No Difference in 5-year Clinical or Radiographic Outcomes Between Kinematic and Mechanical Alignment in TKA: A...

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Clinical Trials

Background:

• Kinematic alignment in total knee arthroplasty (TKA) aims to replicate pre-arthritic anatomy, differing from traditional neutral mechanical alignment.
• Limited mid-term comparative data exists for survivorship and functional outcomes between these TKA alignment techniques.

Purpose of the Study:

• To compare kinematic alignment versus mechanical alignment in TKA at 5 years.
• To evaluate differences in patient-reported outcomes, survivorship free from revision/reoperation, and radiographic aseptic loosening.

Main Methods:

• A randomized controlled trial involving 99 primary TKAs for osteoarthritis.
• Patients were randomized to mechanical alignment (computer navigation) or kinematic alignment (patient-specific cutting blocks).
• Outcomes assessed included various patient-reported scores, survivorship analysis, and radiographic evaluation for aseptic loosening.

Main Results:

• No significant differences in patient-reported outcome measures were observed between the kinematic and mechanical alignment groups at 5 years.
• Survivorship free from reoperation and revision showed no significant difference between the two alignment techniques.
• One case of radiographic aseptic loosening was noted in the mechanical alignment group, with none in the kinematic alignment group.

Conclusions:

• Mid-term functional and radiographic outcomes are similar for kinematic and mechanical alignment in TKA.
• The anticipated improvements in patient outcomes with kinematic alignment were not realized in this study.
• Routine use of kinematic alignment is not recommended outside research due to potential long-term concerns regarding component loosening.