The traction force required for dislocation agreed closely to the expected precalculated SPR values of 58.6 N (A), 76.4 N (B) and 96.7 N (C), which proves the joint stabilising effect of AP in the presence of the essential prerequisites (spherical ball articulating in a hemispherical socket, hermetically closed joint capsule and/or labrum, which contains a small amount of fluid and excludes air). The measured SPR was directly proportional to the square of the joint diameter. Indirectly, it was concluded that the dislocation work at rest is directly proportional to the joint diameter cubed. Consequently, the risk of dislocation after total hip arthroplasty (THA) can be reduced by applying bigger, size-adapted hip balls, whose diameter grows according to the outer diameter of the cup. The increasing range of motion is a favourable side-effect. With careful reconstruction of the capsule and insertion of an intracapsular drain, the risk of dislocation in the early postoperative period could be furtherly reduced. Theoretically, artificial labra could be a useful alternative to augment joint stability in THA with a high dislocation tendency instead of constrained liners.