Screw Malposition: Are There Long-term Repercussions to Malposition of Pedicle Screws?

BACKGROUND/INTRODUCTION: Pedicle screws have long been part of the continued advancements in spine surgery. Despite the many techniques that have been devised for their safe placement, malposition of screws continues to occur. Studies have evaluated the possible safe limits of screw malposition, and have given some insight on anatomic variation in spinal deformity. Review of the literature reveals several cases of deleterious long-term sequelae of malpositioned screws. DISCUSSION: With the current experience, proposed recommendations are provided to detect and avoid the potential long-term sequelae. Though the literature has helped to define possible concerning screws, there are no good studies predicting long-term risk. CONCLUSION: Improvements in technology and techniques, advancements in intraoperative confirmation and postoperative surveillance, studies that assist risk stratification, and expert consensus evaluations will help guide surgeons in their decision for addressing misplaced screws.

Are All Hardware Removals Equal?

The objective of this study is to report operative time and associated complications of six types of implants and to determine if surgeons are adequately compensated. Hardware removals were analyzed from 2014-2019. Implants were flexible nails, intramedullary rigid nails, long plates, screw(s), single guided-growth plates, and multiple guided-growth plates. Patient demographics, operative time, blood loss, complications, and relative value units (RVU)/min were collected. RVU/min was used to maximize rate. In total, 392 patients were analyzed. Long plate removals took significantly longer than screw removal, therefore RVU/min was significantly lower (p < 0.001). Long plate removals also took significantly longer, and RVU/min was significantly lower compared to guided-growth plate removal (p < 0.001). Intramedullary nails took significantly longer compared to flexible nails, nearly double the RVU/min (p = 0.02). The results from this study indicate that the RVU/ minute for these six different types of implant removals are not equal. Surgeons can use this data to set up their schedule to ensure maximum utilization. (Journal of Surgical Orthopaedic Advances 30(1):020-023, 2021).

Effects of Fellowship Training on Pediatric Anterior Cruciate Ligament Reconstruction Techniques and Outcomes.

The purpose of this study is to examine differences in pediatric anterior cruciate ligament reconstruction (ACLR) between surgeons with either pediatric or sports medicine fellowship training. Patients were divided into two groups, those performed by either a pediatric or sports medicine fellowship-trained surgeon. One hundred and forty-one patients were identified: 91 (64.5%) by pediatric trained surgeons and 50 (35.4%) by sports medicine trained surgeons. Patients that had ACLR by a pediatric trained surgeon were younger (p = 0.02), had larger body mass index (BMI) (p = 0.027), and more likely to have government assisted insurance (p = 0.006). Pediatric trained surgeons had longer procedure time (p < 0.001), used smaller graft sizes (p = 0.016), used soft tissue grafts (p < 0.001) and used button fixation at both the femur and tibia (p < 0.001). There were no differences regarding meniscus surgery, surgical technique (transphyseal versus physeal sparing), arthrofibrosis, graft failure, and intraoperative complications (p > 0.05). This study shows favorable and comparable results after ACLRs with either pediatric or sports medicine fellowship training. (Journal of Surgical Orthopaedic Advances 30(3):161-165, 2021).

End Vertebra Versus Apical Vertebra: Where Are We More Likely to Misplace in Spine Deformity?

BACKGROUND DATA: Pedicle screws placement remains technically demanding. The thoracic curve apex is considerably difficult due to its unique morphology and severe rotation. In comparison the upper end vertebrae have smaller pedicles and limited soft tissue exposure. This study seeks to evaluate the likelihood of screw misplacement at the end vertebra and apex. METHODS: A retrospective review of preoperative and postoperative computed tomographic (CT) scans of spinal deformity patients who underwent posterior spinal fusion with pedicle screw constructs between 2004 and 2011 was performed. Pedicles located at the upper instrumented vertebra (UIV) and lower instrumented vertebra (LIV), and the major and minor apices were evaluated. Pedicle morphology was studied on preoperative CT and screw placement on postoperative CT. RESULTS: In total, 188 patients met the inclusion criteria, 172 had preoperative CT scans and 133 had postoperative CT scans. The UIV had a significantly lower percentage of normal pedicles (type A) compared with apex major, apex minor, or LIV (59.1% vs. 76.1% vs. 77.3% vs. 98.7%; P<0.001). UIV had significantly the lowest percentage of normal normally placed screws compared with LIV, apex major, or apex minor (69.4% vs. 97.3% vs. 87.6% vs. 92.1%; P<0.001). In a logistic regression adjusted for preoperative Cobb angles, UIV was more likely to have screws misplaced (odds ratio =7.56; 95% confidence interval, 4.01-14.30; P<0.001) and abnormal pedicles (odds ratio=2.81; 95% confidence interval, 1.52-5.19; P=0.001) compared with any other location studied. In abnormal pedicles, 41 (39.8%) of the 103 UIV screws were misplaced, whereas 10 (16.4%) of the 61 apex major, apex minor, or LIV screws were misplaced (P=0.007). CONCLUSIONS: The UIV presents more of a risk for pedicle screw misplacement and abnormal morphology when compared with LIV and apical vertebra. We believe these findings can aid in the surgeon's preoperative and intraoperative management to ensure increased success in accurate and safe pedicle screw placement. LEVEL OF EVIDENCE: Level III.

A pilot cadaveric study of temperature and adjacent tissue changes after exposure of magnetic-controlled growing rods to MRI.

PURPOSE: To test for possible thermal injury and tissue damage caused by magnetic-controlled growing rods (MCGRs) during MRI scans. METHODS: Three fresh frozen cadavers were utilized. Four MRI scans were performed: baseline, after spinal hardware implantation, and twice after MCGR implantation. Cross connectors were placed at the proximal end and at the distal end of the construct, making a complete circuit hinged at those two points. Three points were identified as potential sites for significant heating: adjacent to the proximal and distal cross connectors and adjacent to the actuators. Data collected included tissue temperatures at baseline (R1), after screw insertion (R2), and twice after rod insertions (R3 and R4). Tissue samples were taken and stained for signs of heat damage. RESULTS: There was a slight change in tissue temperature in the regions next to the implants between baseline and after each scan. Average temperatures (°C) increased by 0.94 (0.16-1.63) between R1 and R2, 1.6 (1.23-1.97) between R2 and R3, and 0.39 (0.03-0.83) between R3 and R4. Subsequent histological analysis revealed no signs of heat induced damage. CONCLUSION: Recurrent MRI scans of patients with MCGRs may be necessary over the course of treatment. When implanted into human cadaveric tissue, these rods appear to not be a risk to the patient with respect to heating or tissue damage. Further in vivo study is warranted. LEVEL OF EVIDENCE: N/A.

Ultrasound elastography in children: establishing the normal range of muscle elasticity.

BACKGROUND: Ultrasound elastography allows assessment of tissue elasticity. To the best of our knowledge, the elastography appearance of muscles in normal children has not been described. OBJECTIVE: To determine the US elasticity of muscles in children at rest and following exercise. MATERIALS AND METHODS: Cine elastography of biceps brachii and rectus femoris muscles was obtained at rest and after exercise in 42 healthy children (23 males, 19 females; mean: 11.2 ± 4.4 years, range: 2-18 years). Elastography scores were assigned to each clip based on a five-point color scale. Mean elastography scores and standard deviations were calculated and resting and postexercise elastography scores were compared. RESULTS: Resting muscle elasticity was lower in the biceps brachii than in the rectus femoris (P = 0.008), and higher in the dominant than in the nondominant biceps brachii (P < 0.032). Rectus femoris elasticity was higher in males than females (P = 0.051). Postexercise muscle elasticity significantly increased in both the dominant and nondominant biceps brachii (P < 0.001) and in the rectus femoris (P < 0.001). There was no significant gender-related difference in postexercise muscle elasticity. Biceps brachii elasticity decreased and rectus femoris elasticity increased with increasing body mass index. Younger subjects had a greater change in muscle elasticity with exercise. CONCLUSION: Resting muscle elasticity in children is significantly lower in the biceps brachii than in the rectus femoris and in the nondominant biceps brachii than in the dominant biceps brachii. Elasticity significantly increases immediately postexercise in both muscle groups; resting differences between biceps brachii and rectus femoris elasticity, and dominant and nondominant biceps brachii elasticity, do not persist after exercise. The change in muscle elasticity with exercise is higher in younger children.

Pedicle screws adjacent to the great vessels or viscera: a study of 2132 pedicle screws in pediatric spine deformity.

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.

Single Long-Incision Minimally Invasive Surgery.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The objective of this study is to determine differences in outcomes in patients with adolescent idiopathic scoliosis undergoing spinal deformity correction surgery using a posterior spinal fusion (PSF) approach versus single and triple-incision minimally invasive surgery (MIS). SUMMARY OF BACKGROUND DATA: MIS increased in popularity as surgeons' focus moved towards soft tissue preservation, but it carries technical demands and increased surgical time compared with PSF. PATIENTS AND METHODS: Surgeries performed from 2016 to 2020 were included. Cohorts were formed based on surgical approach: PSF versus single long-incision MIS (SLIM) versus traditional MIS [3-incision MIS (3MIS)]. There were a total of 7 subanalyses. Demographic, radiographic, and perioperative data were collected for the 3 groups. Kruskal-Wallis and χ 2 tests were used for continuous and categorical variables, respectively. RESULTS: Five hundred thirty-two patients met our inclusion criteria, 294 PSF, 179 3MIS, and 59 SLIM.Estimated blood loss (mL) ( P < 0.00001) and length of stay (LOS) ( P < 0.00001) was significantly higher in PSF than in SLIM and 3MIS. Surgical time was significantly higher in 3MIS than in PSF and SLIM ( P = 0.0012).Patients who underwent PSF had significantly lower postoperative T5 to T12 kyphosis ( P < 0.00001) and percentage kyphosis change ( P < 0.00001). Morphine equivalence was significantly higher in the PSF group during total hospital stay ( P = 0.0042).Patients who underwent SLIM and 3MIS were more likely to return to noncontact ( P = 0.0096) and contact sports ( P = 0.0095) within 6 months and reported lower pain scores ( P < 0.001) at 6 months postoperation. CONCLUSION: SLIM has a similar operative time to PSF and is technically similar to PSF while maintaining the surgical and postoperative outcome advantages of 3MIS.

Comparative analysis of perioperative differences between hybrid versus pedicle screw instrumentation in adolescent idiopathic scoliosis.

STUDY DESIGN: Retrospective review of patients with adolescent idiopathic scoliosis (AIS). OBJECTIVE: The objective of the study was to compare perioperative parameters and outcomes between pedicle screw and hybrid instrumentation for the treatment of AIS. SUMMARY OF BACKGROUND DATA: Pedicle screws have been shown to allow for better correction and fewer revisions than hybrid systems. However, no study has compared perioperative parameters and their effects on patient morbidity between these 2 types of instrumentation. METHODS: Fifty-six pediatric patients with AIS were included in the study. Twenty-seven patients were treated with hybrid instrumentation and 29 patients were treated with all pedicle screw (APS) instrumentation. Intraoperative and perioperative measures were compared. RESULTS: The mean preoperative major Cobb angle was 58.7 degrees in the hybrid group and 54.5 degrees in the APS group (P = 0.222). Patients in the hybrid group required more time in the intensive care unit (2.0 vs. 1.1 d, P = 0.041), more time to initial mobilization (5.1 vs. 2.1 d, P < 0.001), and more days using patient-controlled analgesia (5.7 vs. 4.4 d, P = 0.020). The hybrid group averaged less estimated blood loss than the APS group (619.6 vs. 947.4 mL, P = 0.011). There was no difference in surgical time (P = 0.183) or length of stay (P = 0.072) between the groups. Thoracolumbosacral orthoses were used in 81.5% of patients in the hybrid group, but in no patients in the APS group (P < 0.001). Postoperative complications occurred in 37.0% of patients in the hybrid group and 17.2% of patients in the APS group (P = 0.095). CONCLUSIONS: This study demonstrates several advantages of pedicle screw constructs over hybrid constructs in the surgical treatment of AIS. The benefits of pedicle screw systems extend directly to the patient and can lower the overall cost of treatment.

Effect of Pedicle Screw Size on Surgical Outcomes Following Surgery for 412 Adolescent Idiopathic Scoliosis Patients.

STUDY DESIGN: Retrospective Review. OBJECTIVE: The objective of this study was to determine differences in surgical and post-operative outcomes in AIS patients undergoing spinal deformity correction surgery using standard or large pedicle screw size. SUMMARY OF BACKGROUND: Use of pedicle screw fixation in spinal deformity correction surgery is considered safe and effective. Still, the small size of the pedicle and the complex 3D anatomy of the thoracic spine makes screw placement challenging, with improper pedicle screw fixation leading to catastrophic complications including injuries to nerve roots, spinal cord, and major vessels. Thus, insertion of larger diameter screw sizes has raised concerns amongst surgeons, especially in the pediatric population. MATERIALS AND METHODS: AIS patients undergoing PSF between 2013 and 2019 were included. Demographic, radiographic, and operative outcomes collected. Patients in the large screw size group (GpI) received 6.5 mm diameter screw sizes at all levels while standard screw size group (GpII) received 5.0 to 5.5 mm diameter screw sizes at all levels. Kruskall-Wallis and Fisher's exact test performed for continuous and categorical variables respectively.Subanalyses included (1) screw accuracy in patients with available CT scans, (2) stratified analysis of large- and standard-screw patients with ≥60% flexibility rate, (3) stratified analysis of large- and standard-screw patients with <60% flexibility rate, and (4) matched analysis of large- and standard-screw patients by surgeon and year of surgery. RESULTS: GpI patients experienced significantly higher overall curve correction ( P <0.001), with 87.6% experiencing at least one grade reduction of apical vertebral rotation from preoperative to postoperative visit( P =0.008).Patients with larger screws displayed higher postoperative kyphosis. No patient experienced medial breaching. CONCLUSION: Large screw sizes have similar safety profiles to standard screws without negatively impacting surgical and perioperative outcomes in AIS patients undergoing PSF. Additionally, coronal, sagittal, and rotational correction is superior for larger-diameter screws in AIS patients.

Does a dedicated "Scoliosis Team" and surgical standardization improve outcomes in adolescent idiopathic scoliosis surgery and is it reproducible?

PURPOSE: The objective of this study was to determine if standardization improves adolescent idiopathic scoliosis (AIS) surgery outcomes and whether it is transferrable between institutions. METHODS: A retrospective review was conducted of AIS patients operated between 2009 and 2021 at two institutions (IA and IB). Each institution consisted of a non-standardized (NST) and standardized group (ST). In 2015, surgeons changed institutions (IA- > IB). Reproducibility was determined between institutions. Median and interquartile ranges (IQR), Kruskal-Wallis, and χ2 tests were used. RESULTS: 500 consecutive AIS patients were included. Age (p = 0.06), body mass index (p = 0.74), preoperative Cobb angle (p = 0.53), and levels fused (p = 0.94) were similar between institutions. IA-ST and IB-ST had lower blood loss (p < 0.001) and shorter surgical time (p < 0.001). IB-ST had significantly shorter hospital stay (p < 0.001) and transfusion rate (p = 0.007) than IB-NST. Standardized protocols in IB-ST reduced costs by 18.7%, significantly lowering hospital costs from $74,794.05 in IB-NST to $60,778.60 for IB-ST (p < 0.001). Annual analysis of surgical time revealed while implementation of standardized protocols decreased operative time within IA, when surgeons transitioned to IB, and upon standardization, IB operative time values decreased once again, and continued to decrease annually. Additions to standardized protocol in IB temporarily affected the operative time, before stabilizing. CONCLUSION: Surgeon-led standardized AIS approach and streamlined surgical steps improve outcomes and efficiency, is transferrable between institutions, and adjusts to additional protocol changes.

The Volume-Cost Relationship: How Does Surgical Volume Affect Cost and Value in AIS Surgery.

STUDY DESIGN: Retrospective review. OBJECTIVE: The objective of this study was to evaluate and compare distribution of hospital and operating room charges and outcomes during posterior spinal fusion for adolescent idiopathic scoliosis (AIS) patients by high-volume (HV) and standard-volume (SV) surgeons at one institution and examine potential cost savings. SUMMARY OF BACKGROUND DATA: Increased surgical volume has been associated with improved perioperative outcomes after spinal deformity correction. However, there is a lack of information on how this may affect hospital costs. METHODS: Retrospective study of AIS patients undergoing posterior spinal fusion between 2013 and 2019. Demographic, x-ray, chart review and hospital costs were collected and compared between HV surgeons (≥50 AIS cases/y) and SV surgeons (<50/y). Comparative analyses were computed using Wilcoxon rank-sum, Kruskal-Wallis, and the Fisher exact tests. Average values with corresponding minimum-maximum rages were reported. RESULTS: A total of 407 patients (HV: 232, SV: 175) operated by 4 surgeons (1 HV, 3 SV). Radiographic parameters were similar between the groups. HV surgeons had significantly lower estimated blood loss (385.3 vs. 655.6 mL, P <0.001), fewer intraoperative transfusions (10.8% vs. 25.1%, P <0.001), shorter surgery time (221.6 vs. 324.9 min, P <0.001), and lower radiation from intraoperative fluoroscopy (4.4 vs. 6.4 mGy, P <0.001). HV patients had a significantly lower length of stay (4.3 vs. 5.3, P <0.001) and complication rate (0.4% vs. 4%, P =0.04).HV surgeons had significantly lower total costs ($61,716.24 vs. $72,745.93, P <0.001). This included lower transfusion costs ( P <0.001), operative time costs ( P <0.001), screw costs ( P <0.001), hospital stay costs ( P <0.001), and costs associated with 30-day emergency department returns ( P <0.001). CONCLUSION: HV surgeons had significantly lower operative times, lower estimated blood loss and transfusion rates and lower perioperative complications requiring readmission or return to emergency department resulting in lower health care costs. LEVEL OF EVIDENCE: Level III.

Paraspinal muscle approach for neuromuscular scoliosis: A comparative study evaluating deformity correction and perioperative morbidity in 91 patients with minimum 2-year follow-up.

Purpose: We present the paraspinal approach use for neuromuscular scoliosis with focus on deformity correction, perioperative (≤30 days) morbidity and outcome at a minimal follow-up length of 2 years. Methods: We prospectively collected data of 61 neuromuscular scoliosis patients operated using a paraspinal (Wiltse) approach between 2013 and 2019. We additionally collected data of 104 control cases, operated using a midline approach between 2005 and 2016. Fifteen Wiltse, respectively 37 control patients were excluded due to a short follow-up (<2 years), and 22 controls were excluded secondary to lacking follow-up data. Hence, 46 Wiltse and 45 control patients were compared. Results: Wiltse and control patients had comparable follow-up lengths, demographics, deformity corrections, complication rates, number of levels fused, and intensive care unit and hospital lengths of stay. Wiltse cases had a lower estimated blood loss (535 vs 1187 mL; p-value < 0.001), allogenic transfusion rate (48% vs 96%; p-value < 0.001), and operating time (ORT) (337 vs 428 min; p-value < 0.001) than controls. This was also the case when selecting for patients without pelvic fixation (p-values < 0.001). When selecting the cases with pelvic fixation (20 among 91 cases), only the number of levels fused and the ORT differed significantly according to the approach (p-value <0.015 and <0.041). Conclusion: The paraspinal approach for neuromuscular scoliosis is safe, associated with significant deformity correction, reduced estimated blood loss, and allogenic transfusion rate. These potential benefits still need to be evaluated, especially for cases with pelvic fixation, with further follow-up of larger cohorts. Level of evidence: level III.

A Newer Way of Determining LIV in AIS Patients: Rotation of the Touched Vertebrae.

STUDY DESIGN: A retrospective review. OBJECTIVE: The objective of this study was to determine whether fusing to touched vertebra (TV) on prone x-rays (XRs) with minimal rotation (Gd 0/1) allow for shorter fusion with optimal correction. SUMMARY OF BACKGROUND: Previous studies have shown risk of "adding on" when TV is not selected as lowest instrumented vertebra (LIV). Fusion proximal to TV leads to suboptimal results but fusing to TV on standing XRs can result in longer fusions. On lying down XRs, TV moves proximally, and its rotation decreases by a grade. METHODS: TV patients with minimal rotation were selected on prone (TVP) or standing XRs (TVS). Patients fused to rotated (Gd 2+) TV on standing or prone XRs were considered touched vertebra rotated (TVR). In the non-TV (NTV) group, LIV was fused proximal to TV. Disk wedging ≥5° determined risk of "adding-on." To compare patients fused to minimally rotated TV, to those that were not, patients in group A (TVP + TVS) were compared with group B (TVR + NTV).In part II: TVP, TVS, TVR, and NTV patients were compared. Subanalysis compared levels saved as the difference between predicted and real LIV in TVP and TVS patients. Another subanalysis was carried out for Lenke 1+2 and Lenke 3, 4, 5.In part III: XRs of nonoperative adolescents idiopathic scoliosis patients with Cobb <30 and Risser 4/5 were analyzed to determine "acceptable" end vertebra tilt and disc wedging and served as controls. RESULTS: There were a significantly greater number of patients in group B patients(TVR + NTV) with final disk wedging ≥5°, final LIV translation ≥1 and ≥2 cm ( P <0.001).Utilizing prone XRs in TVP saved average 1 level, and 1.2 levels in TVS patients. TVP patients also had similar LIV tilt, disk wedging and coronal balance( P >0.05) to controls. CONCLUSION: Choosing minimally rotated (Gd 0/1) TV on prone XR saves levels without sacrificing radiographic outcomes.

In Scheuermann's kyphosis, a proximal UIV and postop kyphosis value close to patients' PI decreases the risk of PJK.

PURPOSE: Prevalence of proximal junctional kyphosis (PJK) in Scheuermann's kyphosis (SK) varies between 24 and 40%. Multiple factors have been implicated, including kyphosis overcorrection, failure to include proximal end vertebra, and implant choice. This study aimed to determine the goal correction parameters based upon patients' pelvic incidence, and UIV to decrease PJK in Scheuermann's kyphosis. METHODS: X-ray and chart review of SK patients operated with all pedicle screw (PS), hybrid fixation (HF), and anterior/posterior fusions with hybrid fixation (AP). T1/T2 were grouped together as proximal fusion groups compared to T3 and distal groups. RESULTS: 96 total patients: PS (n = 41), HF (n = 24), and AP (n = 31). Overall, at early postop 12 (12.5%) patients had PJK. At final follow-up, 33 (34.4%) had PJK. There was no significant difference between groups at early postop (p = 0.86) or final follow-up (p = 0.67). When correcting kyphosis-PI to > - 10.0° and UIV was chosen to be T1 or T2, PJK developed in 6.1% of patients at final follow-up; when fusing to T1/T2 but with kyphosis-PI < - 10.0°, 38.9% of patients developed PJK. With kyphosis-PI > - 10.0° and UIV at T3 or below, 37.0% of patients developed PJK at final follow-up. When fusing to T3 or below but failing to correct kyphosis-PI to > - 10.0°, 77.8% of patients developed PJK. CONCLUSION: Selecting proximal UIV and avoiding kyphosis-PI mismatch can significantly decrease the prevalence of PJK rather than surgical technique or implant choice. Surgeons treating SK should, therefore, aim to correct kyphosis closer to the patient's pelvic incidence and choose T2/T1 as UIV.

Scheuermann Kyphosis Patients Have a Similar Revision and Infection Rate to Adolescent Idiopathic Scoliosis Patients.

STUDY DESIGN: Multicenter retrospective review. OBJECTIVE: This study aims to address major postoperative complications associated with Scheuermann kyphosis (SK) when compared with adolescent idiopathic scoliosis (AIS) in a large population matched by demographic characteristics, levels fused and operative technique. SUMMARY OF BACKGROUND DATA: Prior studies have found that SK patients are 3.86 times more likely to experience major postoperative complications than in AIS. Historically, however, these studies have often had populations that were significantly different between the two groups in terms of disease severity, demographics, and small sample sizes. METHODS: AIS patients were compared to SK patients between 2006 and 2018 contemporaneously. All surgeries were conducted by six surgeons among two institutions. Complications and revisions were calculated. A sub-analysis comparing SK and AIS patients by age, sex, and levels-fused in one-to-one matched pairs was performed as well as a sub-analysis matched by levels fused only in one-to-one matched pairs. RESULTS: One thousand three hundred twenty two patients were reviewed (1222 AIS; 100 SK). There were 52 (4.3%) complications in the AIS group compared with 20 (20%) complications in the SK group (P < 0.001), with infections and revisions consisting of the majority of complication rates in both cohorts.When matched by age, sex, and levels fused, there were eight complications in the AIS group and 11 in the SK group (P = 0.63), with infection and revision rates being similar, (P = 0.29) and (P = 0.26) respectively.When matched by levels fused only, EBL, operative time and complication rates remained similar (P > 0.05). CONCLUSION: Contrary to previously published literature, our analyses indicate that in a matched population, postoperative complication rates (i.e., infection and revision rates) are not significantly different between SK and AIS patients.Level of Evidence: 4.

Ambulatory Neuromuscular Scoliosis Patients Have Superior Perioperative Results Than Nonambulatory Neuromuscular Scoliosis Patients and Can Approach Adolescent Idiopathic Scoliosis Outcomes After Posterior Spinal Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: This study aims to identify differences in perioperative outcomes between ambulatory patients with neuromuscular scoliosis (ANMS) and adolescent idiopathic scoliosis (AIS) following spinal fusion. SUMMARY OF BACKGROUND DATA: NMS patients have severe curves with more comorbidities and procedural complexity. These patients require extensive fusion levels, increased blood loss, and suffer increased periop complications. However, NMS patients have a variable severity spectrum, including ambulation status. METHODS: Chart and radiographic review of NMS and AIS patients undergoing PSF from 2005 to 2018. NNMS included NMS patients who were completely dependent (GMFCS IV-V). ANMS consisted of community ambulators without significant reliance on wheeled assistive devices (GMFCS I-III). Subanalysis matched by age, sex, levels fused and preoperative Cobb angle was conducted as well. Wilcoxon Rank-Sum, Kruskal-Wallis, χ2, and Fisher exact tests were performed. RESULTS: There were 120 patients in the NNMS group, 54 in ANMS and 158 in the AIS group. EBL was significantly lower for ANMS and AIS patients (P < 0.001). Complications within 30 days were similar between ANMS and AIS (P = 1.0), but significantly higher for NNMS (P < 0.001). Two (1.3%) AIS patients, (1.7%) nonambulatory NMS patients, and one (1.9%) ANMS patient required revision surgery (P = 1.0). However, all NMS patients had increased fusion levels, fixation points, and surgery time (P < 0.05). NNMS had significantly longer ICU (P < 0.001), hospital stay (P < 0.001), intraoperative transfusions (P < 0.001), and fewer patients extubated in the OR (P < 0.001) than ANMS and AIS patients. In the subanalysis, ANMS had similar radiographic measurements, EBL, transfusion, surgery time, extubation rate, and complication rate (P > 0.05) to AIS. CONCLUSION: Our data show radiographic outcomes, infections, revisions, and overall complications for ANMS were similar to the AIS population. This suggests that NMS patients who ambulate primarily without assistance can expect surgical outcomes comparable to AIS patients with further room for improvement in length of ICU and hospital stay.Level of Evidence: 4.

Zero Patient-controlled Analgesia is an Achievable Target for Postoperative Rapid Recovery Management of Adolescent Idiopathic Scoliosis Patients.

STUDY DESIGN: Retrospective review. OBJECTIVE: The objective of this study was to report on one institution's use of single bolus micro-dose intrathecal morphine as part of a rapid recovery pathway during posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) and its comparison to patients whose pain was controlled with patient-controlled analgesia (PCA). SUMMARY OF BACKGROUND DATA: Narcotic substance addiction has risen across all patient populations, including pediatrics. Narcotics have been historically used in complex spine surgeries as a measure of pain control, predominantly provided as PCA and additional take-home medication. METHODS: AIS patients undergoing PSF from 2015 to 2019 were reviewed. In 2018, we instituted a standardized rapid recovery pathway for scoliosis patients undergoing PSF utilizing micro-dose intrathecal morphine (ITM-RRP). Before this, traditional protocol with PCA was used for postoperative management. Perioperative data, morphine consumption and prescription refill requests were compared. RESULTS: There were 373 AIS patients total in this study, of which 250 patients were in the PCA group and 123 in the ITM-RRP Group. Preoperative Cobb angles (P = 0.195), as well as levels fused (P = 0.481) and body mass index (P = 0.075) were similar. 69.4% of ITM-RRP patients had a length of stay ≤3 days, significantly >11.6% of PCA patients (P < 0.001). ITM-RRP patients began ambulating significantly earlier with 84.6% patients out of bed by postoperative day 1 versus 8% PCA patients (P < 0.001). Additionally, ITM-RRP patients had significantly lower VAS pain scores with activity and earlier initial bowel movements (P < 0.001).Postoperative emesis was similar (P = 0.11). No patients had pruritus, respiratory depression, or required supplemental oxygenation. CONCLUSION: This is the first study to show that a rapid recovery protocol utilizing single micro-dose ITM with oral analgesics have adequate recovery, significantly better postoperative pain control and superior perioperative outcomes to traditional protocols using PCA in the AIS population following PSF.Level of Evidence: 3.

Scoliosis Surgery Normalizes Cardiac Function in Adolescent Idiopathic Scoliosis Patients.

STUDY DESIGN: Single-center retrospective chart review with minimum 2-year follow up. OBJECTIVE: To determine incidence of pulmonary hypertension in adolescent idiopathic scoliosis patients and to determine the effect of scoliosis surgery on pulmonary hypertension. SUMMARY OF BACKGROUND DATA: Spinal deformity in adolescent idiopathic scoliosis can increase right atrial and ventricular pressures secondary to restrictive lung disease. Pulmonary hypertension leading to cor pulmonale is the most feared outcome, however mild pulmonary hypertension in adolescent idiopathic scoliosis (AIS) patients has been reported. No study has previously examined changes in the improvement of right heart function following scoliosis surgery. METHODS: Cobb angle, 2D-echo signs of structural heart disease, aortic root dimensions, tricuspid regurgitant jet velocity (TRV), pulmonary function tests (PFTs), arterial blood gas (ABG), and patient demographics reviewed. Right ventricular systolic pressure (RVSP) estimated using Bernoulli equation (4[TRV]2) and right atrial pressure. RVSP ≥36 mmHg is a surrogate marker for pulmonary hypertension. All echocardiograms were read by board certified Pediatric Cardiologists. Logistic regression used to assess for differences in TRV between groups. RESULTS: Mean preoperative RVSP was significantly elevated in AIS patients (26.9 ±â€Š0.49; P < 0.001) compared with controls (17.25 + 0.88). Only 47 (21%) Group 1 patients had elevated preoperative TRV (≥2.8 m/s) versus none in Group 2 (P < 0.001). Additionally, logistic regression showed AIS patients have odds ratio of 3.29 for elevated TRV (P = 0.007)-an indirect measure of pulmonary hypertension. In all Group 3 patients, the cardiac function normalized postoperatively (mean TRV = 2.09 + 0.23; P < 0.001). No association found between Cobb angle, aortic root parameters, or pulmonary function tests. CONCLUSION: This study found 13.9% of patients with adolescent idiopathic scoliosis had elevated TRV while controls had no TRV abnormalities. Additionally, RVSP measurements demonstrated mild pulmonary hypertension in AIS patients. These abnormal values normalized postoperatively, indicating the benefits of scoliosis surgery on cardiac function in adolescent idiopathic scoliosis.Level of Evidence: 3.