Abstract
Background
Constrained condylar knees are used infrequently but are successful for the treatment of the primary or revision knee with ligamentous instability and bony defect. The purpose of the present study is retrospectively analyze clinical and radiological outcome of primary and revision total knee arthroplasty with condylar constrained knee (CCK) prosthesis at a minimum of 5 years.
Methods
Fourteen knees underwent total knee arthroplasty with CCK prosthesis, performed between 2003 and 2009. The average age of the patients at the time of the surgery was 71.4 years (range, 47 to 88 years). The reason for the operation was primary (osteoarthritis) in 2, revision due to aseptic loosening in 9 and infection after total knee arthroplasty in 4 knees. NexGen LCCK was used in all cases. The mean follow-up period was 91months (range, 60 to 128 month).
Results
The mean Knee Society knee score and Knee Society functional score were 82.8 (range, 60 to 92) and 57.2 (range, 10 to 89) points at the time of the final follow-up. The mean knee extension and flexion angle were −3.3 (−20 to 0) and 99.2 (65 to 135) before the operation, and −1.7 (−5 to 0) and 103.2 (80 to 130) at the latest follow-up evaluation. In radiographic results, the mean of postoperative femorotibial angle (FTA) was 178° (range, 168 to 187). In one case, radiolucent line was present in Zone 1 to 4 of tibial component. There were one distal femur fracture and one dislocation of the femorotibial joint, with a rate of re-operation of 14.3%. In these two cases, the time from total knee arthroplasty to re-operation were 7 years and 2 years. There were no revisions for aseptic loosening, patella problems, or fractures. Kaplan-Meier survivorship analysis, with revision or other re-operation as the end point, revealed that the ten-year rate of survival of the components was 87.3%.
Conclusions
Primary and revision total knee arthroplasty with use a constrained condylar knee prosthesis had reproducible clinical success at the mid-term follow-up.
