Use of endoprostheses for proximal femur metastases results in a rapid rehabilitation and low risk of implant failure. A prospective population-based study.

Background And Objectives: Endoprosthesis is considered a durable implant for treating metastatic bone disease of the proximal femur (MBDf).

Objectives:   • What is the revision risk after surgery for MBDf using endoprosthesis versus internal fixation?• When do patients with MBDf treated with endoprosthesis restore quality of life (QoL) and how long time does it take to rehabilitate functional outcome?

Methods: A prospective, population-based, multicentre study of 110 patients. Patients were followed for a minimum of two years after surgery. No patients were lost to implant failure nor survival follow-up.

Results: Forty-four patients were treated with internal fixation and 66 patients received endoprostheses. Two-year implant failure risk for internal fixation was 7% (95CI: 0-14%) versus 2% (95CI: 0-5%) for endoprostheses ( = 0.058).Eq-5D improved to the same level as one month prior to surgery six-weeks after surgery, and the score improved further six months after surgery (median score from 0.603 to 0.694,  = 0.007). MSTS score increased from 12 points after surgery to 23 points six-months after surgery (<0.001).

Conclusions: Endoprosthesis for treatment of MBDf results in low implant failure rate. Patients are satisfied with the functional outcome. QoL is restored six-weeks after surgery. Authors advocate for caution using internal fixation for MBDf due to findings of a possible high early postoperative revision risk.