Titanium niobium nitride mobile-bearing unicompartmental knee arthroplasty results in good to excellent clinical and radiographic outcomes in metal allergy patients with medial knee osteoarthritis

Abstract Background The main purpose of the present study was to analyse the clinical and radiological outcomes of patients with positive skin patch tests who underwent medial mobile-bearing titanium niobium nitride (TiNbN) unicompartmental knee arthroplasty (UKA) during a mid-term follow-up. Methods Thirty-seven patients with positive skin patch tests were included in this prospective study. The clinical evaluation consisted of Oxford Knee Score and Knee Society Score (KSS) reports. Each patient was clinically evaluated the day before surgery (T0) as well as at T1 (11.9 ± 1.3 months) and during the final follow-up T2 (67.2 ± 19.1 months). The positioning of the UKA was evaluated during the final follow-up using standardised radiographs (T2: 67.2 ± 19.1 months). Results Oxford and KSS ranged from a respective mean pre-operative value of 23.0 ± 2.7 and 51.5 ± 5.0 to 42.1 ± 1.7 and 87.6 ± 2.2, respectively, at T1 (p Conclusions The hypoallergenic TiNbN mobile bearing UKA showed comparable results to standard CoCr UKA regardless of the gender, age, BMI and implant size of metal allergy patients with medial knee osteoarthritis. Careful patient selection processes and accurate medical histories played key roles in the choice of hypersensitivity-friendly implants.