Cement retrieval in minimally invasive knee surgery: the 90 degrees ball probe.

Minimally invasive knee surgery has many potential advantages as well as disadvantages. One such disadvantage in both unicompartmental and total knee arthroplasty is the inability to visualize or retrieve extruded cement. We describe the use of a new instrument, a 90 degrees ball probe, which we have used in more than 300 minimally invasive unicompartmental knee arthroplasty cases. It provides a simple, consistent, and safe method of cement retrieval.