The Importance of Awaiting Biopsy Results in Solitary Pathological Proximal Femoral Fractures

Background The optimal surgical treatment for patients presenting with (impending and complete) pathological proximal femoral fractures is predicated on prognosis. Guidelines recommend a preoperative biopsy to exclude sarcomas, however no evidence confirms a benefit. Objective This study aimed to describe the diagnostic accuracy, morbidity and sarcoma incidence of biopsy results in these patients. Material and Methods All patients ( n = 153) presenting with pathological proximal femoral fractures between 2000 and 2019 were retrospectively evaluated. Patients after inadvertent surgery ( n = 25) were excluded. Descriptive statistics were used to evaluate the accuracy and morbidity of diagnostic biopsies. Results Of 112/128 patients who underwent biopsy, nine (8%) biopsies were unreliable either due to being inconclusive ( n = 5) or because the diagnosis changed after resection ( n = 4). Of impending fractures, 32% fractured following needle core biopsy. Median time from diagnosis to surgery was 30 days (interquartile range 21–46). The overall biopsy positive predictive value (PPV) to differentiate between sarcoma and non-sarcoma was 1.00 (95% confidence interval [CI] 0.88–1.00). In patients with a previous malignancy ( n = 24), biopsy ( n = 23) identified the diagnosis in 83% (PPV 0.91, 95% CI 0.71–0.99), of whom five (24%) patients had a new diagnosis. In patients without a history of cancer ( n = 61), final diagnosis included carcinomas ( n = 24, 39.3%), sarcomas ( n = 24, 39.3%), or hematological malignancies ( n = 13, 21.3%). Biopsy ( n = 58) correctly identified the diagnosis in 66% of patients (PPV 0.80, 95% CI 0.67–0.90). Conclusion This study confirms the importance of a preoperative biopsy in solitary pathological proximal femoral fractures due to the risk of sarcoma in patients with and without a history of cancer. However, biopsy delays the time to definite surgery, results can be inconclusive or false, and it risks completion of impending fractures.