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RNA interference (RNAi) is mediated by an ∼21-nt double-stranded small interfering RNA (siRNA) and shows great promise in delineating gene functions and in developing therapeutics for human diseases. However, effective gene silencing usually requires the delivery of multiple siRNAs for a given gene, which is often technically challenging and time-consuming. In this study, by exploiting the type IIS restriction endonuclease-based synthetic biology methodology, we developed the fast assembly of multiplex siRNAs (FAMSi) system. In our proof-of-concept experiments, we demonstrated that multiple fragments containing three, four, or five siRNA sites targeting common Smad4 and/or BMPR-specific Smad1, Smad5, and Smad8 required for BMP9 signaling could be assembled efficiently. The constructed multiplex siRNAs effectively knocked down the expression of Smad4 and/or Smad1, Smad5, and Smad8 in mesenchymal stem cells (MSCs), and they inhibited all aspects of BMP9-induced osteogenic differentiation in bone marrow MSCs (BMSCs), including decreased expression of osteogenic regulators/markers, reduced osteogenic marker alkaline phosphatase (ALP) activity, and diminished in vitro matrix mineralization and in vivo ectopic bone formation. Collectively, we demonstrate that the engineered FAMSi system provides a fast-track platform for assembling multiplexed siRNAs in a single vector, and thus it may be a valuable tool to study gene functions or to develop novel siRNA-based therapeutics., Graphical Abstract, RNA interference shows great promise in delineating gene functions and in developing therapeutics for human diseases. He et al. exploited the type IIS restriction endonuclease-based synthetic biology and developed the fast assembly of multiplex siRNAs (FAMSi) system, which streamlines RNAi-based gene function studies and the development of siRNA-based therapeutics.

STUDY DESIGN Retrospective analysis using the PearlDiver national insurance claims database. OBJECTIVE To investigate the relationship between chronic preoperative selective serotonin reuptake inhibitor (SSRI) prescriptions and nonunion following spine fusion surgery. SUMMARY OF BACKGROUND DATA Contemporary literature has linked SSRIs to decreased bone mineral density and increased rates of future bone fracture. Furthermore, a recent murine model has suggested a potential role in the quality of fracture healing itself. METHODS All single-level lumbar fusion patients were identified. The rate of nonunion diagnosis between 6 and 24 months following surgery was assessed. A stratified analysis of chronic SSRI use and a number of comorbidities was conducted, followed by a multiple logistic regression analysis of nonunion accounting for qualifying risk factors. Finally, subanalyses of individual procedure codes were carried out. RESULTS In total, 7905 single-level lumbar fusion patients were included. In the multivariate analysis, chronic SSRI [odds ratio (OR): 1.558, P=0.004] and tobacco use (OR: 1.500, P=0.011) were identified as independent risk factors for nonunion, whereas patient age over 60 years (OR: 0.468, P

Retrospective cohort study. To investigate the prevalence and incidence rate of rod fractures (RF) in patients undergoing surgery for correction of adult spinal deformity (ASD) with or without the use of interbody fusions in the caudal levels of the fusion construct. Data: Pseudarthrosis and rod fracture after long spinal fusion to the sacrum for correction of ASD remain a concern. We reviewed clinical records of patients who underwent surgery for correction of ASD between 2004 and 2014. All cases were primary (no prior spine fusion) surgeries with long fusion to the sacrum and bilateral spinopelvic fixation. Patients were dichotomized into one of two groups based on whether an interbody fusion was performed at the caudal levels of the fusion construct. The primary outcome of interest was the prevalence and incidence rate of RFs. A total of 230 patients underwent a long segment fusion for correction of ASD with mean follow-up of 55 months. 117 patients had an interbody fusion (IF) while 113 patients did not (NIF). At last follow-up, there was no significant difference in the prevalence of RFs between the cohort of patients IF vs NIF (IF cohort: n = 20, 17.9% vs NIF cohort: n = 15, 14.2%, p = 0.49). However, the incidence rate for bilateral rod fractures was 1.6%/year for IF group vs 1.0%/year for NIF group (p = 0.02). Location of RF was different between the two groups; RF (unilateral and bilateral) above L4 was the most common location in the IF group (n = 17/20; 85%) compared to L4–S1 in the NIF group (n = 11/15; 73%) (p = 0.02). Interbody fusion does not fully protect against rod failure in the lumbar spine in ASD patients with long posterior spinal fusion and may encourage failure at L2–L4, the levels above the interbody fusion. III.

Pediatrics and hand surgery have historically been the orthopaedic subspecialties with the highest female representations. We sought to identify the gender distribution of orthopedic surgical faculty by subspecialty, geography, and educational background. We hypothesized that the proportion of women entering pediatric orthopaedics has decreased since 1980.The Accreditation Council for Graduate Medical Education was used to generate a list of U.S. orthopedic residencies. Program websites were used to collect data regarding each faculty member's gender, residencies, fellowships, and graduation year. t tests were used to compare quantitative data and Fisher's exact tests to compare categorical data. Significance was defined as p0.05.Publicly available data from official websites of U.S. orthopedic residencies.Of 153 residencies, 142 (93%) had accessible faculty lists.Of 3596 orthopedic surgeons, 7.9% were women. Among fellowship-trained faculty, 22% of pediatric orthopedists were women compared with 7.6% of faculty in other orthopedic subspecialties (p0.00001). There was a significantly higher percentage of female faculty in the West (13%) than in any other U.S. census region (p0.001 vs. Midwest, vs. South, and vs. Northeast). A strong correlation with time was found in number of women completing fellowships other than hand or pediatrics from 1980 to 2014 (RAlthough pediatrics remains the most popular fellowship for female orthopedists, women who enter academic orthopedics are increasingly choosing nonpediatric subspecialties.

Mesenchymal stem cells (MSCs) are multipotent progenitors that have the ability to differentiate into multiple lineages, including bone, cartilage, and fat. We previously demonstrated that the least known bone morphogenetic protein (BMP)9 (also known as growth differentiation factor 2) is one of the potent osteogenic factors that can induce both osteogenic and adipogenic differentiation of MSCs. Nonetheless, the molecular mechanism underlying BMP9 action remains to be fully understood. Leptin is an adipocyte-derived hormone in direct proportion to the amount of body fat, and exerts pleiotropic functions, such as regulating energy metabolism, bone mass, and mineral density. In this study, we investigate the potential effect of leptin signaling on BMP9-induced osteogenic differentiation of MSCs. We found that exogenous leptin potentiated BMP9-induced osteogenic differentiation of MSCs both in vitro and in vivo, while inhibiting BMP9-induced adipogenic differentiation. BMP9 was shown to induce the expression of leptin and leptin receptor in MSCs, while exogenous leptin upregulated BMP9 expression in less differentiated MSCs. Mechanistically, we demonstrated that a blockade of JAK signaling effectively blunted leptin-potentiated osteogenic differentiation induced by BMP9. Taken together, our results strongly suggest that leptin may potentiate BMP9-induced osteogenesis by cross-regulating BMP9 signaling through the JAK/STAT signaling pathway in MSCs. Thus, it is conceivable that a combined use of BMP9 and leptin may be explored as a novel approach to enhancing efficacious bone regeneration and fracture healing.

The long-term risk of conversion to lumbar fusion is ill-defined for patients with cauda equina syndrome (CES) treated with decompression. This study aimed to identify the rates of fusion in patients with CES and compare those rates with a matched lumbar spinal stenosis (LSS) group.Patients with CES who underwent decompression were identified in a national database and matched to control patients with LSS. The rates of conversion to fusion were identified and compared. Multivariate logistic regression analysis identified independently associated risk factors. A subanalysis was conducted after stratifying by timing between CES diagnosis and decompression.The rate of lumbar fusion in the CES cohort was 3.6% after 1 year, 6.7% after 3 years, and 7.8% after 5 years, significantly higher than the LSS control group at all time points (1 year: 1.6%, P = 0.001; 3 years: 3.0%, Plt; 0.001; 5 years: 3.8%, Plt; 0.001). CES was independently associated with increased risk of conversion to fusion (odds ratio: 2.13; 95% confidence interval: 1.56 to 2.97; Plt; 0.001). Surgical timing was not associated with risk of conversion to fusion.After 5 years, 7.8% of patients with CES underwent fusion, a markedly higher rate compared with patients with LSS. Counseling patients with CES on this increased risk of future surgery is important for patient education and satisfaction.

Tranexamic acid (TXA) is an anti-fibrinolytic effective in reducing blood loss in orthopedic surgery. The appropriate dosing protocol for adult spinal deformity (ASD) surgery is not known. The purpose of this study was to evaluate two TXA protocols [low dose (L): 10 mg/kg bolus, 1 mg/kg/hr infusion; high dose (H): 50 mg/kg, 5 mg/kg/hr] in complex ASD surgery.Inclusion criteria were ASD reconstructions with minimum 10 fusion levels or planned 3-column osteotomy (3CO). Standard demographic and surgical data were collected. Intraoperative estimated blood loss (EBL) was calculated by suction canisters minus irrigation plus estimated blood lost in sponges, estimated to the nearest 50 mL. Serious adverse events (SAE) were defined a priori as: venothromboembolic event (VTE), cardiac arrhythmia, myocardial infarction, renal dysfunction, and seizure. All SAE were recorded. Simple t tests compared EBL between groups. Mean EBL by total blood volume (TBV), transfusion volume, complications related to TXA were secondary outcomes.Sixty-two patients were enrolled and 52 patients completed the study; 25 were randomized to H and 27 to L. Demographic and surgical variables were not different between the two groups. EBL was not different between groups (H: 1596 ± 933 cc, L: 2046 ± 1105 cc, p = 0.12, 95% CI: - 1022 to 122 cc). EBL as a percentage of TBV was lower for the high-dose group (H: 29.5 ± 14.8%, L: 42.5 ± 26.2%, p = 0.03). Intraoperative transfusion volume (H: 961 ± 505 cc, L: 1105 ± 808 cc, p = 0.5) and post-operative transfusion volume (H: 513 ± 305 cc, L: 524 ± 245 cc, p = 0.9) were not different. SAE related to TXA were not different (p = 0.7) and occurred in 2 (8%) H and 3 (11%) L. There was one seizure (H), 2 VTE, and 2 arrhythmias.No differences in EBL, transfusion volume, nor SAE were observed between H and L dose TXA protocols. High dose was associated with decreased TBV loss (13%). Further prospective study, with pharmacologic analysis, is required to determine appropriate TXA dosage in ASD surgeries.Therapeutic Level II.The study was registered at Clinicaltrials.gov (NCT02053363) February 3, 2014.

OBJECTIVEPseudarthrosis is a common complication of long-segment fusions after surgery for correction of adult spinal deformity (ASD). Interbody fusions are frequently used at the caudal levels of long-segment spinal deformity constructs as adjuncts for anterior column support. There is a paucity of literature comparing rod fracture rates (proxy for pseudarthrosis) in patients undergoing transforaminal lumbar interbody fusion (TLIF) versus anterior lumbar interbody fusion (ALIF) at the caudal levels of the long spinal deformity construct. In this study the authors sought to compare rod fracture rates in patients undergoing surgery for correction of ASD with TLIF versus ALIF at the caudal levels of long spinal deformity constructs.METHODSWe reviewed clinical records of patients who underwent surgery for correction of ASD between 2008 and 2014 at a single institution. Data including demographics, comorbidities, and indications for surgery, as well as postoperative variables, were collected for each patient. All patients had a minimum 2-year follow-up. Patients were dichotomized into two groups for comparison on the basis of undergoing a TLIF versus an ALIF procedure at the caudal levels of long spinal deformity constructs. The primary outcome of interest was the rate of rod fractures.RESULTSA total of 198 patients (TLIF 133 patients; ALIF 65 patients) underwent a long-segment fusion to the sacrum with iliac fixation. The mean ± standard deviation follow-up period was 62.23 ± 29.26 months. Baseline demographic variables were similar in both patient groups. There were no significant differences between groups in the severity of the baseline sagittal plane deformity (i.e., baseline lumbar-pelvic parameters) or the final deformity correction achieved. Mean total recombinant human bone morphogenetic protein 2 (rhBMP-2) dose for L1–sacrum fusion was significantly higher in the ALIF (100 mg) than in the TLIF (62 mg) group. The overall rod failure rate (cases with rod fracture/total cases) within this case series was 19.19% (38/198); 10.60% (21/198) were unilateral rod fractures and 8.58% (17/198) were bilateral rod fractures. At last clinical follow-up, there were no statistically significant differences in bilateral rod fracture rates between the group of patients who had a TLIF procedure and the group who had an ALIF procedure at the caudal levels of the long spinal deformity constructs (TLIF 10.52% vs ALIF 4.61%, p = 0.11). However, the incidence rate (cases per patient follow-up years) for bilateral rod fractures was significantly higher in the TLIF than in the ALIF cohort (TLIF 2.20% vs ALIF 0.70%, p < 0.0001). The reoperation rate for rod fractures was similar between the patient groups (p = 0.40).CONCLUSIONSAlthough both ALIF and TLIF procedures at the caudal levels of long spinal deformity constructs achieved similar and satisfactory deformity correction, ALIFs were associated with a lower rod fracture incidence rate. There were no differences between groups in the prevalence of rod fracture or revision surgery, however, and both groups had low bilateral rod fracture prevalence and incidence rates. One technique is not clearly superior to the other.

Background Context Three-column osteotomy (3CO) is used to correct rigid adult spinal deformity. It presents risk of complications because it involves extensive osseous resection and spinal destabilization. Purpose Our purpose was to characterize the learning curve for performing 3CO in adult spinal deformity patients. Design Retrospective review. Patient Sample A surgical registry at a tertiary care center was used to identify 238 cases of 3CO for correction of adult spinal deformity by 1 surgeon between 2005 and 2014. Patients with at least 1 year of clinical and radiographic follow-up were included (n = 197) (mean duration of follow-up, 43 months; range, 12–121). Outcome Measures We quantified associations between surgeon experience and 1) estimated blood loss per vertebral level fused (EBL/VLF), 2) incidence of new neurologic deficits, 3) incidence of reoperation for instrumentation failure, 4) operative time in minutes, and 5) magnitude of correction at the level of the osteotomy. Methods The learning curve for binary outcomes was demonstrated using a LOWESS smoother plot of the probability of occurrence. Change in risk was calculated using a generalized linear model with link identity and binomial family. The learning curve for continuous variables was demonstrated using a scatter plot and a line of best fit based on linear regression analysis. Alpha = 0.05. Results EBL/VLF decreased by a mean of 19.7 mL (95% confidence interval [CI], 11.3–28.1) with each 10 cases (decrease of 388 mL/level fused by the end of the study period). The risk of a neurologic deficit declined by 7.98% (95% CI: 7.98%, 7.99%) with every 100 cases. The risk of reoperation declined by 1.99% (95% CI: 0.83%, 3.17%) with every 10 cases until the 100th case. After that point, there was no significant change in the probability of reoperation (p > 0.05). The magnitude of correction and operative time did not change with increasing surgeon experience (p > 0.05). Conclusion Incidence of reoperation for instrumentation failure, incidence of new neurological deficits, and estimated blood loss improved with increasing surgeon experience at performing 3CO. Most outcomes, except the risk of reoperation, improved through the last case.

Study Design Clinical case series. Objective To assess objective outcomes of surgical correction of post–external beam radiation therapy (ERBT) kyphosis in a series of five adults. Summary of Background Data EBRT is a well-established treatment for many cancers in children and adults. One complication associated with EBRT is postirradiation spine deformity. Scoliosis is the most common deformity, but kyphosis also occurs frequently. Differences in deformity patterns are likely related to the location and intensity of radiation. To our knowledge, no studies have addressed treatment of these deformities in adults, and the most recent case series (of children) was published in 2005. Methods We present a series of five adults who underwent surgery for postirradiation kyphosis, with a mean follow-up of 3.8 years (range, 2.5–6.2 years). Results Surgery improved the kyphotic deformity in all patients. Overall mean kyphotic deformity correction was 56° and was larger for cervical/cervicothoracic deformities (mean, 76°) than for lumbar deformities (mean, 42°) at midterm follow-up. Patients reported significant improvements in pain and self-image. Consistent with prior case series of children, we observed a high rate of complications (mean, 1.4 complications per patient) in adults. Three patients each underwent an unplanned surgical procedure because of a complication. Conclusion The surgical treatment of postirradiation kyphotic spinal deformity is challenging, with common postoperative complications such as infection, instrumentation failure, and pseudarthrosis. However, with modern surgical techniques and spinal instrumentation, excellent deformity correction can be achieved and maintained. We recommend performing a two-stage procedure for cervicothoracic deformity, with anterior release followed by posterior fusion and instrumentation. In thoracolumbar deformities, correction can be achieved through single-stage posterior fusion. Rigid spinopelvic fixation with sacral-alar-iliac screws and second-stage anterior lumbar interbody fusion at L5–S1 is recommended to reduce nonunion risk. Cement augmentation of proximal and distal anchors can help prevent junctional failure. Level of Evidence Level IV.

Sacropelvic fixation is indicated in various clinical settings, most notably long spinal arthrodesis, reduction of high-grade spondylolisthesis, and complex sacral fractures. The sacropelvis is characterized by complex regional anatomy and poor bone quality. These factors make achieving solid fusion across the lumbosacral junction challenging. However, a better understanding of spinal biomechanics at that level has led to much higher fusion rates than those of the past. The newer fixation techniques are biomechanically superior to previous methods mainly because they achieve bony purchase anterior to the pivot point—first described by McCord et al. in 1994. Today, the two most widely used fixation techniques are iliac screws and S2-alar-iliac screws. Although these techniques are associated with very high rates of fusion, instrumentation-related pain and reoperation remain problematic. This review provides an overview of the regional anatomy and biomechanics at the lumbosacral junction, as well as a summary of fixation techniques with an emphasis on the most widely used techniques today. Level of Evidence IV.

Study Design: Systematic review and meta-analysis. Objectives: Indications for surgical decompression of gunshot wounds to the lumbosacral spine are controversial and based on limited data. Methods: A systematic review of literature was conducted to identify studies that directly compare neurologic outcomes following operative and non-operative management of gunshot wounds to the lumbosacral spine. Studies were evaluated for degree of neurologic improvement, complications, and antibiotic usage. An odds ratio and 95% confidence interval were calculated for dichotomous outcomes which were then pooled by random-effects model meta-analysis. Results: Five studies were included that met inclusion criteria. The total rate of neurologic improvement was 72.3% following surgical intervention and 61.7% following non-operative intervention. A random-effects model meta-analysis was carried out which failed to show a statistically significant difference in the rate of neurologic improvement between surgical and non-operative intervention (OR 1.07; 95% CI 0.45, 2.53; P = 0.88). In civilian only studies, a random-effects model meta-analysis failed to show a statistically significant difference in the rate of neurologic improvement between surgical and non-operative intervention (OR 0.75; 95% CI 0.21, 2.72; P = 0.66). Meta-analysis further failed to show a statistically significant difference in the rate of neurologic improvement between patients with either complete (OR 4.13; 95% CI 0.55, 30.80; P = 0.17) or incomplete (OR 0.38; 95% CI 0.10, 1.52; P = 0.17) neurologic injuries who underwent surgical and non-operative intervention. There were no significant differences in the number of infections and other complications between patients who underwent surgical and non-operative intervention. Conclusions: There were no statistically significant differences in the rate of neurologic improvement between those who underwent surgical or non-operative intervention. Further research is necessary to determine if surgical intervention for gunshot wounds to the lumbosacral spine, including in the case of retained bullet within the spinal canal, is efficacious.

Case A 53-year-old man developed dysphagia 4 years after anterior cervical discectomy and fusion (ACDF), and radiographs revealed a dislodged screw anterior to the ACDF plate. Intraoperatively, the screw was found to be completely embedded within the pharyngeal constrictor muscle fibers and was removed with assistance from otolaryngology without injury to the pharyngeal mucosa. Conclusion Implant migration after ACDF can variably damage tracheoesophageal and retropharyngeal structures, and a multidisciplinary approach involving otolaryngology or thoracic surgery may be required to diagnose and treat these complications.

BACKGROUND CONTEXT Cauda equina syndrome (CES) occurs due to compression of the lumbar and sacral nerve roots and is considered a surgical emergency. Although the condition is relatively rare, the associated morbidity can be devastating to patients. While substantial research has been conducted on the timing of treatment, the literature regarding long-term rates of bladder dysfunction in CES patients is scarce. PURPOSE The aim of this study was to identify long-term rates of bladder dysfunction in CES patients and to compare those rates to non-CES patients who underwent similar spinal decompression. STUDY DESIGN/SETTING Retrospective database study. PATIENT SAMPLE The CES cohort was comprised of 2,362 patients who underwent decompression surgery following CES diagnosis with a 5-year follow-up. These patients were matched to 9,448 non-CES control patients who underwent spinal decompression without a diagnosis of CES. OUTCOME MEASURES Diagnosis of bladder dysfunction, surgical procedure to address bladder dysfunction METHODS Using the national insurance claims database, PearlDiver, CES patients who underwent decompression surgery were identified and 1:4 matched to non-CES patients who underwent similar spinal decompression surgery. The 1-year, 3-year, and 5-year rates of progression to a bladder dysfunction diagnosis and surgical intervention to manage bladder dysfunction were recorded. The CES and non-CES groups were compared with univariate testing, and an analysis of risk factors for bladder dysfunction was performed with multivariate logistic regression analysis. RESULTS A total of 2,362 CES patients who underwent decompression surgery were identified and matched to 9,448 non-CES control patients. After 5 years, CES patients had a 10%–12% increased absolute risk of continued bladder dysfunction and a 0.7%–0.9% increased absolute risk of undergoing a surgical procedure for bladder dysfunction, as compared to matched non-CES patients. Multivariate analysis controlling for age, sex, obesity, tobacco use, and diabetes, identified CES as independently associated with increased 5-year risk for bladder dysfunction diagnosis (odds ratio [OR]: 1.72; 95% confidence interaval [CI] 1.56–1.89; p CONCLUSIONS Understanding the long-term risk for bladder dysfunction in CES patients is important for the future care and counseling of patients. Compared to non-CES patients who underwent similar spinal decompression, CES patients were observed to have a significantly higher long-term likelihood for both bladder dysfunction diagnosis and urologic surgical procedure.

OBJECTIVE Hip-spine syndrome has been well studied since it was first described by Offierski and MacNab in 1983. Today, strong evidence links symptoms of hip and spine pathology to postsurgical outcomes. Recent studies have reported increased rates of hip dislocation in patients previously treated with total hip arthroplasty (THA) who had undergone lumbar fusion procedures. However, the effect of this link on native hip-joint degeneration remains an area of ongoing research. The purpose of this study was to characterize the relationship between use of lumbar fusion procedures and acceleration of hip pathology by analyzing the rate of future THA in patients with preexisting hip osteoarthritis. METHODS This population-level, retrospective cohort study was conducted by using the PearlDiver research program. The initial patient cohort was defined by the presence of diagnosis codes for hip osteoarthritis. Patients were categorized according to use of lumbar fusion after diagnosis of hip pathology. Survival curves with respect to THA were generated by comparison of the no lumbar fusion cohort with the lumbar fusion cohort. To assess the impact of fusion construct length, the lumbar fusion cohort was then stratified according to the number of levels treated (1–2, 3–7, or ≥ 8 levels). Hazard ratios (HRs) were then calculated for the risk factors of number of levels treated, patient age, and sex. RESULTS A total of 2,275,683 patients matched the authors’ inclusion criteria. Log-rank analysis showed no significant difference in the rates of THA over time between the no lumbar fusion cohort (2,239,946 patients) and lumbar fusion cohort (35,737 patients; p = 0.40). When patients were stratified according to number of levels treated, again no differences in the incidence rates of THA over the study period were determined (p = 0.30). Patients aged 70–74 years (HR 0.871, p < 0.001), 75–79 years (HR 0.733, p < 0.001), 80–84 years (HR 0.557, p < 0.001), and ≥ 85 years (HR = 0.275, p < 0.001) were less likely to undergo THA relative to the reference group (patients aged 65–69 years). CONCLUSIONS Although lumbar fusion was initially hypothesized to have a significant effect on rate of THA, lumbar fusion was not associated with increased need for future THA in patients with preexisting hip osteoarthritis. Additionally, there was no relationship between fusion construct length and rate of THA. Although lumbar fusion reportedly increases the risk of hip dislocation in patients with prior THA, these data suggest that lumbar fusion may not clinically accelerate native hip degeneration.

Teeth arise from the tooth germ through sequential and reciprocal interactions between immature epithelium and mesenchyme during development. However, the detailed mechanism underlying tooth development from tooth germ mesenchymal cells (TGMCs) remains to be fully understood. Here, we investigate the role of Wnt/β‐catenin signalling in BMP9‐induced osteogenic/odontogenic differentiation of TGMCs. We first established the reversibly immortalized TGMCs (iTGMCs) derived from young mouse mandibular molar tooth germs using a retroviral vector expressing SV40 T antigen flanked with the FRT sites. We demonstrated that BMP9 effectively induced expression of osteogenic markers alkaline phosphatase, collagen A1 and osteocalcin in iTGMCs, as well as in vitro matrix mineralization, which could be remarkably blunted by knocking down β‐catenin expression. In vivo implantation assay revealed that while BMP9‐stimulated iTGMCs induced robust formation of ectopic bone, knocking down β‐catenin expression in iTGMCs remarkably diminished BMP9‐initiated osteogenic/odontogenic differentiation potential of these cells. Taken together, these discoveries strongly demonstrate that reversibly immortalized iTGMCs retained osteogenic/odontogenic ability upon BMP9 stimulation, but this process required the participation of canonical Wnt signalling both in vitro and in vivo. Therefore, BMP9 has a potential to be applied as an efficacious bio‐factor in osteo/odontogenic regeneration and tooth engineering. Furthermore, the iTGMCs may serve as an important resource for translational studies in tooth tissue engineering.

OBJECTIVEIn this study, the authors’ goal was to determine the intra- and interobserver reliability of a new classification system that allows the description of all possible constructs used across three-column osteotomies (3COs) in terms of rod configuration and density.METHODSThirty-five patients with multirod constructs (MRCs) across a 3CO were classified by two spinal surgery fellows according to the new system, and then were reclassified 2 weeks later. Constructs were classified as follows: the number of rods across the osteotomy site followed by a letter corresponding to the type of rod configuration: “M” is for a main rod configuration, defined as a single rod spanning the osteotomy. “L” is for linked rod configurations, defined as 2 rods directly connected to each other at the osteotomy site. “S” is for satellite rod configurations, which were defined as a short rod independent of the main rod with anchors above and below the 3CO. “A” is for accessory rods, defined as an additional rod across the 3CO attached to main rods but not attached to any anchors across the osteotomy site. “I” is for intercalary rod configurations, defined as a rod connecting 2 separate constructs across the 3CO, without the intercalary rod itself attached to any anchors across the osteotomy site. The intra- and interobserver reliability of this classification system was determined.RESULTSA sample estimation for validation assuming two readers and 35 subjects results in a two-sided 95% confidence interval with a width of 0.19 and a kappa value of 0.8 (SD 0.3). The Fleiss kappa coefficient (κ) was used to calculate the degree of agreement between interrater and intraobserver reliability. The interrater kappa coefficient was 0.3, and the intrarater kappa coefficient was 0.63 (good reliability). This scenario represents a high degree of agreement despite a low kappa coefficient. Correct observations by both observers were 34 of 35 and 33 of 35 at both time points. Misclassification was related to difficulty in determining connectors versus anchors.CONCLUSIONSMRCs across 3COs have variable rod configurations. Currently, no classification system or agreement on nomenclature exists to define the configuration of rods across 3COs. The authors present a new, comprehensive MRC classification system with good inter- and intraobserver reliability and a high degree of agreement that allows for a standardized description of MRCs across 3COs.

Notch is a cell–cell signaling pathway that is involved in a host of activities including development, oncogenesis, skeletal homeostasis, and much more. More specifically, recent research has demonstrated the importance of Notch signaling in osteogenic differentiation, bone healing, and in the development of the skeleton. The craniofacial skeleton is complex and understanding its development has remained an important focus in biology. In this review we briefly summarize what recent research has revealed about Notch signaling and the current understanding of how the skeleton, skull, and face develop. We then discuss the crucial role that Notch plays in both craniofacial development and the skeletal system, and what importance it may play in the future.

Case Traumatic U- and H-type sacral fractures are often unstable, causing spinopelvic dissociation. We describe a minimally invasive approach that allows percutaneous spinopelvic fixation of unstable H-type sacral fractures using a triangular osteosynthesis construct with S2 alar-iliac screws. We present the case of a patient with traumatic lumbopelvic dissociation who underwent percutaneous S2 alar-iliac and iliosacral screw fixation. Conclusions Combined percutaneous S2 alar-iliac and iliosacral screw fixation is a safe option for spinopelvic fixation and avoids the soft-tissue compromise of open approaches. The triangular osteosynthesis construct provides adequate pelvic anchor points to allow immediate weight-bearing.

OBJECTIVEPatients’ expectations for pain relief are associated with patient-reported outcomes after treatment, although this has not been examined in patients with adult spinal deformity (ASD). The aim of this study was to identify associations between patients’ preoperative expectations for pain relief after ASD surgery and patient-reported pain at the 2-year follow-up.METHODSThe authors analyzed surgically treated ASD patients at a single institution who completed a survey question about expectations for back pain relief. Five ordinal answer choices to “I expect my back pain to improve” were used to categorize patients as having low or high expectations. Back pain was measured using the 10-point numeric rating scale (NRS) and Scoliosis Research Society–22r (SRS-22r) patient survey. Preoperative and postoperative pain were compared using analysis of covariance.RESULTSOf 140 ASD patients eligible for 2-year follow-up, 105 patients (77 women) had pre- and postoperative data on patient expectations, 85 of whom had high expectations. The mean patient age was 59 ± 12 years, and 46 patients (44%) had undergone previous spine surgery. The high-expectations and low-expectations groups had similar baseline demographic and clinical characteristics (p > 0.05), except for lower SRS-22r mental health scores in those with low expectations. After controlling for baseline characteristics and mental health, the mean postoperative NRS score was significantly better (lower) in the high-expectations group (3.5 ± 3.5) than in the low-expectations group (5.4 ± 3.7) (p = 0.049). The mean postoperative SRS-22r pain score was significantly better (higher) in the high-expectations group (3.3 ± 1.1) than in the low-expectations group (2.6 ± 0.94) (p = 0.019).CONCLUSIONSDespite similar baseline characteristics, patients with high preoperative expectations for back pain relief reported less pain 2 years after ASD surgery than patients with low preoperative expectations.

OBJECTIVEThe authors evaluated the neurological outcomes of adult spinal deformity patients after 3-column osteotomy (3CO), including severity and long-term improvement of neurological complications, as well as risk factors for neurological deficit at 1 year postoperatively. Although 3CO is effective for correcting rigid spinal deformity, it is associated with a high complication rate. Neurological deficits, in particular, cause disability and dissatisfaction.METHODSThe authors retrospectively queried a prospective database of adult spinal deformity patients who underwent vertebral column resection or pedicle subtraction osteotomy between 2004 and 2014 by one surgeon at a tertiary care center. The authors included 199 adults with at least 1-year follow-up. The primary outcome measure was change in lower-extremity motor scores (LEMSs), which were obtained preoperatively, within 2 weeks postoperatively, and at 6 and 12 months postoperatively. To identify risk factors for persistent neurological deficit, the authors compared patient and surgical characteristics with a declined LEMS at 12-month follow-up (n = 10) versus those with an improved/maintained LEMS at 12-month follow-up (n = 189).RESULTSAt the first postoperative assessment, the LEMS had improved in 15% and declined in 10% of patients compared with preoperative scores. At the 6-month follow-up, 6% of patients continued to have a decline in LEMS, and 16% had improvement. At 12 months, LEMS had improved in 17% and declined in 5% of patients compared with preoperative scores. The only factor significantly associated with a decline in 12-month LEMS was high-grade spondylolisthesis as an indication for surgery (OR 13, 95% CI 3.2–56).CONCLUSIONSAlthough the LEMS declined in 10% of patients immediately after 3CO, at 12 months postoperatively, only 5% of patients had neurological motor deficits. A surgical indication of high-grade spondylolisthesis was the only factor associated with neurological deficit at 12 months postoperatively.

OBJECTIVERecommendations for the surgical treatment of isolated lumbar spinal stenosis (LSS) (i.e., in the absence of concomitant scoliosis or spondylolisthesis) are unclear. The aims of this study were to investigate trends in the surgical treatment of isolated LSS in US adults and determine implications for outcomes.METHODSThe authors analyzed inpatient and outpatient claims from the Truven Health Analytics MarketScan Commercial Claims and Encounters Database for 20,279 patients aged 40–64 years who underwent surgery for LSS between 2010 and 2014. Only patients with continuous 12-month insurance coverage after surgery were included. The rates of decompression with arthrodesis versus decompression only and of simple (1- or 2-level, single-approach) versus complex (> 2-level or combined-approach) arthrodesis were analyzed by year and geographic region. These trends were further analyzed with respect to complications, length of hospital stay, payments made to the hospital, and patient discharge status. Statistical significance was set at p < 0.05.RESULTSThe proportion of patients who underwent decompression with arthrodesis compared with decompression only increased significantly and linearly from 2010 to 2014 (OR 1.08; 95% CI 1.06–1.10). Arthrodesis was more likely to be complex rather than simple with each subsequent year (OR 1.4; 95% CI 1.33–1.49). This trend was accompanied by an increased likelihood of postoperative complications (OR 1.11; 95% CI 1.02–1.21), higher costs (payments increased by a mean of US$1633 per year; 95% CI 1327–1939), and greater likelihood of being discharged to a skilled nursing facility as opposed to home (OR 1.11; 95% CI 1.03–1.20). The South and Midwest regions of the US had the highest proportions of patients undergoing arthrodesis (48% and 42%, respectively). The mean length of hospital stay did not change significantly (p = 0.324).CONCLUSIONSFrom 2010 to 2014, the proportion of adults undergoing decompression with arthrodesis versus decompression only for the treatment of LSS increased, especially in the South and Midwest regions of the US. A greater proportion of these fusions were complex and were associated with more complications, higher costs, and a greater likelihood of being discharged to a skilled nursing facility.

BACKGROUND CONTEXT Rod constructs in adult spinal deformity (ASD) surgery can be variable and modular, in many revision surgeries the new instrumentation is connected to the previous implants for extension of fusion or for junctional failure. Previous studies recently reported a lower rate of rod fractures and nonunion with the addition of extra rods and multi-rod constructs across 3CO site and complex spinal reconstructions. The high rate of rod failures in ASD lead to the adoption of various multi-rod constructs. The effect of rod configuration on the rate of implant failure in multi-rod constructs is unknown. Currently, no classification system exits to describe the different multi-rod constructs to allow comparison of rod configurations across data bases. There is no agreement on the terms used to describe multi-rod constructs. PURPOSE We present a new classification system that allows accurate description of various multi-rod constructs used in spine deformity in terms of rod configuration and density. Rod configurations in 110 ASD patients after long PSF to the sacrum with 4-rod and 3-rod constructs were classified according to the new classification system. Four-rod and 3-rod constructs were divided into two groups based on rod configuration: accessory rod group and satellite rod group. We compared rod failure rate (RF) between the two different groups, accessory vs satellite, to determine the effect or rod configuration on the rod fracture rate. STUDY DESIGN/SETTING Retrospective review of institutional database of ASD patients who underwent PSF to the sacrum with the use of multi-rod constructs, 3-rod and 4-rod constructs. The multi-rod constructs were classified according the new system based on the rod configurations (RC) of the additional rods. PATIENT SAMPLE ASD patients who underwent PSF to the sacrum with the use of multi-rod constructs, 3-rod and 4-rod constructs. OUTCOME MEASURES Radiographic evidence of rod failure, either unilateral or bilateral on follow up radiographs. METHODS Our institutional database of 526 ASD patients fused to sacrum was reviewed, 110 patients with multi-rod constructs were identified and divided into 4-rod or 3-rod constructs. Within the 4-rod or 3-rod groups, constructs were classified according to the rod configuration into either accessory group (A-group) with additional accessory rods or satellite group (S-group) with additional satellite rods. Accessory rods were defined as additional rods connected to the main construct but not attached to any anchors. Satellite rods were defined as shorter additional rods attached to screws or hooks, and either connected or not connected to the main construct. Most of the satellite rods were midline rod with hooks. Accessory and satellite rod configurations for 4-rod and 3-rod constructs were compared for fractures either unilateral or bilateral after a minimum of 2-year follow up. RESULTS The 4-rod constructs included 15 satellite (S-group) and 18 accessory (A-group) rod configurations. Average BMI and % primary to revision surgeries in both groups was not different p=0.38. Rod diameter (5.5 vs 6.35) in both groups was not different p=0.28. Median levels fused in S-group were 15 (13-17) vs A-group 12 (10-15) p=0.11. Interbody fusion was not different, S-group 12 (80%), A-group 15 (83%), p=0.81. Rod failures in S-group occurred in 2 (13.3%) vs 4 (22.2%) in A-group, p=0.47. Duration of time from surgery to rod failure was 27 months in the S-group compared to 14.5 months in A-group. The 3-rod constructs included 42 satellite and 29 accessory rod configurations. Average BMI was not different (p=0.83), the S-group had more revision cases 38 (90.5%) vs 17 (58.6%) for A-group p=0.03. In S-group 14 (33.3%) patients were 5.5 rods, 27 (64.3%) had 6.35 rods vs A-group: 26 (89.6%) 5.5 rods and 3(10.34%) had 6.35 rods, p=0.01. Median levels fused was not different between both groups, but A-group had more interbody fusions performed 12 (41.4%) vs 4 (9.52%) p=0.03. Rod failures in S-group were 7 (16.7%) vs 15 (51.7%) in the A-group, p=0.01. Duration of time from surgery to rod failure in satellite group was 41 months vs accessory group 31 months. CONCLUSIONS Multi-rod constructs with different rod configurations were compared using a new classification system, 4-rod constructs showed no difference in rate of rod failures. In the 3-rod constructs group, accessory rod configurations had more rod failures compared to satellite rod configurations. The multi-rod construct classification system is helpful in comparing different rod configurations in terms of implant complications. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

CASE The S1 and S2 corridors are the typical osseous pathways for iliosacral screw fixation of posterior pelvic ring fractures. In dysmorphic sacra, the S1 screw trajectory is often different from that in normal sacra. We present a case of iliosacral screw placement in the third sacral segment for fixation of a complex lateral compression type-3 pelvic fracture in a patient with a dysmorphic sacrum. CONCLUSION In patients with dysmorphic sacra and unstable posterior pelvic ring fractures or dislocations, the S3 corridor may be a feasible osseous fixation pathway that can be used in a manner equivalent to the S2 corridor in a normal sacrum.

BACKGROUND CONTEXT The coronal plane in adolescent idiopathic scoliosis (AIS) has been extensively studied. However, studies investigating the changes in sagittal parameters before and after posterior spinal fusion in Lenke types 5 and 6 are scarce. Sagittal plane assessment of lumbar lordosis (LL), pelvic tilt (PT) and pelvic incidence (PI) in AIS Lenke 5 & 6 has not been fully delineated. PURPOSE The purpose of this study was to report on the spinopelvic parameters over 2 years. AIS Lenke 5 & 6 pts who underwent PSF were stratified into 3 groups based on amount of preop lumbar lordosis (low LL 60). Sagittal plane and spinopelvic parameters were followed longitudinally over 2 years postop. STUDY DESIGN/SETTING This study was a retrospective review of a prospectively collected multicenter database of patients with AIS who underwent spinal fusion. PATIENT SAMPLE Multicenter database of AIS patients, Lenke 5 and 6, who underwent PSF with 2-year follow-up and radiographic data were included. OUTCOME MEASURES Radiographic spinopelvic parameters including lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT) and thoracolumbar kyphosis (TL kyphosis). METHODS Baseline, 6-week, 6-month, 1-year and 2-year follow-up radiographs were analyzed for sagittal plane parameters (LL, PI, PT and TL kyphosis). Lenke 5 & 6 pts were stratified according to LL into 3 groups; low LL 60. Patients within each LL group were followed from preop to 2 years after PSF for changes in TL kyphosis, LL, PI and PT. RESULTS A total of 242 Lenke 5 (L5) and 223 Lenke 6 (L6) patients were studied. In the L5 pts, the average preop LL was −56 (−24 to −93), average preop PT was 9.3 (−10-26). In L5 pts with preop LL 60 (n=94), postop LL increased to 6 months then plateaued while PT trended down from 6 weeks to 2 years. L6 patients had an average preop LL of-55 (−21 to −91), average preop PT 10(−6 to 52). L6 pts with preop LL 60 (n= 71) LL increased from 6 weeks to 6 months back to preop value and remained unchanged at 2 yrs. PI did not change over time but lumbar lordosis increased over the 2 years. CONCLUSIONS There is an inverse relationship between LL and PT in patients with Lenke types 5&6 when longitudinally tracked over 2 years postoperatively. PI did not change but lumbar lordosis increased over 2 years. When lumbar lordosis increases, sagittal plane adapts to PSF and improves over time. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

BACKGROUND CONTEXT The incidence of pseudarthrosis and rod fracture after long spinal fusion to the sacrum for correction of adult spinal deformity ranges from 20% to 40%. Several strategies have been proposed to decrease pseudarthrosis rates across the lumbosacral junction including rigid sacropelvic fixation, BMP and the use of interbody fusions at the lower lumbar spine. However, rod failures in the lumbar spine after ASD correction remain high despite the use of BMP and sacropelvic fixation. The question whether Interbody fusion is needed with the combination of sacropelvic fixation and use of BMP after long PSF to the sacrum in ASD remains unanswered. PURPOSE To investigate the incidence of rod fractures in patients undergoing surgery for correction of adult spinal deformity with or without the use of interbody fusions in the caudal levels of the fusion construct at L3 and below. We compared the rate of RF in 256 ASD patients who underwent long spinal fusion using BMP and sacropelvic fixation with and without Interbody fusion in the lower lumbar spine. STUDY DESIGN/SETTING Single institution retrospective cohort study. PATIENT SAMPLE Adult spinal deformity patients who underwent PSF to the sacrum with use of bilateral pelvic fixation and BMP with or without interbody fusion performed in the lower lumbar spine L3-S1. OUTCOME MEASURES The primary outcome of interest was the incidence of rod fractures at the lower lumbar spine from L3 to the sacrum. METHODS We reviewed clinical records of patients that underwent surgery for correction of adult spinal deformity between 2008 and 2014. Patient demographics, comorbidities, indications for surgery, as well as intra- and postoperative variables were collected for each patient. Patients were dichotomized into one of two groups based on whether an interbody fusion was performed at the caudal levels of the fusion construct. All patients had a minimum two-year follow-up. 526 ASD patients was reviewed, only primary surgeries were included. Interbody fusions were performed in the lower lumbar spine L3-S1 most commonly at L5-S1. The primary outcome of interest was the rod failure rates from L3-S1. All patients had a minimum 2-year follow-up. RESULTS A total of 256 patients underwent long PSF for correction of ASD, 141 patients had interbody fusion (IF group) at any level L3-S1 with mean follow up of 59 ±29 months and 115 patients had no interbody fusion(NIF group) with 50±22 months mean f/u. At baseline, there were no significant differences between both groups in gender (p=0.97), BMI (p=0.62), smoking status (p=0.40), diabetes(p=0.34) or osteopenia p=0.73. The median number of levels fused in the IF group was 10(7-15) compared with 8 levels (7-15) in the NIF group. BMP and sacropelvic fixation (233 iliac screws and 23 patients had S2AI screws) were used in all patients. Pre-op sagittal plane deformity was not different between both groups. At last follow-up, there was no statistically significant difference in rate of Rod failure between IF n=29(21%) vs NIF n=17(15%) p=0.23. IF group had 19(13%) unilateral rod failures and 10 (7% ) bilateral rod failures. NIF group included 12(10%) unilateral rod failures and 5(4%) bilateral rod failures. The most common location of rod failures was different between the groups, L3-L4 was the most common location in the IF group with 6.5% followed by L5-S1 in 6.1% of patients. Interbody fusion was performed at L4-5 and L5-S1 in the majority of patients that failed at L3-4. In the NIF group L5-S1 was most common location in 6.4% followed by L4-L5 in 2.7% of patients. CONCLUSIONS This study suggests that interbody fusion of the lower lumbar spine in ASD patients may not be associated with a decrease in the incidence of rod failures at the Lubosacral junction. Interbody fusion does not protect against rod failure in the lower lumbar spine in long PSF to the sacrum and may encourage failure at L3-4, the level above the interbody fusion. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Background context To our knowledge, the effect of the staging regimen on the surgical outcome in patients undergoing combined anterior/posterior surgery for the treatment of spinal deformity has not been previously studied. Purpose To compare outcomes of anterior/posterior surgery for adult spinal deformity staged less than 21 days apart versus those 21 or more days apart. Study design A retrospective comparison study. Patient sample Patients aged 40 years or older who underwent combined anterior/posterior fusions for spinal deformities. Outcome measures Self-reported measures, physiological measures, and functional measures. Methods We retrospectively reviewed prospectively collected data for 63 consecutive patients (50 females and 13 males) older than 40 years who underwent combined anterior/posterior fusions for spinal deformities and who had a minimum of 2-year follow-up. We divided them into those who had surgery staged less than 21 days apart (Group 1, N=29) and those who had surgery staged 21 or more days apart (Group 2, N=34). The groups were not statistically different in age; preoperative American Society of Anesthesiologists, Scoliosis Research Society-22 (SRS-22) patient questionnaire, and Oswestry Disability Index (ODI) scores; number of previous surgeries; number of levels fused; or total operative time. Hotelling t square test and the chi-squared test were used to compare clinical and radiographic parameters, complications, and functional outcomes between groups (significance, p Results Compared with Group 1 patients, Group 2 (staged) patients had a lower total estimated blood loss (average, 4.5 L [range, 1.90–8.75 L] vs. 4 L [range, 1.8–10.1 L], respectively), fewer combined hospital days (average, 14 days [range, 7–70 days] vs. 12 days [range, 6–44 days], respectively), and fewer major complications (total, 10 [35%] vs. 6 [18%], respectively). Preoperative SRS-22 and ODI scores were significantly better in Group 2 than in Group 1 at 6 weeks (p Conclusion For patients who require both anterior and posterior surgery for spinal deformity correction, staging the two procedures 21 or more days apart decreases total perioperative transfusion requirements although significantly improving functional outcomes.

Retrospective review.To compare the incidence of proximal junctional kyphosis (PJK) and the clinical, radiographic, and functional outcomes in adults undergoing long posterior spinal fusion with transverse process hooks versus pedicle screws at the uppermost instrumented vertebrae.Proximal junctional kyphosis often occurs after instrumented long spinal fusion. Although there have been numerous studies of PJK development in adolescents with idiopathic scoliosis, few studies have focused on adults.This study reviewed data on 47 consecutive adult patients who underwent long spinal fusion (five or more levels) with hooks or screws at the uppermost instrumented vertebrae, from 2004 through 2009, and had 2-year radiographic and clinical follow-up. The hook group (20 patients) and screw group (27 patients) were similar in terms of age, gender, and levels fused. Proximal junctional kyphosis was defined as a sagittal Cobb angle of at least 10° between the lower end plate of the uppermost instrumented vertebrae and the upper end plate of the 2 immediately superior vertebrae, and at least 10° of progression from the previous measurement. The groups' radiographs, complications, and functional outcomes (Scoliosis Research Society-22 Patient Questionnaire and the Oswestry Disability Index) were compared using Hotelling's tComparing immediate postoperative and final follow-ups, none of the 20 patients in the hook group versus 8 of 27 patients in the screw group (29.6%) developed PJK (p = .01). There were no statistical differences between groups in major or minor complications rates. At final follow-up, patients with hooks had significantly higher functional scores than those with screws (p.05), and patients with PJK had significantly lower functional scores in all Scoliosis Research Society-22 Patient Questionnaire domains except satisfaction.Transverse process hooks were associated with a lower incidence of PJK and higher functional scores than pedicle screws.

Study design Retrospective review. Objective To report and analyze the perioperative complications, radiographical results, and functional outcomes in elderly patients undergoing pedicle subtraction osteotomy (PSO) and/or vertebral column resection (VCR) procedures for spinal deformity correction. Summary of background data To our knowledge, no studies have focused on 3-column osteotomies in the elderly. Methods We retrospectively reviewed prospectively collected data for 51 consecutive patients 60 years or older undergoing 3-column osteotomies for spinal deformity correction (PSO, 36 patients; VCR, 13 patients; PSO and VCR, 2 patients) and who had at least 2 years' follow-up. We analyzed the perioperative complications; the preoperative, postoperative, and final follow-up radiographical measurements; and the preoperative, postoperative, and final follow-up functional outcome scores (using the Scoliosis Research Society-22 questionnaire and Oswestry Disability Index). Hotelling's t2 test and the χ2 test were used for analysis (statistical significance, P Results There were 9 (18%) major complications (5 with PSO and 4 with VCR) and 20 (39%) minor complications (14 with PSO and 6 with VCR). Compared with preoperative values, improvement at 6 weeks after surgery averaged 16° (range, 0°-42°) in thoracic scoliosis, 14° (range, 2°-25°) in lumbar scoliosis, 9° (range, 5°-35°) in thoracic kyphosis, -24° (range, -12° to -68°) in lumbar lordosis, 2.4 cm (range, 0-12 cm) in coronal balance, and 6.9 cm (range, -2 to 20 cm) in sagittal balance. At final follow-up, improvements in the coronal and sagittal balance were maintained. By final follow-up, compared with preoperative state, there were significant improvements in all 5 Scoliosis Research Society-22 domains and in the Oswestry Disability Index. Conclusion In the elderly patient, PSO and VCR can achieve significant restoration of sagittal and coronal balance and significant improvement in quality of life. However, both techniques can lead to serious complications and should be selectively used.

Under the Physician Payments Sunshine Act, “payments or transfers of value” by biomedical companies to physicians must be disclosed through the Open Payments Program. Designed to provide transparency of financial transactions between medication and device manufacturers and health care providers, the Open Payments Program shows financial relationships between industry and health care providers. Awareness of this program is crucial because its interpretation or misinterpretation by patients, physicians, and the general public can affect patient care, clinical practice, and research. This study evaluated nonresearch payments by industry to orthopedic surgeons. A retrospective cross-sectional review of the first wave of Physician Payments Sunshine Act data (August through December 2013) was performed to characterize industry payments to orthopedic surgeons by subspecialty, amount, type, origin, and geographic distribution. During this 5-month period, orthopedic surgeons (n=14,828) received $107,666,826, which included 3% of those listed in the Open Payments Program and 23% of the total amount paid. Of orthopedic surgeons who received payment, 45% received less than $100 and 1% received $100,000 or more. Median payment (interquartile range) was $119 ($34–$636), and mean payment was $7261±95,887. The largest payment to an individual orthopedic surgeon was $7,849,711. The 2 largest payment categories were royalty or license fees (68%) and consulting fees (13%). During the study period, orthopedic surgeons had substantial financial ties to industry. Of orthopedic surgeons who received payments, the largest proportion (45%) received less than $100 and only 1% received large payments (≥$100,000). The Open Payments Program offers insight into industry payments to orthopedic surgeons. [ Orthopedics. 2016; 39(6):e1058–e1062.]

OBJECT In this study, the authors compared outcomes and complications in patients with and without rheumatoid arthritis (RA) who underwent surgery for spinal deformity. METHODS The authors searched the Johns Hopkins University database for patients with RA (Group RA) and without RA (Group NoRA) who underwent long spinal fusion for scoliosis by 3 surgeons at 1 institution from 2000 through 2012. Groups RA and NoRA each had 14 patients who were well matched with regard to sex (13 women/1 man and 12 women/2 men, respectively), age (mean 66.3 years [range 40.5–81.9 years] and 67.6 years [range 51–81 years]), follow-up duration (mean 35.4 months [range 1–87 months] and 44 months [range 24–51 months]), and number of primary (8 and 8) and revision (6 and 6) surgeries. Surgical outcomes, invasiveness scores, and complications were compared between the groups using the nonpaired Student t-test (p < 0.05). RESULTS For Groups RA and NoRA, there were no significant differences in the average number of levels fused (10.6 [range 9–17] vs 10.3 [range 7–17], respectively; p = 0.4), the average estimated blood loss (2892 ml [range 1300–5000 ml] vs 3100 ml [range 1700–5200 ml]; p = 0.73), or the average invasiveness score (35.5 [range 21–51] vs 34.5 [range 23–58]; p = 0.8). However, in Group RA, the number of major complications was significantly higher (23 vs 11; p < 0.001), the number of secondary procedures was significantly higher (14 vs 6; p < 0.001), and the number of minor complications was significantly lower (4 vs 12; p < 0.001) than those in Group NoRA. CONCLUSIONS Long spinal fusion in patients with RA is associated with higher rates of major complications and secondary procedures than in patients without RA.

Background In April 2016, the U.S. Centers for Medicare & Medicaid Services initiated mandatory 90-day bundled payments for total hip and knee arthroplasty for much of the country. Our goal was to determine duration of care, 90-day charges, and readmission rates by discharge disposition and U.S. region after hip or knee arthroplasty. Methods Using the 2008 Medicare Provider Analysis and Review database 100% sample, we identified patients who had undergone elective primary total hip or knee arthroplasty. We collected data on patient age, sex, comorbidities, U.S. Census region, discharge disposition, duration of care, 90-day charges, and readmission. Multivariate regression was used to assess factors associated with readmission (logistic) and charges (linear). Significance was set at p Results Patients undergoing 138,842 total hip arthroplasties were discharged to home (18%), home health care (34%), extended-care facilities (35%), and inpatient rehabilitation (13%); patients undergoing 329,233 total knee arthroplasties were discharged to home (21%), home health care (38%), extended-care facilities (31%), and inpatient rehabilitation (10%). Patients in the Northeast were more likely to be discharged to extended-care facilities or inpatient rehabilitation than patients in other regions. Patients in the West had the highest 90-day charges. Approximately 70% of patients were discharged home from extended-care facilities, whereas after inpatient rehabilitation, >50% of patients received home health care. Among those discharged to home, 90-day readmission rates were highest in the South (9.6%) for patients undergoing total hip arthroplasty and in the Midwest (8.7%) and the South (8.5%) for patients undergoing total knee arthroplasty. Having ≥4 comorbidities, followed by discharge to inpatient rehabilitation or an extended-care facility, had the strongest associations with readmission, whereas the region of the West and the discharge disposition to inpatient rehabilitation had the strongest association with higher charges. Conclusions Among Medicare patients, discharge disposition and number of comorbidities were most strongly associated with readmission. Inpatient rehabilitation and the West region had the strongest associations with higher charges. Level of evidence Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Percutaneous iliosacral screw fixation is a common technique that is widely used for unstable posterior pelvic ring disruptions. Complications of posterior percutaneous iliosacral screw fixation include implant malpositioning and hardware failure. Removal of iliosacral screws in broken or symptomatic hardware is sometimes necessary. To our knowledge, there are few reports addressing pelvic implant removal, and most of those report on anterior pelvic implants and symphyseal plates. There are no reports describing techniques for retrieval of broken iliosacral screws. We present two cases involving removal of broken sacroiliac screws, review the literature regarding iliosacral implant extraction, and identify important aspects of safe extraction of iliosacral screws and the potential complications associated with their retrieval. We further describe a novel and powerful technique to facilitate percutaneous removal of broken screw fragments, using a "push screw" to drive a broken screw fragment from a position buried in bone.

Pelvic insufficiency fractures are fairly common in elderly patients and can be a source of major functional impairment, particularly when they involve the ilium. Early rehabilitation with adequate pain relief has been the traditional method of treatment. The recently developed S2 alar iliac technique involves placing pelvic fixation into the ilium through a pathway from the sacral ala. The bony channel between the second dorsal sacral foramen and the anterior inferior iliac spine is used to provide rigid sacropelvic fixation for adult and pediatric spine deformities. The authors describe a new minimally invasive approach that allows percutaneous stabilization of an iliac fracture with 2 S2 alar iliac screws. A 65-year-old woman with a history of rectal carcinoma that was treated with pelvic radiation had an iliac stress fracture that progressed to nonunion. Extensive nonoperative treatment was unsuccessful, and the patient continued to have symptoms 5 years after the initial diagnosis. An open approach vs a minimally invasive technique was debated. The S2 alar iliac screws were used to stabilize the fracture through a minimally invasive approach. Most of the symptoms resolved in 2 months, with radiographic evidence of union at 6 months. To the authors’ knowledge, this report is the first to describe a percutaneous approach for stabilizing iliac insufficiency fractures. This technique provides a safe surgical option for treating iliac stress fractures in some patients for whom nonoperative treatment fails while avoiding the complications and soft tissue compromise associated with open procedures. Longer follow-up and a larger series are needed to show the safety and efficacy of this technique.

Background Few studies have examined the postsurgical functional outcomes of adults with spinal deformities, and even fewer have focused on the functional results and complications among older adults who have undergone primary or revision surgery for spinal deformity. Our goal was to compare patient characteristics, surgical characteristics, duration of hospitalization, radiographic results, complications, and functional outcomes between adults forty years of age or older who had undergone primary surgery for spinal deformity and those who had undergone revision surgery for spinal deformity. Methods We retrospectively reviewed the cases of 167 consecutive patients forty years of age or older who had undergone surgery for spinal deformity performed by the senior author (K.M.K.) from January 2005 through June 2009 and who were followed for a minimum of two years. We divided the patients into two groups: primary surgery (fifty-nine patients) and revision surgery (108 patients). We compared the patient characteristics (number of levels arthrodesed, type of procedure, estimated blood loss, and total operative time), duration of hospitalization, radiographic results (preoperative, six-week postoperative, and most recent follow-up Cobb angle measurements for thoracic and lumbar curves, thoracic kyphosis, and lumbar lordosis), major and minor complications, and functional outcome scores (Scoliosis Research Society-22 Patient Questionnaire and Oswestry Disability Index). Results The groups were comparable with regard to most parameters. However, the revision group had more patients with sagittal plane imbalance and more frequently required pedicle subtraction osteotomies (p l 0.01). Patients in the primary group required more correction in the coronal plane than did patients in the revision group, whereas patients in the revision group required more correction in the sagittal plane. We found no significant difference between the two groups in the rate of major complications or in the Scoliosis Research Society-22 Patient Questionnaire functional outcome scores. There were significant improvements in many functional outcome scores in both groups between the preoperative and early (six-week) postoperative periods and between the early postoperative period and the time of final follow-up. Conclusions Revision surgery for spinal deformity in adults, although technically challenging and considered to present a higher risk than primary surgery, was shown to have a complication rate and outcomes that were comparable with those of primary spinal deformity surgery in adults. Level of evidence Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Study Design Retrospective comparison. Objective To compare complications and radiographic and functional outcomes of patients undergoing revision spinal deformity surgery, who were 40–64 years of age and 65 years of age or older. Summary of Background Data The effect of age on radiographic and functional outcomes has not been well established in the literature for patients undergoing revision adult deformity surgery. The hypothesis was that the complications and radiographic and functional outcomes of younger and older adult patients would be comparable. Methods The authors retrospectively reviewed prospectively collected data on 109 consecutive patients (84 women and 25 men) undergoing revision spinal deformity surgery who were 40 years of age or older. All surgeries were performed at 1 institution by the senior author. Patients were divided into groups based on age: younger than 65 years of age (70 patients) or 65 years of age or older (39 patients), and complications and radiographic and functional outcomes were compared. All patients had at least 2 years' clinical follow-up. Hotelling's t 2 test and the χ 2 test were used to compare differences; statistical significance was set at p Results There was no significant difference between the 2 groups in major complications (p = .62), minor complications (p = .34), or reoperation rate (p = .08). Major correction was achieved in the coronal and sagittal planes in both groups after surgery. By final follow-up, patients in both groups had significant improvements from baseline in Oswestry disability index (p .05). Conclusions Older adult patients undergoing revision deformity correction surgery achieved functional outcome benefits comparable to those in younger adults without significantly more complications. Surgeons should be aware of these factors when counseling patients regarding revision surgery for deformity correction.