Correction for patient sway in radiographic biplanar imaging for three-dimensional reconstruction of the spine: in vitro study of a new method.

BACKGROUND: Three-dimensional (3D) reconstructions of the spine in the upright position are classically obtained using two-dimensional, non-simultaneous radiographic imaging. However, a subject's sway between exposures induces inaccuracy in the 3D reconstructions. PURPOSE: To evaluate the impact of patient sway between successive radiographic exposures, and to test if 3D reconstruction accuracy can be improved by a corrective method with simultaneous Moire-X-ray imaging. MATERIAL AND METHODS: Using a calibrated deformable phantom perceptible by both techniques (Moire and X-ray), the 3D positional and rotational vertebral data from 3D reconstructions with and without the corrective procedure were compared to the corresponding data of computed tomography (CT) scans, considered as a reference. All were expressed in the global axis system, as defined by the Scoliosis Research Society. RESULTS: When a sagittal sway of 10 degrees occurred between successive biplanar X-rays, the accuracy of the 3D reconstruction without correction was 8.8 mm for the anteroposterior vertebral locations and 6.4 degrees for the sagittal orientations. When the corrective method was applied, the accuracy was improved to 1.3 mm and 1.5 degrees , respectively. CONCLUSION: 3D accuracy improved significantly by using the corrective method, whatever the subject's sway. This technique is reliable for clinical appraisal of the spine, if the subject's sway does not exceed 10 degrees . For greater sway, improvement persists, but a risk of lack of accuracy exists.

Biomechanical evaluation of intra-articular and extra-articular procedures in anterior cruciate ligament reconstruction: a finite element analysis.

BACKGROUND: Intra-articular techniques (single and double bundles) are the most widely used procedures for the anterior cruciate ligament reconstruction. Lemaire introduced in 1967 the extra-articular techniques, and combined intra-articular and extra-articular reconstruction, to better restore the stability of the knee. However, the effectiveness of these procedures (intra-articular, extra-articular combined or not with intra-articular) seems to be controversial. METHODS: In the present study, we developed numerical models of a knee joint to evaluate the effects of these different procedures on the kinematics and biomechanics of the knee during an internal rotation test. Six cases were simulated: intact anterior cruciate ligament, intra-articular reconstructed anterior cruciate ligament (single and double bundles), extra-articular reconstructed anterior cruciate ligament alone, and combination of extra- and intra-articular reconstructions. The loading condition was an internal tibial torque of 2 N m at 0 degrees, 15 degrees, 30 degrees and 45 degrees of knee flexion. Internal rotation of the tibia and forces within the grafts and the ligaments were calculated. FINDINGS: This study showed that both single and double bundles intra-articular reconstructions restore similar internal rotation control and biomechanics of the soft structures as the intact anterior cruciate ligament situation. On the other hand, our results indicate that extra-articular reconstruction reduces appreciably the internal rotation and modifies the charges distribution in the soft structures when compared to the intact anterior cruciate ligament. INTERPRETATION: The extra-articular procedure alters the kinematics of the knee, which might overconstraint the ligaments and the femorotibial joints, leading to the failure of the anterior cruciate ligament reconstruction.

Renal thrombotic microangiopathy in systemic lupus erythematosus: clinical correlations and long-term renal survival.

BACKGROUND: Renal thrombotic microangiopathy (TMA) is an uncommon vascular complication of systemic lupus erythematosus (SLE). Its clinical symptoms and impact on renal survival remain unclear. METHODS: Eight patients aged 25 +/- 6 years with biopsy-proven renal TMA and at least four ARA criteria for the diagnosis of SLE were retrospectively studied over a 7-year period. RESULTS: All patients presented with renal failure (creatinine 3.3 +/- 2.1 mg/dl), six had proteinuria (2.5 +/- 1.3 g/day) with microscopic haematuria in four cases. Six patients had hypertension, which was severe in five cases. Renal histology disclosed arterial and/or arteriolar thrombosis with parietal thickening without angeitis (8 patients), glomerular microthrombi (3 patients), and vascular fibrin deposits (5/6 patients). In two cases, vascular lesions were associated with a mesangial or a proliferative glomerulonephritis. Thrombocytopenia was present in four patients with haemolytic microangiopathic anaemia in one case. Lupus anticoagulant (LA) was detected in five of eight patients, who also had anticardiolipin antibodies (3/7 patients) and/or were positive for VDRL (3/6 patients). Four patients with LA experienced arterial thrombosis and/or repeated spontaneous abortions. Treatment consisted of corticosteroids (8 patients), cytotoxic drugs (4 patients), plasma exchanges and/or intravenous immunoglobulins (4 patients) and antiplatelet and/or anticoagulant therapy (3 patients). Two patients recovered normal renal function and five had persistent renal insufficiency. One patient started haemodialysis on admission and died of sepsis 2 months later. CONCLUSIONS: TMA may be the sole renal complication in SLE and is not usually associated with haemolytic microangiopathic anaemia. In our series renal survival was influenced by the extent and severity of vascular lesions. Despite a frequent association with antiphospholipid antibodies, pathophysiological mechanisms of renal TMA in SLE remain unknown. Renal histology is mandatory for the diagnosis and the prognostic evaluation of renal vasculopathy in SLE.

[Neonatal cholestatic lithiasis associated with E. coli infection]. / Lithiase cholestatique néonatale associée à une infection à colibacilles.

BACKGROUND: Cholestasis associated with gallbladder lithiasis is quite uncommon in the neonate. We report such a case possibly due to a bacterial infection. CASE REPORT: A 25 day-old neonate was admitted because he suffered from cholestatic jaundice associated with biological findings of inflammation. Hepatic cellular function and transaminases were normal. Ultrasonography showed hepatomegaly and a 10 mm diameter gallstone with sludge into the gallbladder. The patient was given cefotaxime plus netilmicine. Soluble antigenes for E coli were positive in the urine. Jaundice and inflammatory findings returned to normal within 10 days and ultrasonography was normal at the age of 20 months. CONCLUSION: Neonatal E coli infection could be responsible for gallstone formation since E coli endotoxin may induce biliary stasis and favours lithogenous action of bacterial glycoproteins.

Cytochrome c oxidase deficiency presenting as recurrent neonatal myoglobinuria.

Markedly reduced cytochrome c oxidase (COX) activity was found in cultured skin fibroblasts of an infant with recurrent episodes of acute myoglobinuria, hypertonia, muscle stiffness and elevated plasma levels of sarcoplasmic enzymes (creatine kinase 96950 U/l, normal below 150) since the age of 3 weeks (COX activity: 36 nmol/min/mg protein; normal 65-440; COX/succinate cytochrome c reductase ratio: 1.4, normal 3.0 +/- 0.4). The expression of the disease in cultured fibroblasts allowed us to carry out a prenatal diagnosis during the next pregnancy. Hitherto, mitochondrial respiratory chain deficiency has not been established as a cause of recurrent myoglobinuria in childhood. Since most cases of myoglobinurias remain poorly understood, we suggest giving consideration to respiratory chain deficiency in elucidating the origin of unexplained recurrent myoglobinuria in childhood, especially when seemingly unrelated symptoms are present.

[Incidence and clinical expressions of microvascular complications in patients receiving kidney graft and treated with cyclosporine]. / Incidence et expressions cliniques des complications microvasculaires chez les greffés rénaux traités par ciclosporine.

Reported cases of HUS/TTP (hemolytic uremic syndrome/thrombotic thrombopenic purpura) with cyclosporin (CsA) are more and more frequent, which led us to evaluate the incidence of microangiopathic process in kidney graft patients. In our first retrospective study we noted 9.4 percent of HUS/TTP among 117 patients. We tried to detect infraclinical hemolytic events prospectively in 40 new patients by systematic measurement of haptoglobin levels after introduction of CsA. The incidence of falls in haptoglobin levels was 25 percent. The immunological context was always noted: rejection crisis in 5 cases, cytomegalovirus infection in 3 cases, isolated markers of lymphocyte-activity in 2 cases. We never found a clinical or infraclinical form of microangiopathic process without a symptomatic or asymptomatic immunological complication. Monitoring haptoglobin levels make it possible to detect early endothelial injuries which could be linked to the future arteriolopathy described with CsA therapy.

[Striatal involvement with abnormal movements in hemolytic-uremic syndrome]. / Atteinte striatale avec mouvements anormaux au cours du syndrome hémolytique et urémique.

Two children with hemolytic-uremic syndrome (HUS) presented with alteration of consciousness and severe abnormal movements related to striatal involvement. They required dialysis and controlled ventilation. Steady improvement in neurologic function was seen during the following weeks, and abnormal movements disappeared. It is suggested that the pathogenesis of neurological dysfunction in these two children was related to intracerebral microangiopathy, because neither systemic arterial hypertension, nor metabolic disturbances were present. This hypothesis is supported by the cerebral blood flow study in one patient. Neuropathologic studies of patients with HUS who presented with CNS symptoms showed vascular thromboses within the CNS: CT scan demonstrated multiple small areas of infarction, particularly in the basal ganglia. The prognosis of HUS is generally worsened in case of severe CNS involvement, but abnormal movements may disappear without sequelae.

Incidence and clinical profile of microvascular complications in renal allografted patients treated with cyclosporine.

The incidence of cyclosporine (CsA) vascular toxicity is open to debate. We attempted to evaluate the incidence of hemolytic accidents in our series of patients taking all clinical forms into consideration. From January, 1989, to December, 1990, 117 patients received kidneys from cadaver donors and were treated with CsA. Five patients presented hemolytic uremic syndrome (HUS) accompanied by a rejection crisis; 6 patients presented hemolytic anemia associated in 2 cases with marked thrombocytopenia without any evidence of rejection. Cytomegalovirus (CMV) infection was diagnosed in 2 patients and bacterial infection preceded hemolysis in 2 other cases, suggesting a triggering factor. In addition, when we systematically determined haptoglobin levels after introduction of CsA treatment, we found asymptomatic hemolytic episodes more frequently. Our incidence of hemolytic accidents was approximately 10%. Hemolysis could indicate ischemic vascular damage leading to arteriolar medial hyalinosis preceding fibrosis in CsA nephrotoxicity. Thus, it would be interesting to detect asymptomatic forms of hemolysis by monitoring haptoglobin levels. This approach could lead to a reduction of the CsA dose in patients presenting low haptoglobin levels, even in the absence of evidence of nephrotoxicity.

[Urological complications following kidney transplantation in childhood]. / Urologichni uslozhneniia sled bubrechna transplantatsiia v detskata vuzrast.

Five urologic complications in the posttransplantation period were performed in a case material of 68 renal transplantations in children, performed at the Transplantation Center in Lille, Northern France over the period 1981-July 1990. Three patients had ureteral stenosis (4.4 per cent), 1 urinary fistula (1.5 per cent) and 1 calculosis (1.5 per cent). All these cases are described and illustrated with figures. Comparing the results with those reported from other leading transplantation centers, the authors point to the low incidence of urologic complications in their case material (7.3 per cent). This encouraging result is attributed to the adequate selection of recipients, preliminary removal of accompanying urologic anomalies, early transplantation (82 per cent before the end of the second year after initiation of hemodialysis), as well as to precise explantation and transplantation.