Accuracy and technical limits of percutaneous pedicle screw placement in the thoracolumbar spine.
Surg Radiol Anat
; 43(6): 843-853, 2021 Jun.
Article
in En
| MEDLINE
| ID: mdl-33449140
ABSTRACT
PURPOSE:
The two-dimensional fluoroscopic method of percutaneous pedicle screw instrumentation has been clinically described as reliable method in the caudal thoracic and lumbosacral spine. Its accuracy has not been clearly reported in the cranial thoracic spine. The aim of this in vitro study was to investigate percutaneous pedicle screw placement accuracy according to pedicle dimensions and vertebral levels.METHODS:
Six fresh-frozen human specimens were instrumented with 216 screws from T1 to S1. Pedicle isthmus widths, heights, transversal pedicles and screws were measured on computed tomography. Pedicle cortex violation ≥ 2 mm was defined as screw malposition.RESULTS:
The narrowest pedicles were at T3-T5. A large variability between transversal pedicle axes and percutaneous pedicle screw was present, depending on the spinal level. Screw malposition rates were 36.1% in the cranial thoracic spine (T1-T6), 16.7% in the caudal thoracic spine (T7-T12), and 6.9% in the lumbosacral spine (L1-S1). The risk for screw malposition was significantly higher at cranial thoracic levels compared to caudal thoracic (p = 0.006) and lumbosacral (p < 0.0001) levels. Cortex violation ≥ 2 mm was constantly present if the pedicle width was < 4.8 mm.CONCLUSION:
Percutaneous pedicle screw placement appears safe in the caudal thoracic and lumbosacral spine. The two-dimensional fluoroscopic method has a limited reliability above T7 because of smaller pedicle dimensions, difficulties in visualizing radiographic pedicle landmarks and kyphosis.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Spinal Fusion
/
Thoracic Vertebrae
/
Pedicle Screws
/
Lumbar Vertebrae
Limits:
Aged80
/
Female
/
Humans
/
Male
Language:
En
Journal:
Surg Radiol Anat
Journal subject:
ANATOMIA
/
RADIOLOGIA
Year:
2021
Document type:
Article
Affiliation country:
Francia