https://www.ncbi.nlm.nih.gov/pubmed/31185118 https://www.healio.com/orthopedics/journals/ortho/%7B3c566f5b-e8f6-4bd4-8021-0f66498ff0d3%7D/early-clinical-outcome-of-lumbar-spinal-fixation-with-cortical-bone-trajectory-pedicle-screws-in-patients-with-osteoporosis-with-degenerative-disease Orthopedics. 2019 Jun 11:1-7. doi: 10.3928/01477447-20190604-01. [Epub ahead of print] Early Clinical Outcome of Lumbar Spinal Fixation With Cortical Bone Trajectory Pedicle Screws in Patients With Osteoporosis With Degenerative Disease. Liu L, Zhang S, Liu G, Yang B, Wu X.   Copyright 2019, SLACK Incorporated. PMID:31185118   DOI:10.3928/01477447-20190604-01