Early failure of unicompartmental knee arthroplasty.

We are reporting the relatively poor results obtained in patients receiving a unicompartmental knee arthroplasty (UKA). Thirty-six patients underwent 39 UKAs from December 2002 to June 2004. All received a DePuy Preservation design (DePuy, Warsaw, In) with an all-poly tibial component. The patients' mean age was 60 years, with an equal distribution of men to women. Of the 39 UKAs, 15 (38%) failed at 9 to 12 months postoperative. All the failures were secondary to loosening of the femoral component. No correlation to failure was found between preoperative antero-posterior (AP) angle, postoperative AP angle, amount of correction obtained, postoperative posterior tibial slope, lateral femoral component alignment, postoperative range of motion, sex, or size of the patient.