The cemented stem in hip arthroplasty - state of the art technique and recommendations

Abstract

The indication for femoral stem cementation should be made on a patient-specific basis, taking physical activity, femoral geometry, and bone tissue quality into account. Age alone should not be the sole justification for cementation. The Dorr classification can serve as decision support for whether a cemented fixation should be used. Femoral neck fractures should generally be cemented. Familiarize yourself with the applied stem philosophy. Force-closed stems typically have a polished surface that allows for subsidence, especially in the first 2 years postoperatively. Stems following the shape-closed philosophy have rougher surfaces and do not allow subsidence. There are various types of cement that differ in viscosity and can be categorized accordingly. These cement types go through four temperature-dependent phases: mixing phase, waiting phase, working phase, and curing phase. Rough implants should be implanted quickly, using wetter cement. For a polished stem, the cement should be slightly firmer. To avoid complications like bone cement implantation syndrome, it is essential to adhere to the state-of-the-art retrograde cementation technique, which recommends pulsatile lavage and vacuum mixing of the cement. Additionally, cement restrictors and pressurizers are used. A thorough understanding of cementation techniques is crucial to ensure a favorable outcome with a uniformly thick cement mantle that encompasses the entire stem. Incorrect cementing can lead to the premature failure of the endoprosthesis.

Keywords: bone cement; bone cement implantation syndrome; cemented hip arthroplasty; cemented stem; cementing technique; force-closed stem; shape-closed stem.

Figure 1

The Singh index grade, describing the DEXA-based trabecular pattern of the femoral neck in an osteoporotic bone stock, from grade I poor bone quality) to grade VI (normal trabecular pattern) (27).

Figure 2

Evaluation and classification of osteoporotic bone changes after Dossick and Dorr (Cortical Index and Canal-Calcar Ratio) and Nobel (CFI).