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May 11, 2016 - TCO

SCO Surgeons First to Perform New Knee Surgery in Minnesota and Western Wisconsin

Surgeons with St. Croix Orthopaedics (SCO) will be the first in Minnesota and western Wisconsin to perform knee surgery using a new procedure, Biomet’s Signature™ knee, which utilizes MRI (magnetic resonance imaging) to create custom positioning guides for use in total knee replacement surgery. The customized scan virtually ensures proper alignment of the knee implant. SCO surgeons Dr. David Palmer and Dr. Nicholas Weiss completed the first surgeries in early December.

“St. Croix Orthopaedics has a long history of bringing innovative orthopaedic treatment and procedures to our patients,” said Dr. David Palmer, co-founder of SCO. “We are continually looking for promising new treatment options. Our purpose, as specialty providers, is to do everything we can to return our patients to their best function and get them back to their lives.”

While thousands have been performed around the country, the Signature™ surgery wasn’t available in Minnesota or western Wisconsin until now.

“This is on the cutting edge of knee replacement,” said Dr. Nicholas Weiss. “It combines minimally invasive surgery and computer assistance. It can be performed in a less invasive manner than current computer assisted approaches, which require screws to be placed in the femur and tibia bones. ”

How it Works:

Unlike traditional knee replacement images, the Signature™ knee requires MRI scans of the patient’s ankle, knee and hip. The scans are customized for each patient and only a handful of imaging facilities are qualified to perform them. St. Croix Imaging, a division of SCO located in Stillwater, MN, is certified to complete the scans which take between 20-30 minutes.

Once completed, the scans are sent to Biomet for review and development of the customized surgical positioning guides. These custom made guides will be placed on the patient’s femoral (thighbone) and tibial (shinbone) bones during surgery, providing a custom jig for bone cuts. The entire process (from MRI to surgery) takes place within 4 weeks.

“Computer generated, patient-specific guides help us place the knee replacement in the best alignment for each patient,” said Dr. Weiss. “This should improve the function and longevity of the knee replacement. ”


The Signature™ pre-navigation system is used to determine the appropriate knee replacement component size and proper alignment to match the patient’s anatomy.
This information is developed prior to the surgery, enabling the surgeon to preoperatively plan the patient’s knee replacement.

In addition, the custom guides are placed directly onto the patient’s femur and tibia, virtually eliminating the need to place instruments inside the thighbone or shinbone to assist with implant alignment and positioning. This results in a potentially less invasive procedure, thus reducing post-operative thigh pain and recovery time.

“The excitement for this technique is driven by our patient,” said Dr. Weiss. “If we can do an even better job of placing knee components with computer assistance and with a truly minimally invasive approach, then we are making our patient’s lives better.”

Dr. Palmer co-founded St. Croix Orthopaedics, P.A., in 1977. He received his medical degree from the University of Minnesota in 1971. After an internship at UCLA Harbor General Hospital, he returned to Minnesota for his residency in orthopaedic surgery at the Veteran’s Administration and University of Minnesota Hospitals. Dr. Palmer is board certified in orthopaedic surgery and is a member of the American Academy of Orthopaedic Surgeons.

Dr. Weiss attended the University of St. Thomas, St. Paul, and graduated from the Medical College of Wisconsin in 1997. After completing his residency at Mayo Clinic, he received fellowship training in sports medicine at the University of Wisconsin Medical School in Madison. Dr. Weiss joined SCO in 2003. Dr. Weiss is certified by the American Board of Orthopaedic Surgery.