Intraoperative three dimensional correction during in situ contouring surgery by using a numerical model.

Area of Science:

• Spine surgery
• Biomechanical engineering
• Medical simulation

Background:

• Scoliosis correction surgery, such as in situ contouring (ISC), involves complex 3D spinal correction.
• Previous methods for analyzing surgical maneuvers were limited and operator-dependent.
• Simulating surgical gestures offers an alternative but existing models lacked flexibility.

Purpose of the Study:

• To quantify intraoperative spinal correction during in situ contouring (ISC) surgery.
• To develop and validate an automated, patient-specific simulation of ISC surgery.
• To improve the understanding of spinal kinematics and correction mechanisms in scoliosis surgery.

Main Methods:

• A numerical study simulating in situ contouring (ISC) surgery was conducted.
• Patient-specific finite-element models (T1-L5 and pelvis) were created for 10 severe idiopathic scoliosis patients.
• An algorithm determined bending maneuver sequences based on surgeon-selected rod shapes, simulating all main surgical steps.

Main Results:

• Simulated bending maneuvers of both rods produced complementary spinal corrections.
• The simulated maneuvers integrated intraoperative corrections from rod-rotation techniques.
• The study computed vertebral kinematics and clinical parameter evolution for each maneuver.

Conclusions:

• Automated patient-specific simulation of ISC surgery enhances understanding of scoliosis correction.
• The simulation accurately assessed virtual postoperative spinal configurations.
• This approach offers insights into the primary mechanisms driving scoliosis surgical correction.