Intraoperative image guidance compared with free-hand methods in adolescent idiopathic scoliosis posterior spinal surgery: a systematic review on screw-related complications and breach rates.

BACKGROUND CONTEXT: Severe adolescent idiopathic scoliosis (AIS) is a three-dimensional spinal deformity requiring surgery to stop curve progression. Posterior spinal instrumentation and fusion with pedicle screws is the standard surgery for AIS curve correction. Vascular and neurologic complications related to screw malpositioning are concerns in surgeries for AIS. Breach rates are reported at 15.7%, implant-related complications at 1.1%, and neurologic deficit at 0.8%. Free-hand screw insertion remains the prevailing method of screw placement, whereas image guidance has been suggested to improve placement accuracy.

PURPOSE: This study aimed to systematically review the screw-related complication and breach rates from posterior spinal instrumentation and fusion with pedicle screws for patients with AIS when using free-hand methods for screw insertion compared with image guidance methods.

STUDY DESIGN: This is a systematic review of prognosis, comparing image guidance with no image guidance in surgery.

PATIENT SAMPLE: One randomized controlled trial and multiple prospective cohort studies that reported complication or breach rates in posterior spinal instrumentation and fusion with pedicle screws for AIS.

OUTCOME MEASURES: Number of complications and breaches reported in databases or recorded from postoperative imaging.

METHODS: Databases searched included MEDLINE, Embase, CINAHL, CENTRAL, and Web of Science. Studies of Level 3 evidence or greater as defined by the Centre for Evidence-Based Medicine were included. Articles were screened to focus on patients with AIS undergoing posterior fusion with pedicle screws or hybrid systems. Two independent reviewers screened abstracts, full texts, and extracted data. The Quality in Prognostic Studies (QUIPS) appraisal tool was used to determine studyrisk of bias (ROB). Level of evidence summary statements were formulated based on consistency and quality of reporting.

RESULTS: Seventy-nine cohort studies were identified, including four comparing computed tomography (CT) guidance with free-hand methods head-to-head, eight on image guidance, and 671. on free-hand methods alone. Moderate evidence from individual head-to-head studies show CT guidance has lower breach rates than free-hand methods. No complications were found in these studies. From individual cohort studies, moderate evidence shows CT guidance has lower point estimates of breach rates than free-hand methods at 7.9% compared with 9.7%-17.1%. Screw-related complication rates are conflicting at 0% in CT navigation compared with 0%-1.7% in 13 low- and moderate-quality studies.

CONCLUSIONS: Although point estimates on breach rates are decreased with CT navigation compared with free-hand methods, complication rates remain conflicting between the two methods. Current evidence is limited by small sample sizes, lack of comparison groups, and poorly predefined complications. Randomized controlled trials with larger samples with standardized definitions and recording of predefined breach and complication occurrences are recommended.