Differences of dynamic (extension vs. flexion) coronal alignment in osteoarthritic (OA) knees undergoing primary total knee arthroplasty (TKA) remain poorly studied. Prospectively collected measurements of dynamic coronal alignment using an imageless computer-navigation system (Stryker©) during primary TKA were analysed. Coronal alignment was represented by the hip-knee-ankle angle and determined at maximal extension and 90° flexion before making any bony cuts or ligamentous releases. Measurements were subgrouped according to coronal alignment in extension as varus (≤-3°), neutral (>−3°, <+3°) or valgus (≥+3°).Background
Methods
The New Zealand Joint Registry was started in 1999. An audit in 2009 showed 98% compliance. Ten year results were published in 2009. For Total Hip Replacement it showed that dislocation was the most common cause for revision (35%). We reviewed the rate of revision for dislocation in the two most common diagnostic groups, Osteoarthritis (86%) and Acute Fracture NOF (3.6%) relative to the two most common surgical approaches, posterior and lateral. We also sought to analyse whether larger femoral head sizes decreased the dislocation rate.Background
Methods