We hypothesized that despite the possible changes in the migration regime in recent years, migrant children would report lower HRQoL because of the stress of dislocation of the family and their social background.
Clinical interview of our patients showed that some of them tended to decrease their activity level after THA because they were afraid of dislocation of the newly operated joint or OA over the nonoperated joint; others would participate in aerobic activity such as swimming to facilitate functional ability.
Register analyses have also shown a higher risk of reoperation because of dislocation for the Vario Cup implant head (which accounts for almost half of the bipolar heads) compared to other bipolar implant heads (Garellick et al. 2010).
Also Bystrom et al. [22] found that the rate of revisions because of dislocation was lower for 32-mm heads than for 28-mm heads.
Among all, crack formation [23], sudden occurrence of pressure-induced phase transformation [24] and, generation of slip bands because of dislocation propagation [9] during the nanoindentation process were identified to have occurred in the different systems.
Bipolar implants had a higher risk of reoperation irrespective of cause (HR = 1.3), because of dislocation (1.4), because of infection (1.3), and because of periprosthetic fracture (1.7).
Revision because of dislocation occurred after a mean time of 2.4 years in the Spectron group, 2.1 years in the Lubinus group, and 2.6 years in the Exeter group.
Also, in the Danish Arthroplasty Register the long-term implant survival for patients with childhood hip diseases were encouraging, although an increased risk of revision because of dislocation in the first 6 postoperative months for patients with acetabular dysplasia was found (Thillemann et al. 2008).
A dual-mobility cup had been used in 206 of the hips belonging to these risk groups, and, notably, none of these had been revised because of dislocation.
