Association of single bolus versus bolus followed by infusion of tranexamic acid with blood loss in adolescent idiopathic scoliosis surgery.

BACKGROUND: Adolescent idiopathic scoliosis (AIS) corrective surgery may involve significant blood loss and blood transfusion requirements. Antifibrinolytic agents such as tranexamic acid (TXA) have been used to reduce blood loss, but its optimal dose is uncertain. The objective of this study is to determine the estimated blood loss and rate of blood transfusion between two groups of AIS patients receiving TXA as a single bolus versus bolus followed by infusion in scoliosis surgery. METHODS: This was a retrospective analysis of a single bolus versus bolus followed by infusion of TXA in AIS surgery. AIS patients undergoing posterior spinal fusion (PSF) from December 2018 to September 2019 at a tertiary university hospital were identified. Inclusion criteria were patients aged between 10 and 21 years who received either a single bolus of 30 mg/kg TXA (Group A) or a single bolus of 30 mg/kg followed by continuous infusion of 10 mg/kg/h of TXA (Group B). Patient demographics, operative data, estimated blood loss, blood transfusion rate, and complications were recorded. RESULTS: A total of 129 AIS patients were included. All operative surgeries were performed by two senior consultants. The mean age was 14.8 ± 3.4 years old, and 89.1% were female. The Cobb angle, number of fusion levels, number of screws, length of skin incision, and duration of surgery were comparable between the two groups. There was no difference in the total estimated blood loss between the two groups: 723.3 ± 279.4 mL (range: 175.0-1607.0 mL) in Group A and 819.4 ± 302.6 mL (range: 330.0-1556.0 mL) in Group B (p = 0.065). There were no complications, and none received blood transfusion. CONCLUSION: TXA when administered as a single bolus or bolus followed by infusion in AIS patients undergoing PSF surgery was associated with similar estimated total surgical blood loss and blood transfusion requirement.

Adolescent Perception of Stiffness After Spinal Fusion Surgery.

Posterior spinal instrumented fusion (PSIF) is a treatment option for adolescent spinal deformity. PSIF leads to loss of spinal segment motion. It is unclear the extent to which spinal stiffness is perceived by adolescent patients after fusion. Focus groups of adolescents between ages 11 and 21 years who underwent PSIF for spinal deformity were performed. Focus groups were evaluated for common themes, and a 36-question survey was designed. Survey responses were analyzed relative to last instrumented vertebra (LIV) and Scoliosis Research Society-22 (SRS-22) scores. Five focus groups were held with 18 patients in total. Three main themes were identified by participants: 56% identified difficulty bending forward, 44% identified difficulty hunching while sitting, and 56% identified difficulty with twisting motions. Patients with more distal LIV reported significant more difficulty with self-care/grooming (P = .014) and chores (P < .001). SRS-22 function/activity scores correlated well with survey categories in self-care/grooming (r = .61; P = .049) and recreation (r = .69; P = .019). Focus groups suggest that spinal stiffness is frequently perceived and leads to alteration in daily tasks in adolescents after spinal fusion.

L4-L5 Facet Dislocation Treated in a Delayed Fashion with Excellent Early Clinical Results.

Introduction: Introduction: Lumbar facet fracture-dislocations are rare injuries that are generated from a significant trauma. Literature regarding these injuries is limited to case reports, and there are even more limited reports concerning whether the delay of operative intervention in neurologically intact patients can achieve good clinical results if concomitant injuries and/or medical issues preclude urgent operative intervention. There has been no consensus on which operative techniques are effective in achieving an anatomic reduction of these injuries. Objectives: A case report of an L4-L5 facet fracture-dislocation with delayed operative intervention and previously not reported adjunctive reduction technique is presented with an excellent clinical outcome result being achieved. Case Report: A 38-year-old female who presented with an L4-L5 facet fracture-dislocation without neurological deficit after an unknown mechanism of injury. Due to concerns for elevated risk of intra and perioperative complications from general anesthesia secondary to recent drug use, the patient ultimately underwent open reduction and L4-L5 posterior instrumentation and fusion, with a resection of the superior aspect of the L5 pedicle being performed to help achieve reduction. The patient did not report any significant lower back pain and remained motor intact at 6-month post-operative, with the only neurological symptom during her post-operative course being hypesthesias in the right L5 dermatome at 6-week post-operative. Conclusion: Excellent clinical results can be achieved with delayed open reduction and posterior stabilization in patients that sustain lumbar facet-fracture dislocations. The precise timing for operative management for patients who sustain these injuries is unknown, but medical stability should be considered before proceeding with an operative intervention in neurological intact patients. Partial resection of the pedicle is a safe and effective reduction technique in certain fracture-dislocation patterns.

Comparison of Hounsfield Unit, Vertebral Bone Quality, and Dual-Energy X-Ray Absorptiometry T-Score for Predicting Cage Subsidence After Posterior Lumbar Interbody Fusion.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To compare Hounsfield unit (HU), vertebral bone quality (VBQ), and dual-energy X-ray absorptiometry (DEXA) T-score in predicting cage subsidence (CS) after posterior lumbar interbody fusion. METHODS: We retrospectively reviewed patients undergoing PLIF and measured L4 HU and VBQ. Baseline characteristics between CS and non-CS groups were compared. Multiple logistic regression analysis was used to identify risk factors for CS. Receiver operating characteristic (ROC) curves were used to explore the predictive value of variables for CS. Subgroup analysis was conducted for patients with available DEXA results. RESULTS: Eighty-four patients were analyzed. The subsidence group was older, with lower L4 HU (92.6 (35.4) vs 130.8 (47.8), P < 0.001) and higher VBQ (3.30 (0.64) vs 2.99 (0.63), P = 0.041) compared to the non-CS group. Low L4 HU (OR 0.979, P = 0.022) was an independent risk factor for subsidence, while VBQ was not. ROC analysis indicated that L4 HU (AUC = 0.733, P < 0.001) exhibited superior predictive performance compared to VBQ (AUC = 0.643, P = 0.032). Subgroup analysis in patients with DEXA showed that the femoral neck T-score (AUC = 0.67, P = 0.037) could differentiate CS, with L4 HU exhibiting the highest predictive ability (AUC = 0.778, P < 0.001), both outperforming VBQ (AUC = 0.645, P = 0.075). CONCLUSIONS: Among the three BMD parameters, only low L4 HU could be an independent risk factor for CS. Preoperative HU is mandatory in patients at risk for osteoporosis when undergoing spine surgery.

Machine learning approach to predict acute kidney injury among patients undergoing multi-level spinal posterior instrumented fusion.

Background: Acute kidney injury (AKI) after spinal fusion is a significant morbidity that can lead to poor post-surgical outcomes. Identifying AKI risk factors and developing a risk model can raise surgeons' awareness and allow them to take actions to mitigate the risks. The objective of the current study is to develop machine learning (ML) models to assess patient risk factors predisposing to AKI after posterior spinal instrumented fusion. Methods: Data was collected from the IBM MarketScan Database (2009-2021) for patients >18 years old who underwent spinal fusion with posterior instrumentation (3-6 levels). AKI incidence (defined by the International Classification of Diseases codes) was recorded 90-day post-surgery. Risk factors for AKI were investigated and compared through several ML models including logistic regression, linear support vector machine (LSVM), random forest, extreme gradient boosting (XGBoost), and neural networks. Results: Among the 141,697 patients who underwent fusion with posterior instrumentation (3-6 levels), the overall rate of 90-day AKI was 2.96%. We discovered that the logistic regression model and LSVM demonstrated the best predictions with area under the curve (AUC) values of 0.75. The most important AKI prediction features included chronic renal disease, hypertension, diabetes mellitus ± complications, older age (>50 years old), and congestive heart failure. Patients who did not have these five key risk factors had a 90-day AKI rate of 0.29%. Patients who had an increasing number of key risk factors subsequently had higher risks of postoperative AKI. Conclusions: The analysis of the data with different ML models identified 5 key variables that are most closely associated with AKI: chronic renal disease, hypertension, diabetes mellitus ± complications, older age (>50 years old), and congestive heart failure. These variables constitute a simple risk calculator with additive odds ratio ranging from 3.38 (1 risk factor) to 91.10 (5 risk factors) over 90 days after posterior spinal fusion surgery. These findings can help surgeons risk-stratify their patients for AKI risk, and potentially guide post-operative monitoring and medical management.

Efficacy of an allograft cellular bone matrix as an alternative to autograft in anterior cervical discectomy and fusion: radiological results & safety.

Background: The predominant surgical procedure employed for patients with symptomatic cervical radiculopathy is anterior cervical discectomy and fusion (ACDF). ACDF typically involves the use of an interbody cage augmented with iliac crest bone graft (ICBG) or local autograft to enhance fusion rate. Substantial complications can arise from autograft use, including donor site morbidity, difficulties with ambulation, and diminished quality of life. This study aims to evaluate the effectiveness and safety of an allograft cellular bone matrix (ACBM) as an osteopromotive bone, in ACDF procedures. Methods: This retrospective, single-center, consecutive case series included 73 patients who underwent an ACDF procedure. The surgical procedure involved the placement of an interbody cage supplemented with anterior plate fixation and an ACBM within the interbody spacer. Patient charts were reviewed to gather demographic information, radiographic findings, as well as perioperative and post-operative complications. Radiographic fusion was assessed at 6 and 12 months by a blinded, musculoskeletal-trained radiologist and a board-certified spinal surgeon reviewer. Any discrepancies were settled by a third, senior reviewer. Complete fusion was defined as: evidence of bridging bone across the disc space on CT, angular motion <3 degrees, and translational motion <2 mm on lateral radiographs. Complications were analyzed at 6, 12, and 15+ months post-operatively to assess clinical outcomes and device performance. Results: A total of 73 patients (50 males, 23 females) with an average age of 54.6 (range, 31-77) years underwent an ACDF procedure between C3-T1 with an ACBM. The breakdown of levels operated on was 26%, 32%, 34%, and 8% for one, two, three, and four level procedures, respectively. There were three patients who received spinal injections for pain within the first year post-operatively. There were two patients who required secondary surgery within the first 12 months where supplemental posterior hardware was needed. Notably, there were no instances of cage subsidence, cage migration, cage/graft removal, or reoperation. There were no cases of chronic dysphasia. At 6 months, 45% of patients with available imaging demonstrated complete fusion, while 97.4% of patients with available imaging demonstrated complete fusion at 12 months. Conclusions: At the 12-month follow-up, our study demonstrates a high fusion rate in a real-world population of up to 4 operative levels. There were no bone graft related complications or incidences of cage migration/subsidence. It is noteworthy that the study involved a significant number of multilevel cases (74% of cases). Despite this, our results align with historical fusion rates and provide support for the utilization of ACBMs as a fusion adjunct in ACDF procedures up to 4 levels.

Health care disparities in complication and mortality rates following surgical management of cauda equina syndrome in New York State.

CONTEXT: While healthcare disparities related to race and ethnicity are well reported for non-emergent conditions, the literature on disparities in outcomes of emergent spinal conditions such as cauda equina syndrome (CES) remains sparse. OBJECTIVE: To evaluate racial disparities in complication, mortality, and readmission rates following surgical intervention for CES. METHODS: This retrospective analysis of The Statewide Planning and Research Cooperative System (SPARCS) database demonstrates that among patients surgically treated for CES in New York between 2015 and 2020. Bivariate and multivariate logistic regression analysis was performed to analyze the association of race and outcome variables after controlling for age, sex, comorbidities, length of stay, insurance, and hospital characteristics. RESULTS: Overall, 2,114 patients who underwent lumbar surgery for CES were identified. The study population was comprised of Black patients (177, 8%), White patients (79%, 1680), and Asian patients (257, 12%). Options for surgery included lumbar decompression (821, 38.8%), fusion (746, 35.3%), or both (547, 25.9%). On multivariate analysis, the odds of 30-day mortality were 2.98-fold greater in Black patients than in other patients (P = 0.029). By 180 and 360 days, the odds of mortality were 4.27 and 3.05-fold greater in Black patients than in other patients, respectively (P < 0.001 each). Thirty-day readmissions were 1.87-fold greater in Black patients than others (P = 0.004). No difference in overall complication rate was found between Black patients and all other race groups (P = 0.306). CONCLUSIONS: Black patients surgically treated for CES face significantly higher rates of mortality and readmission than their non-Black counterparts.

Acute postoperative complications after spine deformity correction in patients with Down syndrome.

Introduction: Down syndrome, or trisomy 21, is the most diagnosed chromosomal abnormality and is associated with multiple orthopedic concerns, including scoliosis. We sought to examine the surgical treatment of scoliosis associated with Down syndrome with an emphasis on specific complications in this population. Methods: A retrospective review of 13 patients with Down syndrome who underwent surgical intervention for spinal deformity between 2000 and 2018 were identified. Postoperative complications were classified using the modified Clavien-Dindo-Sink system. Perioperative and final follow-up radiographic data were analyzed. Results: The mean age at surgery was 14.2 years (11-19) with a mean follow-up of 3.6 years (0.4-6.2) at the time of data collection. Seven (54%) patients had postoperative complications, all related to wound healing. Three patients (23%) had major complications (Clavien-Dindo-Sink grade ≥3). These included one deep surgical site infection, one hematoma, and one seroma, all requiring surgical drainage. Four additional patients (31%) had minor complications (Clavien-Dindo-Sink grade ≤2). Discussion: Surgical intervention for scoliosis in patients with Down syndrome is associated with high complication rates despite the use of more modern surgical techniques and implant types. Complications in this cohort primarily involved wound healing, whereas previous studies described high rates of postoperative implant failure, pseudoarthrosis, and significant curve progression, which were not experienced by the patients in this study. Although the etiology of wound-related complications is unknown, awareness of this risk may help surgeons optimize surgical technique, postoperative monitoring, and preoperative counseling of families. Level of Evidence: IV-single-institution retrospective case series.

Comparison of two modeling approaches for the identification of predictors of complications in children with cerebral palsy following spine surgery.

BACKGROUND: Children with non-ambulatory cerebral palsy (CP) frequently develop progressive neuromuscular scoliosis and require surgical intervention. Due to their comorbidities, they are at high risk for developing peri- and post-operative complications. The objectives of this study were to compare stepwise and LASSO variable selection techniques for consistency in identifying predictors when modelling these post-operative complications and to identify potential predictors of respiratory complications and infections following spine surgery among children with CP. METHODS: In this retrospective cohort study, a large administrative claims database was queried to identify children who met the following criteria: 1) ≤ 25 years old, 2) diagnosis of CP, 3) underwent surgery during the study period, 4) had ≥ 12-months pre-operative, and 5) ≥ 3-months post-operative continuous health plan enrollment. Outcome measures included the development of a post-operative respiratory complication (e.g., pneumonia, aspiration pneumonia, atelectasis, pleural effusion, pneumothorax, pulmonary edema) or an infection (e.g., surgical site infection, urinary tract infection, meningitis, peritonitis, sepsis, or septicemia) within 3 months of surgery. Codes were used to identify CP, surgical procedures, medical comorbidities and the development of post-operative respiratory complications and infections. Two approaches to variable selection, stepwise and LASSO, were compared to determine which potential predictors of respiratory complications and infection development would be identified using each approach. RESULTS: The sample included 220 children. During the 3-month follow-up, 21.8% (n = 48) developed a respiratory complication and 12.7% (n = 28) developed an infection. The prevalence of 11 variables including age, sex and 9 comorbidities were initially considered to be potential predictors based on the intended outcome of interest. Model discrimination utilizing LASSO for variable selection was slightly improved over the stepwise regression approach. LASSO resulted in retention of additional comorbidities that may have meaningful associations to consider for future studies, including gastrointestinal issues, bladder dysfunction, epilepsy, anemia and coagulation deficiency. CONCLUSIONS: Potential predictors of the development of post-operative complications were identified in this study and while identified predictors were similar using stepwise and LASSO regression approaches, model discrimination was slightly improved with LASSO. Findings will be used to inform future research processes determining which variables to consider for developing risk prediction models.

The Use of Thoracoscopic Release in the Surgical Correction of Thoracic Scoliosis in Children.

INTRODUCTION: Recently, the use of thoracoscopic methods in spinal deformity surgery has increased, however, the issue of the effectiveness of combining anterior release with posterior spinal fusion compared to single-stage posterior instrumentation remains controversial, which raises the issue of the effectiveness and feasibility of their use. PURPOSE: To evaluate the effectiveness of endoscopic anterior release for thoracic scoliosis in children. MATERIAL AND METHOD: A retrospective analysis of the results of surgical treatment of 48 patients with idiopathic scoliosis of the thoracic spine aged 12-17 years, with a thoracic curve of more than 60°, was carried out. To determine the stability of deformity, the stability index according to A.I. Kazmin was used. (SI) defined as the ratio of the angle of deformity in the supine position to the angle of deformity in the standing position. Indications for anterior release were incomplete skeletal growth and relatively stable deformities (SI 0.75-0.85). Group 1 included 27 patients operated on in one stage without anterior release, and group 2 included 21 patients in two stages, with preliminary anterior release using video-assisted thoracoscopy. RESULTS: In group 1, the average Cobb angle of deformity was 71.8° with an average stability index of 0.8. In the second group, the average cobb angle of deformity was 69.7°, the average stability index was 0.82. In group 1 after surgery, the average Cobb angle was 27.8°, with an average correction of 63.39%. In the second group, the postoperative deformity angle was 17.4°, the average correction was 76.26%. Thus, we found a statistically significant increase in postoperative correction when using a combined anterior/posterior approach (p < 0.05). CONCLUSION: In the study, in patients with relatively stable deformities, a statistically significant increase in the degree of postoperative correction was revealed (p < 0.05) when using a combined anterior/posterior approach. Performing an anterior thoracoscopic release for thoracic deformities can improve long-term results due to the formation of 360° spinal fusion at the apex of the deformity, as well as turning off the pathogenetic links in the progression of the deformity. LEVEL OF EVIDENCE: III.

The ability of SPEEK to promote the proliferation and osteogenic differentiation of BMSCs on PEEK surfaces.

To investigate the ability of sulfonated polyetheretherketone (SPEEK) to promote the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and compare the effects of different degrees of sulfonation (DS), SPEEK was made with two different DS. The L-SPEEK group had a lower DS, while the H-SPEEK group had a higher DS. The physicochemical properties of both species were evaluated by scanning electron microscopy (SEM), capitilize Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Then, proliferation and osteogenic differentiation between the two groups and with pure polyetheretherketone (PEEK) were compared after surface inoculation of bone marrow mesenchymal stem cells (BMSCs). Scanning electron microscopy (SEM) revealed that the surface of the PEEK substrates could be smooth or coarse, and the degree of roughness increased with increasing sulfonation. FTIR spectroscopy showed that both the L-SPEEK and H-SPEEK samples contained sulfonic acid. TGA and XRD revealed that the components in the two groups were the same, but the intensities were different. After BMSC inoculation, a CCK8 assay revealed that the cells proliferated more on the H-SPEEK surface and little on the L-SPEEK surface compared with the PEEK surface. Then, osteogenic differentiation was verified by immunofluorescence staining for OCN and Runx2, which indicated that H-SPEEK had the greatest effect on improving differentiation. The results of alizarin red staining (ARS) and alkaline phosphatase staining (APS) also revealed this trend. Sulfonation can change the microsurface of PEEK, which can improve both BMSC proliferation and osteogenic differentiation.

Severe Rigid Scoliosis Deformity Correction Using Extended Posterior Release and Instrumentation: A Retrospective Study.

Introduction: Sever rigid scoliotic deformity (magnitude of the curve >80° and <25% correction on bending film) correction is a great challenge to spine surgeons. Severe scoliosis when untreated or not treated properly, may lead to severe complications due to curve progression. The aim of operative management is to achieve significant correction of sagittal, coronal, and rotational deformity to avoid neurodeficit, maintain sagittal balance, and improve cardiopulmonary function. Materials and Methods: In this retrospective study, eight patients with severe rigid scoliosis who underwent through single-staged extended posterior release and spinal fusion between March 2022 and November 2023. The surgical procedures were the excision of the posterior ligament and spinous process, laminectomy, excision of ligament flavum, facetectomy, and posterior spinal fusion utilizing pedicle screws, rods, and sub-laminar wires. Patients were evaluated radiologically using posteroanterior and lateral X-rays of the whole spine and computed tomography scans. Demographic data, pre- and post-operative cobbs angle, osteotomized segment, instrumentation segments, blood loss, operation duration, follow-up duration, and complications were recorded. Results: Pre-operative mean cobbs angle was 94.1° (range 83-110°) and post-operative mean cobbs angle was 33.3° (range 28-42°) with 64.6% scoliosis correction. The mean estimated blood loss was 517 mL (range 300-580 mL). The mean operation duration was 272.5 min (210-340 min). Mean spinal fixation fusion segments were 11.1 (range 8-14). No major complications were noted. Conclusion: Our study concluded that extended posterior-only release, facetectomy, and posterior spinal fusion by utilizing pedicle screws and pre-contoured rods significantly corrected severe and rigid scoliosis with a high correction rate and avoid complications of anterior release. Hence, we can achieve remarkable correction in rigid scoliosis using the proper choice of levels, proper implant, and extended posterior release.

The change in lumbar lordosis from the standing to the lateral position: implications for lateral interbody fusion.

PURPOSE: The purpose of this cross-sectional, observational study was to establish the relationship between standing lumbar lordosis (LL) and lateral decubitus LL. METHODS: Forty-nine subjects, 24 male and 25 female, were prospectively enrolled. Patients with pre-existing spinopelvic pathology were excluded. Standing, relaxed-seated, and lateral decubitus lateral radiographs were obtained. Radiographic variables measured included LL and lordosis change at each lumbar level (e.g. L1-L2). The change in LL when going from a standing to a lateral decubitus position (ΔLL), the correlation between standing and sitting LL compared to lateral decubitus LL, and the correlation between ΔLL and standing pelvic incidence (PI), pelvic tilt (PT), PI-LL mismatch, pelvic femoral angle (PFA), and sacral slope (SS) were calculated. RESULTS: Subjects had an average age of 25.7 ± 2.3 years and body mass index of 24.1 ± 3.0 kg/m2. On average, 11.9°±8.2° (range - 7° to 29°) of LL was lost when transitioning from a standing to the lateral decubitus position. Lateral decubitus LL had a higher correlation with standing LL (R = 0.725, p < 0.001) than with relaxed-seated LL (R = 0.434, p < 0.001). Standing PT and PI-LL mismatch had moderately negative correlations with ΔLL (R=-0.58 and R=-0.59, respectively, both p < 0.05). Standing PI and standing PFA had a low negative correlation with ΔLL (R=-0.31 and R=-0.44, respectively, both p < 0.05) Standing SS and LL had no correlation with ΔLL. CONCLUSIONS: Standing LL was strongly correlated to lateral decubitus LL, although subjects lost an average of 11.9° from the standing to the lateral decubitus position. This has important implications for fusion in the lateral position.

Rule breakers achieve successful shoulder balance: unraveling the myth of upper instrumented vertebrae selection criteria.

PURPOSE: This study compared shoulder balance outcomes in "rule breakers" (RB) vs. "rule followers" (RF) based on commonly utilized upper instrumented vertebrae (UIV) selection guidelines. METHODS: Adolescent idiopathic scoliosis (AIS) patients (Lenke 1-4) who underwent posterior spine fusion (PSF) with minimum 2-year follow-up had radiographic measurement of shoulder balance including first rib angle (FRA), T1 tilt, coracoid process height difference (CPHD), and clavicle angle (CA) at preop, postop, 6-month, 1-year, and 2-year timepoints. Postoperative outcomes were compared between RB and RF groups defined based on the UIV selection guidelines of Rose and Lenke. RESULTS: Among 88 patients (43 RF, 45 RB), age, gender, preoperative T1 tilt, FRA, CA, and CPHD were not significantly different between groups (p > 0.05). Immediately post-surgery, the RF group had more balanced shoulders (CPHD: 11.6 mm vs. 15.7 mm, p = 0.033; CA: 2.8° vs. 3.6°, p = 0.045; FRA: 3.4° vs. 5.1°, p = 0.009; T1 tilt: 4.7° vs. 6.1°, p = 0.045). At 2 years, no difference was observed between RF vs. RB in CA (2.3 vs. 2.2°, p = 0.857) and CPHD (8.5 vs. 8.1 mm, p = 0.791). FRA and T1 tilt were higher in RB vs. RF (FRA: 4.6 vs. 2.9°, p = 0.002; T1 tilt: 5.6 vs. 3.9, p = 0.008). Shoulder balance (CPHD < 1 cm) was achieved in 73.1% of RB and 69.9% of RF at 2-year follow-up (p = 0.216). CONCLUSION: Adherence to commonly accepted UIV selection guidelines did not predict better shoulder balance. The RB group had worse shoulder balance immediately post-surgery, but also improved more over time. These results suggest the need to refine current UIV selection and management. LEVEL OF EVIDENCE: III.

Risk Factors for Sacroiliac Joint Fusion after Instrumented Spinal Fusion.

STUDY DESIGN: Retrospective Cohort Study. OBJECTIVE: To identify risk factors for sacroiliac (SI) joint fusion after instrumented spinal fusion. METHODS: Patients were identified from the PearlDiver BiscayneBay database. Patients who underwent 1 level (CPT: 22840), 3-6 vertebral segment (22842), and 7+ vertebral segment spinal fusions (22843 and 22844) were identified. Patients were separated based on whether they received an SI joint fusion (27280 and 27279) after their spinal fusion. A univariate analysis and multivariate logistic regression was performed to evaluate the associations between patient factors and incidence of SI joint fusion. RESULTS: 549,625 patients who underwent posterior spinal fusions were identified, 6068 of whom underwent subsequent SI joint fusion (1.1%). Factors associated with future SI joint fusion included female gender, patients with obesity, fibromyalgia, diabetes, tobacco use, increased construct length, and prior SI joint injection. Prior SI joint injection had the highest odds ratio (OR: 8.70; 95% CI: 8.25-9.16; P < 0.001), followed by 7+ vertebral segment (OR: 2.17; 95% CI: 2.03-2.33; P < 0.001) and 3-6 vertebral segment fusion (OR: 1.49; 95% CI: 1.42-1.57; P < 0.001). CONCLUSIONS: The highest predictor of requiring subsequent SI joint fusion is a prior SI joint injection. We also found that longer fusion constructs are associated with increased risk for future SI joint fusion.

Insufficient endplate-bone graft contact is a risk factor for high-grade cage subsidence occurring after lateral lumbar interbody fusion supplemented with lateral plate: An analysis of 121 cases.

BACKGROUND: Lateral lumbar interbody fusion (LLIF) is a minimally invasive fusion technique that can be performed with lateral plate. Insufficient contact between the endplate and bone graft may result in cage subsidence. This study aimed to investigate the potential risk factor for high-grade cage subsidence (HCS) occurring after LLIF supplemented with lateral plate. METHODS: Between June 2017 and February 2023, 121 patients (48 males, 73 females; mean age 63.0 years; minimum follow-up period 12 months) undergoing LLIF supplemented with lateral plate were retrospectively reviewed. The incidence of HCS was assessed, and patients were categorized into HCS group or non-HCS group based on the occurrence of HCS. A revision surgery of posterior pedicle screw fixation was performed in patients with cage subsidence and complained with intolerable back pain or radicular symptoms. Comparative analyses were performed on demographic characteristics, surgical variables, and parameters related to endplate-bone graft contact between the two groups. Multivariable logistic regression analysis was employed to identify the potential risk factors associated with HCS. The receiver operating characteristic (ROC) analysis was used to calculate the cutoff values for the risk factors. Clinical outcomes were evaluated using Oswestry Disability Index (ODI), and radiographic fusion at the final follow-up was assessed based on the Bridwell grading system. RESULTS: The HCS group comprised 12 patients, while the non-HCS group included 109 patients. The incidence of HCS occurring after LLIF supplemented with lateral plate was 9.9 %. Compared to non-HCS group, patients in HCS group had lower sagittal and coronal endplate-bone graft contact rates and larger cage-endplate angles. Low sagittal (OR, 1.099; 95 % CI, 1.033-1.169; P=0.003) and low coronal (OR, 1.149, 95 % CI, 1.061-1.243, P=0.001) endplate-bone graft contact rates were determined to be correlated with HCS. The cutoff value of the sagittal and coronal endplate-bone graft contact rate was 63.5 % and 60.9 %. Eleven (91.7 %) patients in HCS group underwent revision posterior pedicle screw fixation. Both HCS and non-HCS groups experienced significant improvements in ODI at the final follow-up, while there were no differences between groups. Ninety-five (87.2 %) patients in non-HCS group, and nine (81.8 %) of the 11 patients who underwent revision surgery in HCS group achieved radiographic fusion at the final follow-up. CONCLUSIONS: The incidence of HCS occurring after LLIF supplemented with lateral plate was 9.9%. Insufficient endplate-bone graft contact is an important risk factor of HCS, and sagittal and coronal endplate-bone graft contact rates can be used as effective predictors for HCS.

Clinical Utility and Patient Compliance With Mobile Applications for Home-Based Rehabilitation Following Transforaminal Lumbar Interbody Fusion.

STUDY DESIGN: Retrospective chart review. OBJECTIVES: Transforaminal lumbar interbody fusion (TLIF) via open or minimally invasive (MI) techniques is commonly performed. Mobile applications for home-based therapy programs have grown in popularity. The purpose of this study was to (1) compare patient-reported outcome measures (PROMs) between postoperative patients who were the most and least compliant in using the mobile-based rehabilitation programs, (2) compare PROMs between open vs MI-TLIF cohorts, and (3) quantify overall compliance rates of home-based rehabilitation programs. METHODS: A retrospective chart review was performed. Patients were automatically enrolled in the rehabilitation program. Patient-Reported Outcomes Measurement Information System (PROMIS) and Oswestry Disability Index (ODI) scores were collected. Patients were separated into two study groups. Compliance rate was calculated as the difference between the number of active participants at the preoperative phase and final follow-up. RESULTS: 220 patients were included. Average follow-up time was 23.2 months. No difference was found in the change in (∆) PROMIS scores (P = 0.261) or ∆ODI scores (P = 0.690) regardless of patient compliance. No difference was found in outcome scores between open vs MI-TLIF techniques stratified by download compliance (downloaded, DL+; did not download, DL-) and phone reminder compliance (set reminder, R+; did not set reminder, R-) postoperatively. Both cohorts demonstrated clinical improvement exceeding minimal clinically important difference at final follow-up. Overall patient compliance was 71% at final postoperative follow up. CONCLUSION: Despite high long-term compliance and rising popularity, mobile applications for home-based postoperative rehabilitation programs have low clinical utility in patients undergoing TLIF.

The Decline of Lumbar Artificial Disc Replacement.

Lower back pain associated with degenerative disc disease is a common occurrence, with many surgical treatments targeting the degenerated disc to relieve symptoms. Current surgical options for degenerative disc disease primarily consist of a discectomy followed by either spinal fusion or artificial disc replacement, with the former being increasingly more common in the lumbar region despite the risk of adjacent segment disease. Though artificial disc replacement aims to provide an increase in range of motion and decreases risk of adjacent segment disease, surgeons are increasingly opting for spinal fusion in the lumbar region. This review investigates underlying factors that may be contributing to this trend by assessing lumbar artificial disc replacement selection criteria, clinical outcomes, surgical technique, complications, revision burden, and overall cost. While these factors had some role in the physician's decision, ultimately the narrow selection criteria and lack of cost reimbursement by insurance has primarily led to the decline in lumbar artificial disc replacement.

Letter to the editor: "Effect of electrical stimulation on the fusion rate after spinal surgery: a systematic review and meta-analysis".

This letter provides feedback on the article Effect of electrical stimulation on the fusion rate after spinal surgery: a systematic review and meta-analysis. The study highlights the clinical efficacy of electrical stimulation (ES) in enhancing fusion rates post-surgery. Future research should focus on identifying optimal ES parameters, long-term safety profiles, and its personalized application based on genetic and metabolic factors. Additionally, exploring the combination of ES with other regenerative therapies and evaluating its cost-effectiveness could further improve clinical outcomes.

Racial and ethnic differences in transfusion rates in adolescent scoliosis surgery: Preoperative anemia as a mediator of disparity.

BACKGROUND: Pediatric patients from minoritized racial and ethnic groups receive red blood cell (RBC) transfusions more frequently while undergoing major surgical procedures. Our objective was to identify the contribution of preoperative anemia to racial and ethnic differences in RBC transfusion rates in adolescent spine surgery. STUDY DESIGN AND METHODS: This is a multicenter, retrospective cohort study of the National Surgical Quality Improvement Program Pediatric database, 2016 to 2021 for patients in the United States and Canada. RESULTS: Adolescents identifying as non-Hispanic Black, Hispanic, and other race/ethnicity presented with higher rates of preoperative anemia than non-Hispanic White adolescents (16.3%, 10.6%, and 9.9%, vs. 7.8%, respectively; p < .0001) and were transfused at higher rates (14.4%, 11.9%, 16.5%, vs. 10.0%, respectively; p < .0001). Minoritized groups demonstrated higher adjusted odds of RBC transfusion compared with non-Hispanic Whites (non-Hispanic Black: aOR 1.45 95% CI 1.26-1.65, Hispanic: aOR 1.17 95% CI 0.96-1.41, other race/ethnicity: aOR 1.63 95% CI 1.26-2.09). Of the total effect of minoritized race and/or ethnicity on RBC transfusion, 13.9% was attributed to the indirect effect through preoperative anemia. DISCUSSION: In this cohort study, patients from minoritized racial and ethnic groups received RBC transfusions at a higher rate than non-Hispanic White patients, and the difference was partially mediated by preoperative anemia. Future efforts to minimize transfusions and improve health equity should target this modifiable risk factor alongside other sources of disparity and discrimination.