Patellofemoraler Gelenkersatz

[Patellofemoral joint replacement: onlay or inlay?]

Patellofemoral prosthesis procedures are still rarely performed in Germany. However, with strict indications and thorough preoperative preparation, it can be a viable alternative to total knee arthroplasty (TKA). If conservative treatment methods prove ineffective, the question arises not only as to whether the advantages of an isolated joint replacement outweigh those of a total prosthesis, but also regarding patellofemoral joint replacement: should an inlay or an onlay prosthesis be used?

[When nothing else works: patellofemoral joint arthroplasty]

Patellofemoral joint replacement is the best treatment option available for isolated patellofemoral arthritis. Especially young patients should be operated on with bone-sparing techniques that also preserve the soft tissues, since these patients are very likely to be revised at some point in their lifetime. Correct patient selection is important for the success of surgery and should include a meticulous clinical examination and imaging. Special attention should be paid to additional pathologies that may also need to be addressed. For the trochlea, there are two different options for treatment with the inlay and onlay system. The retropatellar surface should be replaced. Patellofemoral joint replacement is still rarely performed, so treatment in specialised centres is recommended. National joint registry data show high revision rates, while data from centres show promising results.