Patient Reported Outcomes of Total Knee Arthroplasty with Ultra-congruent Lipped Polyethylene Liners: A Randomized Study.

OBJECTIVES

The purpose of this study is to compare the Depuy curved (CVD) polyethylene insert to the curved plus (CVD+) design in TKA, which has an increased dished curve for increased articulation congruence and thus secondary anterior to posterior stability.

METHODS

A randomized controlled trial with 100 patients was conducted to compare two knee replacement designs (CVD and CVD+ polyethylene inserts) using the Johnson and Johnson DePuy PFC Sigma total knee replacement. All participants, were randomized and blinded to reduce bias. The trial achieved 100% recruitment and maintained blinding throughout the study. Demographics, baseline characteristics, and KOOS scores were recorded pre-operatively, and at 3 and 12 months postoperatively. In addition, physical and mental component scores (PCS and MCS) were collected at 12 months post-operatively.

RESULTS

Sixty patients had preoperative data, split equally into CVD and CVD+ groups. The cohort's average age was 71.47 years, and 72% were female, with no statistically significant demographic differences between groups. Preoperative measures showed no differences in Pain, ADL, or QOL. At 3 months, no significant differences were noted, though the QOL difference was 64.45 ± 16.57 for CVD and 52.94 ± 27.1 for CVD+ (p = 0.15). At 12 months, trends favored the CVD group, but differences in Pain, ADL, QOL, PCS, and MCS were not significant. Complications were similar, except for stiffness, with 0 cases in the CVD group and 3 in the CVD+ group at 3 months; both had 2 additional cases at 12 months.

CONCLUSION

In our study, there was no difference between designs in terms of pain, activities of daily living, and standard outcomes. Further studies are required to support the benefit of increased congruence in the CVD+ design, even though widespread adoption has been common across the industry.