Abstract
Background The objective of this study was to assess the pullout force of a novel sharp-tipped screw developed for single-step, minimally invasive pedicle screw placement guided by neuronavigation compared with the pullout force for traditional screws.
Methods A total of 60 human cadaveric lumbar pedicles were studied. Three different screw insertion techniques were compared: (A) Jamshidi needle and Kirschner wire without tapping; (B) Jamshidi needle and Kirschner wire with tapping; and (C) sharp-tipped screw insertion. Pullout tests were performed at a displacement rate of 10 mm/min recorded at 20 Hz. Mean values of these parameters were compared using paired t tests (left vs right in the same specimen): A vs B, A vs C, and B vs C. Additionally, 3 L1-L5 spine models were used for timing each screw insertion technique for a total of 10 screw insertions for each technique. Insertion times were compared using 1-way analysis of variance.
Results The mean pullout force for insertion technique A was 1462.3 (597.5) N; for technique B, it was 1693.5 (805.0) N; and for technique C, it was 1319.0 (735.7) N. There was no statistically significant difference in pullout force between techniques (P > 0.08). The average insertion time for condition C was significantly less than that for conditions A and B (P < 0.001).
Conclusions The pullout force of the novel sharp-tipped screw placement technique is equivalent to that of traditional techniques. The sharp-tipped screw placement technique appears biomechanically viable and has the advantage of saving time during insertion.
Clinical Relevance Single-step screw placement using high resolution 3-dimensional navigation has the potential to streamline workflow and reduce operative time.
Level of Evidence 5.
Footnotes
Funding NuVasive provided the spinal instrumentation used in the study. Dr Wangsawatwong received scholarship support from Chulalongkorn University, King Chulalongkorn Memorial Hospital, and the Thai Red Cross Society.
Declaration of Conflicting Interests The authors report no conflicts of interest in this work.
Disclosures Juan S. Uribe receives consulting fees and royalties from NuVasive Medical, Inc. and is a consultant for Misonix Inc. and SI-BONE Inc. Jay D. Turner is a consultant for NuVasive Medical, Inc., SeaSpine Holdings, SI-BONE Inc., and AlphaTec Spine, Inc. The remaining authors have nothing to report.
- This manuscript is generously published free of charge by ISASS, the International Society for the Advancement of Spine Surgery. Copyright © 2023 ISASS. To see more or order reprints or permissions, see http://ijssurgery.com.