Neck modularity has been proposed to improve THA accuracy, thanks to the close restoration of anatomy, however it has been associated with issues like early breakages or corrosion. Our Hospital has been using neck modularity since the 90s, so we analyzed retrospectively implants performed between January 2000 and December 2014. The minimum follow up was 1Y. The cohort was composed of 1,033 THAs or 951 patients (82 bilateral), of which 643 females and 390 males. Average patient age was 67.7Y. THA indications were primary Osteoarthritis (80.9%), Fracture (9.0%), Congenital Dysplasia or Congenital Luxation (4.2%), Osteonecrosis (3.2%), other causes (2,7%). The stems used were all cementless, 381 anatomically shaped (36.9%), 635 straight (61.5%), 17 short MIS (1.6%). All necks used were made of Titanium alloy. 419 implants (40.5%) were manufactured by Wright Medical, while 614 (59.5%) were produced by Adler Ortho. A total of 37 revisions has been reported, mainly due to periprosthetic fractures (32.4%), luxation (24.3%), implant mobilization (18.9%) and implant breakage (16.2%). We have recorded 3 modular neck breakages. 4 patients required re-revisions, because of luxations (3) and neck breakage (1). The overall survival rate was 96.4%. We did not observe any component corrosion, probably thanks to the exclusive use of Titanium necks. We had a neck breakages rate of 0.29% and a luxation rate of 0.87%, lower than normally reported in the literature. In conclusion, our experience suggests as neck modularity could be a safe and effective way to reconstruct the proximal femur in THA patients.

Summary Statement

In a retrospective study, FE-based bone strength from CT data showed a greater ability than aBMD to discriminate proximal femur fractures versus controls.