For complication rate, the Henderson classification of complications will be applied. This classification identifies five primary modes of endoprosthetic failure: soft tissue failure (type 1), aseptic loosening (type 2), structural failure (type 3), infection (type 4), and tumour progression (type 5). Wound complications with clinical consequences will be registered separately. Re-operations due to complications will be registered as such in the treatment field as a new operation.