Study led by Dr. Chelsea Bahney published in PLOS Medicine highlights promising biomarker for monitoring fracture recovery
SAN FRANCISCO (Sept.11, 2025) – A new study from the UCSF Department of Orthopaedic Surgery has identified a potential early biomarker for long bone fracture healing, offering a powerful new avenue to track recovery and personalize care. The clinical observational study, led by Chelsea Bahney, PhD, associate professor of orthopaedic surgery, was published this week in PLOS Medicine.
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. 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 non-invasive tool to quantitatively measure fracture healing progress earlier than is currently possible. The team further found that blood sampling can be transferred from a traditional blood draw to a simple finger prick, allowing easier long-term monitoring of patient healing.
“This work began with a small departmental NOVA grant and a collaboration with a UCSF trauma fellow Dr. Zachary Working,” said Dr. Bahney. “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.”
In the study, researchers analyzed data from over 150 patients with acute tibia or femur fractures, comparing their CXM levels over time to 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.
“Dr. Bahney’s work reflects the department’s commitment to collaborative, translational and impactful research,” said Dr. C. Benjamin Ma, 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 our patient care.”
The research was conducted with a multi-institutional team including investigators from UCSF, Oregon Health & Science University (OHSU), the University of Maryland Shock Trauma, and Steadman Philippon Research Institute. It represents the first large-scale clinical assessment of a blood-based biomarker specific to cartilage-to-bone transition in fracture healing.
The full article, Biomarker to Endochondral Phase of Fracture Repair Peaks Earlier than Traditional Markers and Detects Healing Differences in Long Bones: A Clinical Observational Study, is available in PLOS Medicine.
About Chelsea Bahney, PhD
Dr. Bahney is the director of the Laboratory for Regenerative Therapeutics in the Department of Orthopaedic Surgery. Her lab is dedicated to developing innovative treatments and diagnostic tools that make a tangible difference in human health. The scientific focus of the laboratory is rooted in advancing our understanding of the differential mechanisms between tissue repair and regeneration, providing us with the insights needed to address some of healthcare’s most pressing challenges. This project received funding from the UCSF Department of Orthopaedic Surgery and the Orthopaedic Research and Education Foundation (OREF). The lab is currently funded by the NIH and CIRM.
Read online: https://pubmed.ncbi.nlm.nih.gov/40880525/
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