correcting the primary problem led to satisfactory results in this group.

Medium term failure: Medium term failure were found to be due to either liner failure or infection. Replacing the liner and two staged revision for infection gave good results.

Long term failure: All cases in this group were due to plastic failure, which led to aseptic loosening of acetabular shell in five cases and aseptic loosening of cup and femoral stem in further two cases.

Only loose components were replaced.

Analysing this series we conclude that in absence of infection only loose components should be replaced. Well held components should be left alone and only the failing component need to be revised.