Comparison of Posterior Cruciate Ligament Retentionversus Substitution in PFCSigma Rotating-Platform Total Knee Arthroplasty

Chun, Churl Hong; Kim, Dong Chul; Kim, Jeong Woo; Kweon, Seok Hyun; Jeung, Ul Oh; Kim, Seong Hun

Abstract

PURPOSE
The purpose of this study was to assess the results of posterior cruciate ligament-retaining and posterior cruciate ligament-sacrificing total knee arthroplasty using PFC Sigma rotating-platform (RP).
MATERIALS AND METHODS
The subjects for this study were 43 patients who had undergone total knee arthroplasties by means of PFC Sigma RPs from February 2002 to July 2002 and, thereafter, had been observed for a period of at least 36 months. Twenty-two of the patients were categorized to group I, which retained the posterior cruciate ligament and 21 to group II, which substituted for the ligament. All the patients were evaluated for pre- and post-operative ranges of motion, the Hospital for Special Surgery (HSS) knee rating system, and radiographic analysis.
RESULTS
The average flexion contracture was 6.5degrees (+/-1.0o) in group I and 6.7degrees (+/-0.8degrees) in group II pre-operatively, and 1.1degrees (+/-0.3degrees) in group I and 0.9degrees (+/-0.2degrees) in group II at the last follow-up. The average active range of knee motion improved from 87.6degrees (+/-6.5degrees) in group I and 86.6degrees (+/-6.1degrees) in group II pre-operatively, to 123.0degrees (+/-7.8degrees) and 125.1degrees (+/-7.3degrees), respectively, at the last follow-up. The average HSS score improved from 41.1degrees (+/-7.1degrees) in group I and 40.3degrees (+/-5.3degrees) in group II pre- operatively, to 87.3degrees (+/-6.0degrees) and 88.9degrees (+/-4.9degrees), respectively, at the last follow-up. There was also improvement in the average tibio-femoral angle from 8.0degrees in varus to 5.7degrees in valgus in group I and from 10.9 in varus to 5.4degrees in valgus in group II. Radiolucent lines were observed in 4 cases from group I and in 1 case from the group II. No significant progressive periprosthetic osteolysis was observed in the follow-up radiographs of both groups.
CONCLUSION
There were no clinical and radiographic differences between the posterior cruciate ligament-retention and ligament-substitution groups, which indicates the necessity for long-term observation.