Idiopathic scoliosis in three dimensions: a succession of two-dimensional deformities?

STUDY DESIGN: A geometric analysis of computerized three-dimensional (3-D) reconstructions of the spine of adolescents with idiopathic scoliosis. OBJECTIVES: To analyze and describe the 3-D location of scoliotic curves with respect to the global frontal, sagittal, and transverse planes of each subject. SUMMARY OF BACKGROUND DATA: Clinical two-dimensional (2-D) measurements cannot fully describe the 3-D deformity of a scoliotic spine because they are done in the 2-D frontal or sagittal plane projection of a subject and do not correspond to the actual deformity. METHODS: The spinal deformity from T1 to L5 of 50 adolescents with thoracic idiopathic scoliosis was reconstructed in 3-D using a multiplanar digital radiographic technique allowing the visualization of the vertebral line of the spine in any projection using auto CAD software. The curvature was segmented in three distinct curves for each subject: a high thoracic, a thoracic, and a lumbar. A regional plane passing through the two end-vertebrae and the apical vertebra was defined, and a series of geometric manipulations were performed to realign each regional plane with the global axis system of each subject. RESULTS: A total of 91% of the 147 curves studied were found to be entirely contained within its 2-D regional plane, and all scoliotic curves were found to be oriented in a 3-D location different from the classic frontal, sagittal, and transverse orthogonal planes of each subject. CONCLUSION: In thoracic idiopathic scoliosis the deformity of the spine is 3-D, but the regional deformity of each high thoracic, thoracic, or lumbar curve is almost always 2-D. The orientation in space of each 2-D plane is such that it cannot be seen in its true frontal or sagittal projection using standard frontal or sagittal radiologic views of the subject.     

Donor-specific tolerance in a murine model: the result of extra-thymic T cell deletion?

Previously, we established a murine model, that involves the engraftment of fully allogeneic T cell depleted donor bone marrow cells in sublethally irradiated and single dose anti-CD3 treated recipient mice. These mice developed permanent stable multilineage mixed chimerism and donor-specific tolerance without graft-versus-host disease. Recently, we have shown that donor-specific tolerance is not induced and/or maintained by clonal anergy, neither by a Th1/Th2 shift, nor by suppressor or other regulatory processes. In the present study, we investigated whether clonal deletion plays a role in tolerance induction in our model. We studied the kinetics of TCRVbeta8(+) T cells in BALB/c (H-2L(d+))-->dm2 (H-2L(d-)) chimeras, in which combination of mouse strains TCRVbeta8 predominates the anti-donor response. We found that TCRVbeta8(+) T cells were specifically deleted. To our surprise, this deletion was also found in mixed chimeras, thymectomized prior to the conditioning regimen. We conclude that clonal deletion plays a role in the establishment and maintenance of donor-specific tolerance, and that the thymus is not required for this process. In addition, confocal laser-scanning microscopy clearly showed the presence of abundant amounts of donor T cells and some donor antigen presenting cells in the small intestine in thymectomized chimeras and not in other organs, suggesting that T cell selection might take place in this organ in the absence of the thymus.     

Postconditioning of the small intestine: which is the most effective algorithm in a rat model?

Background

Mesenteric ischemia is a serious clinical condition requiring immediate surgical intervention. The unavoidable ischemic-reperfusion (IR) injury may be ameliorated using the appropriate postconditioning protocol. The aim of the present study was to investigate the optimal postconditioning algorithm in a rat model of intestinal ischemic–reperfusion injury.

Materials and methods

Male Wistar rats were randomized into five groups (n = 10), one sham-operated, one IR, and three postconditioned groups, each with different protocols. The animals were subjected to 60 min of mesenteric ischemia, followed by 60 min of reperfusion. Postconditioning was applied at the onset of reperfusion using three different algorithms. Arterial pressure and mucosal microcirculation were monitored throughout the experiment. Mesenteric pH was determined at the early phase of reperfusion. Blood and tissue samples were taken at the end of reperfusion for histologic evaluation, serum lactate dehydrogenase, serum creatine kinase, serum tumor necrosis factor-α, serum interleukin-6, detailed mucosal antioxidant, and scavenger capacity assays.

Results

The shorter and intermediate length cycles of postconditioning enhanced mucosal microcirculation and redox state and significantly delayed the normalization of mesenteric pH. Furthermore, milder histopathologic lesions and lower concentrations of serum necroenzymes and proinflammatory cytokines were detected compared with the IR group. The protective effect of postconditioning using longer cycles could only be seen in a tendentious manner.

Conclusions

In a rat model of intestinal ischemia–reperfusion, the shorter and intermediate length cycles of postconditioning proved to be more effective than the use of longer cycles.     

Is the use of cyanoacrylate in intestinal anastomosis a good and reliable alternative?

Purpose

The present study aims to compare strength, healing, and operation time of experimental intestinal anastomoses performed by polyglactin 910 (Vicryl; Ethicon, Edinburgh, United Kingdom) sutures with ethyl-2-cyanoacrylate glue (Pattex; Henkel, Dusseldorf, Germany).

Material and methods

Ninety-six Sprague-Dawley rats were divided into 2 (groups E and L). Each group was further subdivided into 6 subgroups (EA1, EA2, EA3, EB1, EB2, EB3, LA1, LA2, LA3, LB1, LB2, LB3), each containing 8 rats. Intestinal anastomosis was performed by polyglactin 910 sutures in A subgroups and with ethyl-2-cyanoacrylate in B subgroups. The anastomosis was end to end in A1 and B1, side to side in A2 and B2, and end to side in A3 and B3. Time for anastomosis performance (AT) was recorded. In group E, bursting pressures and hydroxyproline levels were determined on the second postoperative day, whereas in group L, the same measurements were made on the sixth postoperative day. One-way analysis of variance was used for analyses of variance in the groups. Quantitative data were analyzed with Student's t test. P value was considered significant at less than .05.

Results

There was no significant difference between bursting pressures of subgroup pairs on both postoperative days 2 and 6. Hydroxyproline levels and AT were significantly better in B subgroups.

Conclusion

Better healing, shorter AT, and equal strength were achieved with ethyl-2-cyanoacrylate compared with polyglactin 910 sutures in intestinal anastomosis in the experimental setting.     

The study of expanded tri-lobed flap in a rabbit model: possible flap model in ear reconstruction?

Background  

Local flaps are widely used in reconstructive surgery. Tri-lobed skin flap is a relatively new flap and there has been no experimental model of this flap. This flap can be used for repair of full thickness defects in the face, ears and alar region. Based on the size of ears in a rabbit, we designed a model of ear reconstruction using expanded tri-lobed flap. Local flaps are more advantageous in that they provide excellent color and texture matching up with those of the face, adequately restore ear contour, place scars in a favorable location and ideally accomplish these goals in a single stage with minimal donor site morbidity.     

Apical vertebral derotation in the posterior treatment of adolescent idiopathic scoliosis: myth or reality?

Introduction

Direct apical vertebral rotation represents an important goal of posterior surgery for thoracic adolescent idiopathic scoliosis (AIS), so as to obtain a better cosmetic effect and to avoid posterior thoracoplasty. However, the real effectiveness in correction of vertebral rotation, using posterior only procedures, is still open to debate. The aim of the present study is to compare the correction of axial apical rotation obtained with direct rotation procedure versus simple concave rod rotation, in patients treated by posterior fusion for thoracic AIS using pedicle screw-only construct.

Materials and methods

A retrospective review was performed on a total of 62 consecutive patients (one single institution, three different surgeons) affected by AIS, who had undergone a posterior spinal fusion with pedicle screw-only instrumentation between January 2005 and April 2008 at the reference center. All cases presented a main thoracic curve (Lenke type 1 and 2). The angle of rotation (RAsag) of the apical vertebra was measured from the preoperative and last follow-up axial CT. According to the derotation procedure, two groups were identified: a direct vertebral rotation group (DR group; n = 32 patients) and a simple concave rod rotation group (No-DR group; n = 30 patients). There were no statistical differences between the two groups, in terms of age, Risser’s sign, curve patterns, Cobb main thoracic (MT) curve magnitude and flexibility, extension of fusion, offset measurements on the coronal plane and sagittal preoperative contour.

Results

All 62 patients were reviewed at an average follow-up of 3.7 years (range 2.5–4.2 years). The DR group compared to the No-DR group showed a significantly better final correction of apical vertebral rotation (DR 63.4 % vs. No-DR 14.8 %; p < 0.05) and a greater final correction (61.3 vs. 52.4 %; p < 0.05) with better maintenance of the initial correction (−1.7° vs. −1.9°; ns) of the main thoracic curve. Concerning the coronal balance, there was the same aforementioned trend of better results in the DR group, with less final apical MT vertebra translation (DR 2.2 cm vs. No-DR 4.1 cm), greater overall change (preop-final) of lower instrumented vertebra (LIV) coronal tilt (−14.9° vs. −11.1°; p < 0.05); the final global coronal balance (C7–S1) resulted quite better in DR group, but without a significant difference. The T5–T12 kyphosis angle was quite similar in both group before surgery (DR 16.8° vs. No-DR 17.5°) and was little lower at final follow-up evaluation in direct vertebral rotation group (14.5° vs. 16.5°). The T10–L2 sagittal alignment angle was similar in each group before surgery (12.5° in DR vs. 11.8° in No-DR), and at the latest follow-up averaged 5.3° versus 8.2°, respectively. Lumbar lordosis was similar in each group before surgery (DR −42° vs. No-DR −44.1°) and at the final follow-up evaluation (−45.9° vs. −43.2°). At the latest follow-up, SRS-30 and SF-36 findings were similar between the two groups. The complication rate was higher in the simple concave rod rotation group (13.3 vs. 9.3 %), related in two cases to thoracoplasty, which was never utilized in direct rotation patients.

Conclusions

The direct vertebral rotation obtained significantly better final results, when compared to simple concave rod rotation, both concerning correction of apical vertebral rotation and magnitude of MT curve. On the other hand, the DR group presented a little reduction in T5–T12 kyphosis at follow-up, in comparison with concave rod rotation procedure. Both procedures were found to be satisfying from patients’ perspective. Nevertheless overall complication rate was higher in the simple concave rod rotation group, related mainly to thoracoplasty (2 cases), which was never necessary in direct rotation patients.     

Patient-oriented research: a new model for anesthesia in the 2lst century?

Canadian Journal of Anesthesia/Journal canadien d'anesthésie -     

Prevalence of complications in neuromuscular scoliosis surgery: a literature meta-analysis from the past 15 years

Purpose

Our objectives were primarily to review the published literature on complications in neuromuscular scoliosis (NMS) surgery and secondarily, by means of a meta-analysis, to determine the overall pooled rates (PR) of various complications associated with NMS surgery.

Methods

PubMed and Embase databases were searched for studies reporting the outcomes and complications of NMS surgery, published from 1997 to May 2011. We focused on NMS as defined by the Scoliosis Research Society’s classification. We measured the pooled estimate of the overall complication rates (PR) using a random effects meta-analytic model. This model considers both intra- and inter-study variation in calculating PR.

Results

Systematic review and meta-analysis were performed for 68 cohort and case–control studies with a total of 15,218 NMS patients. Pulmonary complications were the most reported (PR = 22.71 %) followed by implant complications (PR = 12.51 %), infections (PR = 10.91 %), neurological complications (PR = 3.01 %) and pseudoarthrosis (PR = 1.88 %). Revision, removal and extension of implant had highest PR (7.87 %) followed by malplacement of the pedicle screws (4.81 %). Rates of individual studies have moderate to high variability. The studies were heterogeneous in methodology and outcome types, which are plausible explanations for the variability; sensitivity analysis with respect to age at surgery, sample size, publication year and diagnosis could also partly explain this variability. In regard to surgical complications affiliated with various surgical techniques in NMS, the level of evidence of published literature ranges between 2+ to 2−; the subsequent recommendations are level C.

Conclusion

NMS patients have diverse and high complication rates after scoliosis surgery. High PRs of complications warrant more attention from the surgical community. Although the PR of all complications are affected by heterogeneity, they nevertheless provide valuable insights into the impact of methodological settings (sample size), patient characteristics (age at surgery), and continual advances in patient care on complication rates.

Electronic supplementary material

The online version of this article (doi:10.1007/s00586-012-2542-2) contains supplementary material, which is available to authorized users.     

Is open thoracotomy still a good treatment option for the management of empyema in children?

BACKGROUND: The incidence of pediatric postpneumonic empyema increases, and there is little consensus on its management. Open thoracotomy has been linked with high morbidity and prolonged hospitalization. Our aim was to review the outcome after open thoracotomy and to provide a set of data for comparison with other treatment modalities. METHODS: Forty-four children (median age, 8 years, 2 months to 16 years) undergoing surgery for postpneumonic empyema between 1993 and 2002 in our unit were studied. RESULTS: The median time from onset of symptoms to admission in a pediatric unit was 8 days (range, 2 to 63 days), the median time from pediatric admission to surgical referral was 3 days (range, 0 to 19 days), and the median time from surgical admission to thoracotomy was 1 day (range, 0 to 2 days). Eight children had a chest drain before surgical admission. Six patients, who were referred late (19 to 69 days), had lung abscesses. A limited muscle sparing thoracotomy (44 patients), formal decortication (36 patients), lung debridement (5 patients), and lobectomy (1 patient) were performed. After thoracotomy, median time to apyrexia was 1 day (range, 0 to 27 days) and drain removal was 3 days (range, 1 to 16 days). A pathogen was isolated in 21 patients. There were no deaths. Four children with abscesses remained septic and had lobectomies (2 patients) and debridements (2 patients). The median postoperative hospital stay was 5 to 53 days. One child had postpneumonic empyema develop and had decortication 3 months postoperatively. At follow-up, all children were doing well and had satisfactory radiographs. The Kaplan-Meier 5-year and 10-year survival rate, freedom from any reoperation, and freedom from hospital readmission were 100%, 87%, and 98%, respectively. CONCLUSIONS: Open thoracotomy remains an excellent option for management of stage II-III empyema in children. When open thoracotomy is performed in a timely manner there is low morbidity and it provides rapid resolution of symptoms with a short hospital stay. However, delayed referrals may result in advanced pulmonary sepsis and a protracted clinical course. The late results are encouraging. Use of thoracoscopy or fibrinolysis should be considered on the basis of their own merit, not on the assumption of probable adverse outcomes after thoracotomy.     

Evaluating trauma center quality: does the choice of the severity-adjustment model make a difference?

CONTEXT: The Major Trauma Outcome Study (MTOS) database was created by the American College of Surgeons over 20 years ago to establish national norms for trauma care. The primary trauma outcome prediction models used for evaluating the quality of trauma care, TRISS and ASCOT (A Severity Characterization of Trauma), were developed using the MTOS database. OBJECTIVE: First, to determine whether TRISS and ASCOT agree on hospital quality. Second, to determine whether TRISS and ASCOT accurately reflect contemporary outcomes in trauma care. DESIGN, SETTING AND PATIENTS: A retrospective cohort study based on 91,112 patients admitted to 69 hospitals between 2000 and 2001 in the National Trauma Databank. Using TRISS and ASCOT, the ratio of the observed to expected mortality rate (O/E ratio) was calculated for each hospital. Hospitals whose O/E ratio was statistically different from 1 were identified as quality outliers. Kappa analysis was used to assess the degree to which TRISS and ASCOT agreed on the identity of hospital quality outliers. RESULTS: TRISS and ASCOT disagreed on the outlier status of 35 of the 69 hospitals. Kappa analysis revealed only fair agreement (kappa = 0.23; p = 0.0015) between TRISS and ASCOT in identifying quality outliers. Thirty-eight hospitals were identified by the TRISS method as high-performance hospitals. CONCLUSION: First, TRISS and ASCOT exhibit substantial disagreement on the identity of quality outliers within the NTDB. Second, an unrealistically high number of hospitals were identified as high-performance outliers using either TRISS or ASCOT. These findings have important implications for the use of TRISS and ASCOT for benchmarking performance and quality improvement.     

Assessing the needs of patients in pain: a matter of opinion?

STUDY DESIGN: A prospective cohort study including patients with nonspecific spinal pain was performed. OBJECTIVES: To investigate whether the use of expert judgment in routine practice can provide a basis for reliable decision making concerning the need for intervention in patients with spinal pain and their ability to benefit from treatment. SUMMARY OF BACKGROUND DATA: A wide range of instruments and techniques are used to assess and treat patients with spinal pain. Many instruments are used without being clinimetrically tested. METHODS: A questionnaire concerning the patients' need of treatment and their potential to assimilate it was sent to experts in the health care arena: physicians, physical therapists, social insurance officers. The experts included were those connected with patients participating in a larger outcome study. Two cohorts of patients (sample 1, n = 217; sample 2, n = 257) were followed for 6 and 12 months, during which time the patients' health and work status were mapped. RESULTS: No acceptable agreement was found between any of the experts' ratings of patients' needs and potential for rehabilitation. Logistic regression showed that the experts' judgments were based almost solely on the age of the patient. The prediction analyses showed that the most consistent predictor of the patients' status at the 6-month follow-up assessment was the patients' own belief in the existence of effective treatments and their perceived ability for learning to cope with the condition. CONCLUSIONS: Expert judgment as exercised in routine practice cannot be used as basis for reliable decision making concerning the need of the patient with spinal pain for intervention and the patient's ability to benefit from treatment.     

Ten-year follow-up evaluation of a school screening program for scoliosis. Is the forward-bending test an accurate diagnostic criterion for the screening of scoliosis?

STUDY DESIGN: A 10-year follow-up evaluation of the effectiveness of school screening for scoliosis performed in a closed island population. OBJECTIVES: To evaluate the diagnostic accuracy of methods used for screening scoliosis and to re-examine the long-term effectiveness of the school scoliosis screening program. SUMMARY OF BACKGROUND DATA: The diagnostic accuracy of the forward-bending test and the long-term efficacy of the screening programs have not been clearly established. METHODS: In 1987, 2700 pupils aged 8 to 16 years from the island of Samos were screened for scoliosis. The Adams forward-bending test, Moire topography, the scoliometer, and the humpometer were used. Radiologic evaluation of the spine was available for each pupil and the number of false-negative and false-positive results of the screening methods was calculated. Subsequently, sensitivity, specificity, and positive and negative predictive values were estimated for each screening technique. Pupils found positive for spinal deformity were then followed up regularly at yearly intervals. In 1997, all positive subjects attended a 10-year clinical and radiologic follow-up, and the remaining subjects were re-evaluated by a postal questionnaire and were clinically examined if necessary. RESULTS: Spinal deformity was found in 153 (5.66%) pupils. Scoliosis (defined as a spinal curvature > or = 10 degrees) was found in 32 pupils, for a prevalence of 1.18%. For scoliosis, the Adams forward-bending test showed a number of false-negative results (in five cases), for a sensitivity of 84.37% and specificity of 93.44%. The sensitivities of Moire topography, the humpometer, and the scoliometer were 100%, 93.75%, and 90.62%, respectively, and specificity was 85.38%, 78.11%, and 79.76% respectively. The negative predictive value of the forward-bending test was inferior to those of the other methods. During this scoliosis screening program, if cutoff limits for referral had been used, such as the asymmetry of two Moire fringes, a humpogram deformity of (D + H) = 10 mm, and 8 degrees of scoliometer angle, it would have been possible to reduce radiologic examination by 89.4%. Three (0.11%) pupils aged between 12 and 14 years with scoliotic deformities greater than 20 degrees underwent satisfactory nonoperative treatment with Boston braces. One pupil with a 40 degrees thoracic curvature, underwent satisfactory surgical treatment because of progression 1 year later. Of the 121 spinal deformities with an initial Cobb angle less than 10 degrees, 44 (35.8%), and of the 29 scoliotic deformities with an initial Cobb angle between 10 degrees and 20 degrees, 14 (48.3%) progressed (a Cobb angle difference of at least 5 degrees in more than one examination). Observation and physiotherapy were the only treatments applied to all except one of the pupils in these groups. CONCLUSIONS: The Adams forward-bending test cannot be considered a safe diagnostic criterion for the early detection of scoliosis (especially when it is used as the only screening tool) because it results in an unacceptable number of false-negative findings. For the early detection of scoliosis, a combination of back-shape analysis methods can be safely used with the introduction of cutoff limits for referral being a useful procedure. The incidence of significant scoliosis is low, and its natural history seems to be independent of early detection. The wide-spread use of school scoliosis screening with the use of the forward-bending test must be questioned.     

Chronic aristolochic acid toxicity in rabbits: a model of Chinese herbs nephropathy?

BACKGROUND: Chinese herbs nephropathy (CHN) is a new type of subacute interstitial nephritis that is attributed to aristolochic acid (AA), which inadvertently has been included in slimming pills. The contribution of other simultaneously prescribed drugs remains disputed. In the present study, the effects of a chronic intake of AA given as a single drug was evaluated through renal histology and function in rabbits. METHODS: Female New Zealand White rabbits were injected intraperitoneally with either 0.1 mg AA/kg or with saline 5 days a week for 17 to 21 months. Body weight, renal function, and urinary excretion of glucose and low molecular weight proteins were monitored prior to sacrifice at the end of the study period. RESULTS: All animals given AA developed renal hypocellular interstitial fibrosis, which was classified into three patterns. Fibrosis was confined to medullary rays (MRs) in pattern I (N = 3), extended to the outer cortical labyrinth (OCL) in pattern II (N = 2), and eventually to the inner cortical labyrinth (ICL) in pattern III (N = 6). Fibrosis in MR and OCL was associated with mainly proximal tubular epithelial cell flattening. All treated animals displayed urothelial atypia. Three of them also developed tumors of the urinary tract. No significant pathologic changes were found in control rabbits. AA-treated animals differed from controls by an impaired growth, increased serum creatinine, glucosuria, tubular proteinuria, and anemia. CONCLUSION: The observed pattern of renal histopathological lesions and disorders of the renal function, as well as urothelial atypia and malignancy, are very reminiscent of CHN. Our observations therefore support a causal role of AA alone in the genesis of this new nephropathy.