Current antifibrinolytics have decreased perioperative blood loss; however, some patients still require transfusions postoperatively. The authors sought to determine the risk factors associated with postoperative transfusions and to establish a “cutoff” preoperative hemoglobin threshold value specific to total knee arthroplasty (TKA) that would identify patients who would benefit from blood conservation programs. The institutional database was queried for primary TKA patients. Preoperative patient demographics and hemoglobin values were determined in addition to intraoperative and postoperative variables, including transfusion rate. Patients were stratified by whether they received a transfusion perioperatively, and risk factors were identified through univariable and multivariable analysis. Optimal cutoff values for hemoglobin were identified by concurrently maximizing the sensitivity and specificity for predicting the risk of a postoperative transfusion event. Men and women were analyzed independently. A total of 532 primary TKAs were included for analysis, and 33 patients (6.2%) required a transfusion. Advanced age ( P =.019), low pre-operative hemoglobin value ( P <.001), and failure to receive tranexamic acid ( P <.001) were associated with increased risk of postoperative transfusion. A preoperative hemoglobin value of 12.5 g/dL was identified as the optimal cutoff for predicting postoperative transfusion requirements across all patients, with a sensitivity of 84.8% and a specificity of 76.4%. Preoperative anemia remains predictive of transfusion following TKA despite current antifibrinolytics. Patients with a preoperative hemoglobin value of less than 12.5 g/dL who are not receiving intravenous tranexamic acid are particularly at risk and should be considered for blood conservation programs. [ Orthopedics . 2019; 42(2):103–109.]

INTRODUCTION:The insertion of 2 elastic stable intramedullary nails (ESINs) is a common treatment for pediatric femur fractures. However, the use of this technique in length-unstable or metadiaphyseal fractures has historically been associated with higher complication rates. To improve stability, the addition of a third ESIN has been assessed biomechanically and clinically, but the addition of a fourth nail has only been evaluated biomechanically. The purpose of this study is to report our surgical technique and radiographic outcomes using a quartet of ESINs in pediatric femur fractures. METHODS:A retrospective review was performed of pediatric patients with length-unstable or metadiaphyseal femur fractures who were treated with 4 ESINs by a single surgeon from 2008 to 2013. Nails were inserted in a retrograde manner, 2 each from medial and lateral starting points. Patients were followed clinically and radiographically until the union and routine removal of hardware. Primary outcomes included fracture union, sagittal, and coronal plane alignment, and complications. RESULTS:Fourteen patients underwent quartet ESIN placement. Two patients were excluded: one for early loss to follow-up and another with a diagnosis of osteogenesis imperfecta. The average patient age was 9.3 years (range, 4 to 14 y) and weight was 47 kg (range, 21 to 95 kg). All fractures achieved radiographic union at mean 5.5 months (range, 2 to 9 mo). Hardware was removed at a mean of 9.4 months (range, 2 to 22 mo) following implantation. At final mean follow-up of 18 months, patients and families reported no functional limitations. There were no hardware failures or revision surgeries. There were no limb length discrepancies or malalignment at the time of final radiographic follow-up. There were 2 minor complications-1 patient with pain secondary to nail migration resulting in prominence at the knee and another with refracture following a fall. The stable refracture occurred before complete fracture union and hardware removal and went on to the union without the need for any additional treatment. CONCLUSIONS:Treatment with a quartet of ESINs should be considered for skeletally immature children with length-unstable or metadiaphyseal femur fractures. In this series, all fractures achieved union without major complications or hardware failure. This modification to traditional elastic nailing techniques is an option for the surgeon to consider as an alternative to rigid intramedullary nailing, submuscular plating, or external fixation. LEVEL OF EVIDENCE:Level IV.

Study Design: Retrospective. Objective: Identify patient risk factors for extended length of stay (LOS) and 90-day hospital readmissions following elective anterior cervical discectomy and fusion (ACDF). Methods: Included ACDF patients from 2013 to 2017 at a single institution. Eligible patients were subset into LOS <2 and LOS ≥2 days, and no 90-day hospital readmission and yes 90-day hospital readmission. Patient and surgical factors were compared between the LOS and readmission groups. Multivariable logistic regression analysis was utilized to determine the association of independent factors with LOS and 90-day readmission rates. Results: Our sample included 1896 patients; 265 (14%) had LOS ≥2 days, and 121 (6.4%) had a readmission within 90 days of surgery. Patient and surgical factors associated with LOS included patient age ≥65 years (odds ratio [OR] 1.72, 95% confidence interval [CI] 1.15-2.56), marriage (OR 0.57, 95% CI 0.43-0.79), private health insurance (OR 0.28, 95% CI 0.15-0.50), American Society of Anesthesiologists (ASA) score (OR 1.52, 95% CI 1.12-1.86), African American race (OR 1.95, 95% CI 1.38-2.72), and harvesting iliac crest autograft (OR 4.94, 95% CI 2.31-10.8). Patient and surgical factors associated with 90-day hospital readmission included ASA score (OR 1.81, 95% CI 1.32-2.49), length of surgery (OR 1.002, 95% CI 1.001-1.004), and radiculopathy as indication for surgery (OR 0.60, 95% CI 0.39-0.96). Conclusions: Extended LOS and 90-day hospital readmissions may lead to poorer patient outcomes and increased episode of care costs. Our study identified patient and surgical factors associated with extended LOS and 90-day readmission rates. In general, preoperative patient factors affected these outcomes more than surgical factors.

Study Design. Retrospective review of prospectively collected data of the first 72 consecutive patients treated with singleposition one-or two-level lateral (LLIF) or oblique lateral interbody fusion (OLLIF) with bilateral percutaneous pedicle screw and rod fixation by a single spine surgeon. Objective. To evaluate the clinical feasibility, accuracy, and efficiency of a single-position technique for LLIF and OLLIF with bilateral pedicle screw and rod fixation. Summary of Background Data. Minimally-invasive lateral interbody approaches are performed in the lateral decubitus position. Subsequent repositioning prone for bilateral pedicle screw and rod fixation requires significant time and resources and does not facilitate increased lumbar lordosis. Methods. The first 72 consecutive patients (300 screws) treated with single-position LLIF or OLLIF and bilateral pedicle screws by a single surgeon between December 2013 and August 2016 were included in the study. Screw accuracy and fusion were graded using computed tomography and several timing parameters were recorded including retractor, fluoroscopy, and screw placement time. Complications including reoperation, infection, and postoperative radicular pain and weakness were recorded. Results. Average screw placement time was 5.9 min/screw (standard deviation, SD: 1.5 min; range: 3-9.5 min). Average total operative time (interbody cage and pedicle screw placement) was 87.9 minutes (SD: 25.1 min; range: 49-195 min). Average fluoroscopy time was 15.0 s/screw (SD: 4.7 s; range: 6-25 s). The pedicle screw breach rate was 5.1% with 10/13 breaches measured as < 2 mm in magnitude. Fusion rate at 6-months postoperative was 87.5%. Two (2.8%) patients underwent reoperation for malpositioned pedicle screws with subsequent resolution of symptoms. Conclusion. The single-position, all-lateral technique was found to be feasible with accuracy, fluoroscopy usage, and complication rates comparable with the published literature. This technique eliminates the time and staffing associated with intraoperative repositioning and may lead to significant improvements in operative efficiency and cost savings.

BACKGROUND CONTEXT Recent literature has reported that surgical treatment for central cord syndrome (CCS) has increased significantly over the last decade. PURPOSE The aim of our study was to investigate the patient and hospital characteristics, treatment practices, and in-hospital mortality associated with management of CCS. STUDY DESIGN/SETTING Retrospective. PATIENT SAMPLE Patients with central cord syndrome. OUTCOME MEASURES Mortality, discharge disposition. METHODS The National Emergency Department Sample was queried from 2009 to 2012 to generate national estimates of patients who presented to the emergency room in the United States and were diagnosed with central cord syndrome. Linkage variables were used to query the associated in-patient stay during the same time period. Significance was set at P<.01 for all analyses. RESULTS From 2009 to 2012, there were 11,975 emergency room visits for CCS (mean age 60 years), of which 80.5% patients initially presented to a trauma center. Most common injury mechanisms were fall (55%), and motor vehicle accident (15%). Concomitant cervical fractures were found in 10% patients. A total of 93% patients were admitted to the hospital directly or after transfer to another facility. Of all patients who were admitted to the hospital, 55% patients were treated nonoperatively, 39% were treated with cervical fusion surgery (62% with anterior cervical decompression and fusion, 32% with posterior cervical decompression and fusion) and 6% were treated with laminoplasty. Post-hospitalization, 61% patients were discharged to a rehabilitation facility and 39% were discharged to home. The overall incidence of in-hospital mortality was 2.6%, and on multivariate analysis, mortality was associated significantly with older patient age (OR 1.06, P<.001) and greater comorbidities (OR 1.72, P<.001). CONCLUSIONS The majority of patients who presented to the emergency room for central cord syndrome in the United States were treated nonoperatively. Advanced age and greater comorbidities were the factors that were most associated with increased risk of in-hospital mortality in patients with central cord syndrome. Recent literature has reported that surgical treatment for central cord syndrome (CCS) has increased significantly over the last decade. The aim of our study was to investigate the patient and hospital characteristics, treatment practices, and in-hospital mortality associated with management of CCS. Retrospective. Patients with central cord syndrome. Mortality, discharge disposition. The National Emergency Department Sample was queried from 2009 to 2012 to generate national estimates of patients who presented to the emergency room in the United States and were diagnosed with central cord syndrome. Linkage variables were used to query the associated in-patient stay during the same time period. Significance was set at P<.01 for all analyses. From 2009 to 2012, there were 11,975 emergency room visits for CCS (mean age 60 years), of which 80.5% patients initially presented to a trauma center. Most common injury mechanisms were fall (55%), and motor vehicle accident (15%). Concomitant cervical fractures were found in 10% patients. A total of 93% patients were admitted to the hospital directly or after transfer to another facility. Of all patients who were admitted to the hospital, 55% patients were treated nonoperatively, 39% were treated with cervical fusion surgery (62% with anterior cervical decompression and fusion, 32% with posterior cervical decompression and fusion) and 6% were treated with laminoplasty. Post-hospitalization, 61% patients were discharged to a rehabilitation facility and 39% were discharged to home. The overall incidence of in-hospital mortality was 2.6%, and on multivariate analysis, mortality was associated significantly with older patient age (OR 1.06, P<.001) and greater comorbidities (OR 1.72, P<.001). The majority of patients who presented to the emergency room for central cord syndrome in the United States were treated nonoperatively. Advanced age and greater comorbidities were the factors that were most associated with increased risk of in-hospital mortality in patients with central cord syndrome.

Acetabular component malpositioning has been associated with major complications including dislocation, edge-loading, stripe wear and squeaking. Anteversion is determined by pelvic orientation; flexion of the pelvis increases and extension decreases acetabular anteversion. The degree of pelvic movement is determined by lumbar spine sagittal balance and it is well established that lumbar arthrodesis procedures influence spinal and pelvic parameters including sagittal balance. The purpose of this study is to determine the impact of prior lumbar arthrodesis and revision lumbar arthrodesis on complications after primary elective THA. A database review using the entire Medicare sample within the PearlDiver database was performed using International Classification of Diseases, 9th Edition codes. The search identified 14,439 patients who underwent primary THA after prior lumbar arthrodesis and 1,157 patients who underwent primary THA after prior revision lumbar arthrodesis. A search for patients who underwent primary THA without prior history of lumbar or revision lumbar fusion yielded 749,403 patients who served as a control. Incidence (IN), odds ratios (ORs) and their respective 95% confidence intervals (CIs) for 30-day, 90-day and overall complications were calculated. The following complications reached statistical significance (p < 0.001) for THA after primary lumbar arthrodesis: bleeding (IN:9.7%, OR:2.33, CI:2.21–2.47), dislocation (IN:5.6%, OR:1.95, CI:1.81–2.09), infection (IN:3.6%, OR:1.99, CI:1.85–2.12), mechanical complication (IN:0.7%, OR:1.42, CI:1.16–1.73), mechanical loosening (IN:2.3%, OR:1.74, CI:1.56–1.94), other mechanical complication (IN:2.1%, OR:2.13, CI:1.90–2.39), DVT/PE (IN:8.4%, OR:1.50, CI:1.42–1.60), acute renal failure (IN:22%, OR:1.20, CI:1.15–1.25), periprosthetic fracture (IN:1.6%, OR:1.45, CI:1.27–1.65), and prosthetic-related complication (IN:30%, OR:1.85, CI:1.78–1.91). Higher complications rates were observed in patients who had revision lumbar arthrodesis: bleeding (IN:12.4%, OR:3.06, CI:2.57–3.65), dislocation (IN:9.7%, OR:3.54, CI:2.92–4.31), infection (IN:5%, OR:3.32, CI:2.71–4.06), mechanical complication (IN:6.9%, OR:14.94, CI:11.88–18.79), mechanical loosening (IN:3.2%, OR:2.41, CI:1.74–3.35), other mechanical complication (IN:3.5%, OR:3.56, CI:2.61–4.87), DVT/PE (IN:10.7%, OR:1.96, CI:1.63–2.36), acute renal failure (IN:25.5%, OR:1.46, CI:1.28–1.66), periprosthetic fracture (IN:2.7%, OR:2.47, CI:1.72–3.52), and prosthetic-related complication (IN:40%, OR:2.88, CI:2.56–3.24). Lumbar arthrodesis and revision lumbar arthrodesis significantly negatively impact postoperative complication rates after THA. Level of Evidence: Therapeutic Level III

OBJECTIVE A previous study found that ultra-low radiation imaging (ULRI) with image enhancement significantly decreases radiation exposure by roughly 75% for both the patient and operating room personnel during minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) (p < 0.001). However, no clinical data exist on whether this imaging modality negatively impacts patient outcomes. Thus, the goal of this randomized controlled trial was to assess pedicle screw placement accuracy with ULRI with image enhancement compared with conventional, standard-dose fluoroscopy for patients undergoing single-level MIS-TLIF. METHODS An institutional review board-approved, prospective internally randomized controlled trial was performed to compare breach rates for pedicle screw placement performed using ULRI with image enhancement versus conventional fluoroscopy. For cannulation and pedicle screw placement, surgery on 1 side (left vs right) was randomly assigned to be performed under ULRI. Screws on the opposite side were placed under conventional fluoroscopy, thereby allowing each patient to serve as his/her own control. In addition to standard intraoperative images to check screw placement, each patient underwent postoperative CT. Three experienced neurosurgeons independently analyzed the images and were blinded as to which imaging modality was used to assist with each screw placement. Screw placement was analyzed for pedicle breach (lateral vs medial and Grade 0 [< 2.0 mm], Grade 1 [2.0-4.0 mm], or Grade 2 [> 4.0 mm]), appropriate screw depth (50%-75% of the vertebral body's anteroposterior dimension), and appropriate screw angle (within 10° of the pedicle angle). The effective breach rate was calculated as the percentage of screws evaluated as breached > 2.0 mm medially or postoperatively symptomatic. RESULTS Twenty-three consecutive patients underwent single-level MIS-TLIF, and their sides were randomly assigned to receive ULRI. No patient had immediate postoperative complications (e.g., neurological decline, need for hardware repositioning). On CT confirmation, 4 screws that had K-wire placement and cannulation under ULRI and screw placement under conventional fluoroscopy showed deviations. There were 2 breaches that deviated medially but both were Grade 0 (< 2.0 mm). Similarly, 2 breaches occurred that were Grade 1 (> 2.0 mm) but both deviated laterally. Therefore, the effective breach rate (breach > 2.0 mm deviated medially) was unchanged in both imaging groups (0% using either ULRI or conventional fluoroscopy; p = 1.00). CONCLUSIONS ULRI with image enhancement does not compromise accuracy during pedicle screw placement compared with conventional fluoroscopy while it significantly decreases radiation exposure to both the patient and operating room personnel.

BACKGROUND:Ankylosing spondylitis (AS) is a chronic autoimmune spondyloarthropathy that primarily affects the axial spine and hips. Progressive disease leads to pronounced spinal kyphosis, positive sagittal balance, and altered biomechanics. The purpose of this study is to determine the complication profile of patients with AS undergoing total hip arthroplasty (THA).METHODS:The Medicare sample was searched from 2005 to 2012 yielding 1006 patients with AS who subsequently underwent THA. Risk ratios (RRs) with 95% confidence intervals (CIs) were calculated for 90-day, 2-year, and the final postoperative follow-up for complications including hip dislocation, periprosthetic fracture, wound complication, revision THA, and postoperative infection.RESULTS:Compared to controls, AS patients had an RR of 2.50 (CI, 1.04-5.99) of THA component breakage at 90-days post-operatively and 1.99 (CI, 1.10-3.59) at 2-years. The RR of periprosthetic hip dislocation was elevated at 90 days (1.44; CI, 0.93-2.22) and significantly increased at 2-years (1.67; CI, 1.25-2.23) and overall follow-up (1.49; CI, 1.14-1.93). Similarly, the RR for THA revision was elevated at 90-days (1.46; CI, 0.97-2.18) and significantly increased at 2-years (1.69; CI, 1.33-2.14) and overall follow-up (1.51; CI, 1.23-1.85).CONCLUSION:Patients with AS are at increased risk for complications after THA. Altered biomechanics from a rigid, kyphotic spine place increased demand on the hip joints. The elevated perioperative and postoperative risks should be discussed preoperatively, and these patients may require increased preoperative medical optimization as well as possible changes in component selection and position to compensate for altered spinopelvic biomechanics.

Concurrent spine and hip disease is common. Spinal deformities can restrict lumbar range of motion and lumbar lordosis, leading to pelvic obliquity and increased pelvic tilt. A comprehensive preoperative workup and component templating ensure appropriate compensation for altered pelvic parameters for implantation of components according to functional positioning. Pelvic obliquity from scoliosis must be measured to calculate appropriate leg length. Cup positioning should be templated on standing radiograph to limit impingement from cup malposition. In spinal deformity, the optimal position of the cup that accommodates pelvic parameters and limits impingement may lie outside the classic parameters of the safe zone.

Concomitant spine and hip disease in patients undergoing total hip arthroplasty (THA) presents a management challenge. Degenerative lumbar spine conditions are known to decrease lumbar lordosis and limit lumbar flexion and extension, leading to altered pelvic mechanics and increased demand for hip motion. In this study, the effect of lumbar spine disease on complications after primary THA was assessed. The Medicare database was searched from 2005 to 2012 using International Classification of Diseases, Ninth Revision, procedure codes for primary THA and diagnosis codes for preoperative diagnoses of lumbosacral spondylosis, lumbar disk herniation, acquired spondylolisthesis, and degenerative disk disease. The control group consisted of all patients without a lumbar spine diagnosis who underwent THA. The risk ratios for prosthetic hip dislocation, revision THA, periprosthetic fracture, and infection were significantly higher for all 4 lumbar diseases at all time points relative to controls. The average complication risk ratios at 90 days were 1.59 for lumbosacral spondylosis, 1.62 for disk herniation, 1.65 for spondylolisthesis, and 1.53 for degenerative disk disease. The average complication risk ratios at 2 years were 1.66 for lumbosacral spondylosis, 1.73 for disk herniation, 1.65 for spondylolisthesis, and 1.59 for degenerative disk disease. Prosthetic hip dislocation was the most common complication at 2 years in all 4 spinal disease cohorts, with risk ratios ranging from 1.76 to 2.00. This study shows a significant increase in the risk of complications following THA in patients with lumbar spine disease. [Orthopedics. 2017; 40(3):e520-e525.].

BACKGROUND CONTEXT: Radiographic parameters including sagittal balance, coronal balance, and lumbar lordosis have been increasingly implicated as potential determinants or markers of functioning in patients with scoliosis. In an effort to stratify disease severity preoperatively and assess response to treatment for patients undergoing spine surgery, several patient-reported functional measures have been employed including the Scoliosis Research Society Questionnaire (SRS-30), Oswestry Disability Index (ODI) and the Short Form Health Survey (SF-12). The degree to which radiographic and functional measures of spinal disease correlate and interact remains unclear.

BACKGROUND CONTEXT: A common complication of cervical laminectomy and fusion with instrumentation (CLFI) is development of postoperative C5 nerve palsy. A proposed etiology is excess nerve tension from posterior drift of the spinal cord after decompression. We hypothesize that laminectomy width will be significantly increased in patients with C5 palsy and will correlate with palsy severity.PURPOSE: The purposes of this study were to evaluate laminectomy width as a risk factor for C5 palsy and to assess correlation with palsy severity.STUDY DESIGN/SETTING: : This is a retrospective, single-institution clinical study.PATIENT SAMPLE: Patient population included all patients with cervical spondylotic myelopathy who underwent CLFI between 2007 and 2014 by a single surgeon. Patients who underwent CLFI for trauma, infection, or tumor or had previous or circumferential cervical surgery were excluded. All patients with a new C5 palsy received a postoperative magnetic resonance imaging. An additional computed tomography (CT) scan was ordered to assess hardware. All control patients received a CT scan at 6 months postoperatively to evaluate fusion.OUTCOME MEASURES: The association between width of laminectomy and development of postopeative C5 palsy was measured.METHODS: Patient comorbidities including obesity, smoking history, and diabetes were recorded in addition to preopertaive and postoperative deltoid and biceps motor strength. Sagittal alignment was measured with C2-C7 Cobb angle preopertaive and postoperative radiographs. The width of laminectomy was measured in a blinded fashion on the postoperative CT scan by two observers.RESULTS: Seventeen patients with C5 nerve palsy and 12 controls were identified. There were no baseline differences in age, sex, diabetes, smoking history, number of surgical levels, or sagittal alignment. Body mass index was significantly higher in the control cohort. There was no significant increase in the C3-C7 laminectomy width in patients with postoperative C5 palsy. The width of laminectomy measurments were highly similar between the two observers. There was no correlation between laminectomy width and palsy severity.CONCLUSIONS: This is the largest series of C5 palsies after laminectomy documented with CT imaging. Laminectomy width was not associated with an increased risk of postoperative C5 palsy at any level. Reduction in laminectomy width may not reduce rate of postoperative nerve palsy. (C) 2016 Elsevier Inc. All rights reserved.

Background: Cervical spondylotic myelopathy ( CSM) is a common and underdiagnosed cause of gait dysfunction, rigidity, and falls in the elderly. Given the frequent concurrency of CSM and hip osteoarthritis, this study is designed to evaluate the relative risk of CSM on perioperative and short-term outcomes after total hip arthroplasty (THA).Methods: The Medicare Standard Analytical Files were searched from 2005 to 2012 to identify all patients undergoing primary THA and the subset of patients with preexisting CSM. Risk ratios with 95% confidence intervals were calculated for 90-day, 1-year, and overall follow-up for common postoperative complications: periprosthetic dislocation, fracture, infection, revision THA, and wound complications.Results: The risk ratios of all surgical complications, including dislocation, periprosthetic fractures, and prosthetic joint infection, were increased approximately 2-fold at all postoperative time points for patients.Conclusion: Preexisting CSM is a significant risk factor for primary THA complications including dislocation, periprosthetic fractures, and prosthetic joint infection. (C) 2016 Elsevier Inc. All rights reserved.

BACKGROUND CONTEXT: Precise screw placement is critical to avoid neurologic and vascular injury during posterior spinal instrumentation for scoliosis correction. Although multiple techniques exist to limit rates of screw malplacement there remains opportunity for improvement in radiation exposure, accuracy, and operating room efficiency.

Traditional open exposure for posterior instrumentation requires significant soft tissue mobilization and causes significant blood loss and increased recovery time. Mal-placed screws can injure nerve roots, the spinal cord, viscera, vasculature and the cardiopulmonary system. Placement of pedicle screws using a minimally invasive technique can decrease bleeding risk, damage to soft tissues, and post-operative pain. The purpose of this study is to compare the radiographic accuracy of open free-hand versus percutaneous technique for pedicle screw placement.

Background Sagittal balance restoration has been shown to be an important determinant of outcomes in corrective surgery for degenerative scoliosis. Lateral interbody fusion (LIF) is a less-invasive technique which permits the placement of a high lordosis interbody cage without risks associated with traditional anterior or transforaminal interbody techniques. Studies have shown improvement in lumbar lordosis following LIF, but only one other study has assessed sagittal balance in this population. The objective of this study is to evaluate the ability of LIF to restore sagittal balance in degenerative lumbar scoliosis. Methods Thirty-five patients who underwent LIF for degenerative thoracolumbar scoliosis from July 2013 to March 2014 by a single surgeon were included. Outcome measures included sagittal balance, lumbar lordosis, Cobb Angle, and segmental lordosis. Measures were evaluated pre-operative, immediately post-operatively, and at their last clinical follow-up. Repeated measures ANOVAs were used to assess the differences between pre-operative, first postoperative, and a follow-up visit. Results The average sagittal balance correction was not significantly different: 1.06cm from 5.79cm to 4.74cm forward. The average Cobb angle correction was 14.1 degrees from 21.6 to 5.5 degrees. The average change in global lumbar lordosis was found to be significantly different: 6.3 degrees from 28.9 to 35.2 degrees. Conclusions This study demonstrates that LIF reliably restores lordosis, but does not significantly improve sagittal balance. Despite this, patients had reliable improvement in pain and functionality suggesting that sagittal balance correction may not be as critical in scoliosis correction as previous studies have indicated. Clinical Relevance LIF does not significantly change sagittal balance; however, clinical improvement does not seem to be contingent upon sagittal balance correction in the degenerative scoliosis population. The DUHS IRB has determined this study meets criteria for an IRB waiver.

Lateral interbody fusion (LIF) via the retroperitoneal transpsoas approach is an increasingly popular, minimally invasive technique for interbody fusion in the thoracolumbar spine that avoids many of the complications of traditional anterior and transforaminal approaches. Renal vascular injury has been cited as a potential risk in LIF, but little has been documented in the literature regarding the etiology of this injury. The authors discuss a case of an intraoperative complication of renal artery injury during LIF. A 42-year-old woman underwent staged T12-L5 LIF in the left lateral decubitus position, and L5-S1 anterior lumbar interbody fusion, followed 3 days later by T12-S1 posterior instrumentation for idiopathic scoliosis with radiculopathy refractory to conservative management. After placement of the T12-L1 cage, the retractor was released and significant bleeding was encountered during its removal. Immediate consultation with the vascular team was obtained, and hemostasis was achieved with vascular clips. The patient was stabilized, and the remainder of the procedure was performed without complication. On postoperative CT imaging, the patient was found to have a supernumerary left renal artery with complete occlusion of the superior left renal artery, causing infarction of approximately 75% of the kidney. There was no increase in creatinine level immediately postoperatively or at the 3-month follow-up. Renal visceral and vascular injuries are known risks with LIF, with potentially devastating consequences. The retroperitoneal transpsoas approach for LIF in the superior lumbar spine requires a thorough knowledge of renal visceral and vascular anatomy. Supernumerary renal arteries occur in 25%-40% of the population and occur most frequently on the left and superior to the usual renal artery trunk. These arteries can vary in number, position, and course from the aorta and position relative to the usual renal artery trunk. Understanding of renal anatomy and the potential variability of the renal vasculature is essential to prevent iatrogenic injury.

BACKGROUND CONTEXT: It is well known that patients with severe radiographic malalignment and functional disability from scoliosis can achieve significant functional improvement and pain relief with corrective surgery. However, thresholds for operative intervention in adult scoliosis patients with moderate deformity and/or functional impairment are not well established. Multiple patient-reported questionnaires have been used to assess scoliosis patients preoperatively and postoperatively; however, the sensitivity of these scores to measure significantly change after treatment is not well understood.