Pediatric Spinal Deformity Correction Research Articles

Novel Machine Vision Image Guidance System Significantly Reduces Procedural Time and Radiation Exposure Compared With 2-dimensional Fluoroscopy-based Guidance in Pediatric Deformity Surgery.

Intraoperative 2-dimensional (2D) fluoroscopy imaging has been commonly adopted for guidance during complex pediatric spinal deformity correction. Despite the benefits, fluoroscopy imaging emits harmful ionizing radiation, which has been well-established to have deleterious effects on the surgeon and operating room staff. This study investigated the difference in intraoperative fluoroscopy time and radiation exposure during pediatric spine surgery between 2D fluoroscopy-based navigation and a novel machine vision navigation system [machine vision image guidance system (MvIGS)]. This retrospective chart review was conducted at a pediatric hospital with patients who underwent posterior spinal fusion for spinal deformity correction from 2018 to 2021. Patient allocation to the navigation modality was determined by the date of their surgery and the date of implementation of the MvIGS. Both modalities were the standard of care. Intraoperative radiation exposure was collected from the fluoroscopy system reports. A total of 1442 pedicle screws were placed in 77 children: 714 using MvIGS and 728 using 2D fluoroscopy. There were no significant differences in the male-to-female ratio, age range, body mass index, distribution of spinal pathologies, number of levels operated on, types of levels operated on, and the number of pedicle screws implanted. Total intraoperative fluoroscopy time was significantly reduced in cases utilizing MvIGS (18.6 ± 6.3s) compared with 2D fluoroscopy (58.5 ± 19.0s) ( P < 0.001). This represents a relative reduction of 68%. Intraoperative radiation dose area product and cumulative air kerma were reduced by 66% (0.69 ± 0.62 vs 2.0 ± 2.1Gycm 2 , P < 0.001) and 66% (3.4 ± 3.2 vs 9.9 ± 10.5mGy, P < 0.001) respectively. The length of stay displayed a decreasing trend with MVIGS, and the operative time was significantly reduced in MvIGS compared with 2D fluoroscopy for an average of 63.6 minutes (294.5 ± 15.5 vs 358.1 ± 60.6min, P < 0.001). In pediatric spinal deformity correction surgery, MvIGS was able to significantly reduce intraoperative fluoroscopy time, intraoperative radiation exposure, and total surgical time, compared with traditional fluoroscopy methods. MvIGS reduced the operative time by 63.6 minutes and reduced intraoperative radiation exposure by 66%, which may play an important role in reducing the risks to the surgeon and operating room staff associated with radiation in spinal surgery procedures. Level III; retrospective comparative study.

Does intraoperative CT navigation increase the accuracy of pedicle screw placement in pediatric spinal deformity surgery? A systematic review and meta-analysis.

Although pediatric spinal deformity correction using pedicle screws has a very low rate of complications, the long-term consequences of screw malposition is unknown. CT navigation has been proposed to improve screw accuracy. The aim of this study was to determine whether intraoperative navigation during pedicle screw placement in pediatric scoliosis makes screw placement more accurate. We also examined radiation exposure, operative time blood loss and complications with and without the use of CT navigation in pediatric spinal deformity surgery. A systematic review of the literature was conducted. After screening, 13 articles were qualitatively and quantitatively analyzed to be used for the review. A random effects meta-analysis using REML methodology was employed to compare outcomes of screw accuracy, estimated blood loss, radiation exposure, and surgical duration. Screws placed with CT navigation surgery were three times as likely to be deemed "acceptable" compared with screws placed with freehand and 2D fluoroscopy assistance, twice as likely to be "perfect", and only 1/3 as likely to be potentially unsafe (all p value < 0.01). EBL was not significantly different between groups; however, operative time was roughly thirty minutes longer on average. Random effects analysis showed no significant difference in effective dose radiation while using CT navigation (p = 0.06). This systematic review of the literature demonstrates that intraoperative navigation results in more accurate pedicle screw placement compared to non-navigated techniques. We found that blood loss was similar in navigated and non-navigated surgery. Operative time was found to be approximately a half hour longer on average in navigated compared to non-navigated surgery. Effective radiation dose trended higher in navigated cases compared to non-navigated cases but did not reach statistical significance.

Effect of the Ultrasonic Bone Scalpel on Blood Loss During Pediatric Spinal Deformity Correction Surgery

Study DesignRetrospective cohort. ObjectiveDetermine the effect of the ultrasonic bone scalpel (UBS) on intraoperative blood loss and surgical time. Summary of Background DataThe UBS has shown beneficial effects in limiting blood loss in spinal surgery, but no study has examined its effect in patients with neuromuscular scoliosis. MethodsClinical records were reviewed for patients aged 9–18 who underwent posterior spinal fusion surgery of five or more levels for scoliosis correction by the senior author from April 2013 until October 2016. Exclusion criteria included: vertebral column resections, previous spinal surgery, cell saver usage, cases complicated by signal loss on monitoring, and incomplete medical records. A total of 84 patients met the criteria and were included in data analysis. The UBS was routinely used for performing osteotomies and facetectomies for all cases operated after March 2015. These cases were compared to a control group who underwent surgery prior to this date in which the UBS was not used. The experimental and control groups were further divided into adolescent idiopathic (AIS) and neuromuscular (NMS) subgroups. ResultsEBL in AIS patients decreased from 1,211 mL in the control group to 771 mL in the UBS group for an average total reduction of 440 mL (95% CI 106, 774, p = .01). In NMS patients, EBL fell from 2,171 mL in controls to 1228 mL in the study group for an average total reduction of 943 mL (95% CI 288, 1598, p < .01). On controlling for weight and number of levels fused, blood loss decreased 26.2% in AIS patients and 46.2% in NMS patients. ConclusionsThe ultrasonic bone scalpel is effective in reducing blood loss in AIS and NMS deformity correction surgery. Surgical time is not adversely affected by its use. Level of EvidenceLevel II, cohort study.

The Deformity Angular Ratio: Does It Correlate With High-Risk Cases for Potential Spinal Cord Monitoring Alerts in Pediatric 3-Column Thoracic Spinal Deformity Corrective Surgery?

A retrospective analysis. The purpose of this study was to determine whether the deformity angular ratio (DAR) can reliably assess the neurological risks of patients undergoing deformity correction. Identifying high-risk patients and procedures can help ensure that appropriate measures are taken to minimize neurological complications during spinal deformity corrections. Subjectively, surgeons look at radiographs and evaluate the riskiness of the procedure. However, 2 curves of similar magnitude and location can have significantly different risks of neurological deficit during surgery. Whether the curve spans many levels or just a few can significantly influence surgical strategies. Lenke et al have proposed the DAR, which is a measure of curve magnitude per level of deformity. The data from 35 pediatric spinal deformity correction procedures with thoracic 3-column osteotomies were reviewed. Measurements from preoperative radiographs were used to calculate the DAR. Binary logistic regression was used to model the relationship between DARs (independent variables) and presence or absence of an intraoperative alert (dependent variable). In patients undergoing 3-column osteotomies, sagittal curve magnitude and total curve magnitude were associated with increased incidence of transcranial motor evoked potential changes. Total DAR greater than 45° per level and sagittal DAR greater than 22° per level were associated with a 75% incidence of a motor evoked potential alert, with the incidence increasing to 90% with sagittal DAR of 28° per level. In patients undergoing 3-column osteotomies for severe spinal deformities, the DAR was predictive of patients developing intraoperative motor evoked potential alerts. Identifying accurate radiographical, patient, and procedural risk factors in the correction of severe deformities can help prepare the surgical team to improve safety and outcomes when carrying out complex spinal corrections. 3.

Neuromonitoring in pediatric spine surgery

Intraoperative neurophysiologic monitoring has an integral role during pediatric spinal deformity correction to mitigate the risk of iatrogenic neurologic injury. This review describes the nuances of pediatric spine surgery as they relate to neurophysiologic monitoring, addresses how the advent of multimodal techniques has expanded the scope of management of complex curvatures, and discusses the role of neuromonitoring during contemporary pediatric spine procedures, including growing rod and vertical expandable prosthetic titanium rib implantation.

Does a Kaolin-Impregnated Hemostatic Dressing Reduce Intraoperative Blood Loss and Blood Transfusions in Pediatric Spinal Deformity Surgery?

Retrospective case-control study. To evaluate the hemostatic benefits of using a kaolin-impregnated dressing during pediatric spinal deformity correction surgery. Minimizing blood loss and transfusions are clear benefits for patient safety. A technique common in both severe trauma and combat medicine that has not been reported in the spine literature is wound packing with a kaolin-impregnated hemostatic dressing. Estimated blood loss and transfusion amounts were analyzed in a total of 117 retrospectively identified cases. The control group included 65 patients (46 females, 19 males, 12.7±4.5 yr, 10.2±4.8 levels fused) who received standard operative care with gauze packing between June 2007 and March 2010. The treatment group included 52 patients (33 females, 19 males, 13.9±3.2 yr, 10.4±4.3 levels fused) who underwent intraoperative packing with QuikClot Trauma Pads (QCTP, Z-Medica Corporation) for all surgical procedures from July 2010 to August 2011. No other major changes in the use of antifibrinolytics or perioperative, surgical, or anesthesia technique were noted. Statistical differences were analyzed using analysis of covariance in R with P value of less than 0.05. The statistical model included sex, age, weight, scoliosis type, the number of vertebral levels fused, and surgery duration as covariates. The treatment group had 40% less intraoperative estimated blood loss than the control group (974 mL vs. 1620 mL) (P<0.001). Patients who received the QCTP treatment also had 42% less total perioperative transfusion volume (499 mL vs. 862 mL) (P<0.01). The use of a kaolin-impregnated intraoperative trauma pad seems to be an effective and inexpensive method to reduce intraoperative blood loss and transfusion volume in pediatric spinal deformity surgery. 3.

Can Radiation Exposure to the Surgeon Be Reduced With Freehand Pedicle Screw Fixation Technique in Pediatric Spinal Deformity Correction? A Prospective Multicenter Study

Prospective multicenter study of patients who underwent pediatric spinal deformity correction with posterior spinal fusion and instrumentation. To quantify radiation exposure to the surgeon during pedicle screw fixation using the freehand technique in pediatric spinal deformity surgery. Pedicle screw placement in thoracic and lumbar spine for spinal deformity is technically demanding and involves radiation exposure. Many experienced spinals surgeons use the freehand technique for pedicle screw fixation in spinal deformity surgery. There are no studies analyzing radiation exposure to the surgeon regarding freehand pedicle screw fixation technique. A prospective multicenter study was designed to evaluate radiation exposure to the operating spinal surgeon who uses the freehand pedicle screw fixation technique in pediatric spinal deformity correction. All of the operating surgeons placed a gamma radiation dosimeter on their chest outside the lead apron during surgery. Surgeons placed pedicle screws in the pediatric spinal deformity using the freehand technique. We included patients who had undergone correction with posterior spinal fusion and instrumentation with all pedicle screw constructs in this study. We analyzed 125 patients with pediatric spinal deformity who were operated on between 2008 and 2012. The average fluoroscopic time was 40.5 ± 21 seconds. The overall average fluoroscopic time for placement of a single pedicle screw and per fixation level were 2.6 ± 1.7 seconds and 3.9 ± 2.5 seconds, respectively. In each surgery, the recorded radiation exposure to the surgeon was less than the minimum reportable dose (<0.010 mSv) with an average of 0.0005 ± 0.00013 mSv per surgery. The use of freehand technique for pedicle screw fixation in spinal deformity correction requires a minimum amount of fluoroscopic use, hence decreasing radiation exposure to the surgeon and patient. 4.

Neuromonitoring changes in pediatric spinal deformity surgery: a single-institution experience

Intraoperative monitoring of the spinal cord has become the standard of care during surgery for pediatric spinal deformity correction. The use of both somatosensory and motor evoked potentials has dramatically increased the sensitivity and specificity of detecting intraoperative neurophysiological changes to the spinal cord, which assists in the intraoperative decision-making process. The authors report on a large, single-center experience with neuromonitoring changes and outline the surgical management of patients who experience significant neuromonitoring changes during spinal deformity correction surgery. The authors conducted a retrospective review of all cases involving pediatric patients who underwent spinal deformity correction surgery at Shriners Hospital for Children, Philadelphia, between January 2007 and March 2010. Five hundred nineteen consecutive cases were reviewed in which neuromonitoring was used, with 47 cases being identified as having significant changes in somatosensory evoked potentials, motor evoked potentials, or both. These cases were reviewed for patient demographic data and surgical characteristics. The incidence of significant neuromonitoring changes was 9.1% (47 of 519 cases), including 6 cases of abnormal Stagnara wake-up tests, of which 4 had corroborated postoperative neurological deficits (8.5% of 47 cases, 0.8% of 519). In response to neuromonitoring changes, wake-up tests were performed in 37 (79%) of 47 cases, hardware was adjusted in 15 (32%), anesthesiology interventions were reported in 5 (11%), hardware was removed in 5 (11%), the patient was successfully repositioned in 3 (6%), and the procedure was aborted in 13 (28%). In 1 of the 4 patients with new postoperative deficits, the deficit had fully resolved by the last follow-up; the other 3 patients had persistent neurological impairment as of the most recent follow-up examination. The authors observed a sensitivity of 100% for intraoperative neuromonitoring. Due to the profound risks associated with spinal deformity surgery, intraoperative neurophysiological monitoring is an integral tool to warn of impending spinal cord injury. Intraoperative neuromonitoring appears to provide a safe and useful warning mechanism to minimize spinal cord injury that may arise during scoliosis correction surgery in pediatric patients.

Idiopathic intracranial hypertension following spinal deformity surgery in children

Idiopathic intracranial hypertension (IIH) after pediatric spinal deformity surgery has not been previously reported. The authors conducted a retrospective analysis of more than 1500 pediatric spinal surgeries performed between 1992 and 2011. From their analysis, they report on 3 adolescent patients who underwent uncomplicated segmental spinal instrumentation for pediatric spinal deformity correction and subsequently developed features of IIH. The common variables in these 3 patients were adolescent age, spinal deformity, being overweight, symptom onset within 2 weeks postoperatively, significant estimated blood loss, and intraoperative use of ε-aminocaproic acid (antifibrinolytic) injection. The authors postulate that the development of IIH could be the result of venous outflow obstruction due to derangement of the epidural venous plexus during surgery. The use of ε-aminocaproic acid could potentially have the risk of causing IIH, probably mediated through hyperfibrinogenemia, although there have not been published cases in the neurosurgical, orthopedic, cardiac, or general surgical literature. Idiopathic intracranial hypertension after spinal deformity correction is a condition that should be recognized by neurosurgeons and orthopedic surgeons, because appropriate intervention with early medical therapy can lead to a satisfactory clinical outcome.

Safety and Efficacy of Concurrent Pediatric Spinal Cord Untethering and Deformity Correction

A retrospective clinical records analysis of concurrent pediatric spinal cord deformity correction and tethered cord release compared with a 2-staged approach. To compare the safety and efficacy of a single-staged approach for pediatric spinal deformity correction and tethered cord release to a conventional 2-staged approach. Tethered cord syndrome (TCS) is frequently associated with scoliosis in the pediatric population. Conventional practice suggests waiting several months after untethering for scoliosis correction; however, some patients will experience progression of their spinal deformity. We report the efficacy and safety of concurrent tethered cord release and scoliosis and/or kyphosis deformity correction in a series of pediatric patients. We retrospectively reviewed 15 consecutive pediatric cases of concurrent spinal cord untethering and deformity correction with fusion for scoliosis and/or kyphosis. The clinical and radiologic presentation, operative details, morbidity, and postoperative outcomes were evaluated. Outcomes of this cohort were then compared with 21 patients who underwent a 2-staged untethering surgery followed by scoliosis correction. We provide a review of the literature of the treatment of tethered cord associated with spine deformities. The mean age of patients undergoing concurrent untethering and curve correction was 9.6 years (5 male, 10 female). Tethered cord was because of myelomeningocele (5 patients), thickened filum terminale (5 patients), lipomyelomeningocele (4 patients), and retethering from an unknown primary TCS etiology (1 patient). The mean scoliosis Cobb angle (±SD) at presentation was 55.4±21.0 degrees (range, 32.3 degrees to 95.0 degrees) whereas average kyphosis was 112.7±43.6 degrees (range, 68.0 degrees to 155.0 degrees). Average postoperative scoliosis curve was 40.0 degrees, resulting in an average correction of 27%; kyphosis curve was 55.7 degrees resulting in an average correction of 50%. The average operation time was 8.6 hours (range, 3.9 to 13.7 h) and the average blood loss was 1266 mL (range, 400 to 5000 mL). Average length of hospitalization was 10.1 days (range, 4 to 34 d). New onset or worsening of neurologic deficits, bowel or bladder dysfunction, or TCS associated pain did not occur in any patients. At a mean follow-up of 5.7 years (range, 1.3 to 11.8 y), only 1 (7%) patient required subsequent surgery for pseudoarthrosis. The 2-staged cohort experienced a longer cumulative operative time (11.2 vs 8.6 h, P<0.05), more total blood loss (1534 vs 1266 mL, P<0.05), longer total days of hospitalization (14.8 vs 10.1 d, P<0.05), and a greater incidence of dural tear (9.5% vs 0%), wound infection (26% vs 0%), and retethering (9.5% vs 0%). Concurrent tethered cord release and spinal fusion for correction of scoliosis and/or kyphosis may be a safe and effective approach in patients likely to experience deformity progression.

Comparison of Thoracic Pedicle Screw to Hook Instrumentation for the Treatment of Adult Spinal Deformity

Retrospective, case-control, matched cohort. Compare the radiographic and clinical outcomes of adult spinal deformity patients treated with thoracic pedicle screw (TPS) or thoracic hook constructs. The efficacy of TPS instrumentation for pediatric spinal deformity correction has been established. Little is known about TPS use in adult spinal deformity. Fifty-six patients (average age, 49 years; average follow-up, 3.58 years) were treated with TPS or thoracic hook constructs for coronal (n = 20) or sagittal (n = 36) plane deformities. Patients were evaluated radiographically and with SRS scores. Coronal deformities treated with TPS demonstrated improved main thoracic curve correction compared with hook constructs at last follow-up (24.8 degrees vs. 13.8 degrees; P < 0.05), despite having larger (59.8 degrees vs. 44.9 degrees; P < 0.05) and more rigid preoperative curves (29.3% vs. 44.9% correction on side-bending radiographs; P < 0.001). Sagittal deformities treated with TPS constructs demonstrated greater thoracolumbar kyphosis correction than hook constructs at last follow-up (12.1 degrees vs. 2.5 degrees; P < 0.05). No TPS patient had a thoracic pseudarthrosis. Four hook patients (14%) had thoracic pseudarthroses. TPS instrumentation allows greater coronal and sagittal plane correction and may reduce the risk of thoracic pseudarthrosis compared with hook constructs when treating adult spinal deformities.