aDepartment of Orthopaedic Surgery, UC Davis Medical Center, Sacramento, CA

bHospital for Special Surgery, New York, NY

Financial Disclosure: The authors report no conflicts of interest.

The authors did not receive support or funding from any organization for the submitted work.

The study was approved by the Institutional Review Board; no informed consent was required as this was a retrospective, radiographic study.

Correspondence to Sean T. Campbell, MD, 4860 Y Street, Suite 3800, Sacramento, CA 95817 Tel.: 916-734-2700 e-mail: [email protected].