Is There a Role for Intramedullary Tissue Sampling During Internal Fixation of Metastatic Disease in Long Bones? A Systematic Review and an Institutional Experience.

Background The purpose of this investigation was to identify and summarize the current utility of intramedullary tissue sampling during long bone internal fixation (IF) for metastatic bone disease (MBD). The secondary aim was to provide the experience of a single institution using this technique. Methods First, a systematic database query of the Cochrane Central Register of Controlled Trials (1976 to 2020), Cochrane Database of Systematic Reviews, Ovid MEDLINE (1946 to 2020), EMBASE, and PubMed (1964 to 2020) was performed. Following article identification, a description of the method of sampling and yield was recorded. Second, an institutional cohort was identified following Institutional Review Board approval. Cases of MBD treated with IF from 2018 to 2020 were reviewed. Data were collected and recorded from cases during which intramedullary reamings were sent for histopathology. Results Ten studies met inclusion criteria. Four of the ten were techniques or technical notes. The remaining six were retrospective reviews in which tissue was sent for histopathology. Among those six, a total of 262 tissue samples were sent, and a negative result was recorded in 37.2% (n = 97) of cases. A total of 18.0% (n = 47) were noted as inadequate for interpretation. For reamings-only studies, the negative rate was higher at 50.5%. In our institutional cohort, a total of 16 tissue samples were sent in the setting of known MBD. The negative rate was 37.5% (n = 6), with zero instances of a change in clinical management after a positive result. Conclusion There are limited descriptions of intramedullary tissue sampling during IF of long bones for MBD. The existing literature, along with our institutional data, suggest this technique is less than optimal for tissue retrieval given the high rates of negative results from samples sent for histopathology. Furthermore, given the lack of clinical impact of a positive sample, we believe a multidisciplinary group should discuss preoperatively the utility of whether treatment might change based off a tissue diagnosis.Level of Evidence: V.