Minimally invasive unicompartmental knee replacement with a nonimage-based navigation system.
In a prospective study, two groups of 20 unicompartmental knee replacements (UKR) each were operated either using a CT-free navigation system or the conventional minimal invasive technique. Radiographic assessment of postoperative alignment was performed by long-leg coronal and lateral radiographs. The results revealed a significant difference between the two groups in favor of navigation. In the computer-assisted group, 95% of UKRs were in a range of 4-0 degrees varus (mechanical axis) compared with 70% in the conventional group. The only inconvenience was a prolonged operation time (+19 min). Due to the limited exposure, the navigation system is helpful in achieving a more precise component orientation. The danger of overcorrection is diminished by real-time information about the leg axis at each step during the operation.
Department of Orthopaedic Surgery, University of Regensburg, PO Box 100662, 93042, Germany. lars.perlick@klinik.uni-regensburg.de
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Perlick
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Bäthis
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Tingart
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Perlick
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Lüring
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Grifka
D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation*; D017760:Bone Malalignment / Q000000981:diagnostic imaging / Q000601:surgery; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation*; D021621:Imaging, Three-Dimensional / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000295:instrumentation*; D011446:Prospective Studies; D025321:Surgery, Computer-Assisted / Q000295:instrumentation*; D036542:Tomography, Spiral Computed / Q000295:instrumentation*; D016896:Treatment Outcome