TY - JOUR
T1 - Pedicle screws adjacent to the great vessels or viscera
T2 - A study of 2132 pedicle screws in pediatric spine deformity
AU - Sarwahi, Vishal
AU - Suggs, William
AU - Wollowick, Adam L.
AU - Kulkarni, Preethi M.
AU - Lo, Yungtai
AU - Amaral, Terry D.
AU - Thornhill, Beverly
PY - 2014/4
Y1 - 2014/4
N2 - STUDY DESIGN: A retrospective study. OBJECTIVE: To determine the incidence of pedicle screws close to vital structures and to identify patient or curve characteristics that increase the risk of screw misplacement. SUMMARY AND BACKGROUND: Most pedicle screw misplacements are asymptomatic, thus they are frequently undetected. This study identifies the rate of screw placement in proximity to vital structures using postoperative computed tomography scans. METHODS: A total of 2132 screws in 101 patients, who underwent posterior spinal fusion for spinal deformity, were reviewed. Screws adjacent to great vessels and viscera were identified and evaluated. Patients with screws at risk (group B) were compared with patients without screws at risk (group A). Patient and curve characteristics were analyzed to determine whether a correlation with screw misplacement exists. RESULTS: A total of 40 at risk screws (∼2%) were identified in 25 patients (∼25%). These 40 screws were in proximity to the aorta (31), left subclavian artery (1), esophagus (3), trachea (3), pleura (1), and diaphragm (1). Of the 31 screws close to the aorta, 10 screws in 6 patients were impinging or distorting the aortic wall. One hundred percent of misplaced screws were in the thoracic spine, 50% were misplaced laterally, 50% were 35 mm long, 57.5% were in pedicles with normal morphology, and 75% were in curves between 40 and 70 degrees. Median screw misplacement rate was 10% in group A and 13% in group B. Adjusted for age and preoperative Cobb angle, patients with a higher misplacement rate were more likely to have screws adjacent to vital organs [adjusted odds ratio: 1.06 (95% confidence interval, 1.01-1.13), P=0.033]. CONCLUSIONS: Although only a small number of screws were at risk, they occurred in a large percentage of patients (25%). A single at-risk screw causes a significant complication for the patient. Postoperative imaging beyond routine X-rays may be needed to detect at-risk screws in asymptomatic patients.
AB - STUDY DESIGN: A retrospective study. OBJECTIVE: To determine the incidence of pedicle screws close to vital structures and to identify patient or curve characteristics that increase the risk of screw misplacement. SUMMARY AND BACKGROUND: Most pedicle screw misplacements are asymptomatic, thus they are frequently undetected. This study identifies the rate of screw placement in proximity to vital structures using postoperative computed tomography scans. METHODS: A total of 2132 screws in 101 patients, who underwent posterior spinal fusion for spinal deformity, were reviewed. Screws adjacent to great vessels and viscera were identified and evaluated. Patients with screws at risk (group B) were compared with patients without screws at risk (group A). Patient and curve characteristics were analyzed to determine whether a correlation with screw misplacement exists. RESULTS: A total of 40 at risk screws (∼2%) were identified in 25 patients (∼25%). These 40 screws were in proximity to the aorta (31), left subclavian artery (1), esophagus (3), trachea (3), pleura (1), and diaphragm (1). Of the 31 screws close to the aorta, 10 screws in 6 patients were impinging or distorting the aortic wall. One hundred percent of misplaced screws were in the thoracic spine, 50% were misplaced laterally, 50% were 35 mm long, 57.5% were in pedicles with normal morphology, and 75% were in curves between 40 and 70 degrees. Median screw misplacement rate was 10% in group A and 13% in group B. Adjusted for age and preoperative Cobb angle, patients with a higher misplacement rate were more likely to have screws adjacent to vital organs [adjusted odds ratio: 1.06 (95% confidence interval, 1.01-1.13), P=0.033]. CONCLUSIONS: Although only a small number of screws were at risk, they occurred in a large percentage of patients (25%). A single at-risk screw causes a significant complication for the patient. Postoperative imaging beyond routine X-rays may be needed to detect at-risk screws in asymptomatic patients.
KW - aorta
KW - esophagus
KW - pedicle screw
KW - posterior spinal fusion
KW - screw misplacement
KW - trachea
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U2 - 10.1097/BSD.0b013e31825bfecd
DO - 10.1097/BSD.0b013e31825bfecd
M3 - Article
C2 - 24658152
AN - SCOPUS:84897065957
SN - 1536-0652
VL - 27
SP - 64
EP - 69
JO - Journal of Spinal Disorders and Techniques
JF - Journal of Spinal Disorders and Techniques
IS - 2
ER -