Greenleaf Orthopaedics has served Lake County residents for over 50 years. The original physicians were Dr’s Penn, Mauer and Baehr. For over 25 years Dr’s Baier, Mayer and Collins have been the main providers of Greenleaf Orthopedics. Selina Carpenter has been Dr. Baier’s PA for over 15 years. Dr. Smyth has been with us for almost 3 years. As the practice of medicine has changed since the earlier days, so has Greenleaf Orthopaedics. It has become too difficult to maintain the personal services of a small private practice in today’s medical/business environment. Unfortunately, our Libertyville office is now closed. We no longer offer Physical Therapy services. Dr’s Mayer and Collins have retired. Dr. Smyth has moved to another location.

Dr. Baier and Selina Carpenter, PA, will continue with the excellent medical care that Greenleaf Orthopaedics is known to offer its patients. They will concentrate their practice to the treatment of arthritis of the hips and knees, and sport medicine knee injuries. They stress the non-surgical treatment of arthritis and knee injuries with medications, cortisone or hyaluronic acid injections, and referrals to therapy. For those patients who conservative approaches no longer provide relief, they specialize in cementless knee replacements with PSI, and anterior hip replacements. These surgeries can be performed as an outpatient or shortened hospital stay of 1-2 days if the patient qualifies. Continue with links on this site for more information.


Orthopaedic Specialists

Orthopedics is the medical and surgical specialty dedicated to the prevention, diagnosis and treatment of diseases and injuries that affect the musculoskeletal system. The orthopedic specialists of Greenleaf believe in treating our patients as we would treat our own family members – providing personal, high-quality care.



I recently chose Dr. Baier to do my total hip replacement. He had been honing his skills with a relatively new anterior approach. He is polite, concise, and is clearly an expert in his field. He has a fantastic staff, who really take the level of patient understanding to a higher level. Dr. Baier and his team insured that I was ready for the procedure, and, more importantly, for the recovery. I was literally dancing a week after surgery, and continue to strengthen through PT at Greenleaf.
— C. Dohrn
I have been going to Greenleaf Orthopedic, S.C. (Dr. Thomas E. Baier) since 2006 for severe left hip pain. The doctor Changed my quality of life. After having complete hip replacement surgery and therapy at your facility, I feel like a new person. Dr. Baier and his staff are very professional, knowledgeable and courteous, and I have complete confidence in the doctor and his team.
— D. Maslo

A major congratulations is due to Dr. Baier. He was just named one of America’s Best Physicians for 2017. We’ve known for years that he is one of the best doctors in America but it’s great to see him get the national recognition he deserves. Congrats Dr. Baier

Dr. Baier Continuing to See Good Results with Anterior Hip Replacements - Now Being Done Outpatient for Select Patients


Thomas Baier, M.D. is continuing to perform the first anterior hip replacements at Advocate Condell Medical Center. This less invasive surgical technique, which replaces the hip joint through a smaller, anterior incision generally leads to a faster and less painful recovery time. Dr. Baier is now performing this surgery, in select patients, on an outpatient basis.