Reconstruction of the limb with a massive endoprosthesis after tumour resection is associated with a risk of aseptic loosening. A number of factors influence this risk. These include:

• anatomical site
• length of resection
• muscle resection
• possibly the use of a fixed hinge knee rather than a rotating hinge knee
• the use of a hydroxyapatite collar

The risk of aseptic loosening is likely highest in the distal femur (13.6%) compared with the proximal femur (11%) and pelvis (7%), but in this paper, implants were also revised for other reasons, including deep infection (1).

Reference
(1) Endoprosthetic Reconstruction for the Treatment of Musculoskeletal Tumours of the Appendicular Skeleton and Pelvis.Jeys LM, Kulkarni A, Grimer RJ, Carter SR, Tillman R, Abudu A.  J Bone Joint Surg Am. 2008; 90: 1265-1271.