Dr. Flatøy grew up in a village called Møst in Kristiansund municipality in Norway.
Dr. Flatøy graduated MD from University Medical School of Debrecen in 2007, and subsequently completed internship and 3 years of orthopaedic residency at Namsos Hospital .   In 2011, while working at Namsos Hospital, Dr. Flatøy was interviewed by NRK after he had treated a cyclist that was hospitalized after colliding with a sheep. 
Dr. Flatøy is a phD student  , and is currently participating in a project consisting of trials that investigate new implants in the field of cemented total hip arthroplasty , with special focus on stems with force closed fixation design and HXLPE acetabular cups. RSA is used as a method of investigation in all trials. Three trials are currently a part of Dr. Flatøy's phD project:
- Migration pattern of a triple tapered stem. A prospective randomized study using RSA.
- Changes in migration pattern after design modifications in triple tapered stem. A prospective randomized study using RSA.
- RSA study of wear and migration in Vitamin E stabilized HXLPE acetabular sockets.
Dr. Flatøy has co-authored the following medical publications:
- Low wear, high stability - promises of success in a moderately cross-linked cup? 
- No medium-term advantage of electrochemical deposition of hydroxyapatite in cementless femoral stems. 5-year RSA and DXA results from a randomized controlled trial. 
- Triple taper stem design shows promising fixation and bone remodelling characteristics: radiostereometric analysis in a randomized controlled trial.