A follow-up study of porous-coated anatomic knee arthroplasty

Ninety-four patients (105 knees) having a porous-coated anatomic total knee arthroplasty were retrospectively studied. The mean follow-up period was 5.8 years. The diagnoses were osteoarthritis (90.5%) and rheumatoid arthritis (9.5%). There were 80 women and 14 men. The mean age at operation was 58.5 years. Clinical evaluation, using the Hospital for Special Surgery knee score along with radiography, was used to assess knee status before and after surgery. The postoperative mean axial alignment was 3 degrees varus compared with 11 degrees varus before surgery. Placement of the prosthetic components was acceptable, with the femoral component in 6.5 degrees of valgus and the tibial component in 1.9 degrees of varus and 1.1 degrees posterior inclination. Complications included eight aseptic loosenings, four patellar maltrackings, one patellar fracture, eight wound problems, and one extension contracture. Most of the patients' knee function improved after surgery. The initial, postoperative range of motion improved in patients receiving continuous passive motion (CPM) immediately after surgery (P = .03) compared to patients without CPM application; however, the long-term follow-up data show no significance (P = .06) whether CPM was used or not. Age, body weight, degree of arthritic change, and modes of fixation yielded no significant influence on the final outcome. The porous-coated anatomic total knee arthroplasty is a valuable alternative procedure in the advanced arthritic knee when the proper candidates are selected, accurate surgical technique is executed and a suitable fixation mode is chosen.