Tibiofemoral alignment is important to determine the rate of
progression of osteoarthritis and implant survival after total knee
arthroplasty (TKA). Normally, surgeons aim for neutral tibiofemoral
alignment following TKA, but this has been questioned in recent
years. The aim of this study was to evaluate whether varus or valgus
alignment indeed leads to increased medial or lateral tibiofemoral
forces during static and dynamic weight-bearing activities. Tibiofemoral contact forces and moments were measured in nine
patients with instrumented knee implants. Medial force ratios were
analysed during nine daily activities, including activities with
single-limb support (e.g. walking) and double-limb support (e.g.
knee bend). Hip-knee-ankle angles in the frontal plane were analysed
using full-leg coronal radiographs. Aims
Patients and Methods
The accurate reconstruction of hip anatomy and
biomechanics is thought to be important in achieveing good clinical
outcomes following total hip arthroplasty (THA). To this end some
newer hip designs have introduced further modularity into the design
of the femoral component such that neckshaft angle and anteversion,
which can be adjusted intra-operatively. The clinical effect of
this increased modularity is unknown. We have investigated the changes
in these anatomical parameters following conventional THA with a
prosthesis of predetermined neck–shaft angle and assessed the effect
of changes in the hip anatomy on clinical outcomes. In total, 44 patients (mean age 65.3 years (standard deviation
( The mean pre-operative neck–shaft angle was significantly increased
by 2.8° from 128° ( Cite this article:
