At all follow-ups the research coordinator/independent tester will attend. At the 6 month follow-up an independent orthopedic surgeon will attend regularly and take care of patients who are not satisfied. The aim is to use the following criteria as subjective complaint: equal or worse than 10 points for the IHOT-33 score compared to baseline. All patients can withdraw without giving a reason at any time (stated in the consent form that all patients need to sign). An unblinded orthopedic surgeon will of course be able to have access to the medical record regarding performed procedures at any time if need for the health of the patient.