[1] Univ Calif San Francisco, Spine Ctr, Sch Med, San Francisco, CA 94143 USA
[2] Univ Calif San Francisco, Spine Ctr, Dept Neurol Surg, San Francisco, CA 94143 USA
[3] Univ Calif San Francisco, Spine Ctr, Dept Orthopaed Surg, San Francisco, CA 94143 USA
[4] Univ Calif San Francisco, Spine Ctr, Inst Neurodegenerat Dis, San Francisco, CA 94143 USA
[5] Zuckerberg San Francisco Gen Hosp, Brain & Spinal Injury Ctr, San Francisco, CA USA
[6] Zuckerberg San Francisco Gen Hosp, Orthoped Trauma Inst, San Francisco, CA USA
[7] Weill Inst Neurosci, San Francisco, CA USA
[8] UCSF Fresno, Dept Neurol Surg, Fresno, CA USA
[9] San Francisco Vet Affairs Healthcare Syst, San Francisco, CA USA