Mid-Flexion Sagittal Stability of Total Knee Arthroplasty Implanted With Kinematic Alignment: A Quantitative Radiographic Laxity Study With Single-Radius Posterior-Stabilized and Condylar-Stabilized Implants.

研究概要

Sixty-five patients with well-functioning primary TKAs were drawn from a randomized parent trial and evaluated 5–8 years postoperatively: Condylar-stabilized (CS) (n=37) vs posterior-stabilized (PS) (n=28). The primary outcome was radiographic sagittal/anteroposterior (AP) laxity at 45° (mid-flexion) and 90° using a Telos device. Secondary outcomes included Knee Society (KS) Pain/Motion, KS Function and Total Composite scores, Forgotten Joint Score (FJS), Lower Extremity Activity Scale (LEAS), range of motion (ROM), and mechanical/anatomic alignment. Overall, the results of the study revealed substantially greater sagittal/anteroposterior (AP) laxity with CS than PS at both 45° and 90° , while PROMs were generally similar; however, women with PS had higher KS Function and Total Composite scores than women with CS. These findings suggest implant design meaningfully influences mid-flexion stability under kinematic alignment, and that increased sagittal laxity may be linked to worse function in women.