Prospective comparative clinical study of ceramic and metallic femoral components for total knee arthroplasty over a five-year follow-up period

The aim of this prospective comparative study was to evaluate the clinical and radiological outcomes of a TKA system, comparing a ceramic (BIOLOX® delta) and metallic (Co28Cr6Mo) femoral component over a five-year follow-up period.

Forty-three TKA patients (17 metallic and 26 ceramic femoral components) were enrolled in the study. Clinical and radiological evaluations were performed preoperatively and at three, 12, 24 and 60 months postoperatively, using the HSS-, WOMAC- and SF36-Scores, in addition to standardized X-rays.

The HSS-Score improved significantly from 58.7 ± 12.7 points preoperatively to 88.5 ± 12.3 points at five-years postoperative in the ceramic group, and 60.8 ± 7.7 to 86.2 ± 9.4 points in the metallic group. WOMAC- and SF-36-Scores showed significant improvement over time in both groups. There were no significant differences between groups for HSS-, WOMAC- and SF-36-Scores, nor for range of motion (p ≤ 0.897) at any follow-up evaluation. Furthermore, radiological evaluation showed no implant loosening or migration in either group.

Mid-term outcomes for the ceramic femoral components demonstrated good clinical and radiological results, as well as comparable survivorship to the metallic femoral component of the same total knee system, and to other commonly used metallic total knee systems. Therefore, ceramic knee implants may be a promising solution for the population of patients with osteoarthritis and metal sensitivity. Long-term studies are required in order to confirm the positive mid-term clinical results, and to follow the implant survival rate in regard to the enhanced wear resistance of ceramic implants.