**6. Practical approach for the use of coated implants**

In all patients with suspected or confirmed allergy against implant materials, informed consent and shared decision-making are crucial to avoid negative psychological effects.

#### **Figure 3.**

*A suggested algorithm for primary TKA [18, 50].*

### *Modern Coatings in Knee Arthroplasty DOI: http://dx.doi.org/10.5772/intechopen.105744*

In primary TKA (**Figure 3**), all patients should be asked about allergies against implant materials before surgery. If an allergy is only self-reported, a test should be performed (usually a skin patch test). If the allergy is confirmed, pros and cons of different implants should be discussed with the patient, and a hypoallergenic implant should be considered. A multilayer-coated or oxidized zirconium implant is the best evaluated option in clinical studies and will probably have the best performance regarding the long-term reduction of metal ion release and wear.

In case of revision TKA (**Figure 4**) and suspected allergy against implant materials, additionally to the rule-out of other causes (especially periprosthetic joint infection), a histopathological evaluation (arthroscopic or open during two-stage revision) should be performed. If there is a confirmed allergy (Krenn type 6), a hypoallergenic implant should be considered as in primary TKA.

**Figure 4.**

*A suggested algorithm for revision TKA [18, 50].*
