A scoping review on the surgical management of metastatic bone disease of the extremities.

Background: Management of metastatic bone disease of the extremities (MBD-E) is challenging, and surgical directions pose significant implications for overall patient morbidity and mortality. Recent literature reviews on the surgical management of MBD-E present a paucity of high-level evidence and global inconsistencies in study design. In order to steer productive research, a scoping review was performed to map and assess critical knowledge gaps.

Methods: The Arksey and O'Malley framework for scoping studies was followed. A comprehensive literature search identified a large body of literature pertaining to the surgical management of MBD-E. Study data and meta-data was extracted and presented using descriptive analytics and a thematic framework. Literature gaps were identified and analyzed.

Results: Three hundred eighty five studies from 1969 to 2017 were included. Studies were categorized into 11 separate themes, with the majority (63%) falling into the "surgical fixation strategies" theme, followed by "complications" at 7% and "prognosis and survival" at 6.2%. Less than 3% of studies were categorized in "patient related outcomes" or "epidemiology" themes. 89% of studies were retrospective and only 6 studies were of level 1 or 2 evidence. We identified a temporal increase in publication by decade, and all studies published on interventional radiology techniques or economic analyses were published after 2007 or 2009, respectively. 64.9% of studies were published in Europe and 20.3% were published in North America. Average patient age was 62 (± 5.2 years), and breast was the most common primary tumour (28%), followed by lung (17%) and kidney (15%). In terms of surgical location, 75% of operations involved the femur, followed by the humerus at 22% and tibia at 3%.

Conclusions: We present a descriptive overview of the current published literature on the surgical management of MBD-E. Critical knowledge gaps have been identified through the development of a thematic framework. Consolidation of literary gaps must involve bolstered efforts towards patient and family-engaged research initiatives and assessment of patient-related surgical outcomes. Multi-disciplinary engagement in developing prospective research will also help guide evidence-based personalized practice for these patients. By building on existing comprehensive patient databases and registries, knowledge on survival and prognostic parameters can be greatly improved.