We sought to determine whether cobalt-chromium alloy (CoCr) femoral
stem tapers (trunnions) wear more than titanium (Ti) alloy stem
tapers (trunnions) when used in a large diameter (LD) metal-on-metal
(MoM) hip arthroplasty system. We performed explant analysis using validated methodology to
determine the volumetric material loss at the taper surfaces of
explanted LD CoCr MoM hip arthroplasties used with either a Ti alloy
(n = 28) or CoCr femoral stem (n = 21). Only 12/14 taper constructs
with a rough male taper surface and a nominal included angle close
to 5.666° were included. Multiple regression modelling was undertaken
using taper angle, taper roughness, bearing diameter (horizontal
lever arm) as independent variables. Material loss was mapped using
a coordinate measuring machine, profilometry and scanning electron
microscopy.Aims
Patients and Methods
The aim of this study was to evaluate the long-term clinical
and radiographic outcomes of the Birmingham Interlocking Pelvic
Osteotomy (BIPO). In this prospective study, we report the mid- to long-term clinical
outcomes of the first 100 consecutive patients (116 hips; 88 in
women, 28 in men) undergoing BIPO, reflecting the surgeon’s learning
curve. Failure was defined as conversion to hip arthroplasty. The
mean age at operation was 31 years (7 to 57). Three patients (three
hips) were lost to follow-up.Aims
Patients and Methods
