The main cause of tibial prosthesis malalignment after total knee arthroplasty in Southern Chinese population

Abstract

Objectives: This study aimed to determine the occurrence rate of malalignment of tibial prosthesis and explore the influencing factors. Methods: 296 patients from Southern China who underwent total knee arthroplasty (TKA) were selected as the research objects. Their general demographic data were recorded. The tibial bowing angle (TBA), tibial length, medial proximal tibial angle (MPTA), tibial plateau shift angle (TPSA), tibial bone loss, lateral distal tibial angle, and overall width of tibial plateau and widths of medial and lateral tibial plateau were measured before TKA. The tibial component coronal alignment angle (TCCA) was measured after the operation. Malalignment of the tibial prosthesis was defined as TCCA 93°. Tibial bowing was indicated by TBA >2°, and lateral bowing was recorded as +. The correlations of TCCA with demographic data and pre-operation imaging measurement parameters were statistically analyzed. Results: Bivariate correlation analysis revealed negative correlations between TCCA and TBA (r = −0.602, P < 0.001) and TPSA (r = −0.304, P < 0.001), and a positive correlation with MPTA (r = −0.318, P < 0.001). Multivariate linear regression analysis demonstrated a significant negative correlation between TCCA and TBA (P < 0.001). The occurrence rate of malalignment of tibial prosthesis was 12.37 %. The occurrence rates of malalignment were 22.54 % in the tibial bowing group and 6.87 % in the non-tibial bowing group, showing statistical differences (P < 0.001). Conclusion: The malalignment rate of tibial prosthesis among Southern Chinese patients is relatively high, possibly attributed to the tibial anatomy anomalies, particularly the tibial bowing. The entry point should be determined based on tibial morphology.

Keywords

• Total knee arthroplasty
• Malalignment
• Tibial bowing
• Medial proximal tibial angle
• Tibial plateau shift angle