Long-term follow-up after surgical treatment of adolescent idiopathic scoliosis using high-density pedicle screw constructs: Is 5-year routine visit required?

PURPOSE: The objective of this study is to determine whether routine follow-up 5 years after adolescent idiopathic scoliosis (AIS) surgery is likely to affect postoperative care for patients treated with high-density pedicle screw constructs, when routine 2-year follow-up has been performed. METHODS: We reviewed 80 patients undergoing surgery for AIS using high-density pedicle screw constructs and followed routinely 2 and 5 years after surgery. Quality of life (QOL) was assessed using the SRS-30 outcome questionnaire. Reoperations occurring between 2 and 5 years after surgery were identified. RESULTS: Curve correction and QOL were similar between 2- and 5-year visits. Two patients required revision surgery after presenting during unplanned visits between the 2- and 5-year follow-ups. One patient presented at the routine 5-year visit with an asymptomatic undisplaced rod fracture without loss of correction, and it was decided to follow-up only as needed. CONCLUSIONS: In AIS patients for whom routine follow-up 2 years after surgery using high-density pedicle screw constructs was uneventful, additional routine 5-year follow-up is not likely to affect postoperative care and revision rate. Patients developing complications and needing reoperation between 2 and 5 years after surgery will most likely present during unplanned visits rather than during routine follow-up appointments. Easy access to emergent visits on an as-needed basis is therefore important for this population if routine 5-year follow-up is not planned. These slides can be retrieved under Electronic Supplementary Material.

A 3D visualization tool for the design and customization of spinal braces.

A new tool was developed and validated on an X-ray dummy to allow personalized design and adjustment of spinal braces. The 3D visualization of the external trunk surface registered with the underlying 3D bone structures permits the clinicians to select pressure areas on the trunk surface for proper positioning of correcting pads inside the brace according to the patient's specific trunk deformities. After brace fabrication, the clinicians can evaluate the actual 3D patient-brace interface pressure distribution visualized simultaneously with the 3D model of the trunk in order to customize brace adjustment and validate brace design with respect to the treatment plan.

Epstein-Barr virus in a malignant lymphoproliferative disorder of B-cells occurring after thymic epithelial transplantation for combined immunodeficiency.

A fatal disseminated polyclonal malignant lymphoproliferative disorder of B-cells (immunoblastic sarcoma) developed shortly after a second thymic epithelial peritoneal implant in a 5-yr-old girl with combined immunodeficiency. The immunodeficiency was characterized by low T-cell numbers and function, very low levels of thymic hormone, dysgammaglobulinemia, and an inability to mount a primary antibody or cell-mediated response to new antigens. At necropsy, the thymus fulfilled morphological criteria for thymic dysplasia. Epstein-Barr virus (EBV) antigen and DNA were identified in neoplastic infiltrates in the lymph nodes and thymus by immunofluorescence for the EBV nuclear antigen and by EBV-specific complementary RNA/DNA hybridization. No antibodies to nuclear antigen, early antigen, or viral capsid antigen of EBV were identified in the serum. The concurrence of these events suggests that the thymic epithelial implant itself may have been instrumental in the pathogenesis of this neoplasm. It is proposed that the thymus may have provided factors which indirectly potentiated the proliferation of EBV-infected B-cells, possibly by induction of nonspecific T-helper cells and perhaps through other thymic humoral factors. It is suggested that some forms of immunoblastic sarcoma, even when polyclonal, and especially those which arise in immunocompromised hosts, may, in some instances, represent an opportunistic form of EBV-induced B-cell neoplasia.

Epstein-Barr virus polymorphic B-cell lymphoma associated with leukemia and with congenital immunodeficiencies.

Polymorphic B-cell lymphoma seen in four patients with congenital immunodeficiencies and in two patients with leukemia receiving chemotherapy was associated with the Epstein-Barr virus (EBV). The tumors had characteristic histologic features: they were polymorphic consisting of a mixture of lymphoblasts and differentiated cells including plasma cells, and areas of hemorrhagic necrosis were prominent. The tumors were either polyclonal, monoclonal, or multiclonal. Patients with congenital immunodeficiencies who developed these tumors died despite radiotherapy, corticosteroids plus acyclovir, or a combination of intravenous (IV) immunoglobulins and alpha 2 interferon. Patients with leukemia recovered when immunosuppressive drugs were discontinued and leukemia has not recurred over a period of 2 and 4 years, respectively, in the two patients.

Comparison of two methods in the determination of the sensitivity of 84 herpes simplex virus (HSV) type 1 and 2 clinical isolates to acyclovir and alpha-interferon.

Two methods, the colorimetric method (neutral red dye uptake), and DNA hybridization using a HSV thymidine kinase gene probe (TK) have been used to examine the sensitivity of 84 herpes simplex virus (HSV) type 1 and 2 clinical isolates to two antiviral drugs, acyclovir (ACV) and alpha-interferon (alpha-IFN). Using the colorimetric method, HSV isolates had ED50s ranging from 0.03 +/- 0.02 micrograms/ml to 0.164 +/- 0.03 micrograms/ml for ACV and 6.3 +/- 5.2 IU/ml to 55.0 +/- 11.4 IU/ml for alpha-IFN. With the DNA hybridization method, ED50s ranged from 0.033 +/- 0.012 micrograms/ml to 0.190 +/- 0.031 micrograms/ml for ACV and 8.5 +/- 5.0 IU/ml to 43.5 +/- 6.0 IU/ml for alpha-IFN. Two strains of HSV-1 were found to be resistant to very high concentrations of ACV (greater than 50.0 micrograms/ml). The values obtained by the two methods showed good correlation (r = 0.724, P = 0.002). Furthermore, our results demonstrate that the two methods are reproducible, reliable and the dye uptake assay is suitable for use in a diagnostic virology laboratory.

Herpes encephalitis. Rapid diagnosis and treatment with antiviral drugs.

The use of specific IgM antibodies and direct electron-microscopic examination of brain biopsies or vesicle fluid was tested as means of raped diagnosis in 6 cases of herpes simplex encephalitis seen consecutively in Montreal. In 2 of 3 biopsies herpes viruses were seen by negative staining of a cell extract within 1 hr. In the negative case, the biopsy was done almost 1 month after onset. In 2 additional cases herpes virus particles were found directly in the fluid of isolated vesicles. In the last 2 cases, who survived, the diagnosis of herpes encephalitis rested upon the demonstration of a greater than 4-fold rise in complement fixing herpes simplex virus antibodies in convalescent sera and upon the appearance late in the course of the encephalitis of specific antibodies in the cerebrospinal fluid. The early appearance of specific IgM antibodies contributed to the diagnosis in 4 of the 6 cases. Antiviral therapy was attempted in alternate cases (3 cases) but was not successful. Brain biopsy is rarely performed for diagnostic purposes but when prompt antiviral therapy is contemplated, the examination of the biopsy material for herpes virus particles by electron microscopy in negative staining and thin sections can rapidly and reliably confirm the diagnosis.

Standardization and kinetics of in vitro bovine blood lymphocyte stimulation with bovine rotavirus.

Two groups of 3-month old calves were immunized intramuscularly with attenuated bovine rotavirus and boosted 21 and 42 days later. The first group of three calves were vaccinated with live virus emulsified with incomplete Freund's adjuvant (IFA) and the second group was immunized with live virus suspended in phosphate buffered saline (PBS). Three other calves, serving as controls, were inoculated with PBS emulsified with IFA. The specific cell-mediated and antibody responses of the animals were studied. Preliminary analysis of in vitro peripheral blood lymphocyte transformation to bovine rotavirus determined optimal conditions as: 96 h culture period, 5 X 10(5) cells per culture in RPMI 1640 medium containing 10% heat-inactivated bovine fetal serum and the use of inactivated virus in the cell culture at a concentration of 5 X 10(6) median tissue culture infective dose before inactivation. Specific blastic stimulation was observed on calves immunized with the rotavirus emulsified with IFA after the second and third vaccine inoculation with stimulation index values varying from 2.00 to 5.73. Serum neutralizing antibody titers of 1/25,600 were also induced in the same calves. Calves immunized with rotavirus-PBS suspension developed a mean antibody titer of 1/1,600, but showed no specific lymphocyte stimulation. No increase in specific immune responses was detected in the control animals.

Variability of strap tension in brace treatment for adolescent idiopathic scoliosis.

STUDY DESIGN: A mechanical evaluation of brace strap tensions to document their variability in different patient positions and to assess their biomechanical effectiveness. OBJECTIVES: To measure the strap tensions at which adolescents with scoliosis are wearing their braces and to determine the variations in strap tension in different patient positions. SUMMARY OF BACKGROUND DATA: The biomechanical action of thoracolumbosacral orthoses in still not well understood, and there is no standardized strap tension at which the brace should be fastened to obtain optimal results. METHODS: This study was conducted in 34 adolescents with idiopathic scoliosis wearing thoracolumbosacral orthoses. Brace straps were instrumented with load cells and tightened at four tensions (the ones prescribed by their treating physician and three standardized values: 20, 40, and 60 N). In each case, the tension was recorded while the patients assumed nine positions corresponding to normal daily tasks. The variability of strap tension was evaluated by comparing the changes from the original standing position. RESULTS: The prescribed tensions measured in thoracic and pelvic straps were markedly variable. The greatest changes in tension occurred when the patients were lying down. Relaxation of strap tension was found when the patients returned to the standing position after having completed the tasks. CONCLUSIONS: If strap tension affects the biomechanical actions of the brace, these results indicate that regular brace strap tension adjustments are needed and raise questions about the efficacy of nighttime bracing to correct spinal deformities.

Giant cell pneumonia due to respiratory syncytial virus. Occurrence in severe combined immunodeficiency syndrome.

A 6-month-old male infant with a severe combined immunodeficiency syndrome was hospitalized for progressive respiratory distress. Examination during hospitalization disclosed widespread pulmonary infiltrates that did not respond to intensive therapy. The patient died eight days after admission. Autopsy disclosed Pneumocystis carinii pneumonia and widespread giant cell pneumonia. Respiratory syncytial virus (RSV) was grown from a lung specimen obtained at autopsy. Specific immunofluorescent staining of the cytoplasm of alveolar lining cells with RSV antiserum was demonstrated. The electron microscopic appearance of giant cells was compatible with RSV infection. The RSV should be added to the list of viruses causing giant cell pneumonia.

Lack of scientific evidence for the treatment of lateral epicondylitis of the elbow. An attempted meta-analysis.

We have reviewed 185 articles published since 1966 to assess the scientific evidence for methods of treatment for lateral epicondylitis of the elbow. Of the 185 articles, 78 discussed treatment, but since the natural history of the syndrome is uncertain we considered only those series with concurrent control groups. Only 18 of these were randomised and controlled studies. We then graded these papers for scientific validity, using the methods of Chalmers et al (1981). The mean score of the 18 articles was only 33%, with a range from 6% to 73%. A minimum of 70% is required for a valid clinical trial, and we therefore concluded that there was insufficient scientific evidence to support any of the current methods of treatment. There were too many methodological differences to allow a quantitative meta-analysis, but our qualitative review established the importance of the natural evolution of the syndrome and of the placebo effect of all treatments. Properly designed, controlled trials are needed.

Immune response of pregnant heifers and cows to bovine rotavirus inoculation and passive protection to rotavirus infection in newborn calves fed colostral antibodies or colostral lymphocytes.

The efficacy of an adjuvanted bovine rotavirus vaccine in pregnant cattle (15 heifers and 2 cows) was studied. Each of 4 animals was inoculated IM at 8, 5, and 2 weeks before parturition with a water-in-oil emulsion containing live purified bovine rotavirus, mineral oil, and a mannide oleate compound. Four other animals were treated identically, except that muramyl dipeptide was added to the virus preparation. Five additional animals were inoculated orally at the same time intervals with adjuvant-free viral suspension, and 4 other pregnant animals inoculated only with buffer served as uninoculated controls. Kinetic studies of the specific immune responses were determined by quantification of the rotavirus-neutralizing antibodies and by a rotavirus lymphocyte stimulation test in vitro. Results showed that only the emulsions induced marked enhancement of rotavirus antibody titers in the serum, colostrum, and milk of inoculated cows. Colostral and milk lymphocytes isolated from these cows had a positive in vitro proliferative response to rotavirus stimulation, which lasted at least 21 days after parturition. The values of the stimulation index obtained with the colostral/milk lymphocytes were higher than those of the blood lymphocytes, reflecting increased lymphocyte activity in the colostrum/milk. However, addition of muramyl dipeptide to the emulsion preparation did not exert any potentiating effect on the immune response to rotavirus. Calves fed for the first 5 days after birth with a rotavirus-immune cell-free colostrum supplement were protected from a rotavirus challenge exposure on the third day after birth. Virus was not detectable in their feces.(ABSTRACT TRUNCATED AT 250 WORDS)

The diagnosis of Epstein-Barr virus-associated polymorphic B cell lymphoma in immunocompromised patients: Review of methods.

Polymorphic B cell lymphoma and diffuse B cell lymphoproliferation associated with Epstein-Barr virus infection is increasingly reported in immunodeficient patients. Accurate diagnosis of these pathologies is essential because the appropriate treatment regimens for the patients in question differ from those for patients with other lymphoproliferative diseases. Two complementary techniques are currently used in the diagnosis and characterization of Epstein-Barr virus-associated B cell lymphomas and diffuse B cell lymphoproliferation. Immunofluorescence allows specific detection of Epstein-Barr nuclear antigens in lymphomatous tissue. Molecular hybridization with the Bam H1-W and/or Bam H1-NJ probes confirms the presence of the Epstein-Barr virus genome in tumour cells. The Bam H1-NJ probe is also useful in determining the clonality of the tumour and the replication mode, episomal or linear, of the viral genome. The polymerase chain reaction method allows detection of the Epstein-Barr virus genome within 24 h in these tumours and is more sensitive.

[Dorso-lumbal pain and idiopathic scoliosis in adolescence]. / Douleur dorso-lombaire et scoliose idiopathique de l'adolescence.

Current knowledge on the association between back pain and idiopathic scoliosis is often contradictory. The presence, localisation and importance of pain was evaluated for a cohort of 426 adolescents with AIS. Patients were recruited from a scoliosis clinic in a pediatric hospital. A questionnaire and an analogue visual scale graduated from 0 (no pain) to 100 (maximal pain) were used in order to verify more precisely, the importance of the association between AIS and back pain. Chisquare, linear regression and Student T-test were used for statistical analysis. 239 patients with right thoracic and left lumbar curves (RTLL) had a prevalence of pain of 54%. The mean of maximum pain intensity was 49 mm +/- 20. No relation was found between the severity of the scoliosis and back pain. The two groups (with and without pain) were comparable. Cobb angles were about the same for the thoracic and lumbar regions, as well as kyphosis and lordosis, weight, height and age. Risser sign, sex, brace and pelvic tilt were the only variables associated with pain (p < 0.0001). Association between AIS and pain is more frequent than generally reported. Pain appears to be more related with pelvic tilt than severity of the scoliosis.

Study of patient positioning on a dynamic frame for scoliosis surgery.

The goal of this clinical trial was to measure patient geometry on a dynamic positioning frame in various prone positions. Fourteen subjects (2 males and 12 females) were recruited from the scoliosis clinic at Ste-Justine Hospital on a volunteer basis. The subjects were AIS patients who were potential candidates for surgery. The Cobb angle, averaged 50 degrees (32 degrees-64 degrees). The mean age was 14.1 years (11-17). A Polaris system (Northern Digital inc, Canada) with 10 passive reflective markers was used to measure various indices of the patient's trunk geometry. Acquisitions were made while the unanaesthetized patient was in five different prone positions: I similar to the standard positioning on a Relton-Hall frame; II addition of a force applied to the ribcage at the apex of the curve; III application of a force at the apex of the curve in the lumbar region; IV, the shoulder pads were elevated to increase the patient's kyphosis; V adjustment of each pad and the application of thoracic and lumbar forces to obtain an optimal correction. The measurements of trunk geometry at each position were compared using position I as a base. A paired student t-test determined a significant difference between positions. When comparing position I to position II there was a significant difference and correction of the rib hump. There was also a significant change in shoulder angle that resulted in over correction. Position III had a significantly negative change in the rib hump. During position IV, there was a measurable increase in kyphosis. During the optimal correction, position V, a significant increase in spine length was observed as well as a significant correction in rib hump and shoulder angle. Patient trunk geometry can be improved by the application of different forces on a dynamic positioning frame. Caution is necessary as over correction and unintended negative effects were observed. The optimal patient position has not yet been found and future studies are directed at determining this.

[Herniated disk and congenital spinal stenosis in the adolescent]. / Hernie discale et sténose congénitale du canal lombaire chez l'adolescent.

PURPOSE OF THE STUDY: The goal of this study was to demonstrate the relationship between herniated discs and congenital spinal stenosis. A retrospective study was conducted on patients seen in our center over a five year period. MATERIAL AND METHODS: The CT-Scan evaluation was essential for the measurement of the diameter of the spinal canal. Data were compared with the values obtained in ten normal subjects. RESULTS: Twelve complete charts of adolescents with herniated discs were reviewed and in all cases a spinal stenosis was established. The mean diameter of the canal was 8.1 mm for the patient group compared with 18.1 mm for the control group. CONCLUSION: The relationship of herniated discs and spinal stenosis found here is greater than the one reported in the literature. This relationship accounts for the importance of neurological (9/12 patients) involvement found in our series in comparison with adults. This also explains the failure of conservative treatment.