Does posterior cruciate ligament sacrifice influence dynamic balance after total knee arthroplasty? Comparison of cruciate-retaining and cruciate-substituting designs in bilaterally operated patients.

PURPOSE

This study aimed to evaluate whether the posterior cruciate ligament sacrifice during total knee arthroplasty (TKA) has any effect on postoperative standing balance or not.

METHODS

The patients who underwent bilateral TKA with either CR or PS design were analyzed. 30 patients (10 PS, 20 CR) were included for the final analysis. TKA designs were compared in terms of Lysholm score, range of motion, and balance characteristics including somatosensorial, vestibular, and visual balance scales, adaptation, limits of stability, and weight-bearing/squat tests by computerized dynamic posturography.

RESULTS

The mean follow-up time was 59 months for CR, 49 months for PS group. The average Lysholm score values were 94 for CR and 95 for PS group, indicating functionally similar patient groups. The average knee flexion was found significantly higher in PS group (114°) compared to CR group (102°) ( = 0.009). In the CR group, motor adaptation tests (toes up/toes down) were found to be better ( = 0.034). In the on-axis velocity parameter (linear goal orientation) of limits of stability test, PS group patients were found to be more successful ( = 0.035).

CONCLUSIONS

The use of CR implants can be recommended in patients with a high risk of falling since they provide better motor adaptation providing rapid reactions to rapid surface changes. Better linear goal orientation in PS group, providing a faster movement in an intended direction, should be considered when planning the ideal implant for the patients with relevant activities.