Summary

A retrospective, non-randomized study to compare clinical and functional outcomes of patients undergoing cemented TKA to those with an uncemented implant, using the same implant design.

Abstract

Objectives:
The ideal fixation method in total knee arthroplasty (TKA) is still controversial, with doubts about whether uncemented implants may guarantee equivalent results than cemented TKAs. The aim of this retrospective study was to compare clinical and functional outcomes of patients undergoing cemented TKA to those
with an uncemented implant, using the same implant design.

Methods

We carried out a retrospective, non-randomized study, including 109 TKA (Zimmer® NexGen cruciate retaining (CR) (Zimmer, Warsaw, USA) implanted by a single surgeon between 2013 and 2015 for primary osteoarthritis, comparing 2 groups depending on the tibial component fixation method, one cementless (Group A, n = 60) and one cemented (Group B, n = 46). Patients of both groups were matched for gender, body mass index (BMI), length of total operative time, postoperative Knee injury and Osteoarthritis Outcome Score (KOOS) values and postoperative pain Visual Analogue Scale (VAS).
Group A consisted of a mean age of 68.1 years (range 43 to 79) and a mean BMI of 28,62 (range 20,96 to 43). Group B consisted of a mean age of 72.7 years (range 49 to 79) and a mean BMI of 27,1(range 18,43 to 37,47).

Results

Patients of both groups were available for final follow-up evaluation at a mean of 10,6 years (range 8,9 to 11.8 ys). There was no difference in gender (p=0,1598), BMI (p=0,07), postoperative VAS (p=0,3433) and postoperative KOOS values (p=0,3912), but the total operative time was shorter in the cementless group (51,1 ± 15,7 compared with 62,4 ± 27,9 minutes, p=0,0108). Five patients (8,3%) in Group A and three patients (6,5%) in Group B were symptomatic at the last follow up, without significant difference among the two groups (p=0,7288). One revision surgery after a traumatic event was needed in Group A. In Group B no revision surgeries were required. There was one case of postoperative complication in Group A, and no complications in Group B.

Conclusions

This study presents satisfactory clinical long-term outcomes with both versions of the Zimmer® NexGen CR prosthesis. Furthermore, a significant reduction in operative time with the cementless procedure has been reported.