Posterior Instrumented Fusion Research Articles

The Impact of the Lowest Instrumented Vertebra on the Correction of the Minor Curve During Selective Fusion in Patients With Adolescent Idiopathic Scoliosis.

Retrospective single-center data analysis. The aim of this investigation was to give advises for choosing the LIV in selective fusion to reach the best correction of the minor curve and sagittal profile. Scoliotic curves can be classified as structural or nonstructural. If selective fusion is performed, the nonstructural curves are not instrumented. The choice of the lowest instrumented vertebra (LIV) and the impact of different levels of the LIV on the correction of the minor curve in the frontal profile and on the sagittal balance is under debate. Forty-seven consecutive patients treated by posterior instrumented fusion were included in this retrospective investigation. Impact of the level of the LIV with regard to distance to end vertebra (EV), to the stable vertebra (StV), to the sagittal infliction point (IP), and to the apex of the lumbar lordosis on the correction of the minor curve was analyzed. Distance of LIV to EV was significant with regard to correction of the minor curve if it was more than 5 levels (P<0.001). Distance of LIV to StV was significant with regard to correction of the minor curve if it was more than 4 levels (P<0.01). Distance of LIV to IP was significant with regard to correction of the minor curve if it was more than 2 levels (P<0.01). Choosing a LIV that was more than 2 levels higher or lower than the sagittal infliction point showed a significantly higher correction of the minor curve. We therefore recommend to keep that distance when LIV is chosen.

Is Next-day Discharge Safe After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis?

While the implementation of enhanced recovery after surgery protocols and improvements in pain control have decreased the length of stay (LOS) after scoliosis surgery, adolescents are typically hospitalized for several days after posterior spinal instrumented fusion (PSF). The purpose of this study was to determine whether next-day discharge after PSF for adolescent idiopathic scoliosis (AIS) had an equivalent safety profile compared with longer LOS. The secondary purpose was to examine perioperative factors associated with next-day discharge. We performed a retrospective study of all patients who underwent PSF for AIS at a single institution from 2017 to 2022. We compared patients based on postoperative LOS with an early discharge group consisting of those who were discharged on the first postoperative day 1 (POD1; n = 40) and a standard discharge group consisting of those who were discharged after POD1 (n = 71). We documented preoperative variables, including patient demographics and curve characteristics, intraoperative variables, including levels fused, implant density, operative time, and blood loss, and postoperative variables, including emergency department (ED) visits within 30 days and hospital readmissions within 90 days. One hundred eleven patients were included with a mean curve magnitude of 67 degrees. Forty patients (36%) were discharged on POD1. There were one (3%) ED visit and 2 (5%) readmissions in the early discharge group and 3 (4%) ED visits and 2 (3%) readmissions in the standard discharge group (P = 0.64 and 0.55, respectively). Patients in whom intravenous methadone was used intraoperatively were more likely to discharge POD1 (P = 0.02). There were no other significant differences in perioperative variables between the two groups including: BMI, distance from home to hospital, magnitude of main curve, curve flexibility, number of levels fused, estimated blood loss, implant density, operative time, or postoperative pain scores. Next-day discharge after PSF for AIS has an equivalent safety profile compared with longer LOS. Over one-third of patients were discharged on POD1, and there was no statistically significant difference in ED visits or hospital readmissions between the groups. Patients in whom intravenous methadone was used intraoperatively were more likely to discharge POD1. In a retrospective study of posterior spinal fusions for AIS, we found no increase in ED visits or hospital readmissions for those discharged the next day. Level III.

Effects of pelvic fixation strategies and multi-rod constructs on biomechanics of the proximal junction in long thoracolumbar posterior instrumented fusions: a finite-element analysis.

To assess the effect of various pelvic fixation techniques and number of rods on biomechanics of the proximal junction of long thoracolumbar posterior instrumented fusions. A validated spinopelvic finite-element (FE) model was instrumented with L5-S1 ALIF and one of the following 9 posterior instrumentation configurations: (A) one traditional iliac screw bilaterally ("2 Iliac/2 Rods"); (B) T10 to S1 ("Sacral Only"); (C) unilateral traditional iliac screw ("1 Iliac/2 Rods"); (D) one traditional iliac screw bilaterally with one midline accessory rod ("2 Iliac/3 rods"); (E) S2AI screws connected directly to the midline rods ("2 S2AI/2 Rods"); and two traditional iliac screws bilaterally with two lateral accessory rods connected to the main rods at varying locations (F1: T10-11, F2: T11-12, F3: T12-L1, F4: L1-2) ("4 Iliac/4 Rods"). Range of motions (ROM) at T10-S1 and T9-T10 were recorded and compared between models. The T9-T10 intradiscal pressures and stresses of the T9-10 disc's annulus in addition to the von Mises stresses of the T9 and T10 vertebral bodies were recorded and compared. For T10-S1 ROM, 4 iliac/4 rods had lowest ROM in flexion and extension, while 2 S2AI/2 rods showed lowest ROM in rotation. Constructs with 3 or 4 rods had lower stresses on the primary rods compared to 2-rod constructs. At the proximal adjacent disc (T9-10), 4 iliac/4 rods showed lowest ROM, lowest intradiscal pressures, and lowest annular stress in all directions (most pronounced in flexion-extension). Under flexion and extension, 4 iliac/4 rods also showed the lowest von Mises stresses on the T10 vertebral body but the highest stresses on the T9 vertebral body. Dual iliac screws with 4 rods across the lumbosacral junction and extending to the thoracolumbar junction demonstrated the lowest T10-S1 ROM, the lowest adjacent segment disc (T9-T10) ROM, intradiscal pressures, and annular stresses, and the lowest UIV stresses, albeit with the highest UIV + 1 stresses. Additional studies are needed to confirm whether these biomechanical findings dictate clinical outcomes and effect rates of proximal junctional kyphosis and failure.

P296. The contribution of intraoperative computed tomography integrated directly with robotic navigation: analysis of the first 80 consecutive posterior thoracolumbar instrumented fusions

P296. The contribution of intraoperative computed tomography integrated directly with robotic navigation: analysis of the first 80 consecutive posterior thoracolumbar instrumented fusions

Lateral lumbar and thoracic interbody fusion (LLIF) for thoracolumbar spine trauma (Trauma LLIF): A single-center, retrospective observational cohort study

BackgroundPain, disability and progressive kyphosis is a common problem after traumatic injury of the thoracolumbar (TL-) junction. Surgical treatment may include long-segment posterior or short-segment anterior-posterior fusion. We aim to report our experience with the application of short-segment posterior instrumented fusion with anterior column support using lateral lumbar or thoracic interbody (LLIF) cages. MethodsIn this retrospective, single-center observational cohort study we included consecutive patients treated surgically for traumatic injury of the TL-junction (Th10/11-L2/3) by posterior instrumentation/fusion and LLIF. We measured segmental kyphosis, complications, and outcomes until last follow-up (about 3 years postoperative). ResultsWe identified 61 patients (mean age 39.0 years (SD 13.3); 23 females (37.7%)) with A3 fractures without (n=48; 78.7%) or with additional sagittal split component (n=11; 18.0%. Additional posterior tension band injury was present in n=26 (42.6%). The affected levels of injury were Th12/L1 in n=25 (41.0%) and Th11/12 in n=22 (36.1%). The segmental kyphotic angle was 14.6° (6.7°) preoperative and remained significantly reduced at all times of follow-up at discharge (5.4°±5.5°; p<0.001), at 90 days (7.2°±5.5°; p<0.001), after partial hardware removal (7.2°±6.0°; p<0.001) and at last follow-up (8.1°±6.3°; p<0.001). We noticed a tendency for less progression of kyphosis in the group with two-staged, compared to single-staged bisegmental surgery (mean difference (MD) 3.1° after partial hardware removal, p=0.064). During follow-up, n=11 experienced complications (18%), n=58 (95.1%) had an excellent or good outcome and solid fusion was noticed in n=60 (98.4%). Conclusions“Trauma LLIF” should be considered as possibility for short-segment anterior-posterior fusion for injuries of the TL- junction. We observed most reproducible and long-lasting kyphosis reduction with a temporary bisegmental, two-staged procedure resulting in monosegmental fusion (posterior instrumentation/fusion with delayed LLIF and partial hardware removal to release the non-injured caudal motion segment).

Machine learning approach to predict venous thromboembolism among patients undergoing multi-level spinal posterior instrumented fusion.

The absence of consensus for prophylaxis of venous thromboembolism (VTE) in spine surgery underscores the importance of identifying patients at risk. This study incorporated machine learning (ML) models to assess key risk factors of VTE in patients who underwent posterior spinal instrumented fusion. Data was collected from the IBM MarketScan Database [2009-2021] for patients ≥18 years old who underwent spinal posterior instrumentation (3-6 levels), excluding traumas, malignancies, and infections. VTE incidence (deep vein thrombosis and pulmonary embolism) was recorded 90-day post-surgery. Risk factors for VTE were investigated and compared through several ML models including logistic regression, linear support vector machine (LSVM), random forest, XGBoost, and neural networks. Among the 141,697 patients who underwent spinal fusion with posterior instrumentation (3-6 levels), the overall 90-day VTE rate was 3.81%. The LSVM model demonstrated the best prediction with an area under the curve (AUC) of 0.68. The most important features for prediction of VTE included remote history of VTE, diagnosis of chronic hypercoagulability, metastatic cancer, hemiplegia, and chronic renal disease. Patients who did not have these five key risk factors had a 90-day VTE rate of 2.95%. Patients who had an increasing number of key risk factors had subsequently higher risks of postoperative VTE. The analysis of the data with different ML models identified 5 key variables that are most closely associated with VTE. Using these variables, we have developed a simple risk model with additive odds ratio ranging from 2.80 (1 risk factor) to 46.92 (4 risk factors) over 90 days after posterior spinal fusion surgery. These findings can help surgeons risk-stratify their patients for VTE risk, and potentially guide subsequent chemoprophylaxis.

Ponte osteotomies for treatment of spinal deformities: they are not all made equal.

To compare surgical outcomes of Ponte's osteotomies for treatment of adolescent idiopathic scoliosis (AIS), Scheuermann's kyphosis (SK), and adult scoliosis (AdS). We conducted a retrospective review of patients with AIS, SK, and AdIS who underwent posterior spinal instrumented fusion (PSIF) at our Institution from January 2019 to December 2022. Demographics, imaging, and intraoperative data (including number of osteotomies performed, blood losses, surgical timing, and complications) were extracted from patient charts. A total of 80 patients (62 AIS, 7 SK, and 11 AdS) were enrolled in the study. All patients were treated with a PSIF and a total of 506 Ponte osteotomies were performed (5.8 ± 4.1, 9.3 ± 2.4, and 7.5 ± 2.5 average osteotomies per patient in the AIS, SK, and AdS group, respectively; p = 0.045). Average time per osteotomy was 6.3 ± 1.5min in the AIS group, and 5.8 ± 2.1 and 8.7 ± 4.0 in the SK and AdS group, respectively (p = 0.002). Blood loss was significantly smaller in the SK group (8.6 ± 9.6ml per osteotomy) compared to AIS group (34.9 ± 23.7ml) and AdS group (34.9 ± 32.7ml) (p = 0.001). A total of 4 complications were observed in the AIS group (1.1%) and 2 complications in the AdS group (2.4%), but this was not statistically significant. Our study shows that Ponte's osteotomies are safe and effective in surgical treatment of AIS, SK, and AdS. Blood loss and execution time per osteotomy are significantly smaller in the SK group compared to AIS and AdS. No significant differences were noted in terms of complications between the three groups.

Impact of Different Operative Techniques for Patients With Adolescent Idiopathic Scoliosis on Frontal Curve Correction and Sagittal Balance.

Surgical correction of adolescent idiopathic scoliosis from the posterior approach can be performed by the "all screws" technique; hybrid technique with screws and hooks; hybrid technique or with screws, hooks, and tapes; or selective fusion (SF) or nonselective fusion (NSF). The aim of the present investigation was to analyze the influence from different operative techniques on frontal curve correction and sagittal profile in patients with adolescent idiopathic scoliosis. We conducted a retrospective analysis on 55 consecutive patients with scoliosis who had been treated by posterior instrumented fusion. We collected demographic data and analyzed pre- and postoperative radiographs. Statistical analysis was performed using SPSS version 25. Because data showed normal distribution, t tests were performed. Twenty-two patients were treated using the hybrid technique with screws and hooks; 25 were treated using the hybrid technique with screws, hooks, and tape; and 8 were treated using the all screws technique. An SF was performed in 32 patients and NSF in 23 patients. There was no significant difference with regard to curve correction of the main curve between the different techniques. Correction of the minor curve was significantly higher in NSF than in SF patients. In SF, there was a correction of the minor curve of 43.9%. Impact on sagittal balance showed no significant differences between NSF and SF. The different operative techniques did not show a difference with regard to the correction of the main curve. NSF showed a significantly higher degree of correction of the minor curve than SF. However, we still found a correction of 43.9% of the noninstrumented minor curve in SF. Thus, SF and hybrid techniques do not lead to inferior radiographic outcome. SF and hybrid techniques are safe and effective techniques that could be used as an alternative to NSF and all screw fixation in the operative treatment for scoliosis.

Delayed presentation of Wilkie’s syndrome after scoliotic curve correction surgery: a case report

BackgroundSuperior mesenteric artery (SMA) syndrome, also known as Wilkie’s syndrome, is a rare but serious complication following scoliosis correction surgery. It occurs as a result of mechanical compression of third part of duodenum between the SMA and aorta. This condition occurs most commonly in significantly underweight patients with deformities, and usually during the first week following spinal deformity corrective surgeries. The angle between the abdominal aorta and the SMA gets reduced following spinal lengthening during deformity correction surgery causing compression of third part of duodenum resulting in development of SMA syndrome.Case presentation.We present a case of 17-year-old male with congenital scoliosis with a 70-degree scoliotic curve who underwent spinal deformity correction surgery with posterior instrumented fusion. Post-operative course was uneventful and the patient was discharged after suture removal on post-operative day 15. The patient presented after 21-days of symptom onset on post-operative-day 51, with a 3 week history of post-prandial vomiting, abdominal pain and distension which resulted in rapid weight loss of 11 kg. A CT-angiogram showed obstruction at third part of duodenum. After reviewing clinical and radiological profile of the patient, a diagnosis of SMA syndrome was made. Conservative management was tried, but due to rapid deterioration of patient condition and symptoms of complete intestinal obstruction, the patient was treated surgically by gastro-jejunostomy and side-to-side jejuno-jejunostomy, which improved his condition.ConclusionSMA syndrome can occur much later than previously reported cases and with potentially life-threatening symptoms following scoliosis correction. Having a high index of suspicion, early recognition of condition and institution of appropriate treatment are essential to prevent occurrence of severe complications including risk of intestinal perforation and mortality. This case highlights management of delayed onset of SMA syndrome, with presentation further delayed after symptom onset, as is common in developing parts of the world, due to limited availability and accessibility of resources, and low socio-economic status of large segments of the population.

Biomechanical analysis of a trans-discal, multi-level stabilization screw (MLSS) at the upper instrumented vertebra (UIV) of long posterior thoracolumbar instrumentations

PurposeTo evaluate proximal junctional biomechanics of a MLSS relative to traditional pedicle screw fixation at the proximal extent of T10-pelvis posterior instrumentation constructs (T10-p PSF).MethodsA previously validated three-dimensional osseoligamentous spinopelvic finite element (FE) model was used to compare proximal junctional range-of-motion (ROM), vertebral body stresses, and discal biomechanics between two groups: (1) T10-p with a T10-11 MLSS (“T10-11 MLSS”) and (2) T10-p with a traditional T10 pedicle screw (“Traditional T10-PS”).ResultsThe T10-11 MLSS had a 5% decrease in T9 cortical bone stress compared to Traditional T10-PS. Conversely, the T10 and T11 bone stresses increased by 46% and 98%, respectively, with T10-11 MLSS compared to Traditional T10-PS. Annular stresses and intradiscal pressures (IDP) were similar at T9-T10 between constructs. At the T10-11 disc, T10-11 MLSS decreased annular stresses by 29% and IDP by 48% compared to Traditional T10-PS. Adjacent ROM (T8-9 & T9-10) were similar between T10-11 MLSS and Traditional T10-PS. T10-11 MLSS had 39% greater ROM at T10-11 and 23% less ROM at T11-12 compared to Traditional T10-PS.ConclusionsIn this FE analysis, a T10-11 MLSS at the proximal extent of T10-pelvis posterior instrumentation resulted in increased T10 and T11 cortical bone stresses, decreased discal annular stress and IDP and increased ROM at T10-11, and no change in ROM at the adjacent level. Given the complex and multifactorial nature of proximal junctional kyphosis, these results require additional biomechanical and clinical evaluations to determine the clinical utility of MLSS on the proximal junctions of thoracolumbar posterior instrumented fusions.

412 Incisional Negative Pressure Wound Therapy Following Posterior Instrumented Spinal Fusion: A Single Surgeon’s Experience and Cost-Benefit Analysis

INTRODUCTION: Surgical site infections (SSIs) following spine surgery are associated with significant morbidity and resource utilization. METHODS: We retrospectively reviewed all patients who received posterior instrumented spinal fusion by the senior author between July 2017 and December 2019 at a Level I trauma center. Statistical analysis was performed using Chi-square and Student’s t-tests. RESULTS: A total of 85 patients with standard surgical dressings and 144 patients with iNPWT were included for analysis. Patients in the iNPWT group were significantly older (61.8 vs. 58.5 years, p = 0.042) and more likely to be diabetic (36.8% vs. 23.5%, p = 0.037). Surgeries in the iNPWT group were associated with significantly greater blood loss (1298 mL vs. 998 mL, p = 0.036) and involved more instrumented levels (6.6 vs. 4.9, p &lt; 0.0001). Prophylactic iNPWT use was associated with significantly lower rates of wound dehiscence (21.5% vs. 34.1%, p = 0.036) and SSI requiring operative treatment (8.3% vs. 21.2%, p = 0.005). The incidence of wound dehiscence requiring operative wound revision was lower with iNPWT (14.6% vs. 24.7%, p = 0.056), though it did not reach statistical significance. Number needed to treat (NNT) with iNPWT to prevent one SSI was 7.79. The cost of preventing one operative SSI was $5,096. Cost-benefit analysis demonstrated a potential mean savings of $26,149 per operative SSI and $326,862 per 100 patients undergoing posterior instrumented spinal fusion with iNPWT. CONCLUSIONS: Prophylactic iNPWT use significantly reduced rates of wound dehiscence, SSI requiring operative treatment, and affords a potential SSI-related cost savings of $326,862 per 100 patients treated.

928 Autologous Rib Graft for Posterior Cervical Fusion in Pediatrics: Efficacy and Complications

INTRODUCTION: Cervical instability in the pediatric population presents unique challenges. Indication for fusion include instability or deformity from multiple causes. A recent meta-analysis showed high failure rate of successful arthrodesis after pediatric craniocervial fusion (over 30%). We describe use of autologous rib graft with BMP to augment fusion, evaluating efficacy and complication from this technique. METHODS: A retrospective study was performed between 2020 and 2023 of all pediatric patients (age 0-18) who underwent autologous rib grafting with extra-small BMP-2 for posterior craniocervical arthrodesis at a single institution. Patients with less than 3 month post-operative follow-up and no post operative CT were excluded. Primary outcomes include presence of fusion on CT, perioperative complication, and complication from rib harvest. RESULTS: Twenty-one patients met inclusion criteria. Ten were male, with average age 10 years (range 2 to 18). 87 total levels were fixated and fused, with no fixation screws misplaced on post operative CT. There were no surgical site infections, post operative seroma, or unplanned return to OR. All patients had solid fusion on postoperative CT. Average follow up was 268 days, with range of 45 days to 3 years. No patient had pain at the rib harvest on any post operative visit, and all rib incisions healed without complication. CONCLUSIONS: Our preliminary results suggest that autologous rib graft with extra-small BMP-2 is an effective strategy to achieve a high rate of fusion in pediatric patients undergoing posterior instrumented craniocervical fusion. In our series, we found an acceptable safety profile, with no seroma, surgical site infection, return to the OR, or rib harvest complication.

475 Molybdenum-Rhenium Rods in Complex Adult Spine Surgery Without Rod Fractures: A Multicenter Retrospective Case Series

INTRODUCTION: In complex spine surgery, current pedicle screw systems with 5.5 mm titanium, cobalt chromium or stainless steel rods have rod failure rates of approximately 9% with a minimum of 1-year follow-up. The fracture rate with these alloys increases to approximately 22% in PSO cases.1 Molybdenum-rhenium has demonstrated superior yield strength and fatigue endurance limit compared to Ti-6Al-4V and CoCr. METHODS: Retrospective, multicenter, case series. Inclusion criteria were = 4 levels posterior instrumented fusion with 4.5 mm molybdenum-rhenium rods, age = 18 yrs and 6 months or longer radiographic and followup. RESULTS: One hundred and fifty-nine (159) consecutive patients from ten different medical centers that had spinal surgery from August 2019 until April 2022 met inclusion criteria. Mean age was 63 ± 11.8 years; 50% women; 31% smokers; 19% diabetic and the mean BMI was 30 ± 7.3. The mean number of levels fused was 5.9 ± 2.7; 22.6% 4 levels, 64.2% 5-9 levels and 13.2% 10 levels or greater. Approximately half were thoracolumbar (27.7%) or thoracolumbar to pelvis (24.5%) and approximately half were lumbar-sacral (47.2%). Thirty-eight patients (24%) had a PSO and 59 patients (39%) had a SPO. All cases were done with molybdenum-rhenium 4.5 mm diameter rods. There were no RFs reported in the 159 cases (0/159; 0.0%) at 22.36 months mean follow-up. CONCLUSIONS: There was no incidence of RF in the 159 consecutive patients who underwent complex spine surgery involving multiple levels and osteotomies. A pedicle screw system based upon molybdenum-rhenium 4.5 mm rods provides superior fracture resistance particularly in complex spine procedures. 1 Smith JS, et al., Prospective multicenter assessment of risk factors for rod fracture following surgery for adult spinal deformity. J Neurosurg Spine. 2014 Dec; 21(6): 994-1003.

The Incidence of Screw Failure in Fenestrated Polyaxial Pedicle Screws vs. Conventional Pedicle Screws in the Treatment of Adolescent Idiopathic Scoliosis (AIS).

Background: Adolescent idiopathic scoliosis (AIS) is a spinal pathology affecting 0.47-5.2% of the population, often requiring surgical intervention to control deformity progression. Posterior spinal instrumentation and fusion with pedicle screw fixation are standard procedures for AIS curve correction; however, implant failure remains a significant complication, especially in multi-level fusions. This retrospective cohort study aims to compare the failure rates between conventional pedicle screws (CPSs) and fenestrated pedicle screws (FPSs) in AIS treatment, with a focus on investigating potential causes of these failures. Methods: This study, conducted from January 2016 to December 2020, involves a two-center retrospective analysis of AIS patients undergoing posterior instrumented fusion. Results: Data from a total of 162 patients (122 females and 40 males) revealed a mean age of 14.95 years (range: 11-18). The CPS group consisted of 80 patients (56 females and 24 males), whereas the FPS group consisted of 82 patients (66 females and 16 males) stratified by Risser grade and Lenke Classification. Radiological assessments, clinical outcomes, and SRS-22 scores were evaluated pre-operatively, at 6 months, and post-operatively (minimum follow-up of 2 years). Conclusions: Fenestrated pedicle screws (FPSs) pose concerns due to their lower mechanical strength compared to solid screws. Understanding their limitations and optimizing their application in AIS treatment is essential.

Impact of a quality improvement initiative and monthly multidisciplinary meetings on outcomes after posterior spinal fusion for adolescent idiopathic scoliosis.

Several studies have demonstrated the benefits of enhanced recovery after surgery (ERAS) protocols for patients with adolescent idiopathic scoliosis (AIS) undergoing posterior spinal instrumented fusion (PSIF). However, there are relatively few studies investigating the effect of regular multidisciplinary team meetings on level selection, surgical performance parameters, and patient outcomes after PSIF for AIS. The aim of this study was to assess changes in intra- and postoperative outcomes following multidisciplinary team meeting implementation for patients undergoing PSIF for AIS. The medical records of 96 adolescents (10 to 18years old) diagnosed with AIS and undergoing PSIF at a major academic institution from 2017 to 2022 were retrospectively reviewed. A quality improvement (QI) initiative was implemented in February 2020, including institution of monthly multidisciplinary conferences focusing on preoperative indications, level selection, postoperative review of surgical performance parameters for previous cases, and discussion and optimization of postoperative ambulation and pain control protocols. Patients were placed into "Pre-QI" (treated pre-February 2020) and "Post-QI" (treated post-February 2020) cohorts. Patient demographics, comorbidities, deformity characteristics, intraoperative variables, ambulation status, postoperative complications, length of stay (LOS), and unplanned readmission rates were assessed. Of the 96 study patients, 44 (45.8%) were in the Pre-QI cohort, and 52 (54.2%) were in the Post-QI cohort. Mean major curve was not significantly different between the two cohorts (Pre-QI: 58.0 ± 7.3° vs Post-QI: 57.9 ± 14.5°, p = 0.169). The Pre-QI cohort had a greater mean minor curve degree (Pre-QI: 42.7 ± 11.8° vs Post-QI: 36.8 ± 12.4, p = 0.008). The Pre-QI cohort had significantly greater mean spinal levels fused (Pre-QI: 11.7 ± 1.7 vs Post-QI: 10.4 ± 2.6, p = 0.009), significantly greater mean estimated blood loss (Pre-QI: 1063.6 ± 631.5ml vs. Post-QI: 415.8 ± 189.9ml, p < 0.001), significantly greater mean operative time normalized to levels fused (Pre-QI: 0.6 ± 0.1h/level fused vs Post-QI: 0.4 ± 0.1h/level fused, p < 0.001), and a significantly greater proportion of patients with intraoperative drain placement (Pre-QI: 93.2% vs Post-QI: 5.8%, p < 0.001). The Post-QI cohort had significantly shorter time to postoperative ambulation (Pre-QI: 2.1 ± 0.9days vs Post-QI: 1.3 ± 0.5days, p < 0.001). A significantly greater proportion of patients in the Pre-QI cohort developed any postoperative complication (Pre-QI: 72.7% vs Post-QI: 34.6%, p < 0.001), and mean LOS was significantly greater among Pre-QI patients (Pre-QI: 4.5 ± 1.1days vs Post-QI: 3.2 ± 0.8days, p < 0.001). Discharge disposition (p = 0.758) and 30-day unplanned readmissions (p = 0.207) were similar between the cohorts. Our findings suggest that monthly multidisciplinary pediatric spine team meetings may improve patient care. Further studies exploring the incorporation of QI implementation with frequent multidisciplinary team meetings into existing ERAS protocols are merited.

Oblique anterior column realignment with a mini-open posterior column osteotomy for minimally invasive adult spinal deformity correction: illustrative case.

Adult spinal deformity (ASD) occurs from progressive anterior column collapse due to disc space desiccation, compression fractures, and autofusion across disc spaces. Anterior column realignment (ACR) is increasingly recognized as a powerful tool to address ASD by progressively lengthening the anterior column through the release of the anterior longitudinal ligament during lateral interbody approaches. Here, we describe the application of minimally invasive ACR through an oblique antepsoas corridor for deformity correction in a patient with adult degenerative scoliosis and significant sagittal imbalance. A 65-year-old female with a prior history of L4-5 transforaminal lumbar interbody fusion and morbid obesity presented with refractory, severe low-back and lower-extremity pain. Preoperative radiographs showed significant sagittal imbalance. Computed tomography showed a healed L4-5 fusion and a vacuum disc at L3-4 and L5-S1, whereas magnetic resonance imaging was notable for central canal stenosis at L3-4. The patient was treated with a first-stage L5-S1 lateral anterior lumbar interbody fusion with oblique L2-4 ACR. The second-stage posterior approach consisted of a robot-guided minimally invasive T10-ilium posterior instrumented fusion with a mini-open L2-4 posterior column osteotomy (PCO). Postoperative radiographs showed the restoration of her sagittal balance. There were no complications. Oblique ACR is a powerful minimally invasive tool for sagittal plane correction. When combined with a mini-open PCO, substantial segmental lordosis can be achieved while eliminating the need for multilevel PCO or invasive three-column osteotomies.

Intraspinal cervicothoracic junction chondrosarcoma: illustrative case.

Chondrosarcoma is an uncommon spinal tumor that can present as an extraskeletal mass. Rarely, these tumors present as dumbbell tumors through the neural foramina, mimicking schwannomas or neurofibromas. A 46-year-old female presented with 2 years of worsening right-arm radiculopathy. Magnetic resonance imaging of the thoracic spine revealed a peripherally enhancing extramedullary mass through the right T1 foramen and compressing the spinal cord. Computed tomography showed the mass to be partially calcified. She underwent C7-T2 laminectomy and C6-T3 posterior instrumented fusion with gross-total resection of an extradural mass. Pathology revealed a grade I chondrosarcoma. Her symptoms improved postoperatively, with some residual right-arm radicular pain. Intraspinal extradural dumbbell conventional chondrosarcoma is rare, with only 9 cases, including ours, reported. Patient ages range from 16 to 72 years old, and male sex is more common in these cases. The most common location is the thoracic spine, and our case is the only reported one in the cervicothoracic junction. These tumors often mimic schwannomas on imaging, but chondrosarcoma should remain in the differential diagnosis, because management of these tumors differs. Chondrosarcoma may benefit from more aggressive resection, including en bloc resection, and may require adjuvant radiotherapy.

Single position, prone oblique lateral interbody fusion (OLIF)-case illustration and technical considerations.

Oblique lateral interbody fusion (OLIF) is a powerful method to treat various spinal conditions and is frequently combined with posterior instrumentation. This is traditionally performed in dual positions, with the patient first in lateral then turned prone. Single position lateral surgery (SPS-L) has been studied in a bid to improve surgical efficiency and reduce operative costs, but various limitations have been identified. More recently, the single position prone surgery (SPS-P) has been described as an alternative to address some of these limitations. This case illustrates a patient who underwent SPS-P using an OLIF corridor with subsequent posterior decompression and instrumentation. The benefits and limitations of this procedure compared to the conventional techniques are highlighted in this case. We present the case of a 75-year-old female presenting with thoracic myelopathy over T11/12 and concurrent L2-4 spinal stenosis. She underwent OLIF of L2/3 and L3/4, posterior decompression of T11/12 and L2/3, and posterior instrumented fusion from T10-L4 via a single prone position. We aim to describe the advantages of this approach and the challenges encountered through our experience. SPS-P offers numerous benefits compared to the already powerful SPS-L. In the upper levels of the lumbar spine, a pre-psoas approach may also be feasible. However, the prone lateral technique does not replace all patients suited for a lateral interbody fusion but should be seen as a viable option for selected cases such as those with previous fusion at the L5/S1 with adjacent degeneration requiring extension and posterior fixation.

High triglyceride-glucose index is associated with low postoperative satisfaction in patients with posterior instrumented lumbar fusion.

This study aimed to determine the effect of the preoperative triglyceride-glucose (TyG) index on the postoperative quality of life, patient satisfaction, and surgical outcomes in patients who underwent posterior lumbar instrumentation and fusion surgery. This was a retrospective single-center cohort study (n = 136). Patients were divided into three groups according to the TyG index: < 25th percentile (L), 25-75 percentile (N), and > 75th percentile (H). Pearson correlation analysis was used to evaluate the relationship between the TyG index and the quantitative variables. Scatterplot and receiver operating characteristic (ROC) curve analysis were used to assess the relationship of the preoperative TyG index with postoperative Oswestry disability index (ODI) and physical function (PF) scores. The TyG index showed a significant correlation with postoperative ODI score. TyG index showed a significant negative correlation with postoperative PF score. On ROC curve analysis, postoperative ODI score ≥ 38 (optimal cut-off) had 79% sensitivity and 92% specificity for predicting high TyG index (group H) (p = 0.016). Postoperative PF score ≤ 80 predicted group H patients with 97% sensitivity and 75% specificity (p = 0.001). The area under the ROC curve was 0.74 (p = 0.016) for the postoperative ODI and 0.79 (p = 0.001) for the postoperative PF. In patients who underwent posterior lumbar instrumentation and fusion surgery, a high preoperative TyG index may predict poor postoperative ODI and PF scores, indicating lower patient satisfaction.

A Sodium Oxychlorosene-Based Infection Prevention Protocol Safely Decreases Postoperative Wound Infections in Adult Spinal Deformity Surgery.

This study sought to determine the efficacy of a complex multi-institutional sodium oxychlorosene-based infection protocol for decreasing the rate of surgical site infection after instrumented spinal surgery for adult spinal deformity (ASD). Infection prevention protocols have not been previously studied in ASD patients. A retrospective analysis was performed of patients who underwent posterior instrumented spinal fusion of the thoracic or lumbar spine for deformity correction between January 1, 2011, and May 31, 2019. The efficacy of a multi-modal infection prevention protocol was examined. The infection prevention bundle consisted of methicillin-resistant Staphylococcus aureus testing, chlorhexidine gluconate bathing preoperatively, sodium oxychlorosene rinse, vancomycin powder placement, and surgical drain placement at the time of surgery. About 254 patients fit the inclusion criteria. Among these patients, nine (3.5%) experienced post-surgical deep-wound infection. Demographics and surgical characteristics amongst infected and non-infected cohorts were similar, although diabetes trended towards being more prevalent in patients who developed a postoperative wound infection (p=0.07). Among 222 patients (87.4%) who achieved a minimum of two years of follow-ups, 184 patients (82.9%) experienced successful fusion, comparing favorably with pseudarthrosis rates in the ASD literature. Rates of pseudarthrosis and proximal junction kyphosis were similar amongst infected and non-infected patients. An intraoperative comprehensive sodium oxychlorosene-based infection prevention protocol helped to provide a low rateof infection after major deformity correction without negatively impacting other postoperative procedure-related metrics.