Dr. Zacharias and Dr. Ben-Zev Perform PAO Procedure at Froedtert Pleasant Prairie Hospital


Healthy Connections is published by Froedtert Pleasant Prairie Hospital.

“Very few orthopedic surgeons in the United States have the training to perform this procedure, and a limited number of facilities even offer this procedure as an option for patients,” said Dr. Anthony Zacharias, Froedtert Pleasant Prairie Hospital Orthopedic Surgeon- Sports Medicine. “A periacetabular osteotomy (PAO) procedure is rare given the technical demand required for successful outcomes. With Dr. Ben-Zev and myself having advanced training with this surgery and technology, it is with great pride that we can say that our community hospital here at Froedtert Pleasant Prairie Hospital offers this PAO procedure.”


A PAO is a surgical procedure used to correct acetabular, or hip, dysplasia. Hip dysplasia is a condition where the hip socket does not fully form and is shallower than a normal hip socket. This incomplete development of the hip socket, which affects approximately one out of every one thousand people, results in the hip socket being misaligned or too shallow to adequately support the femoral head, the upper end of the thigh bone. The consequences of this can be early onset of osteoarthritis, hip labral tears, restricted mobility, the necessity of a hip replacement at a young age, and pain- lots of pain.

Models of the hip bone, the 4 cuts, and the reorientation of the bone for a PAO Procedure

“Prior to this PAO procedure, patients with developmental dysplasia of the hip, suffering from pain in their twenties and thirties and even their teens, were given the options of living with the pain or getting a total hip replacement. Undergoing a hip replacement at the age of thirty is not ideal. Now, we can reorient the bone and effectively prevent or delay the need for a hip replacement by delaying the onset of arthritis,” said Dr. Zacharias. “It’s a phenomenal advancement in orthopedic surgery!”

“A PAO procedure is considered one of the most technically demanding surgeries in all of orthopedics,” said Dr. Jonathan Ben-Zev, Froedtert Pleasant Prairie Hospital Orthopedic Surgeon- Hip and Knee Specialist. “It is difficult to perform, hard to get right, has little room for error, and has high complication rates. It helps to have two fellowship-trained orthopedic surgeons. Dr. Zacharias and I work as a team to make the surgery go smoothly and safely. We practice every detail of the procedure together in the lab and are completely dedicated to the advancement of orthopedic surgery here at Froedtert Pleasant Prairie Hospital.”

During a PAO procedure, four precise cuts around the hip socket are made and the bone is reoriented to provide better coverage and support of the femoral head. Incredibly, this reorientation of the bone does not affect posture or gait. “The goal of a PAO is hip preservation,” said Dr. Zacharias. “When performed correctly, the patient’s hip will now age like a regular hip.”

Posterior view of the models of the hip bone, the 4 cuts, and the reorientation of the bone for a PAO Procedure


Four cuts may not sound like much, but the best resources in the world ensure those cuts are made precisely and safely.

“We work with technicians in Switzerland to create custom templates for the surgery,” said Dr. Zacharias. “The templates must be exact and specific for each patient. Remember, we are cutting and realigning the hip bone. There is no margin for error. Every action must be planned and performed precisely.”

Dr. Ben-Zev said, “Froedtert Pleasant Prairie Hospital invested in the special instrumentation to perform these challenging cases. We are fortunate to have specialized surgical tables, x-ray systems that allow for real-time intra-operative measurements, and access to custom templating tools to help us achieve good outcomes for this hip preservation procedure. Dr. Zacharias and I both love what we do, and being in an environment that supports high level collaboration and world-class technologies is exciting.”

Jonathan Ben-Zev, M.D. Orthopedic Surgeon- Hip and Knee Specialist


From pre-operative physical therapy to post-operative follow-ups, convenience is key at Froedtert Pleasant Prairie Hospital.

“The convenience of this campus for our patients is outstanding,” said Dr. Ben-Zev. “Physical Therapy is located in the same building as Orthopedics. Our nursing and office staff teams make scheduling easy for patients. Collaboration between the surgeons and therapists regarding patient care is easy because of our proximity. With Dr. Zacharias, Dr. Gegenheimer, Dr. Al-Sawaf, Dr. Mehdi, and myself at our Prairie Ridge Orthopedic Clinic, our team can provide patients with complete orthopedic care from adolescents to geriatrics. Offering PAO procedures now places this facility in an even more unique category in the state of Wisconsin. Dr. Zacharias and I both live in this community, and we care about building this practice into a leading-edge resource for the people who live here.”

Dr. Zacharias said, “We want you to know that we are here for you and that we truly care about finding solutions for all our patients. If you are having hip pain, please contact us to get evaluated.”

Anthony Zacharias, M.D. Orthopedic Surgeon- Sports Medicine

For more information or to schedule an appointment, contact the Prairie Ridge Orthopedic Clinic at (262) 656-3590.