2023 ISAKOS Biennial Congress ePoster
Accuracy of the Component Alignment and Sizing in Total Knee Arthroplasty: Preoperative Templating and Postoperative Evaluation Using CT-Based 3D Pre-Operative Planning Software
Takayuki Koya, MD, PhD, Tokyo JAPAN
Atsushi Sato, MD, PhD, Yokohama, Kanagawa JAPAN
Jun Oike, MD, PhD, Koto, Tokyo JAPAN
Masataka Ota, MD, Tokyo JAPAN
Kanako Izukashi, MD, Yokohama, Kanagawa JAPAN
Takayuki Okumo, MD, PhD, Tokyo, Tokyo JAPAN
Saki Yagura, MD, Kawasakishi Miyamaeku, Kanagawa JAPAN
Naoki Okuma, MD, Yokohama, Kanagawa JAPAN
Fumiyoshi Kawashima, MD, Tokyo JAPAN
Hiroshi Takagi, MD, PhD, Tokyo JAPAN
Koji Kanzaki, Prof., Yokohama JAPAN
Department of Orthopaedic Surgery, Showa University Koto Toyosu Hospital, Tokyo, JAPAN
FDA Status Not Applicable
Summary
CT-based 3D pre-operative planning software(ZedKnee; LEXI) could help place TKA components more accurately
ePosters will be available shortly before Congress
Abstract
Background
Accurate component placement and good ligament balance are essential in total knee arthroplasty (TKA). The conventional mainstream technique of preoperative templating and postoperative evaluation in TKA were mainly performed based on two-dimensional X-ray images. However, three-dimensional templating and evaluation using CT or MRI data have recently become more common, which enables them to be more accurate. Hence, the purpose of this study was to evaluate the preoperative templating and postoperative accuracy of the component alignment and sizing in TKA using CT-based 3D pre-operative planning software (ZedKnee; LEXI, Tokyo, Japan)
Methods
We retrospectively included 150 patients, 219 knees (115 females, 35 males; 75.1±7.5 years old on average), who underwent primary TKA using Posterior Stabilized Fixed Bearing of ATTUNE (Depuy Synthes, Warsaw, IN, USA) at our institute in July 2015 to December 2020. We imported preoperative and three-day postoperative DICOM data of whole-leg CT from the hip joints to the ankle joints into ZedKnee software for preoperative templating and postoperative evaluation, respectively, and assessed pre and postoperative component size matching rate and component alignment accuracy.
Results
The femoral and tibial component size concordance rate was 71.7% (157/219) and 66.8% (144/219), respectively. Postoperative femoral and tibial components were placed at 2.2±2.2° varus against the 3D mechanical axis, 0.4±2.8° extended, and 3.9±2.2° externally rotated against the posterior condylar axis (PCA), and 0.8±1.9° varus, 4.3±2.2° tilted posteriorly, and 7.0±7.1° internally rotated, respectively.
Conclusion
According to our postoperative evaluation, using 3D planning software in the preoperative planning of TKA could help result in good component placement. However, there was a tendency for the femoral component to be placed with a slight varus and the tibial component to be internally rotated, which showed greater variability compared to the previous studies. Therefore, the results indicate that further improvement and refinement of intraoperative techniques are needed to reflect preoperative planning more accurately.