Does Robotic-Assisted Functional Knee Positioning Result in Better Functional Outcomes One Year After Surgery

Area of Science:

• Orthopedic Surgery
• Robotics in Medicine
• Biomechanical Engineering

Background:

• Robotic-assisted total knee arthroplasty (TKA) enables individualized implant placement using functional knee positioning (FKP).
• This study compares patient-reported outcomes between mechanically aligned TKA (MA-TKA) and functionally positioned TKA (FP-TKA).

Purpose of the Study:

• To compare patient-reported outcome measures (PROMs) between MA-TKA and FP-TKA.
• To evaluate functional recovery, pain, range of motion, and length of stay following TKA.

Main Methods:

• 145 propensity score-matched pairs of MA-TKA and FP-TKA patients were analyzed from an institutional dataset.
• FP-TKA involved individualizing implant position to balance the knee, minimizing soft tissue release.
• MA-TKA utilized standard mechanical alignment and gap balancing techniques. Outcomes measured included r-WOMAC scores, length of stay (LOS), and range of motion.

Main Results:

• No significant difference in r-WOMAC pain or function at six months, though FP-TKA trended favorably.
• At one year, FP-TKA showed significantly improved function scores (2.94 vs. 4.38; p=0.02) compared to MA-TKA.
• FP-TKA cohort had a shorter LOS (1.75 vs. 2.36 days; p<0.0001); no significant differences in knee flexion or extension at six weeks.

Conclusions:

• FP-TKA demonstrated functional improvements at one year, potentially due to minimized dissection and personalized implant positioning.
• While not reaching minimal clinically important difference, the trend suggests FP-TKA may enhance patient outcomes.
• Robotic-assisted FKP may offer advantages in functional recovery and hospital resource utilization in TKA.