This study will be based on a retrospective review of patients who received endoprosthetic reconstruction for pathologic fracture of the proximal femur. The objectives would be two-fold: (1) to compare rates ofambulation, pain, and survival to the historic cohort and (2) to identify predictors of ambulation in the current population.

Inclusion Criteria:

• Participants have received endoprosthetic reconstruction for pathologic fracture of the proximal femur

Exclusion Criteria:

• Participants with fractures greater than 3mm from the lesser trochanter
• Participants without histopathologic confirmation of tumor

For this retrospective data review, the study team will query the orthopaedic caisis database and IDB to obtain a list of all participants who have received endoprosthetic reconstruction for pathologic fracture of the proximal femur.

• Memorial Sloan Kettering Cancer Center supports the international committee of medical journal editors (ICMJE) and the ethical obligation of responsible sharing of data from clinical trials. The protocol summary, a statistical summary, and informed consent form will be made available on clinicaltrials.gov when required as a condition of Federal awards, other agreements supporting the research and/or as otherwise required. Requests for deidentified individual participant data can be made beginning 12 months after publication and for up to 36 months post publication. Deidentified individual participant data reported in the manuscript will be shared under the terms of a Data Use Agreement and may only be used for approved proposals. Requests may be made to: crdatashare@mskcc.org.