aMedisch Spectrum Twente, Enschede, The Netherlands

bDiakonessenhuis, Utrecht, The Netherlands

cAlrijne Hospital, Leiderdorp, The Netherlands

dLeiden University Medical Center, Leiden, The Netherlands

Financial Disclosure: The authors declare no conflicts of interest.

R.S.M.P. collected the patient data. R.S.M.P., J.B.M. and M.R.B. analyzed the patient data. M.G.J.G., T.P.M.V.V. and S.H.M.V. supported with conception and design of the study, analyzing and interpreting the data. R.S.M.P. and J.B.M. wrote the manuscript. All authors helped write the manuscript and have read and approved the final version.

This study was reviewed by the Medical Ethics Committee of Leiden University Medical Center (P.16.069), who determined that the study was not subject to the Dutch Medical Research Involving Human Subjects Act. The board of directors of the Alrijne Hospital (Leiderdorp, the Netherlands) approved the study.

All patients in this study provided written informed consent authorizing the use and disclosure of their protected health information.

Correspondence to Joost B. Malkus, MD, Resident orthopeadics, the department of Orthopaedic surgery, Medisch Spectrum Twente, Koningsplein 1, 7512KZ, Enschede, The Netherlands Tel.: +31886245000; e-mail: [email protected]