Robotic-assisted total hip arthroplasty: from planning to robotization

Background: Total hip arthroplasty (THA) outcomes are frequently compromised by component malpositioning, which contributes to approximately 40% of revision surgeries. Traditional manual techniques and standard navigation systems often fail to prevent medial or superior shifts in the center of rotation, potentially leading to impingement, accelerated wear, and limb length discrepancy.

Objective: This article evaluates the application of robotic-arm assisted technology in THA, focusing on preoperative planning, intraoperative execution, and clinical evidence regarding implant accuracy and patient outcomes.

Key Points: The system utilizes preoperative CT-based 3D modeling to facilitate surgeon-directed adjustments of acetabular orientation, center of rotation, and femoral offset. Intraoperative robotic guidance constrains acetabular reaming and component impaction, ensuring adherence to the plan within a reported 3.5° margin of error. Comparative data indicate that robotic assistance significantly increases the proportion of implants placed within established safe zones compared to manual or fluoroscopic methods. Furthermore, the technology facilitates bone preservation through single-stage reaming and maintains accuracy regardless of patient body mass index. While a learning curve of approximately 35 cases is noted, early functional data, including Harris Hip Scores, suggest outcomes superior to conventional techniques at one year. However, increased operative time and equipment costs remain significant factors for consideration.

Conclusion: Robotic-arm assisted THA provides a reproducible method for achieving precise component positioning and restoring hip biomechanics. It minimizes errors related to manual instrumentation and offers a data-driven approach to managing complex anatomical variations and improving surgical predictability.