Effect of tibia-first, restricted functional alignment technique on gap width changes, and component positioning in...

Area of Science:

• Orthopedic Surgery
• Biomechanical Engineering
• Medical Robotics

Background:

• Total knee arthroplasty (TKA) aims to restore knee function and alleviate pain in patients with osteoarthritis.
• Achieving optimal gap balance is crucial for TKA success, influencing implant stability and patient outcomes.
• Robotic arm assistance offers enhanced precision in bone resection and implant placement during TKA.

Purpose of the Study:

• To quantitatively assess the predictability of post-resection gap dimensions in robotic arm-assisted TKA.
• To evaluate the attainment of balanced knee gaps using a restricted functional alignment (FA) technique.
• To determine the effectiveness of a tibia-first, gap-balancing approach in robotic TKA.

Main Methods:

• Retrospective cohort study of 100 patients undergoing robotic arm-assisted TKA with a restricted FA technique.
• Tibial cuts based on preoperative anatomy, followed by femoral component adjustment for gap balance.
• Ligament balancing assessed using a robotic system at 10° and 90° flexion; evaluation of implant alignment and PROMs.

Main Results:

• Significant increases in lateral and medial gaps observed after bone resections (p < 0.001).
• The tibia-first, gap-balancing technique resulted in 98% of balanced gap measurements (≤2mm laxity).
• Improved patient-reported outcome measures (PROMs) noted one year post-surgery (p < 0.05).

Conclusions:

• The tibia-first, restricted FA technique effectively achieves a well-balanced knee in robotic arm-assisted TKA.
• Despite variations in gap dimensions, the technique demonstrates high success rates in achieving balanced gaps.
• Robotic assistance with this technique leads to improved patient outcomes in TKA.