Universal intramedullary instrumentation for unicompartmental total knee arthroplasty.

Certainly the advantages of unicompartmental total knee arthroplasty (TKA) are appealing as opposed to tricompartmental arthroplasty. Patients who have had unicompartmental arthroplasty have significant preservation of existing bone stock. They have an improved range of motion and they are definitely easier to revise. This reduces hospitalization time as well as costs with retention of more normal anatomy. In patients with unicompartmental disease with minimal patellofemoral changes, clinical results are certainly encouraging in terms of patient satisfaction with unicompartmental arthroplasty as opposed to tricompartmental arthroplasty. Restoration of function is unquestionably closer to normal than with tricompartmental arthroplasty. The advantages of an intramedullary instrumentation system for unicompartmental disease allows for a more standard method of placing unicompartmental prosthetic components so that less "eyeballing" occurs. Furthermore, utilization of a system that allows for more precise anatomical cuts should allow for better component fit as well as a return to a more normal femoral-tibial angle.