Dr. Deehan is board-certified by the American Board of Orthopedic Surgeons and a fellow of the American Academy of Orthopedic Surgeons. After achieving a Bachelor of Science in Biology from Princeton University, he received his doctorate from University of Medicine and Dentistry, New Jersey where he also completed an internship in general surgery and a residency in orthopaedic surgery.

He has issued a large number of research papers regarding topics such as joint replacement and fracture repair in children's orthopedics. Dr. Deehan enjoys the sport of wrestling, and had the honor of being a four-year Varsity Letterman on Princeton University's wrestling team. He has also served as the primary physician for the New Jersey State High School Wrestling Championships.