Born in Milan, in 1963, he is married with Chiara and father of three girls: Cecilia, Camilla, and Carlotta.

He started his career in 1990 at the Orthopedic Clinic of San Raffaele Hospital in Milan. A few years later, he moved to England where he became a Research Fellow at the University of Oxford in the Orthopaedic Paediatric Department at Nuffield Orthopaedic Centre. There he received funding for a PhD, internationally recognized as the highest academic qualification for research.

He was only 34 years old when he became Head of the Orthopedic Pediatric and Traumatology Department at Bristol Royal Hospital for Sick Children. At the same time he became Associate Professor at the University of Bristol.

After 10 years of experience in England, in 2001 he decided to return to Italy where he wanted to establish a pioneering center in the field of Pediatric Orthopedics, with particular attention to children’s disabilities.
Humanitas Research Hospital gave him this opportunity and he founded the Operative Department of Pediatric Orthopedics and Neuro-Orthopedics, of which he is still in chief.

Prof. Portinaro is also the Scientific Director of the Fondazione Ariel, a non-profit organization, which he founded in 2003. Fondazione Ariel provides guidance and support services for families with children affected by Cerebral Palsy and other neuromotor disabilities. It also promotes research projects to develop knowledge and discover new treatments for childhood neuromotor disorders.

In 2010 the Faculty of Medicine and Surgery of the University of Milano chose him as director of the Orthopedic Departiment at Humanitas Research Center, where he also became scientific-didactic coordinator of the entire orthopedic area. Taking advantage of his experience in England he set up a model of faculty that allows students in Medicine and Surgery to receive the most up-to-date and relevant teachings, thanks to the collaboration of international surgeons specialized in different Branches of Orthopedics.

Since November 2022, he has been Senior Consultant of Pediatric Neuro-Orthopedics at FONDAZIONE IRCCS CA’ GRANDA OSPEDALE MAGGIORE POLICLINICO (Milan) and Consultant of Pediatric Orthopedics and Neuro-Orthopedics at HUMANITAS RESEARCH  HOSPITAL (Rozzano, Milan).

In the last years Saudi German Hospital invited Prof. Portinaro to its International Visiting Professor program in Saudi Arabia. He has held this position since August 2023.