After getting the green light for surgery during the Italian MotoGP weekend, the Repsol Honda star had travelled to the USA on Tuesday.
While the three previous operations involved trying to heal and cure a serious infection in the original fracture, sustained in the 2022 Spanish Grand Prix, the latest operation was to re-align the bone in order to improve mobility and reduce pain.
That realignment involved making a cut in the humerus and rotating the bone by 30-degrees, before fixing it in its new place using a plate and screws.
'Lasting three hours, Dr. Joaquin Sanchez Sotelo and his team performed a humeral osteotomy,' said a Repsol Honda statement. 'The surgery was deemed a success without complications by Dr Sanchez Sotelo as Marc Marquez entered the post-operative stage of his treatment at the Mayo Clinic.
'Marquez will remain in the US for the coming days to guarantee his immediate post-operative recovery before returning to Spain to continue his treatment plan.'
"Today we had the opportunity to operate on the right humerus of Mr. Marc Marquez," said Dr. Sanchez Sotelo, Chair of the Division of Shoulder and Elbow Surgery at the Mayo Clinic.
"The procedure was completed in approximately three hours. Despite the complexity of the procedure, the final outcome was satisfactory.
"Surgery consisted in removing the proximal two screws of the posterior plate previously placed by Dr. Samuel Antuña on December of 2020, followed by a rotational humeral osteotomy.
"Such procedure involves creating a transverse cut of the humeral bone to rotate the humerus along its long axis.
"The amount of rotation performed today was approximately 30 degrees of external rotation. The humerus was stabilised in the new position using an anterior plate with multiple screws.
"Surgery was completed uneventfully. We would like to wish Mr. Marquez a swift recovery and a successful return to his professional career."
Marquez, again being replaced by HRC test rider Stefan Bradl, is expected to be sidelined for at least several months and thus turn his attention to 2023.
The Spaniard, who took three victories last season despite the ongoing arm problems and reoccurrence of diplopia, remains Honda’s only MotoGP race winner since early 2018.
The 29-year-old didn’t feature on the podium during his six races this year, which were interrupted by another case of double vision in Mandalika, although he had the pace to once again fight for victory in COTA without a startline technical issue.
Marquez is contracted to Repsol Honda until the end of 2024, but the identity of the other Honda riders for next season are still to be decided.