Stable Spondylolisthesis: Should Management Change Based on Presence of Facet Cysts?

STUDY DESIGN: This is a retrospective cohort review. OBJECTIVE: To determine whether a correlation exists between facet cysts and lumbar instability. SUMMARY OF BACKGROUND DATA: Lumbar facet cysts are common degenerative entities observed in patients with low-grade spondylolisthesis at a rate of 10%-50%. Surgical management with partial facetectomy with or without fusion remains controversial. METHODS: Review of 86 patients with lumbar degenerative spondylolisthesis is performed. Preoperative magnetic resonance imagings were reviewed for the presence of lumbar facet cysts and Facet Fluid Indices (FFI)-calculated as the ratio of facet fluid width to facet width. Instability was defined as a difference of >3 mm in vertebral displacement between flexion and extension radiographs. T tests and the Pearson correlation analyses were used to determine statistical significance. RESULTS: In total, 26 patients had unstable and 60 had stable spondylolisthesis. Facet cysts were present at an overall prevalence of 30.1%-in 10/26 patients in the unstable group and in 18/60 patients in the stable group (P>0.05). The average FFIs for the unstable and stable groups were 0.13 and 0.09, respectively (P>0.05). FFI in patients with facet cysts was significantly higher than those without (P<0.05). In addition, the group with facet cysts had a significantly higher proportion of patients with FF effusions >3 mm. CONCLUSIONS: Lack of correlation with instability hints that the presence of facet cysts may not indicate instability in lumbar degenerative spondylolisthesis. Therefore, presence of facet cysts in static magnetic resonance imaging revealing spondylolisthesis should not preclude the physician from performing dynamic films to evaluate for instability. Significantly higher FFI in patients with facet cysts reaffirms the degenerative pathophysiology involved in their formation. Although this is not an outcomes study, it does spark interest into whether patients with stable spondylolisthesis and concurrent facet cysts are suitable for partial facetectomy alone with fusion.

Comparing the Effectiveness of Sagittal Balance, Foraminal Stenosis, and Preoperative Cord Rotation in Predicting Postoperative C5 Palsy.

STUDY DESIGN: Retrospective cohort review. OBJECTIVE: To determine whether preoperative cord rotation is independently correlated with C5 palsy when analyzed alongside measures of sagittal balance and foraminal stenosis. SUMMARY OF BACKGROUND DATA: Postoperative C5 palsy is a well-documented complication of cervical procedures with a prevalence of 4%-8%. Recent studies have shown a correlation with preoperative spinal cord rotation. There have been few studies, however, that have examined the role of sagittal balance and foraminal stenosis in the development of C5 palsy. METHODS: A total of 77 patients who underwent cervical decompression-10 of whom developed C5 palsy-were reviewed. Sagittal balance was assessed using curvature angle and curvature index on radiographs and magnetic resonance image (MRI). Cord rotation was assessed on axial MRI. C4-C5 foraminal stenosis was assessed on sagittal MRI using area measurements and a grading scale. Demographics and information on surgical approach were gathered from chart review. Correlation with C5 palsy was performed by point-biserial, χ, and regression analyses. RESULTS: Point-biserial analysis indicated that only cord rotation showed significance (P<0.01). There was no statistical significance shown with surgical approach, sex, or age. In addition, changes in sagittal balance did not correlate with presence of C5 palsy. Logistic regression model yielded cord rotation as the only significant independent predictor of C5 palsy. For every degree of axial cord rotation, the likelihood ratio for suffering a C5 palsy was 3.93 (95% confidence interval, 2.01-8.66; P<0.05). CONCLUSIONS: This supports the independent capability of preoperative cord rotation to predict postoperative C5 palsy. Lack of correlation with measures of neuroforaminal stenosis potentially points to mechanisms other than direct compression as the etiology. In addition, the lack of correlation with postoperative changes in sagittal balance hints that measures of curvature angle and curvature index may not be appropriate to accurately predict this complication. LEVEL OF EVIDENCE: Level 3.

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.

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.

Lumbar degenerative disc disease and tibiotalar joint arthritis: a 710-specimen postmortem study.

Research has associated lumbar spinal disease with lower extremity arthrosis. These studies focused solely on the lumbar spine's connection with hip or knee pathology, failing to investigate potential ankle relationships. We specifically explored the interplay between lumbar disc degeneration and tibiotalar joint arthritis. Lumbar disc degeneration and tibiotalar joint arthritis was graded 0 to 4, according to osteophytosis of the vertebral rim and talar surface in 710 randomly selected cadaveric specimens. We corrected for confounding factors of age, sex, race, and height. A significant association was found between lumbar disc degeneration and tibiotalar joint arthritis (P < .01). Lumbar disc degeneration encompassing 3 intervetebral discs demonstrated the highest odds for development of severe tibiotalar joint arthritis. Severe lumbar degenerative disc disease was more prevalent than severe tibiotalar joint arthritis in individuals age 20 years and older. Furthermore, the presence of severe lumbar degeneration significantly predisposes individuals to the development of severe ankle arthritis (P < .05). Gait changes resulting from disc degeneration or neural compression in the lumbar spine may play a role in ankle osteoarthritis development. This association must be considered when treating patients with lumbar disc degeneration and leg pain.

Characterization of lumbar spinous process morphology: a cadaveric study of 2,955 human lumbar vertebrae.

BACKGROUND CONTEXT: Despite the interest in lumbar spinous process (SP)-based surgical innovation, there are no large published studies that have characterized the morphometry of lumbar SPs. PURPOSE: To provide accurate level-specific morphometric data with respect to human lumbar SPs using a human cadaveric lumbar spine model and to describe the morphometric variation of lumbar SPs with respect to gender, race, and age. STUDY DESIGN: An anatomic observational study. METHODS: This study used 2,955 cadaveric lumbar vertebrae from 591 adult spines at the Hamann-Todd Human Osteological Collection. Specimens were aged 20 to 79 years. Each vertebra was photographed in standardized positions and measured using ImageJ software. Direct measurements were made for the SP length, width, height, slope, and caudal morphology. Gender, race, and age were recorded and analyzed. RESULTS: Spinous process length was 24.8±4.6 mm (L5) to 33.9±3.9 mm (L3). Effective length varied from 19.5±2.6 mm (L1) to 24.6±3.3 mm (L4). Height was shortest at L5 (18.2±2.7 mm). Caudal width was greater than the cranial width. Slope, caudal morphology, and radius measures showed large interspecimen variation. Slope at L5 was steeper than other levels (23.7°±10.5°, p<.0001). Most specimens demonstrated convex caudal morphology. L4 had the highest proportion of convexity (80.7%). L1 was the only level with predominantly concave morphology. Measurements for female SPs were smaller, but the slope was steeper. Anatomic and effective SP lengths were longer for specimens from white individuals. Specimens from black individuals had larger width and height, as well as steeper slope. Black specimens had more convex morphology at L4 and L5. With increasing age, the SP length, effective length, and width increased. Height increased with age only at L4 and L5. Slope and caudal radius of curvature decreased with age, and increasingly convex morphology was noted at most levels. CONCLUSIONS: This large cadaveric study provides level-specific morphometric data regarding the osseous dimensions of lumbar SPs relevant to techniques and devices targeting the lumbar SPs or the interspinous space. Of particular importance is the recognition that L5 has relatively different morphology when compared with more cranial levels. Potentially important differences were noted comparing women with men, black with white, and aging populations.

Congenital stenosis and adjacent segment disease in the cervical spine.

Symptomatic adjacent segment disease (ASD) after anterior cervical fusion (ACF) is reported in 25% of patients at 10 years postoperatively. Debate continues as to whether this degeneration is due to the natural history of the disk or the changed biomechanics after ACF. This study explored whether congenital stenosis predisposes patients to an increased incidence of ASD after ACF. A retrospective review of 635 patients with myelopathy or radiculopathy was performed; 364 patients had complete records for review. Patients underwent 1- to 5-level ACF (94 one-level, 145 two-level, 79 three-level, 45 four-level, and 1 five-level). Radiographs were evaluated for bony congenital stenosis using validated parameters, and ASD was measured according to Hilibrand's criteria and correlated with symptomatic ASD. Congenital stenosis was found in 21.7% of patients and radiographic ASD in 33.5%, with a significant association between these parameters. However, symptomatic ASD occurred in 11.8% of patients; no association between congenital stenosis and symptomatic ASD or myelopathy and ASD was found. Clinical results demonstrated excellent or good Robinson scores in 86.2% of patients and Odom scores in 87% of patients. Despite mostly excellent to good outcomes, symptomatic ASD is common after ACF. Although congenital stenosis appears to increase the incidence of radiographic ASD, it does not appear to predict symptomatic ASD.

Takotsubo Cardiomyopathy following a L2-L5 Laminectomy and Fusion In Situ with Bone Morphogenic Protein.

Takotsubo cardiomyopathy (TC) is a rare, transient cardiomyopathy, with symptoms mimicking myocardial infarction. It has been reported to typically occur in postmenopausal women and is often triggered by an intense physical or emotional event with stimulation of the sympathetic response; the exact etiology, however, is uncertain. Bone morphogenic protein (BMP) is widely used in spinal fusions and has been associated with numerous perioperative complications. BMP is known to stimulate sympathetic pathways. In this paper, we present the case of a patient with a 7-hour episode of TC after a spinal fusion with bone morphogenic protein. The patient's symptoms resolved and long-term followup has been uneventful. This is the first paper to describe TC in the setting of spine or other major orthopaedic surgery and it suggests another possible area for further investigation in peri-operative events potentially associated with the use of bone morphogenic protein.

T1 intralaminar screws: an anatomic, morphologic study.

In some scenarios, such as complex revisions or tumor cases, intralaminar screw placement in the upper thoracic spine can be used to supplement or replace traditional pedicle screw placement. Despite the theortic feasibility of placing these screws, no thorough anatomic study has evaluated the morphology of the T1 lamina for screw placement.Anatomic data of the T1 lamina, including height, width (the upper, middle, and lower one-third segments), and length (with and without penetration of the facet articulation) were analyzed for 112 T1 vertebrae. The placement of screws with widths of 3.5 or 4 mm and screws with lengths of 24 or 26 mm in the T1 lamina was feasible in all of the laminas measured with the exception of 2 outliers. Furthermore, relationships were found between T1 lamina size and patient height and between T1 lamina size and sex, but no relationship was found between T1 lamina size and race.The morphology of the T1 lamina allows for the simple and safe placement of common screw diameters and is a viable salvage or alternative to the traditional pedicle screw.

Correlation of slipped capital femoral epiphysis with disk degeneration.

SUMMARY OF BACKGROUND DATA: Spinal osteoarthritis is greater in patients with known hip pathology secondary to alterations in spinopelvic geometry. To our knowledge, no study has investigated the long-term impact of slipped capital femoral epiphysis (SCFE) on the spine. OBJECTIVE: To evaluate the relationship between SCFE and the presence of degenerative disk disease and facet arthrosis. STUDY DESIGN: An anatomic study of disk degeneration in cadaveric lumbar spines with SCFE. METHODS: An observational study was performed on 25 cadaveric specimens with SCFE and 647 controls that were identified out of 3100 total cadaveric specimens in an osteological collection. The specimens were evaluated for disk degeneration and facet arthrosis at L1/2 to L5/S1 using the classification of Eubanks and colleagues. Linear regression analyses were then used to determine the relationship between SCFE and lumbar disk and facet degeneration at each level, correcting for confounding factors such as age, sex, and race. RESULTS: Linear regression demonstrated a significant association (P<0.01) that was found between SCFE and degenerative disk disease at all levels from L1/2 to L5/S1. In addition, a significant association (P<0.01) was found between SCFE and facet arthrosis at all levels from L1/2 to L5/S1. CONCLUSIONS: The findings of this study show a relationship between SCFE and lumbar disk degeneration and facet arthrosis. This relationship may prove useful in predicting the course of spinal osteoarthritis in patients with SCFE.

Cervical endplate and facet arthrosis: an anatomic study of cadaveric specimens.

STUDY DESIGN: An anatomic, epidemiologic study of cervical endplate and facet arthrosis in cadaveric spines. OBJECTIVE: To determine the prevalence of cervical endplate and facet arthrosis and the relationship between these 2 entities in a large population sample. SUMMARY OF BACKGROUND DATA: Cervical endplate and facet arthrosis are common radiographic findings, which have both been linked to pain. However, the prevalence and relationship between cervical endplate and facet arthrosis has not been clearly defined. METHODS: The cervical vertebrae 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 were also recorded. Stepwise multiple linear regression was used to analyze any association between race, age, sex, endplate arthrosis, and facet arthrosis. Factors with P values <0.05 remained in the analysis. Two-tailed t tests for matched samples were used to analyze any difference between mean endplate and facet arthrosis severity scores among patients within the same decades of life. RESULTS: Concurrent cervical endplate and facet arthrosis was present in 77% of the study population. Stepwise multiple linear regression revealed significant (P<0.01) associations between endplate and facet arthrosis and between age and facet arthrosis. Race and sex did not correlate with facet arthrosis. In addition, patients in age groups 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) endplate arthrosis in comparison with facet arthrosis. CONCLUSIONS: Concurrent cervical endplate and facet arthrosis is a common condition. Cervical endplate arthrosis and advancing age are associated with cervical facet arthrosis independent of race and sex. Cervical endplate arthrosis precedes facet arthrosis.

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.

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 OVCF's 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.

Does smoking influence fusion rates in posterior cervical arthrodesis with lateral mass instrumentation?

BACKGROUND: Smoking is associated with reduced fusion rates after anterior cervical decompression and arthrodesis procedures. Posterior cervical arthrodesis procedures are believed to have a higher fusion rate than anterior procedures. QUESTIONS/PURPOSES: We asked whether smoking (1) would reduce the fusion rate in posterior cervical procedures; and (2) be associated with increased pain, decreased activity level, and a decreased rate of return of work as compared with nonsmokers. METHODS: We retrospectively reviewed 158 patients who had a posterior cervical fusion with lateral mass instrumentation and iliac crest bone grafting between 2003 and 2008. Fusion rates and Odom Criteria grades were compared among smokers and nonsmokers. The minimum followup was 3 months (average, 14.5 months; range, 3-72 months). RESULTS: Smokers and nonsmokers had similar fusion rates (100%). Although 80% of patients had Odom Criteria Grade I or II, smokers were five times more likely to have Grade III or IV with considerable limitation of physical activity. Age, gender, and diagnosis did not influence fusion rates or the Odom Criteria grade. CONCLUSIONS: In contrast to the effect of smoking on anterior cervical fusion, we found smoking did not decrease posterior cervical fusion with lateral mass instrumentation and iliac crest bone grafting. Posterior cervical fusion with lateral mass instrumentation should be considered over anterior procedures in smokers if the abnormality can appropriately be addressed from a posterior approach. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Antifibrinolytics in major orthopaedic surgery.

Total joint arthroplasty and deformity surgery of the spine can require complex reconstructive procedures accompanied by the potential for major blood loss. In an attempt to minimize the perioperative blood loss associated with these procedures, recent focus has concentrated on the efficacy of pharmacologic agents. Antifibrinolytics such as epsilon-aminocaproic acid, tranexamic acid, and aprotinin have been shown to reduce perioperative blood loss, autologous blood donation, transfusions, and associated costs in cardiac as well as major orthopaedic surgery. These agents reduce perioperative blood loss by inhibition of clot breakdown. Prospective, randomized studies have shown that the use of these agents can be effective in reducing the perioperative blood loss and transfusion requirements in total joint arthroplasty, pediatric scoliosis surgery, and adult reconstructive surgery of the spine. Aprotinin, however, is currently under suspension from use pending further evaluation of a trial. Although concerns exist about increased thrombotic events with the use of these agents, large meta-analyses suggest that antifibrinolytics can be safely and efficaciously employed to decrease perioperative blood loss and transfusion requirements.

Cervical radiculopathy: nonoperative management of neck pain and radicular symptoms.

Cervical radiculopathy is a disease process marked by nerve compression from herniated disk material or arthritic bone spurs. This impingement typically produces neck and radiating arm pain or numbness, sensory deficits, or motor dysfunction in the neck and upper extremities. Magnetic resonance imaging or computed tomographic myelography can confirm neurologic compression. The overall prognosis of persons with cervical radiculopathy is favorable. Most patients improve over time with a focused, nonoperative treatment course. There is little high-quality evidence on the best nonoperative therapy for cervical radiculopathy. Cervical collars may be used for a short period of immobilization, and traction may temporarily decompress nerve impingement. Medications may help alleviate pain and neuropathic symptoms. Physical therapy and manipulation may improve neck discomfort, and selective nerve blocks target nerve root pain. Although the effectiveness of individual treatments is controversial, a multimodal approach may benefit patients with cervical radiculopathy and associated neck pain.

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.

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 degrees . This differed from an age-matched control group, 92.1 degrees (P < 0.0001). Every 1 degrees 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.

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.