A Dual-Pivot Pattern Simulating Native Knee Kinematics Optimizes Functional Outcomes After Total Knee Arthroplasty.

Area of Science:

• Orthopedic Surgery
• Biomechanical Engineering
• Rehabilitation Science

Background:

• Limited research correlates total knee arthroplasty (TKA) kinematics with functional outcomes.
• Understanding specific knee motion patterns is crucial for improving TKA results.

Purpose of the Study:

• To investigate if native-like knee kinematics (lateral pivot in early flexion, medial pivot in high flexion) enhance clinical outcomes after TKA.
• To identify specific kinematic patterns associated with superior functional results post-TKA.

Main Methods:

• Intraoperative knee kinematics were recorded in 120 TKAs using sensor trials.
• Kinematic patterns were classified based on the center of rotation in three flexion zones.
• Knee Society Scores, pain, and satisfaction were analyzed against kinematic patterns.

Main Results:

• TKAs with an early lateral/late medial pivot pattern showed higher Knee Society function scores (P = .018) and greater improvement from baseline (P = .008).
• Patients with this pattern reported a significant decrease in feeling their knee is abnormal (P = .011) and higher satisfaction (P = .003).
• The ideal kinematic pattern yielded superior functional outcomes at 1-year compared to less ideal patterns.

Conclusions:

• An early lateral pivot followed by a medial pivot in later flexion correlates with improved function and patient satisfaction after TKA.
• Mimicking the dual-pivot motion of native knees may be key to enhancing TKA outcomes.