Different Types of Primary Stability and their Impact on the Radiographic Results (Bone Stock and Secondary Stability)

Abstract

With an uncemented implant, the zone of primary stability corresponds to the zone of the femur where there is an intimate contact between the cortex and the implant in the form of a surface. So, different types of primary stability can be identified: proximal, global, diaphyseal (short or long) or by means of a 3-point contact.

• Secondary bone stock. With a qualitative assessment, there is not a statistically significant difference between secondary bone stock and the different types of primary stability (p = 0.6). In contrast, with a numerical assessment, the evolution of bone stock varies significantly between one type of primary stability and another (p < 0.0001). In a statistical study between diaphyseal stability versus global/proximal/3-point and the length of the implant, a borderline significant difference is found (p = 0.07).

• Secondary stability (weighted score). In quantitative assessment, patients who ultimately had a lack of secondary stability enjoyed significantly more often diaphyseal primary stability (p = 0.05). In numerical assessment, on average, secondary stability varies significantly in function of the type of primary stability (p < 0.0001). Diaphyseal primary stability (especially diaphyseal long) is the least favorable for secondary stability, especially if proximal stabilization of the implant is not assured at the end of the intervention.

An erratum to this chapter can be found at http://dx.doi.org/10.1007/978-3-319-03614-4_21