Kinematic versus mechanical alignment in total knee arthroplasty: a preliminary study

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Rehabilitative Medicine

Background:

• Total knee arthroplasty (TKA) has high success rates, but approximately 15% of patients experience unsatisfactory clinical outcomes.
• Current mechanical alignment (MA) techniques in TKA can alter natural knee kinematics, potentially impacting long-term survivorship and function.
• Restoring pre-arthritic knee alignment is increasingly recognized as a strategy to improve kinematics and functional results.

Purpose of the Study:

• To evaluate and compare the short-term functional outcomes of kinematic alignment TKA (KA-TKA) versus mechanical alignment TKA (MA-TKA).
• To assess the efficacy of KA-TKA in potentially improving patient function and satisfaction post-surgery.

Main Methods:

• A prospective study included skeletally mature patients undergoing isolated TKA for knee osteoarthritis.
• Patients were divided into two homogeneous groups: KA-TKA (n=13) and MA-TKA (n=13).
• Clinical and functional scores (VAS, KOOS-PS, MCS-12, KSS) were collected pre- and post-operatively at a 3-month follow-up.

Main Results:

• At 3-month follow-up, the KA-TKA group demonstrated statistically significant improvements across most tested scores compared to the MA-TKA group.
• The MCS-12 score was comparable between the two groups.
• The study included 26 patients (mean age 69.3 years; 38.5% male).

Conclusions:

• This preliminary study suggests that KA-TKA may lead to superior short-term functional outcomes compared to MA-TKA.
• Further research with larger sample sizes is warranted to confirm these findings and establish reliable clinical evidence for KA-TKA.
• Kinematic alignment represents a promising alternative surgical technique for total knee replacement.