The load sharing classification of spine fractures

Area of Science:

• Spinal surgery
• Orthopedic trauma
• Biomechanical analysis

Background:

• Short-segment instrumentation is used for three-column spinal fractures.
• First-generation VSP (Steffee) screws and plates with autograft fusion were employed.
• Screw breakage occurred in 10 of 28 patients during a 3-4 year follow-up.

Purpose of the Study:

• To develop a system to predict screw breakage in spinal fracture surgery.
• To identify factors contributing to implant failure in short-segment fixation.
• To aid in surgical planning and patient selection for spinal fracture treatment.

Main Methods:

• Retrospective analysis of preoperative radiographs and CT scans.
• Evaluation of 28 patients with three-column spinal fractures treated with short-segment instrumentation.
• Development of a point system (load sharing classification) based on injury characteristics.

Main Results:

• Screw fractures were associated with greater vertebral body injury.
• The load sharing classification grades vertebral body damage, fragment spread, and corrected kyphosis.
• A system was developed to quantify spinal injury severity.

Conclusions:

• The load sharing classification predicts screw breakage with short-segment posterior pedicle screw implants.
• This system aids in describing spinal injuries for retrospective studies.
• It assists in selecting fractures for anterior reconstruction with strut grafting.