Search Results

You are looking at 1 - 5 of 5 items for

  • Author or Editor: Paul Sponseller x
Clear All Modify Search
Restricted access

Bryan W. Cunningham, Paul D. Sponseller, Ashley A. Murgatroyd, Jun Kikkawa and P. Justin Tortolani

OBJECTIVE

The objective of the current study was to quantify and compare the multidirectional flexibility properties of sacral alar iliac fixation with conventional methods of sacral and sacroiliac fixation by using nondestructive and destructive investigative methods.

METHODS

Twenty-one cadaveric lumbopelvic spines were randomized into 3 groups based on reconstruction conditions: 1) S1–2 sacral screws; 2) sacral alar iliac screws; and 3) S1–iliac screws tested under unilateral and bilateral fixation. Nondestructive multidirectional flexibility testing was performed using a 6-degree-of-freedom spine simulator with moments of ± 12.5 Nm. Flexion-extension fatigue loading was then performed for 10,000 cycles, and the multidirectional flexibility analysis was repeated. Final destructive testing included an anterior flexural load to construct failure. Quantification of the lumbosacral and sacroiliac joint range of motion was normalized to the intact spine (100%), and flexural failure loads were reported in Newton-meters.

RESULTS

Normalized value comparisons between the intact spine and the 3 reconstruction groups demonstrated significant reductions in segmental flexion-extension, lateral bending, and axial rotation motion at L4–5 and L5–S1 (p < 0.05). The S1–2 sacral reconstruction group demonstrated significantly greater flexion-extension motion at the sacroiliac junction than the intact and comparative reconstruction groups (p < 0.05), whereas the sacral alar iliac group demonstrated significantly less motion at the sacroiliac joint in axial rotation (p < 0.05). Absolute value comparisons demonstrated similar findings. Under destructive anterior flexural loading, the S1–2 sacral group failed at 105 ± 23 Nm, and the sacral alar iliac and S1–iliac groups failed at 119 ± 39 Nm and 120 ± 28 Nm, respectively (p > 0.05).

CONCLUSIONS

Along with difficult anatomy and weak bone, the large lumbosacral loads with cantilever pullout forces in this region are primary reasons for construct failure. All reconstructions significantly reduced flexibility at the L5–S1 junctions, as expected. Conventional S1–2 sacral fixation significantly increased sacroiliac motion under all loading modalities and demonstrated significantly higher flexion-extension motion than all other groups, and sacral alar iliac fixation reduced motion in axial rotation at the sacroiliac joint. Based on comprehensive multidirectional flexibility testing, the sacral alar iliac fixation technique reduced segmental motion under some loading modalities compared to S1–iliac screws and offers potential advantages of lower instrumentation profile and ease of assembly compared to conventional sacroiliac instrumentation techniques.

Restricted access

Sensitivity of human glioma and brain cells to natural killer cell lysis

Effects of serum concentration, epidermal growth factor, and time in culture

Rene L. Myers, Ronald L. Whisler, Ralph E. Stephens, Craig A. Sponseller, Kimberly Livingston, Paul M. Spring and Allan J. Yates

✓ Using an in vitro monolayer natural killer (NK) cytolysis assay, the authors examined the effects of serum concentration and epidermal growth factor (EGF) on sensitivity to NK cytolysis. It was found that target cells cultured in high concentrations of serum (10% fetal bovine serum (FBS)) had higher cytotoxicity levels than those in low serum concentrations (0% to 0.5% FBS). Exposure of target cells to EGF had no effect on their sensitivity to NK cytolysis. Both glioma cell lines showed decreased NK cell sensitivity with longer times in culture. The results of cytofluorometric studies on these cell lines indicate that the differences in NK cell sensitivity may reflect the growth fraction of the target population and that a population with a higher proportion of cycling cells is more susceptible to lysis by NK cells. Whether it is possible to separate the proliferative rate of these cells from their NK cell sensitivity is unknown, but worthy of consideration.

Free access

Nancy Abu-Bonsrah, C. Rory Goodwin, Gezzer Ortega, Fizan Abdullah, Edward Cornwell, Rafael De la Garza-Ramos, Mari L. Groves, Michael Ain, Paul D. Sponseller and Daniel M. Sciubba

OBJECTIVE

Spinal arthrodesis is routinely performed in the pediatric population. However, there is limited information on the short-term outcomes of pediatric patients who have undergone spine fusion. Thus, the authors conducted a retrospective review of the Pediatric National Surgical Quality Improvement Program (NSQIP) database to determine the short-term mortality, complication, reoperation, and readmission rates of pediatric patients who underwent spinal arthrodesis for all indications.

METHODS

The Pediatric NSQIP database was queried for all patients who underwent spinal arthrodesis between 2012 and 2014. Patient demographics, comorbidities, body mass index, American Society of Anesthesiologists classification, and operative time were abstracted. Short-term mortality, reoperation, and readmission rates and complications were also noted. Univariate and multivariate analyses were performed to delineate patient risk factors that influence short-term mortality, complications, reoperation, and readmission rates.

RESULTS

A total of 4420 pediatric patients who underwent spinal fusion were identified. Common indications for surgical intervention included acquired/idiopathic scoliosis or kyphoscoliosis (71.2%) and genetic/syndromic scoliosis (10.7%). The mean patient age was 13.7 ± 2.9 years, and 70% of patients were female. The overall 30-day mortality was 0.14%. Multivariate analysis showed that female sex and pulmonary comorbidities significantly increased the odds of reoperation, with odds ratios of 1.43 and 1.78, respectively.

CONCLUSIONS

In the NSQIP database for pediatric patients undergoing spinal arthrodesis for all causes, there was a 3.6% unplanned reoperation rate, a 3.96% unplanned readmission rate, and a 9.0% complication rate. This analysis provides data for risk stratification of pediatric patients undergoing spinal arthrodesis, allowing for optimized care.

Full access

Rafael De la Garza Ramos, C. Rory Goodwin, Nancy Abu-Bonsrah, Amit Jain, Emily K. Miller, Nicole Huang, Khaled M. Kebaish, Paul D. Sponseller and Daniel M. Sciubba

OBJECTIVE

The aim of this study was to investigate the incidence of and factors associated with complications following idiopathic scoliosis surgery in adolescents.

METHODS

The Nationwide Inpatient Sample database was used to identify patients 10–18 years of age who had undergone spinal fusion for adolescent idiopathic scoliosis (AIS) from 2002 to 2011. Twenty-three unique in-hospital postoperative complications, including death, were examined. A series of logistic regressions was used to determine if any demographic, comorbid, or surgical parameter was associated with complication development. Results of multiple logistic regression analyses were reported as odds ratios with 95% confidence intervals. All analyses were performed after the application of discharge weights to produce national estimates.

RESULTS

A total of 36,335 patients met the study inclusion criteria, 7.6% of whom (95% CI 6.3%–8.9%) developed at least one in-hospital complication. The 3 most common complications were respiratory failure (3.47%), reintubation (1.27%), and implant related (1.14%). Major complications such as death, pancreatitis, disseminated intravascular coagulation, visual loss, spinal cord injury, cardiac arrest, sepsis, nerve root injury, deep vein thrombosis, pulmonary embolism, shock, malignant hyperthermia, myocardial infarction, and iatrogenic stroke each had an incidence ≤ 0.2%. On multiple logistic regression analysis, an increasing age (OR 0.80) was associated with significantly lower odds of complication development; patients who were male (OR 1.80) or who had anemia (OR 2.10), hypertension (OR 2.51), or hypothyroidism (OR 2.27) or underwent revision procedures (OR 5.55) were at a significantly increased risk for complication development. The rates of postoperative complications for posterior, anterior, and combined approaches were 6.7%, 10.0%, and 19.8%, respectively (p < 0.001). Length of fusion (< 8 vs ≥ 8 levels) was not associated with complication development (p = 0.311).

CONCLUSIONS

Analysis of 36,335 patients who had undergone surgery for AIS revealed that younger patients, male patients, patients with a history of anemia, hypertension, or hypothyroidism, as well as those undergoing revision or anterior or combined approaches may have higher rates of postoperative complications. However, the overall complication rate was low (7.6%), and major complications had a rate ≤ 0.2% for each event. These findings suggest that surgery for AIS remains relatively safe, and future prospective investigations may further help to decrease the postoperative morbidity rate.