Abstract
BackgroundAccurate femoral rotational alignment is of vital importance for successful total knee arthroplasty (TKA). The value of computer-assisted surgery TKA (CAS-TKA) in increasing the accuracy of femoral rotational alignment remains controversial. We hypothesize that outcomes are related to the severity of preoperative varus and valgus deformity and that CAS-TKA may be beneficial under certain circumstances.MethodsBetween January 2007 and December 2013, patients with osteoarthritis and varus angulation in the mechanical axis (MA) ≥ 15° and valgus angulation in the MA ≥ 10° (based on hip-to-ankle standing radiography) who underwent TKA were divided into four groups. CAS-TKA and conventional TKA outcomes were compared in patients who had preoperative advanced genu varum and advanced genu valgum deformities. The accuracy of component alignment and postoperative limb alignment was determined using radiographic parameters and computed tomography (CT).ResultsOne hundred and eight patients (144 knees) were included in the analysis. For patients with preoperative advanced genu varum deformity, a significant difference was detected in the sagittal femoral angle (p < 0.001), but no significant improvement of femoral rotational alignment was noted (p = 0.127). In patients with preoperative advanced genu valgum deformity, a significant difference was found in the sagittal femoral angle (p = 0.034). The femoral rotational angle was significantly closer to the proper position in the CAS-TKA group (p < 0.001). When comparing the percentage of knees achieving the proper alignment, there was a decrease in the amount of outlier for the femoral rotational angle for CAS-TKA in advanced genu valgum deformity (p = 0.011).ConclusionsOur data demonstrate that CAS-TKA is beneficial in obtaining proper femoral rotational alignment in patients with advanced genu valgum deformity (preoperative MA ≥ 10° valgus). In patients with advanced genu varum deformity (preoperative MA ≥ 15° varus), CAS-TKA did not improve the femoral rotational alignment.
Highlights
Total knee arthroplasty (TKA) can reduce pain and restore proper function in patients with osteoarthritis [1]
After analyzing the radiographic data in patients with advanced genu varum deformity, we noted that the preoperative and postoperative coronal mechanical axis (MA) was very similar between groups A and B
Similar frontal femoral (FF), femoral rotational (FR), frontal tibial (FT), and sagittal tibial (ST) angles were noted between the two techniques in advanced varus deformity
Summary
Total knee arthroplasty (TKA) can reduce pain and restore proper function in patients with osteoarthritis [1]. Other studies have reported that CAS-TKA did not provide better outcomes [23,24,25,26] This inconsistency may be partially due to different types (varus or valgus deformity) and severity of preoperative knee deformity seen in the study populations. Substantial variations in femoral anatomy, bone loss, maltracking of the patella, and the soft tissue contracture may be presented in patients with larger varus and valgus deformities [16, 22, 27,28,29,30,31,32,33] These factors may lead to distortion of bony landmarks, which may lead to errors in determining the reference axis for the femoral component rotation and malposition of the components [22, 27,28,29,30,31,32,33]. We hypothesize that outcomes are related to the severity of preoperative varus and valgus deformity and that CAS-TKA may be beneficial under certain circumstances
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
