Unicompartmental porous coated anatomic total knee arthroplasty.

Unicompartmental arthroplasty has been advocated for management of the older patient with unicompartmental arthritis. Implant breakage and loosening has led to modifications of implant design to metal backing and porous coating for potential bone ingrowth. A review of 28 cementless porous coated anatomic total knee arthroplasties two years after the operation revealed good to excellent results in 20 knees (71%). Six knees in five patients required revision for persistent pain. Only fibrous tissue ingrowth was observed. Five knees were considered potential failures based upon persistent pain and roentgenographic evidence of component loosening. This implant design is not acceptable with cementless fixation.