O1138 OSTEOLYSIS AND WEAR – WEAR RATE IN POLYETHYLENE CUPS OF LOOSE TOTAL HIP REPLACEMENTS

Abstract

Aims: Periprosthetic osteolysis, generally ascribed to cup polyethylene debris is the most common reason for revision THR. We carried out a radiological – retrieval study in 63 patients undergoing revision THR in order to explore potential correlation between osteolysis and wear in the cup. Material and Methods: 43 intact polyethylene liners were retrieved following revision THR because aseptic loosening. Radiological osteolysis was assessed from the De Lee and Gruen zones. The linear wear depth in the cups was measured using the shadowgraph technique and the volumetric wear was assessed using the Hashimoto formula. Statistical analysis was performed using the SPSS® software package. Results: There was a statistically significant inverse correlation between Volumetric Wear Rate (VWR)-Total Femoral Osteolysis (TFO) (p=0.024), VWR -Total Osteolysis TO (p=0.003), Volumetric Wear (VW) – TFO (p=0.015), and a trend between VW – TO (p=0.087). This shows that increased levels of osteolysis appear to be associated with lower VWR. Conclusions: Overall these results demonstrate an overall inverse relationship between long term wear of the polyethylene and periprosthetic osteolysis in pre-revision patients. Restriction in the mobility-activity could be a reason for that.