Ball-Tipped Probe Type Demonstrates Variation in Detecting Pedicle Screw Tract Breaches by Trainees in Lumbar Spine Model

Purpose There is a lack of research investigating the variance and accuracy of different pedicle probe designs for detecting pedicle tract breaches. This study aims to assess the accuracy of three different ball-tip probes in detecting pedicle breaches in a lumbar spine model as assessed by orthopaedic surgery trainees. Methods Pedicle tracts were created bilaterally in six lumbar Sawbones models using a 2mm drill bit. L1-L5 pedicles were randomized to no breach, superior, inferior, medial, or lateral breaches. Breach presence and location were assessed using one of three ball-tip probes with varying head diameter and shaft flexibility. Residency year, spine case logs and probe preference were recorded. Probe accuracy; level of agreement between participants by specific probe; and correlation between accuracy, case volume, and residency year were assessed. Results For all probes, breach detection was 80.5%, and location accuracy was 64.1%. There was no difference in breach detection between different probes. Probe B was significantly more accurate (68.8%) than probes A or C (63.3% ; 60.3%; p = 0.02) in identifying breach locations. Inter-rater reliability was highest for Probe C regarding breach presence and location (k = 0.24 and 0.21, respectively; fair) relative to probes A or B. Spine case logs were not correlated with the ability to identify a breach or its location. Residency year was positively correlated with identifying breach location (r = 0.47, p = 0.04). Conclusion All probes demonstrated high accuracy in breach detection, yet detecting breach location and inter-rater reliability varied between probe designs. Probe design preference did not correlate with accuracy.