TY - JOUR
T1 - Which Malpositioned Pedicle Screws Should Be Revised?
AU - Floccari, Lorena V.
AU - Larson, A. Noelle
AU - Crawford, Charles H.
AU - Polly, David W
AU - Ledonio, Charles Gerald T
AU - Blakemore, Laurel
PY - 2018/1/1
Y1 - 2018/1/1
N2 - Background:Up to 10% of free-hand pedicle screws are malpositioned, and 1 in 300 patients may undergo return to surgery for revision of malpositioned screws. The indications for revision of asymptomatic malpositioned screws have not been carefully examined in the literature. We sought to evaluate the threshold among spinal deformity surgeons for revision of malpositioned screws.Methods:Twelve experienced spine surgeons reviewed x-ray and computed tomographic images of 32 malpositioned pedicle screws with variable degrees of anterior, medial, and lateral breeches. The surgeons were asked whether based on the image they would revise the screw: (1) intraoperatively before rod placement; (2) intraoperatively after rod placement; (3) in clinic with an asymptomatic patient. For each scenario, we assumed stable neuromonitoring and no neurological changes. Agreement and multirater κ was calculated.Results:There was good agreement as to which screws were malpositioned (80% agreement, κ=0.703). After the rod was placed or postoperatively (scenarios 2 and 3), surgeons less frequently recommended screw revision, and there was greater variability among the surgeons' recommendations. For return to surgery from clinic for asymptomatic screw revision, % agreement was only 65% (κ=0.477). The majority recommended revision surgery for screws which approached the dura (10/12) or the aorta (7/12 surgeons). Half of the surgeons recommended revision surgery for an asymptomatic screw if the entire screw diameter was in the canal. Revision surgery was not recommended for asymptomatic patients with screws partially violating the canal (<1/2 the screw diameter), malpositioned laterally in the rib head, or with small anterior cortical violations remote from a vascular structure.Conclusions:There is significant variability of opinion among surgeons regarding which malpositioned screws can be safely observed in an asymptomatic patient. Given the frequency of malpositioned screws and morbidity of surgical return to surgery, more long-term data are needed to develop practice guidelines for determining which screws require revision surgery.Level of Evidence:Level III - retrospective comparative study.
AB - Background:Up to 10% of free-hand pedicle screws are malpositioned, and 1 in 300 patients may undergo return to surgery for revision of malpositioned screws. The indications for revision of asymptomatic malpositioned screws have not been carefully examined in the literature. We sought to evaluate the threshold among spinal deformity surgeons for revision of malpositioned screws.Methods:Twelve experienced spine surgeons reviewed x-ray and computed tomographic images of 32 malpositioned pedicle screws with variable degrees of anterior, medial, and lateral breeches. The surgeons were asked whether based on the image they would revise the screw: (1) intraoperatively before rod placement; (2) intraoperatively after rod placement; (3) in clinic with an asymptomatic patient. For each scenario, we assumed stable neuromonitoring and no neurological changes. Agreement and multirater κ was calculated.Results:There was good agreement as to which screws were malpositioned (80% agreement, κ=0.703). After the rod was placed or postoperatively (scenarios 2 and 3), surgeons less frequently recommended screw revision, and there was greater variability among the surgeons' recommendations. For return to surgery from clinic for asymptomatic screw revision, % agreement was only 65% (κ=0.477). The majority recommended revision surgery for screws which approached the dura (10/12) or the aorta (7/12 surgeons). Half of the surgeons recommended revision surgery for an asymptomatic screw if the entire screw diameter was in the canal. Revision surgery was not recommended for asymptomatic patients with screws partially violating the canal (<1/2 the screw diameter), malpositioned laterally in the rib head, or with small anterior cortical violations remote from a vascular structure.Conclusions:There is significant variability of opinion among surgeons regarding which malpositioned screws can be safely observed in an asymptomatic patient. Given the frequency of malpositioned screws and morbidity of surgical return to surgery, more long-term data are needed to develop practice guidelines for determining which screws require revision surgery.Level of Evidence:Level III - retrospective comparative study.
KW - malposition
KW - pediatric spine
KW - pedicle screw
KW - spine revision
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U2 - 10.1097/BPO.0000000000000753
DO - 10.1097/BPO.0000000000000753
M3 - Article
C2 - 27078232
AN - SCOPUS:84963568681
VL - 38
SP - 110
EP - 115
JO - Journal of Pediatric Orthopaedics
JF - Journal of Pediatric Orthopaedics
SN - 0271-6798
IS - 2
ER -