Patient satisfaction following total knee arthroplasty using restricted kinematic alignment

Area of Science:

• Orthopedic Surgery
• Biomechanical Engineering

Background:

• Total knee arthroplasty (TKA) aims to restore function and alleviate pain.
• Alternative alignment strategies, including kinematic and restricted kinematic alignment, are explored to enhance TKA outcomes.
• Preoperative varus deformity is a common consideration in TKA patient selection.

Purpose of the Study:

• To evaluate the clinical results and patient satisfaction of TKA performed using a restricted kinematic alignment concept.
• To compare outcomes between restricted kinematic alignment and traditional neutral mechanical alignment in TKA.

Main Methods:

• A prospective study of 109 patients (115 knees) undergoing primary TKA with restricted kinematic alignment for preoperative varus deformity.
• Patients were stratified into three groups based on varus deformity severity (1-5°, 6-10°, >10°).
• Comparison with a matched cohort of 115 TKAs using neutral mechanical alignment and manual instrumentation.

Main Results:

• Restricted kinematic alignment group reported significantly higher patient satisfaction (93% vs. 81%, p < 0.006) and a higher mean Likert score (4.7 vs. 4.3, p < 0.001).
• Improved scores were observed in the kinematic group for KOOS, WOMAN, Forgotten Joint Score, and KSS scores at mean 17-month follow-up.
• The most frequent complication in both groups was arthrofibrosis requiring manipulation under anesthesia (6.1% kinematic vs. 7.8% mechanical).

Conclusions:

• Restricted kinematic alignment, facilitated by advanced technology for precise bone cuts and soft-tissue balancing, leads to excellent patient satisfaction in primary TKA.
• Further long-term studies are necessary to ascertain the durability of the restricted kinematic alignment method.