Endoscopic treatment of lumbar degenerative disc disease: a narrative review of Full-Endoscopic and Unilateral Biportal Endoscopic Spine Surgery.

BACKGROUND: Degenerative lumbar spine disease is the leading cause of disability and work absenteeism worldwide. Lumbar microdiscectomy became the standard treatment for herniated discs and stenotic disease. With the evolution of different techniques, endoscopic spinal surgery emerged to minimize the surgical footprint while providing at least non-inferior results. Currently, two different types of endoscopic spine procedures are dominating the surgical scenario: "Full-Endoscopic" (FE) and Unilateral Biportal Endoscopic"(UBE) Spine Surgery. The aim of this study is to describe and analyze their indications, their technical characteristicswithitsadvantagesanddisadvantagesofbothtechniquesandtheirfuture trends. METHODS: We performed a narrative review of the most relevant articles published up to August 2023 through a Pub Med search. The search terms "Full-Endoscopic Spine Surgery" and "Unilateral Biportal Endoscopic Spine Surgery" were used. The articles selected, were independently reviewed by 3 authors and 55 full text articles were reviewed. RESULTS: The FE and UBE Spine Surgery techniques were described. The FE technique is performed with a monoportal access under constant saline irrigation. The FE comprises the transforaminal and the interlaminar approaches, and the indication depends from the pathology to treat, and still remains controversial. UBE can approach also the spine from a posterior, postero lateral,and para spinal route. It uses two different ports addressed to a target with continuous irrigation. The process of establishing these two portals is called triangulation. CONCLUSION: FE and UBE spine surgery have demonstrated outcomes comparable to open surgery, minimizing complications and surgical footprint.

Single-Position Prone Lateral Lumbar Interbody Fusion Technique Guide: Surgical Tips and Tricks.

Lateral lumbar interbody fusion (LLIF) is a popular technique as it allows for the placement of a large interbody implant through a retroperitoneal, transpsoas working corridor. Historically, the interbody is placed with the patient in lateral decubitus and then repositioned to prone for the posterior instrumentation. While this has been an effective and successful technique, removing the interoperative flip would improve the efficiency of these cases. This has led to modified LLIF approaches including single-position prone LLIF (pLLIF). This modification has shown to be an efficient and powerful technique; however, learning to navigate the LLIF approach in the prone position has its own challenges. The purpose of this article is to provide a detailed description of our pLLIF technique while simultaneously introducing surgical tips to overcome the challenges of the approach and optimize the implantation of the interbody device.

Perioperative Complications and Health-related Quality of Life Outcomes in Severe Pediatric Spinal Deformity.

STUDY DESIGN: Prospective multicenter cohort study. OBJECTIVE: To evaluate perioperative complications and mid-term outcomes for severe pediatric spinal deformity. SUMMARY OF BACKGROUND DATA: Few studies have evaluated the impact of complications on health-related quality of life (HRQoL) outcomes in severe pediatric spinal deformity. METHODS: Patients from a prospective, multicenter database with severe pediatric spinal deformity (minimum of 100 degree curve in any plane or planned vertebral column resection (VCR)) with a minimum of 2-years follow-up were evaluated (n=231). SRS-22r scores were collected preoperatively and at 2-years postoperatively. Complications were categorized as intraoperative, early postoperative (within 90-days of surgery), major, or minor. Perioperative complication rate was evaluated between patients with and without VCR. Additionally, SRS-22r scores were compared between patients with and without complications. RESULTS: Perioperative complications occurred in 135 (58%) patients, and major complications occurred in 53 (23%) patients. Patients that underwent VCR had a higher incidence of early postoperative complications than patients without VCR (28.9% vs. 16.2%, P =0.02). Complications resolved in 126/135 (93.3%) patients with a mean time to resolution of 91.63 days. Unresolved major complications included motor deficit (n=4), spinal cord deficit (n=1), nerve root deficit (n=1), compartment syndrome (n=1), and motor weakness due to recurrent intradural tumor (n=1). Patients with complications, major complications, or multiple complications had equivalent postoperative SRS-22r scores. Patients with motor deficits had lower postoperative satisfaction subscore (4.32 vs. 4.51, P =0.03), but patients with resolved motor deficits had equivalent postoperative scores in all domains. Patients with unresolved complications had lower postoperative satisfaction subscore (3.94 vs. 4.47, P =0.03) and less postoperative improvement in self-image subscore (0.64 vs. 1.42, P =0.03) as compared to patients with resolved complications. CONCLUSION: Most perioperative complications for severe pediatric spinal deformity resolve within 2-years postoperatively and do not result in adverse HRQoL outcomes. However, patients with unresolved complications have decreased HRQoL outcomes.

Time to surgery for adolescent idiopathic scoliosis: How long does it take? A multicenter study.

Study design: Retrospective review of multicentric data. Objectives: To estimate the time from initial visit to surgery in adolescent idiopathic scoliosis (AIS) patients and the main reasons for the time to surgery in a multicenter study. Methods: This retrospective study evaluated 509 patients with AIS from 16 hospitals across six Latin American countries. From each hospital's deformity registry, the following patient data were extracted: demographics, main curve Cobb angle, Lenke Classification at the initial visit and time of surgery, time from indication-for-surgery to surgery, curve progression, Risser skeletal-maturity score and causes for surgical cancelation or delay. Surgeons were asked if they needed to change the original surgical plan due to curve progression. Data also were collected on each hospital's waiting list numbers and mean delay to AIS surgery. Results: 66.8% of the patients waited over six months and 33.9% over a year. Waiting time was not impacted by the patient's age when surgery first became indicated (p = 0.22) but waiting time did differ between countries (p < 0.001) and hospitals (p < 0.001). Longer time to surgery was significantly associated with increasing magnitude of the Cobb angle through the second year of waiting (p < 0.001). Reported causes for delay were hospital-related (48.4%), economic (47.3%), and logistic (4.2%). Oddly, waiting time for surgery did not correlate with the hospital's reported waiting-list lengths (p = 0.57). Conclusion: Prolonged waits for AIS surgery are common in Latin America, with rare exceptions. At most centers, patients wait over six months, most commonly for economic and hospital-related reasons. Whether this directly impacts surgical outcomes in Latin America still must be studied.

Single-Position Transpsoas Corpectomy and Posterior Instrumentation in the Thoracolumbar Spine for Different Clinical Scenarios.

BACKGROUND: The concept of single-position spine surgery has been gaining momentum because it has proven to reduce operative time, blood loss, and hospital length of stay with similar or better outcomes than traditional dual-position surgery. The latest development in single-position spine surgery techniques combines either open or posterior pedicle screw fixation with transpsoas corpectomy while in the lateral or prone positioning. OBJECTIVE: To provide, through a multicenter study, the results of our first patients treated by single-position corpectomy. METHODS: This is a multicenter retrospective study of patients who underwent corpectomy and instrumentation in the lateral or prone position without repositioning between the anterior and posterior techniques. Data regarding demographics, diagnosis, neurological status, surgical details, complications, and radiographic parameters were collected. The minimum follow-up for inclusion was 6 months. RESULTS: Thirty-four patients were finally included in our study (24 male patients and 10 female patients), with a mean age of 51.2 (SD ± 17.5) years. Three-quarter of cases (n = 27) presented with thoracolumbar fracture as main diagnosis, followed by spinal metastases and primary spinal infection. Lateral positioning was used in 27 cases, and prone positioning was used in 7 cases. The overall rate of complications was 14.7%. CONCLUSION: This is the first multicenter series of patients who underwent single-position corpectomy and fusion. This technique has shown to be safe and effective to treat a variety of spinal conditions with a relatively low rate of complications. More series are required to validate this technique as a possible standard approach when thoracolumbar corpectomies are indicated.

Why are frailty indices not used systematically during preoperative spine consultations?

INTRODUCTION: Frailty indices are highly predictive of major medical and mechanical complications, lengths of hospital stay, and mortality rates after spine procedures. However, several barriers limit the extent to which spine surgeons employ these indices. The main purposes of the current study were to assess the use of frailty indices by Latin-American spine surgeons and identify the main barriers perceived to restrict their clinical application. METHODS: For this cross-sectional survey, a questionnaire evaluating the demographic characteristics of participating surgeons and their utilization of frailty indices were created in Google form and sent by e-mail to every registered member of AO Spine Latin America between October and November 2020. RESULTS: Of the 1047 surgeons sent the survey, 293 responded (response rate=28%). Half of the surgeons (51.7%) said they were unfamiliar with the terms ¨frailty´ and ¨frailty index", while 70.3% claimed not to use any frailty scale during their pre-operative assessments. The most frequently utilized index was the modified Frailty Index (mFI) (18%). The most important perceived barrier was the excessive amount of time required to calculate each patient's frailty score. Ninety-two percent of the spine surgeons felt sure that these scores could influence their therapeutic decisions, while 91% desired an easier-to-use risk-prevention scale. CONCLUSION: The main perceived barriers restricting the use of frailty indices were the time required to complete them, lack of index validation, and need for specific instruments to calculate the index score.

Setting for single position surgery: survey from expert spinal surgeons.

PURPOSE: To describe a comprehensive setting of the different alternatives for performing a single position fusion surgery based on the opinion of leading surgeons in the field. METHODS: Between April and May of 2021, a specifically designed two round survey was distributed by mail to a group of leaders in the field of Single Position Surgery (SPS). The questionnaire included a variety of domains which were focused on highlighting tips and recommendations regarding improving the efficiency of the performance of SPS. This includes operation room setting, positioning, use of technology, approach, retractors specific details, intraoperative neuromonitoring and tips for inserting percutaneous pedicle screws in the lateral position. It asked questions focused on Lateral Single Position Surgery (LSPS), Lateral ALIF (LA) and Prone Lateral Surgery (PLS). Strong agreement was defined as an agreement of more than 80% of surgeons for each specific question. The number of surgeries performed in SPS by each surgeon was used as an indirect element to aid in exhibiting the expertise of the surgeons being surveyed. RESULTS: Twenty-four surgeons completed both rounds of the questionnaire. Moderate or strong agreement was found for more than 50% of the items. A definition for Single Position Surgery and a step-by-step recommendation workflow was built to create a better understanding of surgeons who are starting the learning curve in this technique. CONCLUSION: A recommendation of the setting for performing single position fusion surgery procedure (LSPS, LA and PLS) was developed based on a survey of leaders in the field.

When to Consider Stand-Alone Lateral Lumbar Interbody Fusion: Is There a Role for a Comeback With New Implants?

OBJECTIVE: To perform a comprehensive review of the literature about the role of stand-alone lateral lumbar interbody fusion (LLIF). METHODS: A MEDLINE review was conducted including studies about stand-alone LLIF for any condition. The opinions of the authors were also considered. Studies that included biomechanical, cadaveric, or clinical aspects of stand-alone cages were revised to obtain data about the pros, cons, and limitations of the technique. Comparative studies with 360° (lateral + posterior) fusions were also analyzed. RESULTS: A total of 36 studies were identified. After reviewing the abstracts, 18 full articles of interest for the objective of this review were analyzed. Recommendations based on the literature were made. Although most of the recommendations in the literature were about augmentation with pedicle screws, there may be a role for stand-alone LLIF in some particular cases. Specific technical aspects should be considered to reduce the failure rate. CONCLUSION: Although there might be some specific indications for stand-alone LLIF, it should be considered an exception rather than the rule.

Spinous Process Splitting Laminectomy for Lumbar Spinal Stenosis: 2D Operative Video.

Degenerative lumbar spinal stenosis involves an acquired reduction in the spinal canal diameter due to osteoarthritic changes on the disk, facet joints, and ligaments and may result in spinal cord or cauda equina compression.1 This process may lead to pain radiating to the legs, neurogenic claudication, and neurologic deficit. First-line treatment includes conservative care such as physical therapy, spinal injections, and lifestyle changes. If this strategy is insufficient to achieve symptom relief, surgical management is recommended.1,2 Surgery generally encompasses a decompression procedure through a posterior approach. There are several techniques to accomplish this in the context of severe bilateral stenosis including standard open laminectomy, unilateral laminectomy with bilateral decompression, and a tubular approach with bilateral decompression (e.g., "over-the-top technique").2 Among these, the spinous process splitting laminectomy has emerged as a strategy that allows decompressing the spinal canal through a familiar anatomy to the surgeon while respecting paravertebral muscles.3,4 This technique involves exposure of the laminae by cutting through the spinous process and then separating both halves and muscles attached at the sides. The main advantage is that the insertion of these paravertebral soft tissues is preserved, the required retraction is reduced and postoperative pain is decreased.4 Moreover, the learning curve to achieve a successful decompression employing the splitting laminectomy is substantially shorter than with other minimally invasive approaches, such as tubular. This video aims to show the steps to perform this technique (Video 1). We report the case of a 74-year-old male who presented with left sciatica and neurogenic claudication. The images showed multilevel degenerative lumbar spinal stenosis, with severe bilateral compression at L4-5, without signs of instability. Surgical alternatives were discussed with the patient, and it was decided to perform an L4-5 spinous process splitting laminectomy. The patient had a good evolution with an unremarkable postoperative course.

Single-Position Surgery versus Lateral-Then-Prone-Position Circumferential Lumbar Interbody Fusion: A Systematic Literature Review.

OBJECTIVE: We sought to compare the outcomes of single-position (SP) circumferential lumbar interbody fusion in lateral decubitus versus dual-position (DP) fusion. METHODS: A systematic literature review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in PubMed, Web of Science, and Scopus databases to identify comparative studies reporting the outcomes of SP lumbar interbody fusion versus DP. For risk of bias assessment, the ROBINS-I (risk of bias in nonrandomized studies of interventions) tool was used. RESULTS: Four comparative studies were included from an initial search of 3780 papers. All 4 studies were retrospective cohort studies comparing outcomes of SP versus DP LLIF. A total of 349 patients were operated using SP versus 254 using DP. All studies involved reported operating time, estimated blood loss, length of stay, change in segmental lordosis, and complications. From a general perspective, baseline variables were similar in both groups in all the studies and all reported a significant decrease in operative time and length of stays with SP. CONCLUSIONS: Literature comparing SP versus lateral-then-prone lumbar fusion shows a tendency toward shorter operating time and hospital stays in SP lumbar fusion while maintaining similar perioperative outcomes.

Safe and effective performance of pediatric spinal deformity surgery in patients unwilling to accept blood transfusion: a clinical study and review of literature.

BACKGROUND: Pediatric deformity surgery traditionally involves major blood loss. Patients refusing blood transfusion add extra clinical and medicolegal challenges; specifically the Jehovah's witnesses population. The objective of this study is to review the safety and effectiveness of blood conservation techniques in patients undergoing pediatric spine deformity surgery who refuse blood transfusion. METHODS: After obtaining institutional review board approval, we retrospectively reviewed 20 consecutive patients who underwent spinal deformity surgery and refused blood transfusion at a single institution between 2014 and 2018. We collected pertinent preoperative, intraoperative and most recent clinical and radiological data with latest follow-up (minimum two-year follow-up). RESULTS: Twenty patients (13 females) with a mean age of 14.1 years were identified. The type of scoliotic deformities were adolescent idiopathic (14), juvenile idiopathic (1), neuromuscular (3) and congenital (2). The major coronal Cobb angle was corrected from 55.4° to 11.2° (80% correction, p <  0.001) at the latest follow-up. A mean of 11.4 levels were fused and 5.6 levels of Pontes osteotomies were performed. One patient underwent L1 hemivertebra resection and three patients had fusion to pelvis. Estimated blood loss, percent estimated blood volume loss, and cell saver returned averaged 307.9 mL, 8.5%, and 80 mL, respectively. Average operative time was 214 min. The average drop in hemoglobin after surgery was 2.9 g/dL. The length of hospital stay averaged 5.1 days. There were no intraoperative complications. Three postoperative complications were identified, none related to their refusal of transfusion. One patient had in-hospital respiratory complication, one patient developed a late infection, and one patient developed asymptomatic radiographic distal junctional kyphosis. CONCLUSIONS: Blood conservation techniques allow for safe and effective spine deformity surgery in pediatric patients refusing blood transfusion without major anesthetic or medical complications, when performed by an experienced multidisciplinary team. LEVEL OF EVIDENCE: Level IV.

Late spinal infections following posterior spinal fusion in pediatric deformities: treatment using single-stage titanium implant exchange.

PURPOSE: Late infection following posterior spinal fusion (PSF) for deformity is a leading cause of revision. The purpose of this study is to evaluate clinical and radiographic outcomes following a single-stage debridement and exchange of spinal implants with titanium in adolescent patients with late-onset infections following PSF METHODS: A retrospective review of prospectively collected data of adolescent patients with spinal deformity, who were surgically treated with PSF was collected. Patients were included for the study if they developed late arising infection (> 1 year after index posterior fusion for the deformity) from 2006-2019. Treatment consisted of irrigation, debridement, implant exchange with titanium screws and rods, and antibiotics. Parameters evaluated include radiographic Cobb angles, operative data, and clinical data, all at minimum 2-year follow-up. RESULTS: 31 patients (29 with AIS and 2 with Scheuermann's kyphosis) developed late spinal infections. Mean age was 11.4 ± 2.3 years, 84% female, mean time from index surgery was 52.5 months. 25 had all stainless steel implants and 6 had cobalt chrome during the index procedure. Positive cultures were obtained in 5 patients (2 Staphylococcus Aureus, 1 Staphylococcus epidermidis, 1 Peptostreptococcus, 1 Pseudomonas aeruginosa) with cultures followed till 7 days post-operatively. At 2-years following the exchange, there was no change in coronal and sagittal alignment. Three (9%) patients developed subsequent infection necessitating implant removal. CONCLUSION: A single-stage procedure consisting of implant removal, irrigation, and debridement, and replacement with all titanium implants is an effective treatment strategy in patients developing late wound infection following PSF with regards to maintenance of curve correction and minimizing recurrent infections.

Delayed quadriparesis after posterior spinal fusion for scoliosis: a case series.

STUDY DESIGN: A multicenter retrospective IRB exempt case series analyzing clinical and radiographical data of patients treated by three surgeons over the past two decades was conducted. OBJECTIVE: To examine the factors involved in the development of quadriparesis in patients who underwent posterior spinal fusion for scoliosis. Delayed spinal cord infarcts usually present at the region of instrumentation according to reports from the Scoliosis Research Society. Nonetheless, there is a lack of data regarding factors associated with delayed quadriparesis following posterior spinal fusion METHODS: Evaluated variables were age, Cobb angle, blood loss, and curve correction percentage. Postoperative imaging was also evaluated to determine factors indicative of the etiology of the quadriparesis. RESULTS: Eight patients presented delayed postoperative quadriparesis. All patients had a postoperative examination equal to that of baseline. The first patient deteriorated at 6 h postoperatively and the most delayed patient presented 4 days postoperatively. Six patients had neuromuscular disorders and 2 had adolescent idiopathic scoliosis. Mean age was 13.7, mean curve magnitude was 78.7°, mean percent curve correction was 71% and the mean estimated blood loss was 1185 cc. Seven of eight patients had documented peri- or postoperative hypotension. CONCLUSIONS: Cervical infarction is the likely cause of delayed quadriparesis after posterior spinal fusion. Even though the underlying etiology continues to be unclear, postoperative hypotension, curve magnitude, percent curve correction, and the presence of cervical kyphosis/stenosis may be contributory and need to be closely evaluated. LEVEL OF EVIDENCE: IV, Case Series.

The variability in the management of acute surgical site infections: an opportunity for the development of a best practice guideline.

BACKGROUND: Multiple studies have reported on the risks and preventative measures associated with acute surgical site infection (SSI) in patients with adolescent idiopathic scoliosis (AIS). Few studies have evaluated treatment and results. The purpose of this study was to evaluate the need for development of best practice guidelines based on the management of an acute SSI across 9 different centers. METHODS: A prospectively collected, multicenter database of patients undergoing surgical correction of AIS was reviewed for all acute SSI. Infection characteristics, treatment methods, and outcomes were summarized. RESULTS: Twenty-three (0.6%) from a total of 3926 AIS patients were treated for an acute SSI, all of which resolved. Twenty patients had documentation of the infection treatment (10 deep infections, 10 superficial). All ten patients with deep infections underwent operative incision and drainage. Six patients ultimately found to have a superficial infection underwent I&D and another 3 had dressing changes in the office. In the deep group, one patient had instrumentation exchanged and seven patients had bone graft removed. All 16 patients who underwent operative I&D had cultures obtained with 11 positive cultures. All deep infection patients were started on IV antibiotics for 2 days to 6 weeks prior to conversion to oral antibiotics. Five of six operative superficial infections were begun on IV antibiotics with conversion to oral antibiotics. Total antibiotic administration ranged from 5 days to 7 months in the deep infection group and 1 to 6 weeks in the superficial group. CONCLUSIONS: While deep infections are consistently treated with I&D, there is significant variability in the surgical and medical management of acute SSI. Considering the universal resolution of the infection, there is opportunity for the development of BPG to minimize treatment morbidity and cost, while optimizing outcomes for this major complication. LEVEL OF EVIDENCE: Therapeutic-IV.

Improving Health-related Quality of Life for Patients With Nonambulatory Cerebral Palsy: Who Stands to Gain From Scoliosis Surgery?

INTRODUCTION: It is unclear what factors influence health-related quality of life (HRQOL) in neuromuscular scoliosis. The aim of this study was to evaluate which factors are associated with an improvement in an HRQOL after spinal fusion surgery for nonambulatory patients with cerebral palsy (CP). METHODS: A total of 157 patients with nonambulatory CP (Gross Motor Function Classification System IV and V) with a minimum of 2-year follow-up after PSF were identified from a prospective multicenter registry. Radiographs and quality of life were evaluated preoperatively and 2 years postoperatively. Quality of life was evaluated using the validated Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD) questionnaire. Patients who had an increase of 10 points or greater from baseline CPCHILD scores were considered to have meaningful improvement at 2 years postoperatively. 10 points was chosen as a threshold for meaningful improvement based on differences between Gross Motor Function Classification System IV and V patients reported during the development of the CPCHILD. Perioperative demographic, clinical, and radiographic variables were analyzed to determine predicators for meaningful improvement by univariate and multivariate regression analysis. RESULTS: A total of 36.3% (57/157) of the patients reported meaningful improvement in CPCHILD scores at 2 years postoperatively. Preoperative radiographic parameters, postoperative radiographic parameters, and deformity correction did not differ significantly between groups. Patients who experienced meaningful improvement from surgery had significantly lower preoperative total CHPILD scores (43.8 vs. 55.2, P<0.001). On backwards conditional binary logistic regression, only the preoperative comfort, emotions, and behavior domain of the CPCHILD was predictive of meaningful improvement after surgery (P≤0.001). CONCLUSION: Analysis of 157 CP patients revealed a meaningful improvement in an HRQOL in 36.3% of the patients. These patients tended to have lower preoperative HRQOL, suggesting more "room for improvement" from surgery. A lower score within the comfort, emotions, and behavior domain of the CPCHILD was predictive of meaningful improvement after surgery. Radiographic parameters of deformity or curve correction were not associated with meaningful improvement after surgery. LEVEL OF EVIDENCE: Level II-retrospective review of prospectively collected data.

The Pros and Cons of Operating Early Versus Late in the Progression of Cerebral Palsy Scoliosis.

STUDY DESIGN: Retrospective review of prospective data. OBJECTIVE: To delineate a curve threshold where further delay of surgery significantly increased the risks for patients with cerebral palsy (CP) scoliosis. SUMMARY OF BACKGROUND DATA: Two approaches exist in the management of CP scoliosis: a proactive one where surgery is recommended once there is a risk of progression (Cobb > 50°) and a reactive one where surgery is recommended after the patient/caregiver may have significant challenges caused by a large deformity. METHODS: A prospectively collected CP scoliosis surgical registry was queried for patients with minimum two years of follow-up. Three groups were delineated based on the distribution of curve magnitudes: <70° (proactive), 70°-90°, and >90° (reactive). Radiographic, surgical, and quality of life outcome data were compared between the groups using analysis of variance and chi-square analyses. RESULTS: There were 38 patients in the <70° group, 44 in the 70°-90° group, and 42 in the >90° group. They were similar in age. The >90° group had significantly longer operative time (p < .001), a higher percentage of anterior/posterior procedures (31% vs 5%), and a higher infection rate requiring I&D (16.7%) than the other groups (<70°: 5.3%; 70°-90°: 6.8%; p < .05). The percentage blood volume loss was significantly higher in the >90° group compared to <70°. There were no differences in length of hospitalization or intensive care unit stay. Preoperatively, the Caregiver Priorities and Child Health Index of Life with Disabilities (CPchild) QOL score was significantly higher for the <70° group. At two years, the <70° and 70°-90° groups reached similar QOL scores, whereas the >90° trended toward a lower postoperative QOL. CONCLUSIONS: Being proactive (Cobb <70°) has no advantage in terms of decreasing risks or improving outcomes compared to curves 70°-90°. However, delaying surgery to a curve greater than 90° increases the risk of infection, blood loss, and the need for anterior/posterior procedures. Ideally, surgery should be recommended for curves less than 90°.

L3 translation predicts when L3 is not distal enough for an "ideal" result in Lenke 5 curves.

PURPOSE: Determining whether to fuse a Lenke 5 curve to L3 or to L4 is often a difficult decision. The purpose of this study was to determine preoperative variables predictive of an "ideal" or "less than ideal" outcome for Lenke 5 curves instrumented to L3. METHODS: A multicentre registry of adolescent idiopathic scoliosis patients was queried for surgically treated Lenke 5 curves with a lowest instrumented vertebra (LIV) of L3 and minimum 2 years of follow-up. Five seasoned surgeons qualitatively rated the 2-year postoperative images as "ideal" or "less than ideal" with respect to correction and alignment. Preoperative and postoperative radiographic variables were compared between the two groups. Multivariate regression analysis was performed to determine variables most predictive of a "less than ideal" outcome. RESULTS: One hundred and thirty-nine patients met criteria. Twenty-three were considered "less than ideal" by ≥ 3 surgeons; 81 were unanimously "ideal". Preoperatively, the "less than ideal" group had significantly stiffer curves, greater apical translation, and greater LIV angulation and translation. Multivariate regression found that preoperative L3 translation (p = 0.009) was the single most important predictor of a "less than ideal" outcome: < 3.5 cm consistently resulted in an "ideal" outcome, while > 3.5 cm risked a "less than ideal" result. CONCLUSION: While multiple variables are important in achieving an "ideal" outcome in Lenke 5 curves, this study found preoperative L3 translation was the most important predictor of success with an L3 translation < 3.5 cm being a potential threshold for selecting L3 as the LIV. These slides can be retrieved under Electronic Supplementary Material.

Progressive decline in pulmonary function 5 years post-operatively in patients who underwent anterior instrumentation for surgical correction of adolescent idiopathic scoliosis.

PURPOSE: To evaluate changes in pulmonary function tests (PFT) at 5 years post-operatively in patients with adolescent idiopathic scoliosis (AIS) and to determine whether these changes are progressive or static after 2 years. METHODS: AIS surgical patients with pre-operative and 5 year post-operative forced expiratory volume (FEV) and forced vital capacity (FVC) were included. The percentage of patients with pulmonary impairment at 5 years was calculated. Repeated measures ANOVA was used to evaluate changes between pre-operative PFT and 5 years post-operative PFT and to determine whether the changes differed between curve types and approach. A sub-analysis of patients with 2 year data was performed to determine whether PFT changes were static or progressive. RESULTS: Two hundred and sixty-two patients had undergone pre-operative and 5 year post-operative PFTs. At 5 years, 42% were normal, 41% had mild impairment, and 17% had moderate-severe impairment. Overall, there was a decline in % predicted FVC (p < 0.05); FEV remained stable. There was no difference based on major curve type (p > 0.05). Anterior instrumentation cases declined significantly between pre-operative PFT and 5 years post-operative PFT (FEV: - 10% open, - 6% thoracoscopic; FVC: - 13% open, - 8% thoracoscopic) (p ≤ 0.02). The posterior cases remained stable (2% FEV, p = 0.7; - 0.6% FVC, p = 0.06). A subgroup of 90 patients with 2 year post-operative PFTs demonstrated that changes were progressive between 2 and 5 years post-operatively. The average change in FVC from 2 to 5 years was significantly different between the anterior open (- 9%) and posterior-only (0.7%) groups (p = 0.015). CONCLUSION: In patients who underwent anterior instrumentation, PFTs declined from the pre-operative to the 5 years post-operative time point. There was a progressive decline of 4-10% beyond 2 years post-operatively. Patients who underwent posterior instrumentation remained stable. These slides can be retrieved under Electronic Supplementary Material.

Anatomic Trajectory for Iliac Screw Placement in Pediatric Scoliosis and Spondylolisthesis: An Alternative to S2-Alar Iliac Portal.

STUDY DESIGN: Single-center retrospective study. OBJECTIVE: To analyze two-year postoperative outcomes following spinopelvic fixation in pediatric patients using the anatomic trajectory (AT) portal for iliac screws. SUMMARY: Iliac fixation is crucial in situations requiring fusion to sacrum. Challenges include complex anatomy, pelvic deformation, severe deformity, and previous surgery. The PSIS portal requires significant dissection, rod connectors, and complex bends. The SAI portal requires navigating the screw across the SI joint to the ilium. The anatomic trajectory (AT), first reported in 2009, is between the PSIS and SAI portal, without prominence, connectors, or complex bends. METHODS: Fifty-four patients aged ≤18 years requiring instrumentation to the Ilium with minimum follow-up of two years (mean 44 months) were clinically and radiographically evaluated. Changes in coronal curve magnitude and pelvic obliquity were assessed using paired t test for patients with cerebral palsy. Spondylolisthesis reduction was assessed in patients with moderate- to high-grade spondylolisthesis (Meyerding grade 3 and 4). RESULTS: A total of 108 iliac screws were inserted using AT portal in 54 patients. Twenty-eight neuromuscular and syndromic patients had an initial mean coronal curve of 85° corrected to 23° at two years (p < .001) and a pelvic obliquity of 22° corrected to 4° (p < .001). Twenty patients with moderate- to high-grade spondylolisthesis treated with reduction and interbody fixation improved significantly with respect to their slip angles (7° ± 14.7° to -7.9° ± 6.1°, p = .003). In the neuromuscular group, two surgical site infections occurred, two had implant fractures, and 12 had asymptomatic iliac screw loosening, none requiring revision. In the spondylolisthesis group, there were no neurologic complications and one had prominent screw requiring removal. Of 108 iliac screws, 2 rod connectors were employed. CONCLUSION: Iliac screw insertion using the AT portal is a safe and effective method of pelvic fixation in pediatric patients with satisfactory radiographic correction and minimal complications. LEVEL OF EVIDENCE: Level 4.