Marker-based versus model-based radiostereometric analysis of total knee arthroplasty migration: a reanalysis with comparable mean outcomes despite distinct types of measurement error

Abstract

(2019) Marker-based versus modelbased radiostereometric analysis of total knee arthroplasty migration: a reanalysis with comparable mean outcomes despite distinct types of measurement error,

A radiostereometric and clinical long-term follow-up study of the surface replacement trapeziometacarpal joint prosthesis

“…An incorrect rotational alignment of the reference model can lead to incorrect rotations and hence inaccurate translation measurement. This effect of rotation on translation is explained by Beardsley et al and Van Hamersveld et al [ 21 , 22 ] Therefore, striving for a well three-dimensional spread and stable rigid body as a reference for migration calculation is still important, even if rotations are left out of consideration. However, the small size of the surrounding bone makes it difficult to ensure this in the TMC joint.…”

Risk Factors for Tibial Component Loosening

“…For example, it would be of interest to analyze the effect of certain biomarkers and bone mineral density on migration in such a large group of patients with long-term migration data. Another limitation was that different RSA methods were used across studies, which might result in patients from 1 study being more susceptible to certain types of measurement errors than others 13 . However, we did statistically correct for clustering of patients within each study.…”

“…In uncemented components, high initial migration may also be physiological and merely part of a biphasic migration pattern with high initial migration (i.e., a settling phase) before stabilizing 2,6 . Previous long-term follow-up RSA studies have shown that long-lasting biological fixation can be achieved despite high initial migration in both uncemented components with a hydroxyapatite coating and uncemented components made of highly porous metal 12,14,26 . Uncemented components without an osseointegration-promoting surface, however, more often show a prolonged settling phase (possibly >2 years) or may not stabilize at all 14,27 .…”

“…All studies were randomized controlled trials (RCTs) that compared implants of the same manufacturer within each study with either different fixation methods, different insert designs, or slight alterations in tibial component design (Table I). One study (by Henricson and Nilsson) was changed in design from an RCT to a comparison of 2 consecutive cohorts for logistical reasons 12 . All primary studies were approved by local ethics committees, and approval for the pooling of data was waived for the present study (entry no.…”

“…Details of the RSA methods used were described in each of the individual studies (Table I). It is known that translations are systematically overestimated in marker-based RSA using polyethylene insert markers, as compared with model-based RSA, because of the different reference origin used for migration calculations 13 ; thus, pooling translation data from studies using different RSA methods may not be justifiable. In contrast, maximum total point motion, which is the length of the translation vector of either the point on the tibial component (for model-based RSA) or the marker that moved the most, is not overestimated by 1 method compared with the other.…”