Pedicle screws adjacent to the great vessels or viscera

A study of 2132 pedicle screws in pediatric spine deformity

Vishal Sarwahi, William Suggs, Adam L. Wollowick, Preethi M. Kulkarni, Yungtai Lo, Terry D. Amaral, Beverly Ann Thornhill

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

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.

Original languageEnglish (US)
Pages (from-to)64-69
Number of pages6
JournalJournal of Spinal Disorders and Techniques
Volume27
Issue number2
DOIs
StatePublished - 2014

Fingerprint

Viscera
Spine
Pediatrics
Aorta
Pedicle Screws
Spinal Fusion
Subclavian Artery
Pleura
Diaphragm
Trachea
Esophagus
Thorax
Retrospective Studies
Odds Ratio
Tomography
X-Rays
Confidence Intervals

Keywords

  • aorta
  • esophagus
  • pedicle screw
  • posterior spinal fusion
  • screw misplacement
  • trachea

ASJC Scopus subject areas

  • Clinical Neurology
  • Surgery
  • Orthopedics and Sports Medicine

Cite this

Pedicle screws adjacent to the great vessels or viscera : A study of 2132 pedicle screws in pediatric spine deformity. / Sarwahi, Vishal; Suggs, William; Wollowick, Adam L.; Kulkarni, Preethi M.; Lo, Yungtai; Amaral, Terry D.; Thornhill, Beverly Ann.

In: Journal of Spinal Disorders and Techniques, Vol. 27, No. 2, 2014, p. 64-69.

Research output: Contribution to journalArticle

Sarwahi, Vishal ; Suggs, William ; Wollowick, Adam L. ; Kulkarni, Preethi M. ; Lo, Yungtai ; Amaral, Terry D. ; Thornhill, Beverly Ann. / Pedicle screws adjacent to the great vessels or viscera : A study of 2132 pedicle screws in pediatric spine deformity. In: Journal of Spinal Disorders and Techniques. 2014 ; Vol. 27, No. 2. pp. 64-69.
@article{b0413870645b46a1b7ec2377e4bf1480,
title = "Pedicle screws adjacent to the great vessels or viscera: A study of 2132 pedicle screws in pediatric spine deformity",
abstract = "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.",
keywords = "aorta, esophagus, pedicle screw, posterior spinal fusion, screw misplacement, trachea",
author = "Vishal Sarwahi and William Suggs and Wollowick, {Adam L.} and Kulkarni, {Preethi M.} and Yungtai Lo and Amaral, {Terry D.} and Thornhill, {Beverly Ann}",
year = "2014",
doi = "10.1097/BSD.0b013e31825bfecd",
language = "English (US)",
volume = "27",
pages = "64--69",
journal = "Journal of Spinal Disorders",
issn = "1536-0652",
publisher = "Lippincott Williams and Wilkins",
number = "2",

}

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 Ann

PY - 2014

Y1 - 2014

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

UR - http://www.scopus.com/inward/record.url?scp=84897065957&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84897065957&partnerID=8YFLogxK

U2 - 10.1097/BSD.0b013e31825bfecd

DO - 10.1097/BSD.0b013e31825bfecd

M3 - Article

VL - 27

SP - 64

EP - 69

JO - Journal of Spinal Disorders

JF - Journal of Spinal Disorders

SN - 1536-0652

IS - 2

ER -