International Orthopaedics June 2017, Volume 41, Issue 6, pp 1101–1105

Retrieval analysis of ceramic-coated metal-on-polyethylene total hip replacements

Khatkar, H., Hothi, H., de Villiers, D. et al.
Hip

Purpose

Ceramic coatings have been used in metal-on-polyethylene (MOP) hips to reduce the risk of wear and also infection; the clinical efficacy of this remains unclear. This retrieval study sought to better understand the performance of coated bearing surfaces.

Methods

Forty-three coated MOP components were analysed post-retrieval for evidence of coating loss and gross polyethylene wear. Coating loss was graded using a visual semi-quantitative protocol. Evidence of gross polyethylene wear was determined by radiographic analysis and visual inspection of the retrieved implants.

Results

All components with gross polyethylene wear (n = 10) were revised due to a malfunctioning acetabular component; 35 % (n = 15) of implants exhibited visible coating loss and the incidence of polyethylene wear in samples with coating loss was 54 %, significantly (p = 0.02) elevated compared to samples with intact coatings (14 %).

Conclusions

In this study we found evidence of coating loss on metal femoral heads which was associated with increased wear of the corresponding polyethylene acetabular cups.


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