He is one of the leading hip arthroscopy surgeons in the UK and has performed nearly 1500 of these procedures, making The Manchester Hip Clinic one of the highest volume centres in the country. He has pioneered the use of stem cells and cartilage grafting in hip surgery to regenerate cartilage damage.

He has pioneered the use Robotics in hip replacements and was the first person to carry out a MAKO robotic hip replacement in the North West of England and has the largest series to date. He performs the full range of hip replacement surgery from young patients with childhood disease to older patients who wish to maintain an active lifestyle.

He is a keen educator and leads (lower limb) a Masters program at Salford University and has published many papers in peer reviewed journals. In 2017, The Manchester Hip Clinic (and Spire Manchester) was the only private hospital involved in a large multi-centre NHS trial into the effectiveness of hip arthroscopic surgery. He works closely with industry to develop new education programs, techniques and surgical devices to improve patient care.

Professor Fehily treats patients from all over the UK and internationally. He is the lead hip surgeon for the Hip and Groin Clinic, senior Surgeon at the Manchester Hip Clinic, is a member of the Orthteam Hip Unit and has been a registered Consultant in the United Arab Emirates, having practiced in Dubai.

He is the lead on many surgeon education courses, training other consultants from all over the UK and Europe in both key-hole and robotic hip replacement techniques with many Consultants visiting him at Spire Manchester to learn these innovative techniques.

He regularly treats high-level athletes, ranging from dedicated amateurs to Commonwealth, World Championship, Olympic and Premier League competitors. He regularly treats professional athletes from sports including football, rugby, taekwondo, squash and athletics amongst many others.