Accuracy and perforation rate of free-hand pedicle screw insertion in thoracic spine

Abstract

Background
To assess the accuracy and perforation rate of free-hand pedicle screw insertion in thoracic spine, patients aged 15–70 years with dorsal vertebrae pathology with or without neurological deficit undergoing dorsal spine pedicle screw fixation using free-hand technique were included. Revision surgery and patients who needed deformity correction surgery were excluded. The accuracy of pedicle screw placement was assessed by Gertzbein and Robbins classification scores on computed tomography scans. Microsoft Excel and statistical softwares were used for data cleaning and statistical analysis. Categorical and continuous variables were reported in proportions and mean ± standard deviation. A paired sample t-test was used to assess and determine whether there was a mean difference between the two sets of observations. The statistical significance was determined at a 5% level.


Results
Seventy (36.26%) pedicle screws were inserted for infective pathology, and 91.7% of pedicle screws showed no breach. Thoracic spine 3–7 vertebra demonstrated the highest breach rate (11/16) (68.75%). The direction of the breach was lateral in ten screws (62.5%) and medial in six screws (37.5%), and there was no inferior and superior breached screw. The breach was not statistically significant.


Conclusions
Free-hand technique has excellent accuracy and insignificant perforation rate in instrumentation of the thoracic spine.