Comparison of alignment and position of prosthesis between portable accelerometer-based navigation device and conventional instrumentation in total knee arthroplasty with valgus deformity

Abstract

Objective: To explore the differences of alignment and position of prosthesis between portable accelerometer-based navigation device (PAD) and conventional instrumentation (CI) in total knee arthroplasty (TKA) with valgus deformity. Methods: Patients with knee osteoarthritis and valgus deformity who underwent primary TKA in Peking University Third Hospital from January 2017 to December 2020 were enrolled in this retrospective study and were divided into PAD group and CI group according to the surgical instruments. Five male patients and 44 female patients were included with a mean age of (67.2±7.0) years. The differences in preoperative general data, preoperative and postoperative alignment between the two groups were studied. Results: A total of 49 patients (25 patients in the PAD group and 24 in the CI group) were enrolled in this study. There were no statistically significant differences in gender, age, height, weight, body mass index, surgical side, preoperative hip-knee-ankle (HKA) angle, preoperative HKA angle deviation, Keblish classification and Ranawat classification between the two groups (all P>0.05). There was no significant difference in the accuracy of postoperative HKA angle (2.0°±1.4° vs 3.0°±2.2°, P=0.082), coronal femoral component angle (CFCA) (1.5°±1.2° vs 2.1°±1.6°, P=0.144) and coronal tibial component angle (CTCA) (1.2°±0.8° vs 1.3°±1.0°, P=0.695) between the two groups; but the standard deviation of the above-mentioned three indices in PAD group were all smaller than those in CI group. The rate of outliers of postoperative HKA angle of the PAD group was smaller than that in the CI group (P<0.05), but there was no significant difference in the rate of outliers of CFCA and CTCA between the two groups (both P>0.05). Conclusion: TKA assisted by PAD can provide good alignment and prosthesis position in patients with valgus deformity, and it is superior to TKA with CI in terms of precision and rate of outliers of postoperative overall alignment of lower extremity.