Aaron Fields, PhD
Associate Professor
Orthopaedic Surgery
School of Medicine

His undergraduate research was on the use of probabilistic techniques to evaluate knee implant performance, and both of his graduate thesis projects focused on discovering the mechanisms of vertebral fragility using high-resolution computational models. Aaron was appointed to a faculty position at UCSF after completing his post-doctoral fellowship in Orthopaedic Surgery in 2015. His background includes extensive research in experimental and computational biomechanics. Aaron is an active member of the Orthopaedic Research Society and the International Society for the Study of the Lumbar Spine.

Aaron currently directs the Orthopaedic Biomechanics and Biotransport Laboratory at UCSF. The lab's broad research interests are related to structure-function relationships in musculoskeletal tissues, with a particular focus on the mechanisms of nutrient transport in bone and cartilage and harnessing nutrient transport for tissue repair and regeneration. The lab combines engineering and biology approaches for (1) understanding the effects of aging and disease on structure-transport relationships and (2) developing translatable diagnostic and therapeutic strategies. An overall theme of this research is the use of advanced experimental and computational tools to measure how tissue constituents at the nano- and microscales impact whole-organ behavior.

Current projects: 1. diagnostic tools for assessing endplate permeability and therapies for enhancing endplate permeability

2. role of lacunar-canalicular system permeability in osteonecrosis of the femoral head

3. nanoscale and microscale contributions to diabetic skeletal fragility

• Protocol for Biospecimen Collection and Analysis Within the BACPAC Research Program.
  Pain medicine (Malden, Mass.) 2023 Fields AJ, Dudli S, Schrepf A, Kim A, Pham B, Gallego E, Mendoza S, Meropol SB, Darwin J, Sowa G, Vo NV
• The Back Pain Consortium (BACPAC) Research Program Data Harmonization: Rationale for Data Elements and Standards.
  Pain medicine (Malden, Mass.) 2023 Batorsky A, Bowden AE, Darwin J, Fields AJ, Greco CM, Harris RE, Hue TF, Kakyomya J, Mehling W, O'Neill C, Patterson CG, Piva SR, Sollmann N, Toups V, Wasan AD, Wasserman R, Williams DA, Vo NV, Psioda…
• The Back Pain Consortium (BACPAC) Research Program: Structure, Research Priorities, and Methods.
  Pain medicine (Malden, Mass.) 2023 Mauck MC, Lotz J, Psioda MA, Carey TS, Clauw DJ, Majumdar S, Marras WS, Vo N, Aylward A, Hoffmeyer A, Zheng P, Ivanova A, McCumber M, Carson C, Anstrom KJ, Bowden AE, Dalton D, Derr L, Dufour J, …
• Bullying, harassment, and discrimination of musculoskeletal researchers and the impact of the COVID-19 pandemic: an international study.
  European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society 2023 Martin JT, Asimakopoulos D, Hornung AL, Toro SJ, Le Maitre CL, Chahine NO, Fields AJ, Gawri R, Giers MB, Smith LJ, Tang SY, Zehra U, Haglund L, Samartzis D
• Deep-learning-based biomarker of spinal cartilage endplate health using ultra-short echo time magnetic resonance imaging.
  Quantitative imaging in medicine and surgery 2023 Bonnheim NB, Wang L, Lazar AA, Chachad R, Zhou J, Guo X, O'Neill C, Castellanos J, Du J, Jang H, Krug R, Fields AJ
• Intradiscal treatment of the cartilage endplate for improving solute transport and disc nutrition.
  Frontiers in bioengineering and biotechnology 2023 Habib M, Hussien S, Jeon O, Lotz JC, Wu PI, Alsberg E, Fields AJ
• ISSLS Prize in Bioengineering Science 2023: Age- and sex-related differences in lumbar intervertebral disc degeneration between patients with chronic low back pain and asymptomatic controls.
  European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society 2023 Bonnheim NB, Lazar AA, Kumar A, Akkaya Z, Zhou J, Guo X, O'Neill C, Link TM, Lotz JC, Krug R, Fields AJ
• UTE-MRI for Spinal Applications.
  MRI of Short and Ultrashort-T_2 Tissues 2023 Noah B. Bonnheim, Misung Han, Aaron J. Fields, Cynthia Chin, Roland Krug
• Evidence-based interventions to treat chronic low back pain: treatment selection for a personalized medicine approach.
  Pain reports 2022 Mauck MC, Aylward AF, Barton CE, Birckhead B, Carey T, Dalton DM, Fields AJ, Fritz J, Hassett AL, Hoffmeyer A, Jones SB, McLean SA, Mehling WE, O'Neill CW, Schneider MJ, Williams DA, Zheng P, Wasan AD
• Influence of patient-specific factors when comparing multifidus fat infiltration between chronic low back pain patients and asymptomatic controls.
  JOR spine 2022 Ballatori AM, Shahrestani S, Nyayapati P, Agarwal V, Krug R, Han M, Fields AJ, O'Neill C, Demir-Deviren S, Lotz JC, Bailey JF
• Spatial distribution of fat infiltration within the paraspinal muscles: implications for chronic low back pain.
  European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society 2022 Khattab K, Dziesinski LK, Crawford R, Ballatori A, Nyayapati P, Krug R, Fields A, O'Neill CW, Lotz JC, Bailey JF
• The contributions of cartilage endplate composition and vertebral bone marrow fat to intervertebral disc degeneration in patients with chronic low back pain.
  European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society 2022 Bonnheim NB, Wang L, Lazar AA, Zhou J, Chachad R, Sollmann N, Guo X, Iriondo C, O'Neill C, Lotz JC, Link TM, Krug R, Fields AJ
• Using hierarchical unsupervised learning to integrate and reduce multi-level and multi-paraspinal muscle MRI data in relation to low back pain.
  European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society 2022 Torres-Espin A, Keller A, Johnson GTA, Fields AJ, Krug R, Ferguson AR, Hargens AR, O'Neill CW, Lotz JC, Bailey JF
• Paraspinal Muscle in Chronic Low Back Pain: Comparison Between Standard Parameters and Chemical Shift Encoding-Based Water-Fat MRI.
  Journal of magnetic resonance imaging : JMRI 2022 Sollmann N, Bonnheim NB, Joseph GB, Chachad R, Zhou J, Akkaya Z, Pirmoazen AM, Bailey JF, Guo X, Lazar AA, Link TM, Fields AJ, Krug R
• Non-enzymatic glycation of annulus fibrosus alters tissue-level failure mechanics in tension.
  Journal of the mechanical behavior of biomedical materials 2021 Werbner B, Lee M, Lee A, Yang L, Habib M, Fields AJ, O'Connell GD
• Development of a standardized histopathology scoring system for human intervertebral disc degeneration: an Orthopaedic Research Society Spine Section Initiative.
  JOR spine 2021 Le Maitre CL, Dahia CL, Giers M, Illien-Junger S, Cicione C, Samartzis D, Vadala G, Fields A, Lotz J
• Measurement of vertebral endplate bone marrow lesion (Modic change) composition with water-fat MRI and relationship to patient-reported outcome measures.
  European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society 2021 Fields AJ, Ballatori A, Han M, Bailey JF, McCormick ZL, O'Neill CW, Demir-Deviren S, Krug R, Lotz JC
• Automatic Vertebral Body Segmentation Based on Deep Learning of Dixon Images for Bone Marrow Fat Fraction Quantification.
  Frontiers in endocrinology 2020 Zhou J, Damasceno PF, Chachad R, Cheung JR, Ballatori A, Lotz JC, Lazar AA, Link TM, Fields AJ, Krug R
• Evaluation of human cartilage endplate composition using MRI: Spatial variation, association with adjacent disc degeneration, and in vivo repeatability.
  Journal of orthopaedic research : official publication of the Orthopaedic Research Society 2020 Wang L, Han M, Wong J, Zheng P, Lazar AA, Krug R, Fields AJ
• Serum Biomarkers for Connective Tissue and Basement Membrane Remodeling are Associated with Vertebral Endplate Bone Marrow Lesions as Seen on MRI (Modic Changes).
  International journal of molecular sciences 2020 Dudli S, Ballatori A, Bay-Jensen AC, McCormick ZL, O'Neill CW, Demir-Deviren S, Krug R, Heggli I, Juengel A, Karppinen J, Brunner F, Farshad M, Distler O, Lotz JC, Fields AJ
• Osteocyte dysfunction promotes osteoarthritis through MMP13-dependent suppression of subchondral bone homeostasis.
  Bone research 2019 Mazur CM, Woo JJ, Yee CS, Fields AJ, Acevedo C, Bailey KN, Kaya S, Fowler TW, Lotz JC, Dang A, Kuo AC, Vail TP, Alliston T
• Measuring and reporting of vertebral endplate bone marrow lesions as seen on MRI (Modic changes): recommendations from the ISSLS Degenerative Spinal Phenotypes Group.
  European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society 2019 Fields AJ, Battié MC, Herzog RJ, Jarvik JG, Krug R, Link TM, Lotz JC, O'Neill CW, Sharma A, ISSLS Degenerative Spinal Phenotypes Group
• The Relationship Between Endplate Pathology and Patient-reported Symptoms for Chronic Low Back Pain Depends on Lumbar Paraspinal Muscle Quality.
  Spine 2019 Bailey JF, Fields AJ, Ballatori A, Cohen D, Jain D, Coughlin D, O'Neill C, McCormick Z, Han M, Krug R, Demir-Deviren S, Lotz JC
• Matrix modification for enhancing the transport properties of the human cartilage endplate to improve disc nutrition.
  PloS one 2019 Dolor A, Sampson SL, Lazar AA, Lotz JC, Szoka FC, Fields AJ
• Nutrient supply and nucleus pulposus cell function: effects of the transport properties of the cartilage endplate and potential implications for intradiscal biologic therapy.
  Osteoarthritis and cartilage 2019 Wong J, Sampson SL, Bell-Briones H, Ouyang A, Lazar AA, Lotz JC, Fields AJ
• Associations between vertebral body fat fraction and intervertebral disc biochemical composition as assessed by quantitative MRI.
  Journal of magnetic resonance imaging : JMRI 2019 Krug R, Joseph GB, Han M, Fields A, Cheung J, Mundada M, Bailey J, Rochette A, Ballatori A, McCulloch CE, McCormick Z, O'Neill C, Link TM, Lotz J
• Estrogen signaling in arcuate Kiss1 neurons suppresses a sex-dependent female circuit promoting dense strong bones.
  Nature communications 2019 Herber CB, Krause WC, Wang L, Bayrer JR, Li A, Schmitz M, Fields A, Ford B, Zhang Z, Reid MS, Nomura DK, Nissenson RA, Correa SM, Ingraham HA
• Effects of dynamic loading on solute transport through the human cartilage endplate.
  Journal of biomechanics 2018 Sampson SL, Sylvia M, Fields AJ
• Contribution of the endplates to disc degeneration.
  Current molecular biology reports 2018 Fields AJ, Ballatori A, Liebenberg EC, Lotz JC
• Tidemark Avulsions are a Predominant Form of Endplate Irregularity.
  Spine 2018 Berg-Johansen B, Jain D, Liebenberg EC, Fields AJ, Link TM, O'Neill CW, Lotz JC
• FGF and TGFβ signaling link form and function during jaw development and evolution.
  Developmental biology 2018 Woronowicz KC, Gline SE, Herfat ST, Fields AJ, Schneider RA
• Cartilage Endplate Thickness Variation Measured by Ultrashort Echo-Time MRI Is Associated With Adjacent Disc Degeneration.
  Spine 2018 Berg-Johansen B, Han M, Fields AJ, Liebenberg EC, Lim BJ, Larson PE, Gunduz-Demir C, Kazakia GJ, Krug R, Lotz JC
• Publication trends in spine research from 2007 to 2016: Comparison of the Orthopaedic Research Society Spine Section and the International Society for the Study of the Lumbar Spine.
  JOR spine 2018 Martin JT, Gullbrand SE, Fields AJ, Purmessur D, Diwan AD, Oxland TR, Chiba K, Guilak F, Hoyland JA, Iatridis JC
• Larger vertebral endplate concavities cause higher failure load and work at failure under high-rate impact loading of rabbit spinal explants.
  Journal of the mechanical behavior of biomedical materials 2018 Dudli S, Enns-Bray W, Pauchard Y, Römmeler A, Fields AJ, Ferguson SJ, Helgason B
• Contributions of Material Properties and Structure to Increased Bone Fragility for a Given Bone Mass in the UCD-T2DM Rat Model of Type 2 Diabetes.
  Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research 2018 Acevedo C, Sylvia M, Schaible E, Graham JL, Stanhope KL, Metz LN, Gludovatz B, Schwartz AV, Ritchie RO, Alliston TN, Havel PJ, Fields AJ
• Structure-function relationships at the human spinal disc-vertebra interface.
  Journal of orthopaedic research : official publication of the Orthopaedic Research Society 2017 Berg-Johansen B, Fields AJ, Liebenberg EC, Li A, Lotz JC
• Role of Osteoblast Gi Signaling in Age-Related Bone Loss in Female Mice.
  Endocrinology 2017 Millard SM, Wang L, Wattanachanya L, O'Carroll D, Fields AJ, Pang J, Kazakia G, Lotz JC, Nissenson RA
• Glucocorticoid suppression of osteocyte perilacunar remodeling is associated with subchondral bone degeneration in osteonecrosis.
  Scientific reports 2017 Fowler TW, Acevedo C, Mazur CM, Hall-Glenn F, Fields AJ, Bale HA, Ritchie RO, Lotz JC, Vail TP, Alliston T
• Pathobiology of Modic changes.
  European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society 2016 Dudli S, Fields AJ, Samartzis D, Karppinen J, Lotz JC
• Theoretical effects of fully ductile versus fully brittle behaviors of bone tissue on the strength of the human proximal femur and vertebral body.
  Journal of biomechanics 2015 Nawathe S, Yang H, Fields AJ, Bouxsein ML, Keaveny TM
• Alterations in intervertebral disc composition, matrix homeostasis and biomechanical behavior in the UCD-T2DM rat model of type 2 diabetes.
  Journal of orthopaedic research : official publication of the Orthopaedic Research Society 2015 Fields AJ, Berg-Johansen B, Metz LN, Miller S, La B, Liebenberg EC, Coughlin DG, Graham JL, Stanhope KL, Havel PJ, Lotz JC
• Trabecular plates and rods determine elastic modulus and yield strength of human trabecular bone.
  Bone 2014 Wang J, Zhou B, Liu XS, Fields AJ, Sanyal A, Shi X, Adams M, Keaveny TM, Guo XE
• Cartilaginous end plates: Quantitative MR imaging with very short echo times-orientation dependence and correlation with biochemical composition.
  Radiology 2014 Fields AJ, Han M, Krug R, Lotz JC
• Comparison of vertebral and intervertebral disc lesions in aging humans and rhesus monkeys.
  Osteoarthritis and cartilage 2014 Bailey JF, Fields AJ, Liebenberg E, Mattison JA, Lotz JC, Kramer PA
• Structural parameters determining the strength of the porcine vertebral body affected by tumours.
  Computer methods in biomechanics and biomedical engineering 2014 Sahli F, Cuellar J, Pérez A, Fields AJ, Campos M, Ramos-Grez J
• Dependence of mechanical properties of trabecular bone on plate-rod microstructure determined by individual trabecula segmentation (ITS).
  Journal of biomechanics 2013 Zhou B, Liu XS, Wang J, Lu XL, Fields AJ, Guo XE
• Influence of biochemical composition on endplate cartilage tensile properties in the human lumbar spine.
  Journal of orthopaedic research : official publication of the Orthopaedic Research Society 2013 Fields AJ, Rodriguez D, Gary KN, Liebenberg EC, Lotz JC
• Innervation of pathologies in the lumbar vertebral end plate and intervertebral disc.
  The spine journal : official journal of the North American Spine Society 2013 Fields AJ, Liebenberg EC, Lotz JC
• The role of the vertebral end plate in low back pain.
  Global spine journal 2013 Lotz JC, Fields AJ, Liebenberg EC
• Seeing double: a comparison of microstructure, biomechanical function, and adjacent disc health between double- and single-layer vertebral endplates.
  Spine 2012 Fields AJ, Sahli F, Rodriguez AG, Lotz JC
• Vertebral fragility and structural redundancy.
  Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research 2012 Fields AJ, Nawathe S, Eswaran SK, Jekir MG, Adams MF, Papadopoulos P, Keaveny TM
• Micromechanics of the human vertebral body for forward flexion.
  Journal of biomechanics 2012 Yang H, Nawathe S, Fields AJ, Keaveny TM
• Trabecular architecture and vertebral fragility in osteoporosis.
  Current osteoporosis reports 2012 Fields AJ, Keaveny TM
• Influence of vertical trabeculae on the compressive strength of the human vertebra.
  Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research 2011 Fields AJ, Lee GL, Liu XS, Jekir MG, Guo XE, Keaveny TM
• Mechanisms of initial endplate failure in the human vertebral body.
  Journal of biomechanics 2010 Fields AJ, Lee GL, Keaveny TM
• Role of trabecular microarchitecture in whole-vertebral body biomechanical behavior.
  Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research 2009 Fields AJ, Eswaran SK, Jekir MG, Keaveny TM
• Multi-scale modeling of the human vertebral body: comparison of micro-CT based high-resolution and continuum-level models.
  Pacific Symposium on Biocomputing. Pacific Symposium on Biocomputing 2009 Eswaran SK, Fields AJ, Nagarathnam P, Keaveny TM
• Effects of knee simulator loading and alignment variability on predicted implant mechanics: a probabilistic study.
  Journal of orthopaedic research : official publication of the Orthopaedic Research Society 2006 Laz PJ, Pal S, Fields A, Petrella AJ, Rullkoetter PJ