Black disc morphology during routine lumbar discectomy with subsequent diagnosis of enterococcal discitis.

Background: Enterococcus faecalis is reported infrequently as an infectious cause of discitis. In the literature, the diagnosis is commonly made based on the clinical picture coupled with blood cultures, imaging, and tissue cultures. Case Description: A 62-year-old male with chronic lower back pain underwent lumbar decompression for a lumbar disc. At surgery, the patient had significant black discoloration of the disc material. Later, the cultures demonstrated E. faecalis infectious discitis. Conclusion: Here is an example of enterococcal lumbar discitis found during a routine lumbar discectomy. As operative cultures revealed E. faecalis, the patient required not one but two operations (i.e., second for seroma/ hematoma due to infection) following which antibiotic therapy eradicated the infection.

Treatment of unilateral L5-S1 locked facet in a pediatric patient.

Background: Traumatic unilateral lumbosacral facet dislocations are rare injuries. The majority of cases are treated with open reduction and instrumented spinal fusions. Only less commonly can they be managed conservatively. Case Description: A 7-year-old unrestrained passenger was involved in a high-speed motor vehicle accident. X-ray/magnetic resonance/computed tomography imaging documented a unilateral L5-S1 facet dislocation and multiple lumbar/sacral fractures. The patient underwent open reduction and temporary L5-pelvic instrumentation without fusion; the instrumentation was removed 10 weeks later at which point follow-up imaging showed preserved lumbosacral stability. Conclusion: Open reduction with temporary instrumentation without fusion was successfully utilized to treat a unilateral L5-S1 facet dislocation in a 7-year-old child.

Stabilizing effect of the rib cage on adjacent segment motion following thoracolumbar posterior fixation of the human thoracic cadaveric spine: A biomechanical study.

BACKGROUND: Although the rib cage provides substantial stability to the thoracic spine, few biomechanical studies have incorporated it into their testing model, and no studies have determined the influence of the rib cage on adjacent segment motion of long fusion constructs. The present biomechanical study aimed to determine the mechanical contribution of the intact rib cage during the testing of instrumented specimens. METHODS: A cyclic loading (CL) protocol with instrumentation (T4-L2 pedicle screw-rod fixation) was conducted on five thoracic spines (C7-L2) with intact rib cages. Range of motion (±5 Nm pure moment) in flexion-extension, lateral bending, and axial rotation was captured for intact ribs, partial ribs, and no ribs conditions. Comparisons at the supra-adjacent (T2-T3), adjacent (T3-T4), first instrumented (T4-T5), and second instrumented (T5-T6) levels were made between conditions (P ≤ 0.05). FINDINGS: A trend of increased motion at the adjacent level was seen for partial ribs and no ribs in all 3 bending modes. This trend was also observed at the supra-adjacent level for both conditions. No significant changes in motion compared to the intact ribs condition were seen at the first and second instrumented levels (P > 0.05). INTERPRETATION: The segment adjacent to long fusion constructs, which may appear more grossly unstable when tested in the disarticulated spine, is reinforced by the rib cage. In order to avoid overestimating adjacent level motion, when testing the effectiveness of surgical techniques of the thoracic spine, inclusion of the rib cage may be warranted to better reflect clinical circumstances.

Obesity and calcification of the ligaments of the spine: a comprehensive CT analysis of the entire spine in a random trauma population.

BACKGROUND CONTEXT: Obesity, which is currently surging to epidemic levels within the United States, has been linked to hyperostotic conditions like diffuse idiopathic skeletal hyperostosis (DISH) and ossification of the posterior longitudinal ligament (OPLL). Excess adipose tissue and insulin-resistance may cause a systemic increase in serum levels of proinflammatory cytokines and these signals can affect bone metabolism. Spinal ligaments and discs may have receptors for these signaling molecules. Anecdotal observations at this institution suggested that there is a clinically important subset of younger patients with obesity and multilevel stenosis in the presence of unusual calcification of the spinal ligaments that is distinct from DISH. PURPOSE: To determine if there is an association between truncal obesity and calcifications of the spine in nonelderly adults. STUDY DESIGN/SETTING: This is a retrospective analysis of 214 sequential trauma patients between the ages of 29 and 50. Patients' age, sex, truncal obesity, history of hypertension, and diabetes were assessed for association with ligamentous calcification of the spine. PATIENT SAMPLE: Sequential trauma patients were chosen from our institution's trauma database between 2006 and 2007. METHODS: Full spine computed tomography (CT) imaging was examined for bone formation in the region of the anterior longitudinal ligament (ALL) and annulus, posterior longitudinal ligament (PLL) and annulus, and the ligamentum flavum (LF). Visceral and subcutaneous abdominal fat were also evaluated. The authors report no study funding sources or conflicts of interest. OUTCOME MEASURES: Calcification of the ALL, PLL, and LF were assigned a score at each level and then combined for a total calcification score (TCS) for the entire spine. Obesity was estimated using a truncal body mass index (TBMI) by using a previously validated CT derived truncal total adiposity volume (TAV). RESULTS: ALL calcification was associated with age, male gender, hypertension, and increased adiposity. PLL calcification was significantly associated with age and hypertension. LF calcification was only associated with increased obesity. CONCLUSIONS: In our analysis of nonelderly patients, LF calcification was independently associated with truncal obesity. This implies obesity plays a greater role in calcification than could be accounted for by simply age-related degeneration or gender.

The use of routine thoracoabdominal CT scans in the polytrauma patient to estimate obesity.

OBJECTIVE: To utilize data from routine CT scans to quantify obesity in polytrauma patients without the need to obtain a height and weight. DESIGN AND METHODS: We utilized a comprehensive database including multidetector CT thoracoabdominal images of all polytrauma patients admitted to a Level 1 trauma center. One thousand one hundred seventy-four patients were reviewed from 2006 to 2008 and of these, 162 had previous documentation of Body Mass Index (BMI) or height and weight measurements as an outpatient within 6 months of trauma activation and with a truncal girth smaller than the scanning area of the CT machine. Truncal Adiposity Volume (TAV) was calculated from three dimensional reconstructions (3DRs) of the CT scans of the thorax and abdomen obtained in the emergency department. RESULTS: Statistical analysis yielded a fairly good correlation between TAV and BMI (correlation coefficient = 0.77; p-value < 0.0001). The intra-observer and inter-observer correlations in measuring TAV were high; 0.99 and 0.98 respectively. A linear regression equation of BMI on TAV was estimated and it had a form: 3DR BMI = 20.81+0.00064×TAV. In conclusion, TAV provides a reproducible means of evaluating obesity in trauma patients from routinely obtained CT scans. CONCLUSIONS: The TAV eliminates the often problematic task of obtaining a height and weight in a trauma patient and it correlates fairly well with the most commonly used clinical method of quantifying patient adiposity, BMI. This method may provide a more direct measurement of adiposity than does BMI, and holds promise for improving trauma care and research in the obese patient.

L5 nerve root decompression after malunion of surgically managed vertically unstable pelvic ring injuries.

We describe the outcomes of late decompression of the L5 nerve root after malunion of surgically managed pelvis injuries. Four patients underwent decompression of the L5 nerve root. Surgery included hemilaminotomy with facetectomy at L5-S1 followed by decompression of the L5 nerve root laterally from the surrounding displaced sacral ala. L5-S1 fusion was not performed. Radiographs and Oswestry Disability Index (ODI) scores were obtained for each patient at latest follow-up. In all patients, adequate decompression required removal of bone to the anterior aspect of the sacral ala inferiorly to the level of the superior endplate of S1, and there was resolution of L5 radicular pain. Late decompression of the proximal course of the L5 nerve root provided pain relief without resultant radiographic pelvis or L5-S1 instability.

The significance of facet joint cross-sectional area on magnetic resonance imaging in relationship to cervical degenerative spondylolisthesis.

BACKGROUND CONTEXT: Characteristic changes of the facet joints, including synovial cysts, facet joint hypertrophy, and facet joint effusions, on magnetic resonance imaging (MRI) and computed tomography have been associated with lumbar degenerative spondylolisthesis. The cervical facets have not been examined for associations with cervical degenerative spondylolisthesis similar to those seen in the lumbar spine. PURPOSE: To define abnormalities of the facet joints seen on supine MRI that correlate with cervical spondylolisthesis seen on upright radiographs. STUDY DESIGN: Retrospective radiographic review of consecutive patients with a universally applied standard. PATIENT SAMPLE: A total of 204 consecutive patients from a single institution, with both an MRI and upright radiographs, were reviewed. OUTCOME MEASURES: Sagittal plane displacement on upright lateral radiographs was compared with MRI. The total area of the facet joint and the amount of facet joint asymmetry were measured on an axial MRI. METHODS: The data were analyzed to determine a significant association between the cervical degenerative spondylolisthesis and the following: facet joint asymmetry, increased total area of the facet joint, and age. RESULTS: Degenerative spondylolisthesis was seen in 26 patients at C3-C4 and in 27 patients at C4-C5. Upright radiographs identified significantly more degenerative spondylolisthesis than MRIs at levels C3-C4 and C4-C5, 26 versus 6 (p<.001) at C3-C4 and 27 versus 11 (p<.001) at C4-C5. Patients with degenerative spondylolisthesis were more likely to be older, have a larger total facet area, and more facet asymmetry at C3-C4 and C4-C5 (p<.05). CONCLUSIONS: Supine MRIs underestimate sagittal displacement compared with upright lateral radiographs. Asymmetric facet hypertrophy at C3-C4 and C4-C5 is associated with degenerative spondylolisthesis on upright lateral films even in the absence of anterolisthesis on supine MRIs.

A proteomic study of protein variation between osteopenic and age-matched control bone tissue.

The focus of this study was to identify changes in protein expression within the bone tissue environment between osteopenic and control bone tissue of human femoral neck patients with osteoarthritis. Femoral necks were compared from osteopenic patients and age-matched controls. A new method of bone protein extraction was developed to provide a swift, clear view of the bone proteome. Relative changes in protein expression between control and osteopenic samples were quantified using difference gel electrophoresis (DIGE) technology after affinity chromatographic depletion of albumin and IgG. The proteins that were determined to be differentially expressed were identified using standard liquid chromatography mass spectrometry (LC/MS/MS) and database searching techniques. In order to rule out blood contamination, blood from age-matched osteoporotic, osteopenic and controls were analyzed in a similar manner. Image analysis of the DIGE gels indicated that 145 spots in the osteopenic bone samples changed at least ± 1.5-fold from the control samples (P < 0.05). Three of the proteins were identified by LC/MS/MS. Of the proteins that increased in the osteopenic femurs, two were especially significant: carbonic anhydrase I and phosphoglycerate kinase 1. Apolipoprotein A-I was the most prominent protein that significantly decreased in the osteopenic femurs. The blood samples revealed no significant differences between groups for any of these proteins. In conclusion, carbonic anhydrase I, phosphoglycerate kinase 1 and apolipoprotein A-I appeared to be the most significant variations of proteins in patients with osteopenia and osteoarthritis.

Cytokine-mediated inflammatory reaction following posterior cervical decompression and fusion associated with recombinant human bone morphogenetic protein-2: a case study.

STUDY DESIGN: Case study with unique laboratory analysis. OBJECTIVE: To present a potentially serious adverse event that may occur in unique individuals when using recombinant human bone morphogenetic protein-2 (rhBMP-2) to augment fusion in posterior cervical spine surgery. SUMMARY OF BACKGROUND DATA: The use of rhBMP-2 to augment posterior cervical decompression and fusion has not been approved by the Food and Drug Administration but has been advocated as safe to use by case series studies and multiple authors. METHODS: A 66-year-old patient with myelopathy underwent posterior cervical decompression and fusion, using rhBMP-2 as a bone graft substitute. The patient had complete resolution of symptoms after surgery until day 6, when she experienced increasing pain and weakness. T2 magnetic resonance images revealed a high intensity fluid collection compressing the cervical cord posteriorly. Emergent decompression was performed and the patient improved until postoperative day 12 when the same clinical scenario occurred. Symptoms again improved with surgical debridement. The clear, nonsanguineous fluid was sent for a quantitative cytokine panel each time. The case is reviewed with specific reference to the evolving literature regarding rhBMP-2 use in the spine, and the findings of seroma analysis. RESULTS: The fluid analysis of the seroma fluid at the time of both debridements showed impressive elevations in inflammatory cytokines, especially IL-6 and IL-8. CONCLUSION: Acute inflammatory reactions to rhBMP-2 can occur in the posterior cervical spine and can lead to significant morbidity. Host factors, BMP-2 dosage, and carrier factors all likely play a role in these complex reactions and must be considered every time an "off label" usage of rhBMP-2 is considered. More study is clearly indicated.

Clinical and radiographic assessment of transforaminal lumbar interbody fusion using HEALOS collagen-hydroxyapatite sponge with autologous bone marrow aspirate.

BACKGROUND CONTEXT: Studies have suggested that the use of bone marrow aspirate (BMA) with HEALOS (DePuy Spine, Raynham, MA), a collagen-hydroxyapatite sponge (CHS), is an effective substitute for autologous iliac crest bone graft when used in fusion procedures of the lumbar spine. PURPOSE: To assess clinical and radiographic outcomes after implantation of BMA/CHS in patients undergoing transforaminal lumbar interbody fusion (TLIF) with posterolateral fusion (PLF). STUDY DESIGN/SETTING: Case series radiographic outcome study. PATIENT SAMPLE: Twenty patients. OUTCOME MEASURES: Radiographs/computed tomography (CT) scans. METHODS: From September 2003 to October 2004, 20 patients (22 interbody levels) were implanted with BMA/CHS via TLIF/PLF with interbody cages and posterior pedicle screws. All patients were retrospectively identified and invited for a 2-year prospective follow-up. Plain radiographs with dynamic films and CT scans were taken, and fusion was assessed in a blinded manner. RESULTS: Follow-up averaged 27 months (range: 24-29). Primary diagnosis included spondylolisthesis (17 patients), scoliosis with asymmetric collapse (2 patients), and postdiscectomy foraminal stenosis (1 patient). The overall fusion rate was 95% (21/22 levels, 19/20 patients). Anteriorly bridging bone was observed in 91% of the anteriorly fused levels (20/22), of which 65% (13/20) occurred through and around the cage and 35% (7/20) around the cage only. Unilateral or bilateral bridging of the posterior fusion masses was observed in 91% (20/22), with 55% occurring bilaterally (12/22). In 4 (18%) cases, bridging only occurred either posteriorly (2 cases) or anteriorly (2 cases). Complications included one deep wound infection. CONCLUSIONS: At the 2-year follow-up, BMA/CHS showed acceptable fusion rates in patients undergoing TLIF/PLF, and can be considered as an alternative source of graft material.