Diagnostic yield of percutaneous versus open surgical biopsy for tibial bone lesions: A retrospective review.

e23505 Background: Accurate histologic diagnosis is critical for tibial bone tumors, which are among the most common sites for primary bone sarcomas. While percutaneous biopsy (PB) offers minimally invasive sampling, diagnostic accuracy varies by anatomic location. Site-specific data comparing PB to open surgical biopsy (OSB) for tibial lesions is limited. This study compared the diagnostic yield of PB versus OSB for tibial bone lesions and identified factors associated with diagnostic success. Methods: Retrospective cohort study at a tertiary institution, including all tibial bone biopsies from 2015-2025. Primary outcome was diagnostic yield, defined as adequate tissue for definitive histopathologic diagnosis. Diagnostic rates were compared using chi-square tests. Anatomic location, pathologic fracture presence, and technical factors were analyzed for association with diagnostic success. Results: Of 104 tibial biopsies (60 OSB, 44 PB), OSB demonstrated significantly higher diagnostic rate (85% vs 52.3%, p < 0.001). OSB was 1.63 times more likely to yield a diagnosis (95% CI:1.24-2.13) with a number-needed-to-treat of 3.1. Among OSB, diaphyseal lesions had a higher rate of achieving a diagnosis than epiphyseal/metaphyseal (93.9% vs 74.1%, p = 0.032). Pathologic fractures showed a dramatic difference, with OSB achieving 100% diagnostic rate (8/8) versus PB achieving only 20% (1/5, p = 0.013). For PB, mid-diaphyseal (22.2%) and metaphyseal (33.3%) locations had the lowest diagnostic rates. Image guidance modality, needle gauge, and instrument type did not significantly affect outcomes within each biopsy type. Among non-diagnostic cases, 33.3% of OSB and 14.3% of PB ultimately proved malignant. Conclusions: OSB provides significantly superior diagnostic yield compared to PB for tibial lesions, particularly for pathologic fractures and metaphyseal/epiphyseal locations. The substantial difference in diagnostic rates supports preferential use of OSB for tibial bone lesions when feasible, especially given that one-third of non-diagnostic OSB cases ultimately represent malignancy. To our knowledge, this is the first study to examine the impact of tibial anatomic location on biopsy diagnostic yield. Diagnostic outcomes by biopsy method. Outcome OSB (n=60) PB (n=44) p-value Diagnostic rate 85.0% 52.3% <0.001 Relative risk (95% CI) 1.63 (1.24-2.13) - - Repeat biopsy required 16.7% 27.3% 0.287 Pathologic Fracture Diagnostic Rate 100% (8/8) 20% (1/5) 0.013 Diaphysis Diagnostic Rate 93.9% 53.1% <0.001 Epiphysis/Metaphysis Diagnosis Rate 74.1% 50.0% 0.164 OSB = open surgical biopsy; PB = percutaneous biopsy; CI = confidence interval.