Bryan M. Beaubrun

Full-Body Analysis of Adult Spinal Deformity Patients' Age-Adjusted Alignment at 1 Year

BACKGROUNDnPrevious studies have built a foundation for understanding compensation in patients with adult spinal deformity (ASD) by using full-body stereographic assessments. These mechanisms, in relation to age-adjusted alignment targets, have yet to be studied fully. The aim of this study was to assess lower-limb compensatory mechanisms of patients failing to meet age-adjusted alignment goals.nnnMETHODSnPatients with ASD ≥40 years with full body baseline and follow-up radiographs were included. Patients were stratified by age (40-65 years, >65 years) and spinopelvic correction. Lower-limb compensation parameters (pelvic shift, hip extension, knee flexion [KA], ankle flexion [AA], and global sagittal angle [GSA]) for patients who matched and failed to match age-adjusted alignment targets were compared with analysis of variance and t-test analysis.nnnRESULTSnIn total, 108 patients were included. At 1 year, AA increased with age in the match pelvic tilt (PT) andxa0spinopelvic mismatch (PI-LL) cohorts (PT: AA, 5.6-7.8, Pxa0= 0.041; PI-LL: 4.9-8.8, Pxa0= 0.026). KA, AA, and GSA increased with age in the match sagittal vertical axis (SVA) cohort (KA: 3.8-13.1, Pxa0= 0.002; AA: 5.8-10.2, Pxa0=xa00.008; GSA: 3.9-7.8, P < 0.001), as did KA and GSA in the match T1 pelvic angle group (KA: 1.8-8.7, Pxa0= 0.020; GSA: 2.6-5.7, Pxa0= 0.004).nnnCONCLUSIONSnGreater compensation captured by KA and GSA was associated with age progression in the match SVA and T1 pelvic angle cohorts. In addition, older SVA, PT, and PI-LL match cohorts used increased AA, suggesting that ideal postoperative alignment of aged individuals with ASD involves increased compensation.

Rates of Mortality in Lumbar Spine Surgery and Factors Associated With Its Occurrence Over a 10-Year Period: A Study of 803,949 Patients in the Nationwide Inpatient Sample

ABSTRACT Background: The rate of mortality in surgical procedures involving the lumbar spine has historically been low, and as a result, there has been difficulty providing accurate quantitative mortality rates to patients in the preoperative planning phase. Awareness of these mortality rates is essential in reducing postoperative complications and improving outcomes. Additionally, mortality rates can be influenced by procedure type and patient profile, including demographics and comorbidities. The purpose of this study is to assess rates and risk factors associated with mortality in surgical procedures involving the lumbar spine using a large national database. Methods: The Nationwide Inpatient Sample database was reviewed from 2003 to 2012. A total of 803,949 patients age 18 years or older were identified by ICD-9CM procedure codes for spinal fusion or decompression of the lumbar spine. Mortality was stratified based on type of procedure (simple or complex fusion, decompression), patient demographics and comorbidities, and in-hospital complications. Binary logistic regression was used to identify the risk of death while controlling for comorbidities, race, sex, and procedure performed. Significance was defined as P < .05 differences relative to the overall cohort. Results: Mortality for all patients requiring surgery of the lumbar spine was 0.13%. Mortality based on procedure type was 0.105% for simple fusions, 0.321% for complex fusions, and 0.081% for decompression only. Increased mortality was observed demographically in patients who were male (odds ratio [OR]: 1.75; 95% confidence interval [CI]: 1.51–2.03), black (OR: 1.40; CI: 1.10–1.79), ages 65–74 (OR: 1.46; CI: 1.25–1.70), and age 75+ (OR: 2.70; CI: 2.30–3.17). Comorbidities associated with the greatest increase in mortality were mild (OR: 10.04; CI: 7.76–13.01) and severe (OR: 26.47; CI: 16.03–43.70) liver disease and congestive heart failure (OR: 4.57; CI: 3.77–5.53). The complications with the highest mortality rates were shock (OR: 20.67; CI: 13.89–30.56) and pulmonary embolism (OR: 20.15; CI: 14.01–29.00). Conclusions: From 2003 to 2012, the overall mortality rate in 803,949 lumbar spine surgery patients was 0.13%. Risk factors that were significantly associated with increased mortality rates were male gender, black race, and ages 65–74 and 75+. Comorbidities associated with an increased mortality rate were mild and severe liver disease and congestive heart failure. Inpatient complications with the highest mortality rates were shock and pulmonary embolism. These findings can be helpful to surgeons providing preoperative counseling for patients considering elective lumbar procedures and for allocating resources to treat and prevent perioperative complications leading to mortality. Level of Evidence: 3.

Radiological severity of hip osteoarthritis in patients with adult spinal deformity: the effect on spinopelvic and lower extremity compensatory mechanisms

PurposeSagittal spinal deformity (SSD) patients utilize pelvic tilt (PT) and their lower extremities in order to compensate for malalignment. This study examines the effect of hip osteoarthritis (OA) on compensatory mechanisms in SSD patients.MethodsPatientsxa0≥xa018xa0years with SSD were included for analysis. Spinopelvic, lower extremity, and cervical alignment were assessed on standing full-body stereoradiographs. Hip OA severity was graded by Kellgren–Lawrence scale (0–4). Patients were categorized as limited osteoarthritis (LOA: grade 0–2) and severe osteoarthritis (SOA: grade 3–4). Patients were matched for age and T1-pelvic angle (TPA). Spinopelvic [sagittal vertical axis (SVA), T1-pelvic angle, thoracic kyphosis (TK), pelvic tilt (PT), lumbar lordosis (LL), pelvic incidence minus lumbar lordosis (PI-LL), T1-spinopelvic inclination (T1SPi)] and lower extremity parameters [sacrofemoral angle, knee angle, ankle angle, posterior pelvic shift (P. Shift), global sagittal axis (GSA)] were compared between groups using independent sample t test.Results136 patients (LOAxa0=xa068, SOAxa0=xa068) were included in the study. SOA had less pelvic tilt (pxa0=xa00.011), thoracic kyphosis (pxa0=xa00.007), and higher SVA and T1Spi (pxa0<xa00.001) than LOA. SOA had lower sacrofemoral angle (pxa0<xa00.001) and ankle angle (pxa0=xa00.043), increased P. Shift (pxa0<xa00.001) and increased GSA (pxa0<xa00.001) compared to LOA. There were no differences in PI-LL, LL, knee angle, or cervical alignment (pxa0>xa00.05).ConclusionsPatients with coexisting spinal malalignment and SOA compensate by pelvic shift and thoracic hypokyphosis rather than PT, likely as a result of limited hip extension secondary to SOA. As a result, SOA had worse global sagittal alignment than their LOA counterparts.Graphical abstractThese slides can be retrieved under Electronic Supplementary Material.

Psoas Morphology Differs between Supine and Sitting Magnetic Resonance Imaging Lumbar Spine: Implications for Lateral Lumbar Interbody Fusion

Study Design Retrospective radiological review. Purpose To quantify the effect of sitting vs supine lumbar spine magnetic resonance imaging (MRI) and change in anterior displacement of the psoas muscle from L1–L2 to L4–L5 discs. Overview of Literature Controversy exists in determining patient suitability for lateral lumbar interbody fusion (LLIF) based on psoas morphology. The effect of posture on psoas morphology has not previously been studied; however, lumbar MRI may be performed in sitting or supine positions. Methods A retrospective review of a single-spine practice over 6 months was performed, identifying patients aged between 18–90 years with degenerative spinal pathologies and lumbar MRIs were evaluated. Previous lumbar fusion, scoliosis, neuromuscular disease, skeletal immaturity, or intrinsic abnormalities of the psoas muscle were excluded. The anteroposterior (AP) dimension of the psoas muscle and intervertebral disc were measured at each intervertebral disc from L1–L2 to L4–L5, and the AP psoas:disc ratio calculated. The morphology was compared between patients undergoing sitting and/or supine MRI. Results Two hundred and nine patients were identified with supine-, and 60 patients with sitting-MRIs, of which 13 patients had undergone both sitting and supine MRIs (BOTH group). A propensity score match (PSM) was performed for patients undergoing either supine or sitting MRI to match for age, BMI, and gender to produce two groups of 43 patients. In the BOTH and PSM group, sitting MRI displayed significantly higher AP psoas:disc ratio compared with supine MRI at all intervertebral levels except L1–L2. The largest difference observed was a mean 32%–37% increase in sitting AP psoas:disc ratio at the L4–L5 disc in sitting compared to supine in the BOTH group (range, 0%–137%). Conclusions The psoas muscle and the lumbar plexus become anteriorly displaced in sitting MRIs, with a greater effect noted at caudal intervertebral discs. This may have implications in selecting suitability for LLIF, and intra-operative patient positioning.