Ball-Tipped Probe Type Demonstrates Variation in Detecting Pedicle Screw Tract Breaches by Trainees in Lumbar Spine Model
Jeremy S. Marx1, Mark A. Plantz2*, Jason D. Tegethoff2, Tyler Compton2, John J Carney2, Erik B. Gerlach3, Joseph A. Weiner4,Srikanth N. Divi2, Alpesh A. Patel2, Wellington K. Hsu2
1Department of Spine Surgery, Cleveland Clinic Foundation, Cleveland OH, USA.
2Orthopaedic Surgery, Northwestern University Feinberg School of Medicine, Chicago IL, USA.
3Indiana Spine Group, Carmel IN, USA.
4Department of Spine Surgery, University of Kansas Medical Center, Kansas City KS, USA.
*Corresponding Author: Mark A. Plantz; Address: 676 N. St. Clair St., Suite 1350, Chicago IL 60611, Phone Number: 312-926-4444
https://doi.org/10.58624/SVOAOR.2026.06.018
Received: June 24, 2026
Published: July 25, 2026
Citation: Marx JS, Plantz MA, Tegethoff JD, Compton T, Carney JJ, Gerlach EB, Weiner JA, Divi SN, Patel AA, Hsu WK. Ball-Tipped Probe Type Demonstrates Variation in Detecting Pedicle Screw Tract Breaches by Trainees in Lumbar Spine Model. SVOA Orthopaedics 2026, 6:4, 121-129. doi: 10.58624/ SVOAOR.2026.06.018
Abstract
Introduction: 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.
Keywords: Orthopaedic surgery resident education; Ball-tip probe; Breach accuracy; Spine surgery