Founded in 1967 by Dr. James Flaherty and Dr. Bernard Cahill, the practice, known then as Orthopedic Associates of Peoria, S.C., was located at St. Mark's Court. Dr. Ronald Palmer, a native Peorian, joined the practice in 1979. In 1985, having outgrown their space at St. Mark's Court, Orthopedic Associates of Peoria, S.C., relocated their office to the Hillcrest Medical Plaza.

Dr. Flaherty retired from the practice in 1986. Dr. Mark Phillips, another native Peorian, joined Drs. Cahill and Palmer in practice in 1987. Following continued growth and success, the practice was again faced with relocation. In 1991, the physicians relocated their practice to their present location at 303 N. Kumpf Boulevard and opened the Orthopedic Institute of Illinois. This new facility incorporated clinical offices, an ambulatory surgery center, and Great Plains Sports Medicine and Rehabilitation Center. Additionally in 1991, Dr. James Maxey, a native of Pekin, Illinois joined the practice and Dr. Clark Rians, an internal medicine physician, specializing in Non-surgical Sports Medicine and Rehabilitation became associated with the practice.

In 1994, two additional orthopaedic specialists, Dr. Brian Ted Maurer from Hopedale, Illinois and Dr. Gregory Adamson from Oregon, Illinois, joined the practice. Dr. Richard Driessnack, from St. Joseph, Michigan, joined the practice in 1998 and Dr. Jeffrey Garst, from Harvey, Illinois, joined the practice in February 1999. In June 1999, Dr. Bernard Cahill retired from the practice and Dr. Stephen Orlevitch joined the practice in September 1999.

With the continued growth and addition of physicians, the North Office facility, 7800 N. Sommer Street, was opened in September 1999. Dr. Steven Below joined the practice in September 2001 and was followed by Dr. Piero Capecci in the fall of 2003.

In the fall of 2002, the practice opened the Great Plains Maximum Performance Facility to begin athletic performance enhancement and accommodate additional physical therapy services. In the spring of 2006, a physical therapy office was opened in the EastSide Facility in East Peoria, Illinois.

In 2007, the Orthopedic Institute of Illinois is celebrating its 40th year in practice as the premier orthopaedic group in central Illinois. In conjunction with this event, we have consolidated our practice functions - the Orthopedic Institute of Illinois, Great Plains Sports Medicine and Rehabilitation Center, the Orthopedic Institute of Illinois Ambulatory Surgery Center and Great Plains Maximum Performance - under the umbrella of Great Plains Orthopaedics.