Research Article: Fixation of the fully hydroxyapatite-coated Corail stem implanted due to femoral neck fracture

Date Published: April 24, 2012

Publisher: Informa Healthcare

Author(s): Thord von Schewelov, Henrik Ahlborg, Lennart Sanzén, Jack Besjakov, Åke Carlsson.


Today, dislocated femoral neck fractures are commonly treated with a cemented hip arthroplasty. However, cementing of the femoral component may lead to adverse effects and even death. Uncemented stems may lower these risks and hydroxyapatite (HA) coating may enhance integration, but prosthetic stability and clinical outcome in patients with osteoporotic bone have not been fully explored. We therefore studied fixation and clinical outcome in patients who had had a femoral neck fracture and who had received a fully HA-coated stem prosthesis.

50 patients with a dislocated femoral neck fracture were operated with the fully HA-coated Corail total or hemiarthroplasty. 38 patients, mean age 81 (70–96) years, were followed for 24 months with conventional radiographs, RSA, DEXA, and for clinical outcome.

31 of the 38 implants moved statistically significantly up to 3 months, mainly distally, mean 2.7 mm (max. 20 mm (SD 4.3)), and rotated into retroversion mean 3.3º (–1.8 to 17) (SD 4.3) and then appeared to stabilize. Distal stem migration was more pronounced if the stem was deemed to be too small. There was no correlation between BMD and stem migration. The migration did not result in any clinically adverse effects.

The fully hydroxyapatite-coated Corail stem migrates during the first 3 months, but clinical outcome appears to be good, without any adverse events.

Partial Text

50 patients who were admitted to our hospital between 2006 and 2008 with a dislocated femoral neck fracture, Garden type III or IV, met the inclusion criteria and accepted to participate in the study after having received verbal and written information about it. The ethics committee of Lund University approved the study (LU 33/2006).

31 of the 38 stems had migrated statistically significantly at 3 months. Stems smaller than according to the preoperative plan and stems deemed too be too small on postoperative radiographs subsided more than those that were of adequate size. There was no correlation between BMD and stem migration, and stem position had no influence on distal stem migration. There were, however, only 5 stems inserted in varus and the trend was that these stems subsided more. The statistically significant differences in rotation and migration occurring after 3 months (Figure 4) were very small, and they were below the limits for statistically significant movement. Thus, we do not consider these differences to be clinically significant.