Improved rates of long-term survival in cancer patients has led to an increasing prevalence of metastatic disease, notably to osseous structures. The proximal femur and acetabulum are vital weight-bearing surfaces of the lower extremity and common regions of metastatic spread. There are many reconstructive options that depend on several factors including the location of the lesion, type of lesion, and the prognosis of the patient.
An extensive literature review was conducted searching Pubmed.gov with the key words metastatic, proximal femur, acetabulum, reconstruction, and fixation. This identified pathologic characteristics for various metastatic processes, anatomic considerations for the proximal femur, and periacetabular metastatic lesions. This also identified treatment-sensitive tumors compared to treatment-resistant conditions. Reconstruction was usually recommended specifically considering renal, lung, and gastrointestinal carcinomas as well as previously irradiated bone where healing was unlikely. In addition, this study provides a technique guide for implementation of a proximal femoral prosthetic replacement (PFR).
The management of femoral head or neck lesions are frequently managed by hemiarthroplasty with overall reasonable outcomes. In intertrochanteric or subtrochanteric regions, there have been high failure rates of intramedullary fixation, and 2-year reoperation rate of up to 35% was reported with conversion to endoprosthesis. In comparison to an 85% implant survival in intramedullary constructions, there was a 100% 5-year survival in endoprosthesis reconstruction. Periacetabular lesions that do not impact structural stability can be managed with palliative measures. Those patients experiencing significant pain with contained defects may be managed with cement augmentation. Support of the columns may be required with fixation into the ilium, and those with extensive disease may require en bloc internal hemipelvectomy.
Management of lesions of the proximal femur and acetabulum can be managed with a variety of treatment constructions. The utilization of PFR is increasingly more common especially in the setting of destructive metastatic lesions in the proximal femur as soft-tissue repairs improve ambulatory function. Additionally, the survivorship of endoprosthesis is greater than intramedullary fixation and is recommended for reconstruction for individuals with an expected survivorship greater than 7 mo. Lesions within the periacetabular region that are refractory to nonoperative management may benefit anywhere on the spectrum from intralesional cementation to en bloc hemipelvectomy depending the primary tumor type and degree of osseous involvement.
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