Numeric simulation of bone remodelling patterns after implantation of a cementless straight stem.

Purpose: For further development of better bone-preserving implants in total hip arthroplasty (THA), we need to look back and analyse established and clinically approved implants to find out what made them successful. Finite element analysis can help do this by simulating periprosthetic bone remodelling under different conditions. Our aim was thus to establish a numerical model of the cementless straight stem for which good long-term results have been obtained.

The cementless Bicontact stem in a prospective dual-energy X-ray absorptiometry study.

Purpose: The cementless Bicontact total hip arthroplasty (THA) system (AESCULAP AG, Tuttlingen, Germany) was introduced in 1986/1987 and has been in successful clinical use in an unaltered form up to today. Although good long-term results with the Bicontact stem have been published, it is questionable whether the implant provides the criteria for a state-of-the-art stem regarding proximal bone stock preservation. The purpose of the study was to monitor the periprosthetic bone mineral density (BMD) in a prospective two-year follow-up dual-energy X-ray absorptiometry (DEXA) study.

Bone remodelling around a cementless straight THA stem: a prospective dual-energy X-ray absorptiometry study.

The design of the Bicontact® stem (BBraun, Aesculap, Tuttlingen, Germany) and the implantation technique have undergone no major alterations in the last 20 years leading, and good clinical results have been reported. The aim of our study was to investigate whether the implant encourages beneficial bone remodelling. Twenty-four patients were included in a prospective dual-energy X-ray absorptiometry (DEXA) study of this stem, after appropriate statistical power analysis.

Bone remodelling around the Metha short stem in total hip arthroplasty: a prospective dual-energy X-ray absorptiometry study.

Purpose: On the basis of positive clinical results with mid- and long-term follow-up using the Mayo short stem, the Metha neck-preserving stem (BBraun, Aesculap, Tuttlingen, Germany) was introduced. The purpose of this study was to validate the implant design by direct acquisition of bone remodelling data from total hip arthroplasty (THA) recipients using dual-energy X-ray absorptiometry (DEXA).

Methods: After power analysis, 25 patients were included in this prospective study.