Even High-Volume Surgeons Miss TKA Alignment Targets

New multicenter work has explored the role of a certain surgeon-specific factor that plays a role in implant failure rates in total knee arthroplasty (TKA)—implant malalignment.

The work, “The Impact of Surgeon Volume and Training Status on Implant Alignment in Total Knee Arthroplasty,” was published in the October 2, 2019 edition of The Journal of Bone and Joint Surgery.

Co-author Robert L. Barrack, M.D. the Charles and Joanne Knight Distinguished Professor in the Department of Orthopaedic Surgery at Washington University School of Medicine in St. Louis explained the impetus for this study to OTW: “As far as the impetus for this work, a lot of new technology, such as robotics and custom cutting guides and even custom implants are being offered in an effort to improve on the current technique of utilizing manual cutting guides. We wanted to establish how often surgeons currently miss establish alignment targets with current generation instruments and implants.”

“Further we wanted to see if surgeon volume was a factor in successfully hitting targets and finally how successful trainees under supervision were at hitting targets compared to high volume and low volume non-trainee surgeons.”

The research team analyzed radiographs for 1,570 primary TKAs which had been performed at four private academic and state-funded centers in the U.S. and UK. The team defined three surgeon groups for the study: high-volume non trainee surgeons, low-volume non-trainee surgeons, and trainee surgeons.

Here is what they learned.

According to Dr. Barrack, “One unique aspect of the study was that we included trainees and non-trainees both from the U.S. and the UK.”

“High volume surgeons did do better than low volume surgeons. Surgeons in training did as well as low volume non-trainee surgeons, in fact better in one of three measures.”

“Even among high volume surgeons, however, it was not uncommon to miss at least one alignment target, especially posterior slope of the tibia.”

“A study in now underway to quantify how well missing radiographic targets correlates with symptoms, functions, and satisfaction. Based on the results, though, it does seem warranted to explore ways of increasing accuracy and precision of TKA alignment, particularly avoiding outliers of 5 degrees or more.”