From the Department of Orthopaedic Surgery, University of California - San Francisco (UCSF), San Francisco, CA (Sharfman and Theologis), Department of Neurological Surgery, UCSF, San Francisco, CA (Clark), Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, MO (Gupta).

Correspondence to Dr. Theologis: [email protected]