In 2012, a new set of instruments, called Microplasty (Fig 1.9), was introduced so as to make the operation more reliable. They are a substantial improvement compared to the original Phase 3 instrumentation. For example, they help with achieving the correct tibial resection height; they facilitate positioning of the femoral component and have a system for preventing impingement. The instruments have been optimised for use with the two peg cementless as well as the two peg cemented component.

Figure 1.9. The Microplasty femoral drill guide.

Also in 2012, the Signature patient specific instrumentation for the Oxford Knee was introduced. An MRI scan is obtained pre-operatively and, based on this, the provisional position of the components is determined. The surgeon then has the opportunity to adjust the positioning. Once the correct positioning is confirmed, patient specific guides are produced. During the operation, these are applied and control the positioning of the components although final balancing is achieved using traditional instrumentation. The Signature instruments currently are not as reliable as Microplasty so are not recommended for inexperienced surgeons (Alvand et al., 2015; Barrington & Emerson, 2013). However, it is expected that with time they will improve.