To retrospectively assess the early results of the NexGen Legacy posterior-stabilised total knee prosthesis, which is a newer version of the Insall-Burstein II posterior-stabilised implant.
48 consecutive elderly patients had 60 NexGen Legacy posterior-stabilised total knees. The mean follow-up duration was 21 months. Clinical evaluation was performed according to the Knee Society scores and a scoring system for patellofemoral articulation; radiographic assessment followed the guidelines of the Knee Society. Special emphasis was given to any patellofemoral complications, such as patellar clunk syndrome, patellar maltracking, and other disorders of the extensor mechanism.
Only one patient had mild patellofemoral anterior knee pain at the latest follow-up; 2 patients had patellofemoral crepitus but no pain. No patellar clunk or any other complication of the patellofemoral articulation, such as patellar fracture or subluxation was found. The mean preoperative and postoperative Knee Society scores were 60 and 85 respectively. The mean postoperative knee flexion was 115 degrees.
The overall early results from using the new implant were good, probably because of changes in design of the intercondylar box and its associated cam-and-post mechanism, and a more anatomic trochlea surface, so that the trochlea accommodates the natural patella.