Updated 2/10/2010

SAN FRANCISCO – Knee and limb mechanical axis alignment measurements made using radiographs were found to be inaccurate when compared to measurements obtained intraoperatively using computer-assisted navigation, according to results of a study presented here.

“From my point of view, navigation seems to be a valuable tool for assessing component alignment but, more importantly, it is a more-validated tool than radiographs,” S. David Stulberg, MD, said during the Knee Society/American Association of Hip and Knee Surgeons Specialty Day Meeting…
Stulberg and colleagues analyzed 58 TKAs performed using an image-free computer-assisted navigation system (B. Braun Aesculap).

“Radiographs are not sensitive enough for accurate postoperative measurement,” Stulberg said.

Stulberg noted that many factors affect the accuracy of the measurements used in the study. But, in general, the radiographs tended to have substantial variation compared to the narrow margin of variation seen with the navigation system’s measurements, he said.

For more information:

Yaffe MA, Koo SS, Stulberg SD. Correlation of intra-operative navigation with post-op radiographs. Symposium IV: Computer navigation meets MIS TKA. Presented at the Knee Society/American Association of Hip and Knee Surgeons Specialty Day Meeting. March 8, 2008. San Francisco.