QUALITY CONTROL Authorization to perform C-REX Ring-locking Procedure According to CarpoNovum's regulation (Document 0041: Procedure, Accreditation of Surgeons for Clinical Studies), clinical investigators must be authorized to conduct the C-REX Ring-locking Procedure with C-REX LapAid and C-REX DMH/DMHC by performing at least one surgery on pigs and at least one train-in surgery on patients with the person in charge of the study (Dr. Anders Grönberg). When the clinical investigator is authorized to perform the C-REX Ring-locking Procedure with C-REX LapAid System, he or she receives a certificate. This certificate could also admit the clinical investigator the right to authorize other surgeons to perform C-REX Ring-locking Procedure with C-REX LapAid and C-REX DMH/DMHC (i.e. to perform at least one operations on pigs and at least one train-in operations on patients with the authorized clinical investigator).