Richard A. Tallarico

Risk factors for delayed extubation in thoracic and lumbar spine surgery: a retrospective analysis of 135 patients.

PurposeExtubation may be delayed after spine surgery mainly for the concerns of airway safety. Risk factors for delayed extubation in cervical spine surgery have been described to include prolonged surgery time and amount of crystalloids or blood transfused. To date, risk factors for delayed extubation in thoracic or lumbar spine surgery have not been investigated. We retrospectively reviewed 135 consecutive patients from 2006 to 2009 who underwent thoracic or lumbar spine surgery by one particular surgeon to identify risk factors for delayed extubation.MethodsData including patient factors, surgical time, anesthetic technique, blood loss, crystalloid and colloid administration, transfusion requirements, time to transfusion, and time to extubation were collected and analyzed. Delayed extubation was defined as the patient was not extubated in the operating room at completion of the surgery.ResultsOne hundred and eight patients were extubated in the OR. Delayed extubation occurred in 27 patients. Delayed extubation was significantly related to total operative time (6.6xa0±xa00.4 vs. 5.2xa0±xa00.1xa0h), volume of crystalloid replacement (6,018xa0±xa0408 vs. 4,186xa0±xa0130xa0cm3), volume of total colloids infused (787xa0±xa093 vs. 442xa0±xa036xa0cm3), intraoperative blood transfused (3.7xa0±xa00.5 vs. 0.7xa0±xa00.1 units); blood loss (2,137xa0±xa0286 vs. 832xa0±xa050xa0cm3), and time to starting blood transfusion (106xa0±xa012 vs. 199xa0±xa09xa0min).ConclusionsOur study suggests that intraoperative factors including prolonged surgical time, significant blood loss, larger volume of crystalloid and colloid infusion, and blood transfusion may be risk factors for delayed extubation following thoracic or lumbar spine surgery. Early blood transfusion may also increase the risk of delayed extubation. Patient factors did not affect extubation time.

The Association of Sacral Table Angle Measurements With Spondylolytic and Spondylolisthetic Defects at the Lumbosacral Articulation: A Radiographic Analysis

STUDY DESIGNnRetrospective radiographic study of 6 patients with L5 spondylolysis observed prospectively before the onset of lysis through adulthood. A radiographic analysis of 50 pediatric control subjects was compared with the study group.nnnOBJECTIVEnTo determine whether sacral table angle (STA) measurements bear etiologic association with the development of spondylolysis and/or subsequent spondylolisthesis.nnnSUMMARY OF BACKGROUND DATAnAlthough radiographic parameters in association with spondylolysis and isthmic spondylolisthesis have been studied, no parameter has been shown to definitively have a role in development of this disease process. The STA is a recently described radiographic parameter useful in measuring anatomic changes across the lumbosacral articulation. This measurements role as a predictor of pars lysis and subsequent slippage remains unknown.nnnMETHODSnThe researchers examined the longitudinal plain radiographs of 6 patients observed from childhood, before the development of spondylolysis, through adulthood. Measurements of STA and percent slippage were performed. Fifty pediatric control subjects radiographs were also examined with STA measurements. Statistical analysis was conducted on results.nnnRESULTSnMean STA of the study group before the development of spondylolysis was 95° ± 5.5°. Mean STA from the control group was 97.5° ± 4.3°. No statistical difference was found between groups (p > .05). No index patient had an abnormal STA before spondylolysis (less than 89°, defined as being outside 2 standard deviations from the control mean). Four of 6 index patients with spondylolysis developed spondylolisthesis. A negative correlation (r = .54) was seen for STA as a function of increasing percent slip when assessed longitudinally.nnnCONCLUSIONSnAbnormal STA measurement was not seen before the development of spondylolysis in this study population. Decreasing STAs were seen secondarily in patients with L5 spondylolisthetic progression. This finding points to anatomic change and secondary remodeling of the upper sacrum as a result of slippage.

Analysis of instrumentation failures after three column osteotomies of the spine

BackgroundCorrection of fixed spinal imbalance in a sagittal and/or coronal plane frequently needs a tricolumnar wedge resection when the deformity is rigid. Complications associated with deformity correction surgery are pseudoarthrosis and implant failure located along the construct. The purposes of this study were to assess comparative rates of pseudoarthrosis (implant failure) at weaker points along lumbosacral junction and level of osteotomy, estimate overall incidence of implant failure, and comparatively analyze failures at different points along the construct.MethodsThis was an IRB approved, single center study retrospective analysis. Twenty-six patients who underwent three column osteotomies were grouped according to procedure: pedicle subtraction osteotomy (PSO, (nu2009=u200918)); vertebral column resection (VCR, (nu2009=u20094)); hemivertebra excision (HE, (nu2009=u20092)); and extracavitary corpectomy (EC, (nu2009=u20092)). Follow-up data is presented on all of the study patients. Number of levels of fusion, anchors, percent saturation of fixation levels, type of bone graft and graft substitutes, and rod material and diameter were recorded. Radiographical data was reviewed preoperatively and postoperatively at 2xa0weeks and 3, 6, and 12xa0months and annually to determine sagittal and coronal balance, lumbopelvic parameters, presence or absence of interbody structural support, laterality or rod failure, and time to implant failure.ResultsTwenty-seven percent (7/26) patients demonstrated rod breakage either unilaterally (Nu2009=u20092) or bilaterally (Nu2009=u20095) during follow-up. Seventy-one percent had increasing back pain or worsening sagittal balance, while remaining failures found incidentally. No failures in children were seen.ConclusionTricolumnar osteotomy by posterior approach is a valuable tool. Rod failures found approximately 1xa0year from surgery, with 86% located at level of osteotomy and 14% at lumbosacral junction. Possible reasons are increased stress in the rod at this point and relatively deficient bone stock secondary to wide laminectomy. The low rate of rod breakage at lumbosacral junction may be related to adoption of structural interbody graft and stronger iliac screws. Additional biomechanical studies needed to assess the importance of these factors. This was a level IV study.

Comparison of Surgeon Rating of Severity of Stenosis Using Magnetic Resonance Imaging, Dural Cross-Sectional Area, and Functional Outcome Scores

OBJECTIVEnTo determine the relationship between the severity of stenosis graded using both surgeons visual assessment of spinal stenosis as well as measurement of dural cross-sectional area on magnetic resonance imaging (MRI), with the patients disability.nnnMETHODSnSeven fellowship-trained spine surgeons reviewed MRI studies retrospectively of 30 symptomatic consecutive patients with lumbar stenosis and graded stenosis in the central canal, the lateral recess, and the foramen at T12-L1 to L5-S1 as none, mild, moderate, or severe. Dural cross-sectional area was measured at each level from T12-L1 to L5-S1. All patients completed the questionnaires for Oswestry Disability Index (ODI), Short Form 36 (SF-36), and recorded Visual Analog Scale scores for leg and back pain, and symptom severity scale of the Zurich claudication questionnaire.nnnRESULTSnThere was positive correlation between the right leg pain Visual Analog Scale score and the mean surgeon grades for central and lateral recess stenosis at L4-L5 and lateral recess stenosis at L5-S1. Except for a positive correlation between role physical score and surgeon grade for lateral recess stenosis at L5-S1, we found no correlation between the surgeons grading of stenosis at any level with the ODI or SF-36. We found no correlation between the dural cross-sectional area with the ODI or SF-36. We did not find any correlation between the Zurich symptom severity scale and surgeons grading of stenosis at any level.nnnCONCLUSIONSnAlthough surgeons rely on visual assessment of the severity of stenosis while making surgical decisions, we found that objective and subjective imaging parameters to grade severity of stenosis did not consistently indicate the patients disability level.

Positional effects of transforaminal interbody spacer placement at the L5-S1 intervertebral disc space: a biomechanical study

BACKGROUND CONTEXTnTransforaminal lumbar interbody fusion (TLIF) is an increasingly used alternative fusion method over anterior and posterior lumbar interbody fusions. There are conflicting results on the optimal positioning of interbody devices. No study has addressed the lumbosacral segment, L5-S1, where the lordotic configuration presents unique challenges.nnnPURPOSEnTo determine if there are biomechanical and/or anatomical advantages related toxa0thexa0positioning of an interbody device at L5-S1, either anterior or posterior to the neutral axis.nnnSTUDY DESIGNnAn inxa0vitro biomechanical study using human cadaveric lumbar specimens.nnnMETHODSnLumbar specimens were biomechanically tested using pure moments with and without compressive axial loading. Testing was performed in intact and after TLIF with the implant posterior (TLIF-post) and anterior (TLIF-ant) to neutral axis. Segmental range of motion (ROM) and stiffness were analyzed at the L5-S1 surgical level and the adjacent L4-L5 level. Neuroforaminal height measurements of L5-S1 were analyzed in neutral and end range positions.nnnRESULTSnCompared with the intact condition, ROM decreased more than 75% at L5-S1 and stiffness increased up to 270% with TLIF. There was no significant difference between anterior or posterior placement for ROM and stiffness. There was a change in L5-S1 neuroforaminal height based on the placement, with posterior placement showing a significant increase compared with anterior placement. There were no relative changes in neuroforaminal height under loading after TLIF. Compressive load did not affect the magnitudes or resulting significance of outcome measures at L5-S1 after either TLIFs.nnnCONCLUSIONSnAn interbody spacer with the addition of posterior instrumentation significantly enhances the mechanical stability of L5-S1 regardless of interbody position. There were noticeable increases in terms of construct stability and stiffness after both TLIF-ant and TLIF-post in comparison with the intact condition. A posteriorly placed interbody implant did result in the distraction ofxa0the neuroforamin. Positioning an interbody implant at L5-S1 for TLIF with posterior instrumentation should be at the discretion of the surgeon without consequence to biomechanical stability.

Early Lumbar Nerve Root Deficit After Three Column Osteotomy for Fixed Sagittal Plane Deformities in Adults

ABSTRACT Background: Three-column osteotomy is an effective means of correcting fixed sagittal plane deformities. Deformity correction surgeries may be associated with early postoperative neurological deficits often presenting as palsies involving the lumbar roots. The objective was to retrospectively assess a subset of our series of adult deformity correction surgeries and analyze neurological deficits and associated patient and surgical factors. Methods: Hospital records of 17 patients from a single center were examined. Inclusion criterion were adults (>18 years) who underwent a 3-column osteotomy (pedicle subtraction osteotomy) at the lumbar level for fixed sagittal plane deformities including positive sagittal balance, flat back syndrome, and posttraumatic kyphosis. These also included cases with associated degenerative lumbar scoliosis. Patients were divided in 2 groups: Group 1 with lumbar root deficit and Group 2 with no deficits. We examined the surgical details of the osteotomy, complications during surgery, and observed if the magnitude of correction in the sagittal or coronal plane bore any influence on the nerve deficit. Results: All 17 patients had a single-level resection except 1 patient who had 2-level osteotomy; 23.5% (4 of 17) developed nerve deficit. Nerve deficit presented as bilateral foot drop (1); unilateral extensor hallucis longus (EHL) weakness (2); and unilateral quadriceps weakness (1). The patient with quadriceps weakness partially recovered to functional strength. Two patients with EHL weakness fully recovered; however, the patient with bilateral foot drop did not improve. L5-S1 interbody fusion was done in 3 of 4 cases in Group 1 and 4 of 13 cases in Group 2. Conclusions: Nerve deficits after 3-column corrective osteotomies occurred in 23% cases. All but 1 case had significant improvement. Most nerve palsies are neuropraxia and unilateral and tend to recover. L5 weakness appears most common after high lumbar osteotomies. Significant correction of scoliosis at the osteotomy level (>50%) may be a reason for nerve palsy.

Assessment of Coronal Spinal Alignment for Adult Spine Deformity Cases After Intraoperative T Square Shaped Use

STUDY DESIGNnRetrospectively reviewed surgeries between 2011 and 2015 of patients who underwent posterior spinal deformity instrumentation with constructs involving fusions to pelvis and encompassing at least five levels.nnnOBJECTIVEnMeasure the radiographic outcomes of coronal malalignment (CM) after use of an intraoperative T square shaped instrument in posterior spinal deformity surgeries with at least five levels of fusion and extension to pelvis.nnnBACKGROUNDnNeuromuscular children found to benefit from intraoperative T square technique to help achieve proper coronal spinal balance with extensive fusions. This intraoperative technique used in our posterior spine deformity instrumentation surgeries with the aforementioned parameters.nnnMETHODSnThere were 50 patients: n = 16 with intraoperative T square and n = 34 no-T square shaped device. Subgroups divided based on greater than 20 mm displacement and greater than 40 mm displacement of the C7 plumb line to the central sacral vertical line on either side in preoperative radiographs. We analyzed the demographics and the pre- and postoperative radiographic parameters of standing films: standing CM (displacement of C7 plumb line to central sacral vertical line), and major coronal Cobb angles in total sample and subgroups and compared T square shaped device with no-T square shaped device use by analysis of variance. A p value ≤.05 is statistically significant.nnnRESULTSnIn the total sample, though postoperative CM mean was not statistically different, we observed greater CM corrections in patients where a T square shaped device was used (70%) versus no-T square shaped device used (18%). In >20 mm and >40 mm subgroups, the postoperative mean CM values were statistically lower for the patients where a T square shaped device was used, p = .016 and p = .003, respectively. Cobb corrections were statistically higher for T square shaped device use in both >20 mm and >40 mm subgroups, 68%, respectively.nnnCONCLUSIONnThe intraoperative T square shaped device technique had a positive effect on the amount of spine coronal malalignment correction after its use and for lumbar and thoracic coronal Cobb angles.nnnLEVEL OF EVIDENCEnLevel III.STUDY DESIGNnRetrospectively reviewed surgeries between 2011 and 2015 of patients who underwent posterior spinal deformity instrumentation with constructs involving fusions to pelvis and encompassing at least five levels.nnnOBJECTIVEnMeasure the radiographic outcomes of coronal malalignment (CM) after use of an intraoperative T square shaped instrument in posterior spinal deformity surgeries with at least five levels of fusion and extension to pelvis.nnnBACKGROUNDnNeuromuscular children found to benefit from intraoperative T square technique to help achieve proper coronal spinal balance with extensive fusions. This intraoperative technique used in our posterior spine deformity instrumentation surgeries with the aforementioned parameters.nnnMETHODSnThere were 50 patients: n = 16 with intraoperative T square and n = 34 no-T square shaped device. Subgroups divided based on greater than 20 mm displacement and greater than 40 mm displacement of the C7 plumb line to the central sacral vertical line on either side in preoperative radiographs. We analyzed the demographics and the pre- and postoperative radiographic parameters of standing films: standing CM (displacement of C7 plumb line to central sacral vertical line), and major coronal Cobb angles in total sample and subgroups and compared T square shaped device with no-T square shaped device use by analysis of variance. A p value ≤.05 is statistically significant.nnnRESULTSnIn the total sample, though postoperative CM mean was not statistically different, we observed greater CM corrections in patients where a T square shaped device was used (70%) versus no-T square shaped device used (18%). In >20 mm and >40 mm subgroups, the postoperative mean CM values were statistically lower for the patients where a T square shaped device was used, p = .016 and p = .003, respectively. Cobb corrections were statistically higher for T square shaped device use in both >20 mm and >40 mm subgroups, 68%, respectively.nnnCONCLUSIONnThe intraoperative T square shaped device technique had a positive effect on the amount of spine coronal malalignment correction after its use and for lumbar and thoracic coronal Cobb angles.nnnLEVEL OF EVIDENCEnLevel III.

Surgeon Reliability for the Assessment of Lumbar Spinal Stenosis on MRI: The Impact of Surgeon Experience

Background Treating surgeons visual assessment of axial MRI images to ascertain the degree of stenosis has a critical impact on surgical decision-making. The purpose of this study was to prospectively analyze the impact of surgeon experience on inter-observer and intra-observer reliability of assessing severity of spinal stenosis on MRIs by spine surgeons directly involved in surgical decision-making. Methods Seven fellowship trained spine surgeons reviewed MRI studies of 30 symptomatic patients with lumbar stenosis and graded the stenosis in the central canal, the lateral recess and the foramen at T12-L1 to L5-S1 as none, mild, moderate or severe. No specific instructions were provided to what constituted mild, moderate, or severe stenosis. Two surgeons were “senior” (>fifteen years of practice experience); two were “intermediate” (>four years of practice experience), and three “junior” (< one year of practice experience). The concordance correlation coefficient (CCC) was calculated to assess inter-observer reliability. Seven MRI studies were duplicated and randomly re-read to evaluate inter-observer reliability. Results Surgeon experience was found to be a strong predictor of inter-observer reliability. Senior inter-observer reliability was significantly higher assessing central(p<0.001), foraminal p=0.005 and lateral p=0.001 than “junior” group.Senior group also showed significantly higher inter-observer reliability that intermediate group assessing foraminal stenosis (p=0.036). In intra-observer reliability the results were contrary to that found in inter-observer reliability. Conclusion Inter-observer reliability of assessing stenosis on MRIs increases with surgeon experience. Lower intra-observer reliability values among the senior group, although not clearly explained, may be due to the small number of MRIs evaluated and quality of MRI images. Level of evidence: Level 3.

Lumbar vertebral body and pars fractures following laminectomy

Abstract A 56-year-old alcoholic male incurred L5 vertebral body and bilateral L4 pars fractures with progressive L4 on L5 anterolisthesis following low-energy falls while intoxicated. Recently, he had a L3–S1 laminectomy for lumbar spinal stenosis with claudication. Preoperative imaging and radiographs were negative for pars defects and instability, so an isolated decompressive surgery was performed. Following low-energy falls, his outpatient work-up revealed fractures through the bilateral L4 pedicles and posterior third of L5 vertebral body, with recurrence of axial back pain and bilateral lower extremity radiculopathy. He underwent revision decompression from L4–S1 and posterior instrumented fusion with transforaminal lumbar interbody fusion performed at each revised level. His axial back pain and radiculopathy improved postoperatively. Instability of a lumbar spine fracture pattern can be due to the remote or prior iatrogenic disruption of the posterior ligamentous complex. Our patient benefitted from surgery and his low back pain was resolved.