The impact of postoperative inclination of the joint line on clinical outcomes in total knee arthroplasty using a prosthesis with anatomical geometry

Abstract

The goal of this study was to investigate the impact of postoperative inclination of the joint line on clinical results after total knee arthroplasty (TKA) using a prosthesis with anatomical geometry. This study included 145 primary cruciate-retaining type of knee prosthesis with anatomical geometry. Three years postoperatively, clinical outcomes including the patient-reported outcomes (PROs) were recorded. Limb alignment was evaluated by the hip-knee-ankle (HKA) axis and inclination of the joint line was assessed by the joint line orientation angle (JLOA). Knees were divided into two groups according to the HKA: in-range (− 3 to 3°) and outlier group (< − 3° or > 3°) or the JLOA: in-range (2–4°) and outlier group (< 2° or > 4°), and clinical outcomes were compared between the groups. Postoperative Knee Society Function Score (KS-FS) was significantly higher in the HKA in-range group than the outlier group (p = 0.01). The Knee Society Knee Score and all subscales of the Knee injury Osteoarthritis Outcome Score were comparable between the groups. A multivariate analysis revealed a significant association between age at operation and postoperative KS-FS > of 80 points. Neither HKA in-range nor JLOA in-range were associated with the higher knee function. In conclusion, TKA-postoperative inclination of the joint line was not relevant to the short-term PROs. Treatment strategies that attempt to make joint line inclination in order to improve postoperative PROs should be avoided, and alignment goals such as kinematic alignment should be considered carefully.

Constitutional alignment predicts medial ligament balancing in mechanically aligned total knee arthroplasty for varus knees

“…When assessing gaps intraoperatively, various studies have reported on the difference in gap size with and without trial components [8–10]. This is because with the trial implants in place, the flexion and extension gaps as well as medial tension change due to the effect of the femur component on the surrounding soft tissues [17, 23]. This was found to be true in our practice and therefore, flexion and extension gaps were routinely assessed again with the trial implants in place.…”

A Comparative Study of Clinical Outcomes Between Cruciate-Retaining and Posterior-Stabilized Total Knee Arthroplasty: A Propensity Score-Matched Cohort Study

“…These findings suggest that PCL is degenerated moderately to severely in most osteoarthritic knees and may not function normally if it is retained in CR TKA. However, this is not to say that a CR design should be avoided for elderly patients because many studies have reported successful TKAs that retain a PCL [ 25 - 29 ]. A possible explanation for our observation that the ADL subscale in the PS group was superior to the CR group is that there might be patients whose PCL was severely degenerated and did not function normally in patients receiving the CR implants, considering that the mean age at operation was 76 years old.…”

Restricted kinematically aligned total knee arthroplasty with an anatomically designed implant can restore constitutional coronal lower limb alignment

“…Double-leg standing whole-leg anteroposterior plain radiographs and single-leg standing lateral whole-leg radiographs were obtained to measure the mLDFA, MPTA, coronal HKA [20], coronal JLO [24], PTS, single-leg standing KFA, and sagittal JLO (Figure 1). The aHKA was calculated by subtracting mLDFA from MPTA [19].…”