A new UCSF-led study has identified a potential early blood-based indicator of long bone fracture healing, offering a powerful new avenue to track recovery and personalize care.
The research focused on a novel blood-based biomarker called CXM, a breakdown product of collagen type X — a protein expressed during the cartilage-to-bone transition, which represents a critical step in successful fracture healing.
Measuring fracture healing earlier than currently possible
The investigators found that CXM is reliably measured in the blood and that biomarker levels peaked earlier than current radiographic indicators, showing strong potential as a noninvasive tool to quantitatively measure fracture healing progress earlier than is currently possible. The team further found that blood sampling can be transitioned from a traditional blood draw to a simple finger prick, allowing easier long-term monitoring of patient healing.
In the study, researchers analyzed data from more than 150 patients with acute tibia or femur fractures, comparing their CXM levels over time with a control group without fractures. CXM expression peaked around 25 days post-injury in patients with faster healing — a much earlier signal than what standard imaging can provide. The study also confirmed that CXM levels do not vary significantly by age or sex and that this biomarker can be measured reliably from both venipuncture and finger-prick methods.
Direct impact on personalized patient care
“This work began with a small departmental NOVA grant and a collaboration with UCSF trauma fellow Dr. Zachary Working,” said Chelsea Bahney, PhD, who led the study. “It’s a testament to how early-stage departmental funding and collaboration between clinicians and researchers can lead to discoveries that directly impact patient care.”
The research was conducted with a multi-institutional team, including investigators from UCSF, Oregon Health & Science University, the University of Maryland Shock Trauma Center and the Steadman Philippon Research Institute. It represents the first large-scale clinical assessment of a blood-based biomarker specific to the cartilage-to-bone transition in fracture healing.
“Dr. Bahney’s work reflects the department’s commitment to collaborative, translational and impactful research,” said C. Benjamin Ma, MD, chair of the UCSF Department of Orthopaedic Surgery. “This study not only deepens our scientific understanding of fracture healing but may lead to better tools for clinicians to monitor and support bone healing in real time and personalize patient care.”
