[1] Univ Washington, Harborview Med Ctr, Dept Neurol Surg, 325 9Th Ave, Seattle, WA 98104 USA
[2] Univ Washington, Harborview Med Ctr, Dept Orthopaed & Sports Med, 325 9Th Ave, Seattle, WA 98104 USA
[3] Univ Washington, Harborview Med Ctr, Dept Anesthesiol & Pain Med, 325 9Th Ave, Seattle, WA 98104 USA