To prospectively evaluate the survival rate, follow-up rate, clinical and radiographic results of NexGen® total knee replacement arthroplasty (TKRA).

Between June 1998 and March 2002, 434 knees in 278 patients after TKRA performed by a single-surgeon using the same implant were evaluated prospectively. The preoperative diagnosis was primary osteoarthritis in 399 knees, osteonecrosis in 17 knees, rheumatoid arthritis in 12 knees and post-traumatic arthritis in 6 knees. Data collection, physical examination and radiographic evaluation were carried out at postoperative 1, 2, 3 and 5 years. A telephone survey was carried out for the patients who could not visit the outpatient clinic, and the mean follow-up duration was 4.3 years (3-7 years). The follow-up rate and survival rate was analyzed using the Kaplan-Meier method with the reimplantation cases being counted as a failure. The clinical results were evaluated by the Knee Society Score, and the range of motion and status of the implants were assessed by a radiographic evaluation.

The total follow up rate was 91.0% (395/434). The survival rate was 98.3% at 5 years after surgery and the survival rate excluding the infection cases was 99.0% 5 years after surgery. The Knee Society Total Score improved to 96.8 in the cruciate retaining (CR) type and to 95.2 in the Legacy posterior stabilized (LPS) type. The Knee Society Function Score improved to 82.6 in the CR type and to 73.8 in the LPS type on the final follow up. The average preoperative further flexion was 122.6, which improved to 125.4. The radiographic evaluation revealed 6 cases (1.5%) of osteolysis with reimplantation being performed in 2 cases.

In this prospective study, with a high follow-up rate (91.0%), the survival rate of TKRA using the NexGen® implant was relatively high and satisfactory in terms of the functional improvement. However, a long-term follow-up evaluation will be needed.