The Effect of In-Stem versus Around-Stem Centralizers on Cement Mantle Thickness and Stem Alignment in Total Hip Arthroplasty

The long term success of cemented total hip arthroplasty has been attributed to the presence of a well pressurized, thick cement mantle around a properly designed stem that has been placed in neutral alignment. Femoral centralizers were developed to achieve this goal more consistently.

While some centralizers fit into the distal tip, others fit around the tip of the prosthesis. We undertook a study to compare the effect of an into-distal-tip (IDT) centralizer versus around-distal-tip (ADT) one. A retrospective review of three groups of primary total hip arthroplasty (THA) patients was performed. Group I consisted of a control population of the last 100 consecutive cases performed with no distal centralizer. Group II consisted of the first 100 consecutive cases performed with the IDT design. Group III consisted of 51 consecutive patients performed using an ADT centralizer. All cases were performed with similar cementing technique by the same senior surgeon (E.S.). Our results show that, while adequate mantles can be obtained, either with or without the use of a centralizer, an around-stem centralizer on a tapered distal stem consistently gave a more neutral stem alignment and a thicker, concentric cement mantle.