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Level-Specific Analysis of Intraoperative Computed Tomography-Navigated vs Fluoroscopy-Assisted Lumbar Pedicle Screw
Mario Giordano1, Federico Iaccarino2, Amir Kaywan Aftahy1
1Department of Neurosurgery, International Neuroscience Institute, Hannover, Germany.
Background:
Image-guided pedicle screw placement improves accuracy over fluoroscopy, but level-specific performance and independent predictors in routine care remain incompletely defined. This study aims to compare intraoperative computed tomography (iCT)-navigated vs fluoroscopy-assisted (FA) lumbar screw placement, while quantifying level-specific performance and exploring independent predictors of optimal (grade A) placement.
Methods:
We performed a single-center retrospective, noncontemporaneous cohort study of 229 adults who underwent primary lumbar pedicle screw fixation, including 131 iCT navigated and 98 FA. In total, 1304 lumbar screws were graded on postoperative computed tomography (CT) using the Gertzbein-Robbins scale. Mixed-effects logistic regression estimated odds of Grade A placement with fixed effects for technique, pathology, level, side, and age.
Results:
iCT was associated with higher accuracy than FA (grade A 97% vs 86%), with no grade C breaches under iCT (vs 2% with FA). The advantage was level dependent and most pronounced at L5 (grade A 97.3%-98.2% with iCT vs 79.3%-85.7% with FA); additional statistically significant differences favored iCT at L2 left, L3 left, and L4 left, while L3 right showed a nonsignificant trend. In adjusted analyses, FA was associated with markedly lower odds of grade A placement. Trauma was independently associated with a reduced likelihood of grade A placement, whereas revision surgery served as the reference category and was not an independent predictor; age, level, and side were not independent predictors.
Conclusions:
In this retrospective cohort, iCT navigation was associated with superior radiographic accuracy compared with fluoroscopy and higher rates of optimal screw placement. Traumatic pathology was associated with lower odds of optimal placement.
Clinical Relevance:
iCT-based navigation was associated with an increased likelihood of achieving optimal (Gertzbein-Robbins grade A) lumbar pedicle screw placement compared with fluoroscopy in routine clinical practice. The advantage appears particularly pronounced at L5 and in anatomically challenging scenarios. However, these findings are based on radiographic accuracy only and should be interpreted cautiously, as no direct conclusions on clinical outcomes or complication reduction can be drawn.
