Variables in the analysis were: days to the first postoperative RSA examination, alignment of the stem, postoperative CCD angle, change in CCD angle and offset, categorized distance (0 2, 2 4, 4 6, > 6 mm) to the medial and lateral cortex, the amount of femoral neck resection, and the occurrence of stress shielding (steady-state migration only).
Additional parameters, such as stem neck (CCD) angle, head neck ratio, and the design of the acetabular opening, were also considered.
Significant differences were found in basic anatomic parameters between females and males: anteversion, CCD angle, femur and neck lengths, head offsets and radius, cortical thickness, densities in both Gruen and neck zones.
Procenca and Cabral [22] used two monoblock taper stems with different offset, the Wagner stem (145° CCD angle) and the Conelock stem (135° CCD angle), reporting a decrease of dislocation rate from 12%to3%3%, respectively.
In this study, we used exclusively the high offset stem, which has a CCD angle of 123°.
AP radiographs of the affected hip taken preoperatively and at FU1 were evaluated to compare caput-collum-diaphyseal (CCD) angle, center of rotation (COR), and offset according to the method described by Lecerf et al. [16].
In addition, the risk for failure rises with CCD angles of the cone adapter of 135° and smaller.
It has a built in anatomic anteversion and 117° and 126° CCD angles to closely resemble physiological anatomy.
The stem is available in 7 sizes (left and right) and 3 different caput collum diaphysis (CCD) angles (117°, 126°, and 135°).
The proximal part is available in various sizes and shapes, and can be used with 2 offsets and caput (femoral head) – collum (neck) – diaphysis (CCD) angles (126° and 135°).
CE-angle: Centre-edge-angle; CCD-angle: Caput-collum-diaphysis-angle; FAI: Femoroacetabular impingement; OA: Osteoarthritis; THA: Total hip arthroplasty.
