Intraoperative soft tissue tension and postoperative range of motion in posterior stabilized total knee arthroplasty

Intraoperative soft tissue tension can significantly impact the range of motion following total knee arthroplasty (TKA). However, the level of impact remains unclear. The purpose of this study was to investigate the relationship between intraoperative soft tissue tension and postoperative range of motion. This retrospective study included 504 patients operated with posterior stabilized TKA. During surgery, we adjusted the soft tissue tension from 80 to 160 N for both flexion and extension with the tensor/balancer device and torque driver. Patients were grouped into three categories based on intraoperative soft tissue tension and analyzed with the 1-year postoperative range of motion using one-way analysis of variance (ANOVA). In addition, Pearson's correlation coefficients were determined to assess the association between intraoperative soft tissue tension and postoperative range of motion. The absolute tension value at 90A degrees flexion did not affect the postoperative flexion angle (p = 0.61). The absolute tension value at 0A degrees extension did not affect the postoperative extension angle (p = 0.91). Likewise, the difference of tension between flexion and extension did not affect the postoperative flexion angle (p = 0.86). All comparisons did not have the differences in sex, height, weight, body mass index, diagnosis and preoperative range of motion between three groups. No significant correlation was found in each comparison (r = 0.078, r = 0.031, r = -0.052, respectively). We did not observe a correlation between intraoperative soft tissue tension adjusted from 80 to 160 N and 1-year postoperative range of motion in posterior stabilized TKA.