Comparison of QCT-derived and DXA-derived areal bone mineral density and T scores

Summary  Two-dimensional areal bone mineral density (aBMD) of the proximal femur measured by three-dimensional quantitative computed tomography (QCT) in 91 elderly women was compared to dual-energy X-ray absorptiometry (DXA) aBMD results measured in the same patients. The measurements were highly correlated, though QCT aBMD values were marginally lower in absolute units. Transformation of the QCT aBMD values to T score values using National Health and Nutrition Examination Survey (NHANES) DXA-derived reference data improved agreement and clinical utility. Introduction  World Health Organization guidelines promulgate aBMD (g cm⁻²) measurement of the proximal femur for the diagnosis of bone fragility. In recent years, there has been increasing interest in QCT to facilitate understanding of three-dimensional bone structure and strength. Objective  To assist in comparison of QCT-derived data with DXA aBMD results, a technique for deriving aBMD from QCT measurements has been developed. Methods  To test the validity of the QCT method, 91 elderly females were scanned on both DXA and CT scanners. QCT-derived DXA equivalent aBMD (QCT_DXA aBMD) was calculated using CTXA Hip™ software (Mindways Software Inc., Austin, TX, USA) and compared to DXA-derived aBMD results. Results  Test retest analysis indicated lower root mean square (RMS) errors for CTXA; F test between CTXA and DXA was significantly different at femoral neck (FN) and trochanter (TR) (p < 0.05). QCT underestimates DXA values by 0.02 ± 0.05 g cm⁻² (total hip, TH), 0.01 ± 0.04 g cm⁻² (FN), 0.03 ± 0.07 g cm⁻² (inter-trochanter, IT), and 0.02 ± 0.05 g cm⁻² (TR). The RMS errors (standard error of estimate) between QCT and DXA T scores for TH, FN, IT, and TR were 0.36, 0.40, 0.39, and 0.49, respectively. Conclusions  This study shows that results from QCT aBMD appropriately adjusted can be evaluated against NHANES reference data to diagnose osteoporosis.     

Intraoperative cell salvage in metastatic spine tumour surgery reduces potential for reinfusion of viable cancer cells

Purpose

This study aimed at evaluating our hypothesis that tumour cells, which pass through the intraoperative cell salvage (IOCS) machine, lose viability due to possible injury to the cell membrane during centrifugation and filtration, enabling safe reinfusion even without filtration.

Methods

Thirteen patients who underwent metastatic spine tumour surgery (MSTS) at our institution were recruited. Blood samples (5 ml each) were collected at five different stages during surgery, namely, stage A and B: from patients’ vein during induction and at the time of maximum tumour manipulation; stage C, D and E: from the operative blood prior to IOCS processing, after IOCS processing and after IOCS-LDF (leucocyte depletion filter) processing, respectively. The samples were then analysed for viability of tumour cells using microwell-based culture.

Results

The median age of the patients was 65 years (range 37–77 years). The most common primary tumour was lung, followed by breast, hepatocellular and renal cell carcinoma. The median blood loss was 680 ml (range 300–1500 ml). Analysis of cultured blood samples showed that CTC-containing clusters were developed from some samples before IOCS-LDF processing (stage A: three patients, stage B: three patients and stage C: one patient). None of the samples from stages D and E generated clusters after culture, suggesting the absence of viable cancer cells after IOCS processing.

Conclusions

The salvaged blood may contain some tumour cells after processing with IOCS machine, but these cells are damaged and hence unable to replicate and unlikely to metastasise. The results of this study support the hypothesis that salvaged blood in MSTS is safe for transfusion.

     

Anatomical considerations for cervical pedicle screw insertion: the use of multiplanar computerized tomography measurements in 122 consecutive clinical cases

Background contextSuccessful placement of pedicle screws in the cervical spine requires a sufficient three-dimensional understanding of pedicle morphology to allow accurate identification of the screw axis.PurposeThe goal of the present study was to assess morphologic trends from one level to the next with respect to linear and angular parameters associated with the subaxial cervical pedicles.Study design/settingWe evaluated the pedicle morphology of cervical spine using axial and sagittal computed tomography (CT) imaging. The C3–C7 vertebrae in 122 patients (610 vertebrae) were evaluated (age range, 14–93; mean, 48 years).MethodsThin cut (2.5 mm thickness) axial CT images were measured. Sagittal reconstructions were obtained using 1.25-mm thickness slices. The following pedicle parameters were assessed: pedicle width (PW, the mediolateral diameter of the pedicle isthmus, perpendicular to the pedicle axis), pedicle height (PH, rostro-caudal dimension of the pedicle determined on the sagittal image), maximal screw length (MSL, distance from the posterior cortex of the lateral mass to the anterior wall of the vertebral body along the pedicle axis), and pedicle transverse angle (PTA, angle between the pedicle axis and the midline vertebral body).ResultsThe overall mean PW and PH ranged from 4.7 to 6.5 mm and 6.4 to 7.0 mm, respectively. For both these parameters there was a trend toward increasing size proceeding caudally in the cervical spine. The mean PW and PH was greater in males than in females, and this difference was statistically significant at all levels (p<.0001). The overall mean MSL ranged from 29.9 to 32.9 mm. All intersections of the pedicle axis and the posterior cortex of the lateral mass were located at the most lateral portion of the lateral mass for the C3–C6 vertebrae. The overall mean PTA ranged from 37.8° to 45.3°. The overall mean PTA was approximately 44° from C3 to C6 and 37.8° at C7.ConclusionThe findings of our radiological anatomical study suggest that the preoperative CT scans of patients undergoing cervical transpedicular fixation should be thoroughly analyzed and close attention paid to the pedicle size and its angulation. The placement of cervical pedicle screws should be individualized for each patient and based on detailed preoperative planning.     

A thoracic and lumbar spine injury severity classification based on neurologic function grade, spinal canal deformity, and spinal biomechanical stability

BACKGROUND CONTEXT: Current well regarded thoracic and lumbar spine injury classifications use mechanistic and anatomical categories, which do not directly rely on quantifiable management parameters. Their clinical usefulness is not optimal. PURPOSE: Formulate an injury severity based classification. STUDY DESIGN/SETTING: This retrospective investigation studied patients who suffered thoracic and lumbar spine injuries, and examined the following three quantifiable parameters: 1) neurologic function grade; 2) spinal canal deformity; 3) biomechanical stability. These parameters are the primary clinical indications for management decisions. PATIENT SAMPLE: One hundred twenty-six consecutive patients with spinal trauma admitted to a level 1 tertiary trauma center from January 1997 to November 2005 were enrolled in this study. OUTCOME MEASURES: Spine injury severity was independently scored on three parameters: 1) neurologic function impairment grade according to the modified Frankel grading method and the American Spinal Injury Association (ASIA) function scale; 2) spinal canal deformity from translation and intrusion, measured as percent canal cross-sectional area compromise; 3) failure of five possible biomechanical functions in Denis's three anatomic columns, and a sixth group of unstable deformities. All three columns contribute to tensile function. Only the anterior and middle columns provide compression load-bearing function. A combination of three or more column biomechanical function failure or an unstable deformity renders the injury unstable. METHODS: Five fellowship-trained spine surgeons from one institution took part in the study. Hospital medical records, including admission history and physical examination, discharge summary, and operative report (if surgery was performed), were examined for neurologic deficit. Plain radiographs, computed tomographic scans and magnetic resonance imaging were assessed for canal compromise and biomechanical function status. RESULTS: Injuries were located from T3 to L5, 58% of which were at the thoracolumbar junction (T11-L2). Neurologic impairment occurred in 45% (57/126) of patients, with 19 complete paraplegias (Frankel grade A). The average spinal canal cross-sectional area compromise was 56.1% in neurologically impaired and 14.2% for patients who where neurologically intact. The number of tensile element failure patients in neurologically impaired versus intact are as follow: tri-columns 22/4; two columns 16/8; one column 11/17; all columns intact 8/40. Load-bearing element failed in 55/57 neurologically impaired and 63/69 intact patients. Sixty-seven patients had spinal reconstructive surgery. Their average instability profile score was 4.4 out of 6, and canal compromise score was 3.3 out of 5. CONCLUSIONS: A clinically useful thoracic and lumbar spine injury classification should be based on parameters that are the primary indications for management decisions. The same parameters should be injury severity quantifiable as to guide treatment. In this study we introduced spinal canal deformity and column biomechanical functions as quantifiable parameters in thoracic and lumbar injury severity classification. Validation of this method is beyond the scope of this preliminary study.     

Minimally invasive operative management for lumbar spinal stenosis: overview of early and long-term outcomes

Standard open posterior decompression is well established and familiar to virtually all spine surgeons. However, this traditional surgical treatment of lumbar spinal stenosis (LSS) is often associated with significant postoperative pain, disability, and dysfunction. This article reviews the use of a minimally invasive microendoscopic approach for bilateral decompression of lumbar stenosis by way of a unilateral approach. This technique has been shown to provide symptomatic relief equivalent to that of open discectomy, with significant reductions in operative blood loss, postoperative pain, hospital stay, and narcotic usage. Furthermore, the article explains the rationale, indications, and surgical techniques for minimally-invasive LSS surgery and presents the authors' 4-year outcomes data.     

Reactivation of tuberculous lymphadenitis during pregnancy.

Three patients presenting with tuberculous lymphadenitis during pregnancy are described. By suppressing cell-mediated immunity, pregnancy predisposes the mother to infections of the type in which cellular immunity is important in defence. In this setting, self-healed primary pulmonary or extra-pulmonary tuberculosis may reactivate.     

Airbag associated fatal head injury: case report and review of the literature on airbag injuries

Airbags have been shown to significantly reduce mortality and morbidity in motor vehicle crashes. However, the airbag, like the seat belt, produces its own range of injuries. With the increasing use of airbags in the UK, airbag associated injuries will be seen more often. These are usually minor, but in certain circumstances severe and fatal injuries result. Such injuries have been described before in the medical literature, but hitherto most reports have been from North America. This is the first case report from the UK of serious injury due to airbag deployment and describes the case of a driver who was fatally injured when her airbag deployed in a moderate impact frontal collision where such severe injury would not normally have been anticipated. The range of airbag associated injuries is described and predisposing factors such as lack of seat belt usage, short stature, and proximity to airbag housing are discussed. The particular dangers airbags pose to children are also discussed.     

Mucosal antibodies in inflammatory bowel disease are directed against intestinal bacteria.

In contrast with normal subjects where IgA is the main immunoglobulin in the intestine, patients with active inflammatory bowel disease (IBD) produce high concentrations of IgG from intestinal lymphocytes, but the antigens at which these antibodies are directed are unknown. To investigate the specificities of these antibodies mucosal immunoglobulins were isolated from washings taken at endoscopy from 21 control patients with irritable bowel syndrome, 10 control patients with intestinal inflammation due to infection or ischaemia, and 51 patients with IBD: 24 Crohn's disease (CD, 15 active, nine quiescent), 27 ulcerative colitis (UC, 20 active, seven inactive). Total mucosal IgG was much higher (p < 0.001) in active UC (median 512 micrograms/ml) and active CD (256 micrograms/ml) than in irritable bowel syndrome controls (1.43 micrograms/ml), but not significantly different from controls with non-IBD intestinal inflammation (224 micrograms/ml). Mucosal IgG bound to proteins of a range of non-pathogenic commensal faecal bacteria in active CD; this was higher than in UC (p < 0.01); and both were significantly greater than controls with non-IBD intestinal inflammation (CD p < 0.001, UC p < 0.01) or IBS (p < 0.001 CD and UC). This mucosal IgG binding was shown on western blots and by enzyme linked immunosorbent assay (ELISA) to be principally directed against the bacterial cytoplasmic rather than the membrane proteins. Total mucosal IgA concentrations did not differ between IBD and controls, but the IgA titres against faecal bacteria were lower in UC than controls (p < 0.01). These experiments show that there is an exaggerated mucosal immune response particularly in active CD but also in UC directed against cytoplasmic proteins of bacteria within the intestinal lumen; this implies that in relapse of IBD there is a breakdown of tolerance to the normal commensal flora of the gut.     

Longitudinal monitoring of demineralization peripheral to orthodontic brackets using cross polarization optical coherence tomography

Objectives

The aim of this study was to test the hypothesis that cross-polarization optical coherence tomography (CP-OCT) can be used to longitudinally monitor demineralization peripheral to orthodontic brackets in an extended clinical study.

Methods

A high-speed CP-OCT system was used to acquire 3D volumetric images of the area at the base of orthodontic brackets over a period of 12 months after placement. The reflectivity was measured at 3-month intervals for 12 months to determine if there was increased demineralization. Two teeth were monitored on 20 test subjects and the brackets were bonded using two types of adhesives. This was a randomized controlled clinical study with a split mouth design such that each subject served as his or her own control. On one side, the control premolar was bonded with a bonding agent (Adper Scotchbond from 3 M ESPE, St. Paul, MN) and composite (Transbond XT from 3 M Unitek, Monrovia, CA) that lacked fluoride. On the other side, the experimental premolar was bonded with a fluoride releasing glass ionomer cement (GC Fuji Ortho LC from GC America, Alsip, IL).

Results

There was a small but significant increase in the calculated lesion depth and integrated reflectivity over that depth (ΔR) for both adhesive types (p < 0.0001) indicating increasing demineralization with time. There was no significant difference in the lesion depth (p = 0.22) and ΔR (p = 0.91) between the groups with the fluoride releasing glass ionomer cement and the conventional composite.

Conclusions

CP-OCT was able to measure a significant increase in demineralization (p < 0.0001) at the base of orthodontic brackets over a period of 12 months.     

Cognitive impairment in Parkinson's disease: impact on quality of life of carers

Background

The quality of life (QoL) of informal caregivers of people with Parkinson's disease (PD) (PwP) can be affected by the caring role. Because of cognitive symptoms and diminished activities of daily living, in addition to the management of motor symptoms, carers of PwP and cognitive impairment may experience increased levels of burden and poorer QoL compared with carers of PwP without cognitive impairment. This study aimed to investigate the impact of cognitive impairment in PD upon QoL of carers.

Methods

Approximately 36 months after diagnosis, 66 dyadic couples of PwP and carers completed assessments. PwP completed a schedule of neuropsychological assessments and QoL measures; carers of PwP completed demographic questionnaires and assessments of QoL. Factor scores of attention, memory/executive function and global cognition, as derived by principal component analysis, were used to evaluate cognitive domains.

Results

Hierarchical regression analysis found lower Montreal Cognitive Assessment was a significant independent predictor of poorer carer QoL, in addition to number of hours spent caregiving, carer depression and PD motor severity. Attentional deficits accounted for the largest proportion of variance of carer QoL. Carers of PwP and dementia (n = 9) had significantly poorer QoL scores compared with PwP and mild cognitive impairment (n = 18) or normal cognition (n = 39) carers (p < 0.01).

Conclusions

Attentional deficits were the strongest predictor of carer QoL compared with other cognitive predictors. Carers for those with PD dementia reported the poorest QoL. Interventions such as respite or cognitive behavioural therapy to improve mood and self‐efficacy in carers may improve carer QoL. © 2016 The Authors. International Journal of Geriatric Psychiatry published by John Wiley & Sons, Ltd.