Higher satisfaction after total knee arthroplasty using restricted inverse kinematic alignment compared to adjusted...

Area of Science:

• Orthopedic Surgery
• Biomechanical Engineering
• Robotic Surgery

Background:

• Total knee arthroplasty (TKA) aims for implant survival and functional outcomes.
• Patient-specific alignment is increasingly explored for enhanced functionality and satisfaction.
• Restricted inverse kinematic alignment (iKA) is a tailored approach for TKA.

Purpose of the Study:

• To describe the restricted iKA technique for robotic-assisted TKA.
• To compare clinical outcomes of restricted iKA versus adjusted mechanical alignment (aMA).

Main Methods:

• Retrospective review of 80 robotic-assisted TKA patients (40 restricted iKA, 40 aMA).
• Outcomes measured: Oxford Knee Score (OKS), Visual Analogue Scale (VAS) for satisfaction at 12 months.
• Analysis included patient acceptable symptom state (PASS) thresholds and regression analyses.

Main Results:

• Restricted iKA showed significantly better VAS satisfaction (9.2 vs. 8.5) and higher PASS achievement for OKS (98% vs. 85%) and satisfaction (80% vs. 48%) compared to aMA.
• Patients with preoperative varus deformity had significantly better OKS with restricted iKA (45.4 vs. 41.4).
• Multivariable analysis confirmed improved OKS and satisfaction with restricted iKA.

Conclusions:

• Restricted iKA and aMA provide comparable overall clinical outcomes at 12 months.
• Restricted iKA resulted in a greater proportion of patients achieving PASS thresholds for OKS and satisfaction.
• Restricted iKA demonstrated superior outcomes in knees with preoperative varus deformity.