12 research outputs found
Development and validation of a computational model of the knee joint for the evaluation of surgical treatments for osteoarthritis
A three-dimensional (3D) knee joint computational model was developed and validated to predict knee joint contact forces
and pressures for different degrees of malalignment. A 3D computational knee model was created from high-resolution
radiological images to emulate passive sagittal rotation (full-extension to 658-flexion) and weight acceptance. A cadaveric
knee mounted on a six-degree-of-freedom robot was subjected to matching boundary and loading conditions. A ligamenttuning
process minimised kinematic differences between the robotically loaded cadaver specimen and the finite element
(FE) model. The model was validated by measured intra-articular force and pressure measurements. Percent full scale error
between FE-predicted and in vitro-measured values in the medial and lateral compartments were 6.67% and 5.94%,
respectively, for normalised peak pressure values, and 7.56% and 4.48%, respectively, for normalised force values. The knee
model can accurately predict normalised intra-articular pressure and forces for different loading conditions and could be
further developed for subject-specific surgical planning
Stability of medial opening wedge high tibial osteotomy: a failure analysis
Medial opening wedge high tibial osteotmy (HTO) is often used to treat varus gonarthrosis in young, active, highly demanding patients, although it has many pitfalls, which were evaluated in a consecutive cohort of patients. A retrospective analysis of a consecutive series of 45 patients with 49 medial opening HTO for varus gonarthrosis using a spacer plate (Puddu I, Arthrex, USA) were included. A Chi square test was used to study the effect between the wedge size and complications. Complications occurred in 22 knees (45%). There was no significant difference between groups for individual complications; however, when combined, there were significantly more complications in the >10 mm wedge group (Chi square p = 0.05). The overall complication rate in this series was 45%. The majority were related to intrinsic instability at the osteotomy site (24%) and surgical technique (20%). The evaluated spacer provided inadequate stability