The ABG II stem design made moderate errors in alignment biomechanically tolerable. Alignment defects had no clinical consequences and resulted in minimal differences in bone remodelling.

A prospective study was undertaken on 183 patients who had suffered a femoral neck fracture between 1998 and 1999. The aim was to compare the complication rates for the classical posterior approach and the modified posterior approach. The modified posterior approach used was the one described by Williams et al., which preserved the pyriformis, the labrum and the capsule. Group 1 included 95 patients, who were operated on by the posterior approach. Group 2 included 88 patients, who were operated on by the modified posterior approach. The dislocation rate for the posterior approach was 7.4% (7 cases), and 1.1% (1 case) for the modified posterior approach. This difference was statistically significant (p < 0.05). There were no significant differences in the incidences of other intraoperative and postoperative complications. We concluded that the modified posterior approach significantly increases the stability of a hemiarthroplasty in relation to the classical posterior approach.