Jason D. Eubanks

Risk factors for the development of perioperative complications in elderly patients undergoing lumbar decompression and arthrodesis for spinal stenosis : an analysis of 166 patients

Study Design. Retrospective review. Objective. To quantify and describe perioperative complication rates in a large series of well-matched elderly patients who underwent lumbar decompression and arthrodesis. Summary of Background Data. Posterior lumbar decompression and fusion is frequently performed to treat lumbar stenosis with instability. An increasing number of elderly patients are undergoing operative treatment for degenerative lumbar disease. The reported morbidity of performing decompression and arthrodesis in this population varies widely in the literature, with recent reports showing a high rate of major complications. Methods. A total of 166 patients age 65 or older that underwent primary posterior lumbar decompression and fusion with (group 1; n = 75) or without (group 2; n = 91) instrumentation were included. Hospital records were reviewed for the occurrence of any complications (major and minor), the need for transfusion, estimated length of stay, and disposition at discharge. Logistic regression (with the presence/absence of major complications as the dependent variable) was used to identify risk factors for the occurrence of a complication. Results. Five major complications (3%) occurred (group 1, 1; group 2, 4). Minor complications developed in 30.7% of group 1 and 31.9% of group 2. There were no deaths, and only one perioperative complication was attributable to the use of instrumentation. Decompression/fusion of 4 or more segments was significantly associated with the occurrence of a major complication. Advanced age, the presence of medical comorbidities, or the use of instrumentation did not increase the rate of major or minor complications. The occurrence of either a major or minor complication prolonged hospital stay. Conclusions. Posterior lumbar decompression and fusion can be safely performed in elderly patients, with a low rate of major complications. The addition of instrumentation does not increase the complication rate. These results differ from those previously reported in the literature, which describe a significantly higher rate of complications in this age group, with a prolonged rate of hospitalization.

Prevalence of lumbar facet arthrosis and its relationship to age, sex, and race: an anatomic study of cadaveric specimens.

Study Design. An anatomic, epidemiologic study of facet arthrosis in cadaveric lumbar spines. Objective. To define the prevalence of lumbar facet arthrosis in a large population sample and to examine its association with age, sex, and race. Summary of Background Data. Arthrosis of lumbar facet joints is a common radiographic finding and has been linked to low back pain. However, no population studies have specifically defined the prevalence of facet arthrosis in the lumbar spine in relation to age, sex, and race. Methods. A total of 647 cadaveric lumbar spines were examined by a single examiner for evidence of lumbar facet arthrosis. Information on race, age, and sex were collected. Arthrosis at each facet was graded from 0 to 4 on a continuum from no arthritis to complete ankylosis. Results. Facet arthrosis was present in 53% (L1–L2), 66% (L2–L3), 72% (L3–L4), 79% (L4–L5), and 59% (L5–S1). By decade, facet arthrosis was present in 57% of 20- to 29-year-olds, 82% of 30- to 39-year-olds, 93% of 40- to 49-year-olds, 97% in 50- to 59-year-olds, and 100% in those >60 years old. Fisher exact test and t test demonstrated that men had a greater prevalence and degree of facet arthrosis than women at all lumbar levels (P < 0.001). The lumbar level with the highest prevalence and degree of arthrosis was the L4–L5 level, as compared with each of the other levels (P < 0.001). There was no difference in arthrosis between right versus left facet joints (P > 0.5). Conclusion. Facet arthrosis is a universal finding in the human lumbar spine. Evidence of arthrosis begins early, with more than one half of adults younger than 30 years demonstrating arthritic changes in the facets. The most common arthritic level appears to be L4–L5. Men have a higher prevalence and degree of facet arthrosis than women.

Does lumbar facet arthrosis precede disc degeneration? : A postmortem study

It is believed lumbar degeneration begins in the disc, where desiccation and collapse lead to instability and compensatory facet arthrosis. We explored the contrary contention that facet degeneration precedes disc degeneration by examining 647 skeletal lumbar spines. Using facet osteophytosis as a measure of facet degeneration and vertebral rim osteophytosis as a measure of disc degeneration, we assumed bone degeneration in both locations equally reflected the progression of those in the soft tissues. We graded arthrosis Grade 0 to 4 on a continuum from no arthritis to ankylosis. The data were analyzed for different age groups to examine patterns of degeneration with age. Specimens younger than 30 years of age had a higher prevalence of facet osteophytosis compared with vertebral rim osteophotosis at L1-L2 and L2-L3. Specimens aged 30 to 39 years showed more facet osteophytosis than vertebral rim osteophytosis at L4-L5. Specimens older than 40 years, however, showed more vertebral rim osteophytosis compared with facet osteophytosis at all levels except L4-L5 and L5-S1. This skeletal study suggests facet osteophytosis appears early in the degenerative process, preceding vertebral rim osteophytosis of degenerating intervertebral discs. However, once facets begin deteriorating with age, vertebral rim osteophytosis overtakes continued facet osteophytosis. These data challenge the belief that facet osteophytosis follows vertebral rim osteophytosis; rather, it appears vertebral rim osteophytosis progresses more rapidly in later years, but facet osteophotosis occurs early, predominating in younger individuals.

Cement augmentation of refractory osteoporotic vertebral compression fractures: survivorship analysis.

Study Design. Retrospective cohort. Objective. To compare survivorship after cement augmentation of refractory osteoporotic vertebral compression fractures (OVCFs) with traditional inpatient pain management and bracing. Summary of Background Data. OVCFs can cause debilitating pain and functional decline necessitating prolonged bed rest and high-dose narcotics. Vertebroplasty and kyphoplasty are cement augmentation procedures used to control pain and restore function in patients with OVCFs that are refractory to conservative treatment. Early mobilization is associated with improved survival after other fractures in elderly patients. Methods. A university hospital database was used to identify all participants treated with primary diagnosis of OVCF between 1993 and 2006. Chart review and imaging studies were used to confirm demographics, comorbidities, diagnosis, and treatment. Survival time was determined using hospital data, national death indices and patient follow-up. Exact Fisher tests, Mann-Whitney tests, and proportional hazards regression models with Kaplan-Meier plots compared patients treated with cement augmentation with controls treated with inpatient pain management and bracing. Patients with high-energy trauma, tumors or age more than 60 years were excluded. Results. Within the past 12 years, 46 patients treated with cement augmentation and 129 matched controls met inclusion criteria. They did not differ with respect to age, sex, and comorbidities. A significant survival advantage was found after cement augmentation compared with controls (P < 0.001; log rank), regardless of comorbidities, age, or the number of fractures diagnosed at the start date (P = 0.565). Controlling simultaneously for covariates, the estimated hazard ratio associated with cementation was 0.10 (95% confidence interval [CI] = 0.02–0.43; P = 0.002) for year 1, 0.15 (95% CI = 0.02–1.12; P = 0.064) for year 2, and 0.95 (95% CI = 0.32–2.79; P = 0.919) for subsequent follow-up. The number of OVCFs at the start time of treatment did not affect survival benefit of cementation (P = 0.44). Conclusion. Cement augmentation of refractory OVCF improves survival for up to 2 years when compared with conservative pain management with bed rest, narcotics, and extension bracing, regardless of age, sex, and number of fractures or comorbidities. Therefore, aggressive management should be considered for refractory OVCFs with intractable back pain.

Prevalence of Sacral Spina Bifida Occulta and Its Relationship to Age, Sex, Race, and the Sacral Table Angle: An Anatomic, Osteologic Study of Three Thousand One Hundred Specimens

Study Design. An anatomic, osteologic study of spina bifida occulta (SBO). Objective. To determine the prevalence and patterns of SBO in a large population and examine its relationship to age, sex, and race; then to evaluate SBOs relationship to the sacral table angle (STA) when compared with an age-matched control group. Summary of Background Data. SBO has a reported prevalence of 1.2% to 50% and has been implicated in various pathologic problems. SBO is often associated with spondylolysis or spondylolithesis. The STA has been implicated as an etiologic or predictive factor in the presence of pars defects. Methods. Three thousand one hundred osteologic specimens were evaluated for the presence of SBO. SBO was graded on a scale from 0 to III. Information on the age, sex, race, and STA of each specimen was recorded and measured, respectively. Prevalence and patterns of SBO were enumerated. The STAs of an age-matched control group of 355 specimens were examined. The SBO group and control groups were compared in regards to STA, controlling for age, sex, and race. Results. Overall, 355 specimens displayed SBO, for an overall prevalence of 12.4%. Of the SBO specimens, 68.7% were white, 88.2% were men, 53% were grade I, 37% II, and 10% III. All 3 grades of SBO were more common in men than women (88.2% vs. 11.8%) and more prevalent in whites than blacks (68.7% vs. 31.3%) (P = 0.01). SBO decreased in prevalence with increasing age. The average STA in SBO specimens was 95.9°. This differed from an age-matched control group, 92.1° (P < 0.0001). Every 1° increase in STA resulted in a 6% increased likelihood of SBO. In SBO specimens, the STA decreased with increasing age, contrary to age-matched controls. Conclusion. SBO has an overall prevalence of 12.4% in a large, diverse population. SBO is more common in men and whites and decreases in prevalence with increasing age. The STA is greater in SBO when compared with controls and an increased STA predicts SBO. In SBO, the STA decreases with increasing age.

Correlation of Sacropelvic Geometry With Disc Degeneration in Spondylolytic Cadaver Specimens

Study Design. An anatomic study of sacral inclination, pelvic incidence, pelvic lordosis, and disc degeneration in cadaveric lumbar spines. Objective. To evaluate the relationship between sacropelvic parameters and disc degeneration in subjects with bilateral spondylolysis at L5. Summary of Background Data. L5–S1 disc degeneration is greater in patients with spondylolytic defects (L5–S1) than with an intact pars interarticularis secondary to the instability caused by spondylolysis. Sacral inclination, pelvic incidence, and pelvic lordosis affect sagittal balance and axial forces on the L5–S1 disc. Methods. An observational study was performed on 120 cadaveric specimens with spondylolysis (L5–S1) identified of 3100 total cadaveric specimens. Nine specimens were excluded because of incomplete or degraded skeletal elements; 10 were excluded for having unilateral defects only. The specimens were evaluated for sacral inclination, pelvic incidence, and pelvic lordosis. Disc degeneration and facet arthrosis at L4–L5 and L5–S1 were measured by the classification of Eubanks et al. Linear regression analyses were then used to determine the relationship between sacropelvic parameters and degeneration at the L5–S1 segment, correcting for confounding factors such as age, sex, and race. Results. Linear regression demonstrated a significant association between sacral inclination and disc degeneration at L5–S1 (P = 0.018). Specimens were then divided into two groups, those in the highest quarter of pelvic incidence, and the remainder. Spearman rank correlation demonstrated a significant association between disc degeneration at L5–S1 and the highest quarter of pelvic incidence (P = 0.017). Increasing pelvic lordosis was also associated with an increase in facet arthrosis at L4–L5 (P = 0.006). Conclusion. The findings of this study show a relationship between the sacropelvic geometry and the degree of L5–S1 disc degeneration as well as L4–L5 facet degeneration in spondylolytic specimens. This relationship may prove useful in predicting the course of disc degeneration in patients with spondylolysis.

Prevalence of concurrent lumbar and cervical arthrosis: an anatomic study of cadaveric specimens.

Study Design. An anatomic, epidemiologic study of lumbar and cervical arthrosis in cadaveric spines. Objective. Determine the prevalence of combined lumbar and cervical arthrosis in a large population sample and examine its association with age, sex, and race. Summary of Background Data. Lumbar and cervical arthrosis are common radiographic findings, which have both been linked to pain. However, the prevalence of and temporal relationship between combined lumbar and cervical arthrosis has not been defined. Methods. The lumbar and cervical segments from 234 cadaveric spines were examined by a single investigator for evidence of endplate and facet arthrosis. Arthrosis at each endplate and facet was graded on a continuum from 0 to IV. Race, age at death, and sex of each specimen was recorded. Stepwise multiple linear regression was used to analyze any association between race, age, sex, lumbar arthrosis, and cervical arthrosis. Factors with P-values <0.05 remained in the analysis. T tests for matched samples were used to analyze any difference between the mean lumbar and cervical arthrosis severity among patients within the same decades of life. Results. Concurrent lumbar and cervical arthrosis was present in 80% of the study population. Stepwise multiple linear regression revealed significant (P < 0.01) associations between lumbar arthrosis and cervical arthrosis and between age and cervical arthrosis. Race and sex did not correlate with lumbar or cervical arthrosis. In addition, patients in age groups 20 to 29, 30 to 39, 40 to 49, 50 to 59, 60 to 69, 70 to 79, and 80 to 89 demonstrated more severe (P < 0.01) lumbar arthrosis in comparison to cervical arthrosis. Conclusion. Concurrent lumbar and cervical arthrosis is a common condition. Lumbar arthrosis and advancing age are associated with cervical arthrosis independent of race and sex. Lumbar arthrosis precedes cervical arthrosis. These findings suggest an underlying systemic component for spinal osteoarthritis.

Anatomic variance of interfacet distance and its relationship to facet arthrosis and disk degeneration in the lumbar spine.

Inadequate separation of the L4-S1 facets predisposes individuals to spondylolytic defects. We proposed that decreased interfacet separation is a risk factor for increased lumbar degenerative disease. This study examined the correlation between interfacet distance and degenerative disease of the lumbar spine. Four hundred forty-four cadaveric lumbar spines were examined for evidence of lumbar facet arthrosis and disk degeneration. Arthrosis at each level was graded from 0 to 4 on a continuum from no arthritis to complete ankylosis. These results were then examined in relation to interfacet spread. Interfacet distances were measured at each level (L1-S1). The difference in interfacet spread (L4-S1) was then correlated to facet arthrosis and disk degeneration. In individuals younger than 50 years (n=251), increased interfacet spread (L4-S1) was associated with less facet arthrosis at the L5/Sl level (P<.05). Similarly, in individuals younger than 40 years (n=149), increased interfacet spread (L4-S1) was associated with less disk degeneration at the L5/S1 level (P<.03). Insufficient increase in interfacet distances (L4-S1) correlates with a greater risk of developing and maintaining spondylolytic defects. Similarly, this study suggests that increased interfacet spread (L4-S1) protects against early degenerative changes at the L5/Sl level. The more pyramidal the L4-S1 facet cascade, the lower the arthrosis. This effect appears early in the degenerative process before facet arthrosis and disk degeneration have become ubiquitous. In individuals younger than 50 years, increased interfacet distance correlates with less L5/Sl facet arthrosis.

Predicting Postoperative C5 Palsy Using Preoperative Spinal Cord Rotation

The development of C5 nerve palsy after cervical decompression surgery has been well documented. The goal of this study was to determine whether preoperative spinal cord rotation could be used as a predictor of C5 palsy in patients who underwent posterior cervical decompression at C4-C6. The authors reviewed the records of 72 patients who had posterior decompression and 77 patients who had anterior decompression. With the patients undergoing anterior decompression used as a control group, magnetic resonance imaging scans were analyzed for area of the spinal cord, anterior-posterior diameter, and cord rotation relative to the vertebral body. The rate of C5 palsy was 7.3%. Average degrees of rotation were 3.83°±2.47° and 3.45°±2.23° in the anterior and posterior groups, respectively. A statistically significant association was detected between degree of rotation and C5 palsy. Point-biserial correlations were 0.58 (P<.001) and 0.60 (P<.001) in the anterior and posterior groups, respectively. With a diagnostic cutoff of 6°, the sensitivity and specificity of identifying patients with C5 palsy in the posterior group were 0.67 (95% confidence interval, 0.24-0.94) and 0.95 (95% confidence interval, 0.86-0.98), respectively. The results suggested that preoperative spinal cord rotation may be a valid predictor of C5 nerve palsy after posterior cervical decompression. With mild rotation defined as less than 6°, moderate rotation as 6° to 10°, and severe rotation as greater than 10°, the prevalence of C5 palsy in the posterior group was 2 of 65 for mild rotation, 3 of 6 for moderate rotation, and 1 of 1 for severe rotation.

Magnetic Resonance Imaging of the Cervical Spine Under-Represents Sagittal Plane Deformity in Degenerative Myelopathy Patients

Background In treating patients with cervical myelopathy, surgical approach may be dictated by sagittal balance, highlighting the need for accurate pre-operative assessment. Magnetic Resonance Imaging (MRI) is widely-recognized for its utility in the diagnosis and surgical planning of cervical myelopathy. Plain radiographs (X-rays) are a reliable tool to assess bony alignment. However, they may not always be included in standard pre-operative evaluation, especially in an era of restricted payer-environments. Failure to appropriately acknowledge a patients’ preoperative kyphotic deformity may cause the surgeon to choose a posterior-only approach, which would provide suboptimal sagittal plane correction and decompression of anterior pathology. Methods 101 patients with cervical myelopathy with MRI and plain radiographs were identified. Cervical lordosis and kyphosis were measured using the Cobb method on standing lateral x-ray and sagittal T2-weighted MRI. CI (Ishihara) was also measured on standing lateral x-ray, and sagittal T2-weighted MRI. Bland-Altman plots were generated and used to compare subtle differences in measurement techniques and modalities. Odom’s criteria were recorded. Results The average difference between plain radiograph and MRI measurements for curvature angle was 3.5± 7.2 degrees (p< 0.001), and the average difference between plain radiograph and MRI measurements for curvature index was 1.5± 5.9 degrees (p= 0.015). Conclusions MRI may under-represent the respective sagittal plane deformity in patients with degenerative cervical myelopathy. Clinical Relevance We would recommend the use of standing x-rays when considering surgical planning in all myelopathy patients. This manuscript was reviewed and approved by an institutional review board. Informed consent was not obtained because patient specific identifying information was not used. It was performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments.