Interobserver reliability in evaluation of pedicle screw positions inserted with a modified technique

Area of Science:

• Spine surgery
• Orthopaedic surgery
• Surgical techniques

Background:

• Pedicle screw fixation is a common spinal stabilization technique.
• Accurate screw placement is crucial for surgical success and patient outcomes.
• Assessing pedicle screw position postoperatively typically involves imaging modalities.

Purpose of the Study:

• To evaluate a novel technique for pedicle screw insertion.
• To assess the reliability of plain radiographs and computed tomography (CT) scans in determining pedicle screw position.
• To analyze interobserver reliability in evaluating screw placement across different spinal regions and conditions.

Main Methods:

• A new pedicle screw insertion technique was applied to 201 screws in 27 patients.
• Screw positions were independently evaluated by two orthopaedic surgeons and two radiologists.
• Interobserver reliability was assessed for both plain radiographs and CT scans, stratified by spinal segment and condition.

Main Results:

• Malpositioned screw rates varied: 6.5%-32.8% on plain radiographs and 3.5%-6.5% on CT scans.
• Interobserver reliability was poor for plain radiographs and fair for CT scans.
• The new insertion technique was found to be simple and reproducible.

Conclusions:

• Plain radiographs alone are unreliable for assessing pedicle screw accuracy.
• CT scans offer better interobserver reliability for evaluating screw placement.
• Development of a standardized classification system is recommended to enhance assessment reliability.