Glossary
- p-value
Lowest significance level at which a statistical test would still reject the null hypothesis. Values below 0.05 are usually referred to as being statistically significant.
- Partial knee arthroplasty
In a partial knee prosthesis only part of the joint surface is replaced. A typical example is a unicondylar prosthesis in which only the medial/lateral part of the knee joint is replaced, but not the entire knee joint. Also refer to "Total knee arthroplasty".
- Partially cemented
Partially cemented indicates that one component is not cemented and the other is. Also refer to "Hybrid".
- Patellar component
Component of the retropatellar replacement. While this often only consists of a polyethylene cap, which is cemented into the posterior surface of the patella, there are also designs in which a polyethylene cap is fixed to a metal base plate. Also refer to "Patellar resurfacing".
- Patellar resurfacing
Use of an implant replacing the articulation surface of the kneecap. Also refer to "Complementary surgery".
- Patellofemoral arthroplasty
Artificial replacement of the patella surface and the trochlea (groove in the thighbone).
- Pivot
Describes knee systems designed to support natural rotation/translation kinematics.
- Polyethylene (PE)
Polyethylene (abbreviation PE) is a thermoplastic made by chain polymerisation of ethene [CH2=CH2], from which prosthetic components (e.g. inserts) can be produced. In arthroplasty, ultra high molecular weight polyethylene (UHMWPE) is usually used. This can subsequently be modified by irradiating and coupling to antioxidants. Also refer to hXLPE or mXLPE.
- Posterior stabilised
Design allowing the posterior cruciate ligament to be replaced with a mechanical element such as an articulated polyethylene extension which controls and limits anterior and/or posterior movement.
- Primary implantation
See: "Primary surgery".
- Primary surgery/arthroplasty
The primary implantation of one or more arthroplasty components in a particular joint.
- Prosthetic joint infection
These infections are generally a bacterial colonisation of an implanted endoprosthesis. This is a particularly dreaded complication, which is difficult and time-consuming to treat surgically. Typically, the infection is caused by pathogens that are part of the normal human skin and mucosal flora.
