Titanium niobium nitride knee implants are not inferior to chrome cobalt components for primary total knee arthroplasty.

BACKGROUND: Metal allergy in total knee arthroplasty (TKA) is still a controversial topic. Oxinium, ceramic or titanium niobium nitride (TiNbN) coated implants are available for some knee systems. The hypothesis of this study was that the use of TiNbN-coated components would not lead to inferior results compared to conventional implants and that none of the allergic patients receiving TiNbN-coated implants would require revision for metal allergy.

MATERIALS AND METHODS: This study was a retrospective, 2 to 1 matched pairs study with 40 titanium niobium nitride-coated TKA compared with 80 conventional cobalt chrome implants. No demographic differences between these groups were observed. The mean follow-up for this study was 2 years.

RESULTS: No differences in clinical, radiological, or patient-reported outcome measurements were observed between the two groups. No patients have been revised at this short- to medium-term outcome evaluation.

DISCUSSION: Metal allergy leading to contact or systemic dermatitis is especially linked to chrome and cobalt allergy. Nickel allergy because of knee implants rarely gives cutaneous symptoms, but could potentially lead to peri-prosthetic osteolysis and loosening. The use of titanium niobium nitride implants in case of a positive history of metal allergy could avoid this devastating complication.

CONCLUSION: The use of titanium niobium nitride-coated implants for primary knee osteoarthritis shows similar clinical and radiological outcomes as conventional TKA without revision for loosening at short- to medium-term follow-up. Level of evidence Level IV study.