International Orthopaedics June 2012, Volume 36, Issue 6, pp 1137–1142

Periprosthetic bone mineral density with a cementless triple tapered stem is dependent on daily activity

Hayashi, S., Nishiyama, T., Fujishiro, T. et al.
Hip

Purpose

Periprosthetic bone loss around the femoral stem is frequently found after total hip arthroplasty. We have shown that periprosthetic bone mineral density (BMD) loss using the triple tapered stem is consistently much less in comparison with the straight type component. In this study, we compared periprosthetic BMD change with clinical factors.

Methods

Postoperative dual-energy X-ray absorptiometry was evaluated at follow-up. BMD was determined based on seven Gruen zones. We further compared BMD with clinical examination: body mass index (BMI), age, Harris hip score (HHS) or University of California at Los Angeles (UCLA) activity rating score.

Results

Periprosthetic BMD loss of the triple tapered stem was maintained. Especially, BMD in Gruen zone 1 which was maintained at 96% in comparison with the straight tapered stem. We compared the BMD change with clinical factors. There is no correlation between BMD and BMI, age or HHS. However, we found significant correlation between BMD and UCLA activity rating score in Gruen zones 1 and 2 of the triple tapered stem. Further, the correlation coefficient was increased at 48 months in comparison with 24 months.

Conclusion

The cementless triple tapered stem maintains periprosthetic bone mineral density. Activity may reflect improving periprosthetic bone quality after THA using a triple tapered stem.


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