A comparison of primary and revision total knee arthroplasty using the kinematic stabilizer prosthesis

The first 121 arthroplasties (in 105 patients) in which the cemented kinematic-stabilizer total knee prosthesis was used for primary arthroplasty or surgical revision at the Mayo clinic were reviewed. Sixty-six patients (seventy-nine arthroplasties) were followed for a mean of thirty-seven months. There were fifty-three revision and twenty-six primary arthroplasties. The average range of motion in both groups increased from 95 to 101 degrees. Although none of these patients could ascend stairs without support before the operation, thirty-two (51 per cent) could do so at the time of the final follow-up. The incidence of moderate or severe pain was reduced from 86 to 6 per cent. Moderate or severe ligamentous instability had been present in thirty-three knees (42 per cent) preoperatively, but only five knees had significant medial, lateral, anterior, or posterior instability at final follow-up. The Hospital for Special Surgery knee score increased from an average of 56 points to 83 points in all of the knees. At follow-up, the patients who had had primary arthroplasty had 92 per cent good or excellent results and the patients who had had surgical revision had 81 per cent good or excellent results (p < 0.05). There was no significant difference in the results between the patients who had osteoarthritis and those who had rheumatoid arthritis. Over-all, 85 per cent of the results were good or excellent at final follow-up. Tibial radiolucent lines of one to two millimeters were observed in 29 per cent of the knees at follow-up. Postoperative wound complications occurred in ten knees (13 per cent) and patellar complications, in nine knees (11 per cent). Over-all, complications occurred in twenty-three knees (29 per cent). Five prostheses had to be removed: two because of deep sepsis, two because of persistent instability, and one because the tibial component was malpositioned. Four of the prostheses that had to be removed were in the patients who had surgical revision.