Nighttime Bracing or Exercise in Moderate-Grade Adolescent Idiopathic Scoliosis: A Randomized Clinical Trial

Importance

Moderate-grade adolescent idiopathic scoliosis (AIS) may be treated with full-time bracing. For patients who reject full-time bracing, the effects of alternative, conservative interventions are unknown.

Objective

To determine whether self-mediated physical activity combined with either nighttime bracing (NB) or scoliosis-specific exercise (SSE) is superior to a control of physical activity alone (PA) in preventing Cobb angle progression in moderate-grade AIS.

Design, Setting, and Participants

The Conservative Treatment for Adolescent Idiopathic Scoliosis (CONTRAIS) randomized clinical trial was conducted from January 10, 2013, through October 23, 2018, in 6 public hospitals across Sweden. Male and female children and adolescents aged 9 to 17 years with an AIS primary curve Cobb angle of 25° to 40°, apex T7 or caudal, and skeletal immaturity based on estimated remaining growth of at least 1 year were included in the study. Dates of analysis were from October 25, 2021, to January 28, 2023.

Interventions

Interventions included self-mediated physical activity in combination with either NB or SSE or PA (control). Patients with treatment failure were given the option to transition to a full-time brace until skeletal maturity.

Main Outcomes and Measures

The primary outcome was curve progression of 6° or less (treatment success) or curve progression of more than 6° (treatment failure) seen on 2 consecutive posteroanterior standing radiographs compared with the inclusion radiograph before skeletal maturity. A secondary outcome of curve progression was the number of patients undergoing surgery up until 2 years after the primary outcome.

Results

The CONTRAIS study included 135 patients (45 in each of the 3 groups) with a mean (SD) age of 12.7 (1.4) years; 111 (82%) were female. Treatment success was seen in 34 of 45 patients (76%) in the NB group and in 24 of 45 patients (53%) in the PA group (odds ratio [OR], 2.7; 95% CI, 1.1-6.6). The number needed to treat to prevent curve progression with NB was 4.5 (95% CI, 2.4-33.5). Treatment success occurred in 26 of 45 patients (58%) in the SSE group (OR for SE vs PA, 1.2; 95% CI, 0.5-2.8). Up to 2 years after the primary outcome time point, 9 patients in each of the 3 groups underwent surgery.

Conclusions and Relevance

In this randomized clinical trial, treatment with NB prevented curve progression of more than 6° to a significantly higher extent than did PA, while SSE did not; in addition, allowing transition to full-time bracing after treatment failure resulted in similar surgical frequencies independent of initial treatment. These results suggest that NB may be an effective alternative intervention in patients rejecting full-time bracing.

Trial Registration

ClinicalTrials.gov Identifier: NCT01761305.

Vertebral Hemangiomas: Prevalence, new classification and natural history. magnetic resonance imaging-based retrospective longitudinal study

BACKGROUND AND PURPOSE

To determine the prevalence of vertebral hemangiomas (VHs), establish a new classification of VHs based on their MRI-signal pattern, and study their natural history.

METHODS

MRI of 1000 consecutive patients who underwent at least two MRI with an interval of at least 3 years. Growth rate and change of MRI-signal pattern during the follow-up period were the parameters included in studying the natural history of VHs.

RESULTS

The prevalence of VHs was 41%. VHs were classified as type I-IV with fat-rich VHs (type I), constituted 79% of all VHs. VHs were more common among females 43% versus males 39%, p = .22. The most affected vertebra was L1. Occurrence rates for cervical (1%), thoracic (7%), and lumbar spine (10%) differed significantly (p < .001). The prevalence of VHs increased with age regardless of gender or spinal part involved (p < .001). Only 26% of VHs changed their size and 4% changed their signal during the average follow-up of 7 years. All VHs were slowly growing lesions (average expected growth of <3 mm/10 years). No significant difference between growth rate of VHs type I (0.25 mm/year) and other types of VHs. None of the VHs that were initially reported as "metastases cannot be rule out" showed alarming change in signal or size.

CONCLUSIONS

VH can be classified into four types based on their MRI-signal pattern. Regardless of their type, VHs are slowly growing lesions. The presence of typical morphological pattern should enable radiologists to confidently differentiate them from vertebral metastases.

Neonatal pneumothorax: symptoms, signs and timing of onset in the post-surfactant era

AIM

The primary objective was to describe the incidence, symptoms, clinical signs, and time of onset of neonatal pneumothorax in Örebro County during 2011-2017. Secondary objectives were to describe risk factors, diagnostic procedures, treatments, and mortality and to compare preterm with term/post-term neonates.

MATERIALS AND METHODS

This retrospective population-based descriptive study included all neonates born in Örebro County during 2011-2017 and admitted to the neonatal intensive care unit at Örebro University Hospital at age <28 days with an x-ray verified diagnosis of "Pneumothorax originating in the perinatal period" in their medical record.

RESULTS

Seventy-five neonates matched the inclusion criteria. The incidence of neonatal pneumothorax in Örebro County during the study period was 3.1 (95% CI: 2.5-3.8) per 1000 live births. All neonates were <48 h at debut of respiratory symptoms and the most common symptom was tachypnea. Twelve (16%) received invasive treatment. The mortality rate was 2 (3%), none due to pneumothorax.

CONCLUSION

The incidence of 3.1 per 1000 live births was relatively high, but the frequency of invasive treatment and mortality was low, indicating a high proportion of mild pneumothoraces. The lack of patients aged >48 h indicates that most neonatal pneumothoraces now occur very early in life.

Home phototherapy for hyperbilirubinemia in term neonates-an unblinded multicentre randomized controlled trial

The aim of this study was to assess whether home phototherapy was feasible and safe in a cohort of otherwise healthy term-born neonates who fulfilled the criteria for in-hospital phototherapy. This was a randomized controlled trial in which term newborns with a total serum bilirubin of 18-24 mg/dL (300-400 μmol) were randomized to either home phototherapy or conventional in-hospital phototherapy. The primary outcome measurements were safety and efficacy, length of stay and the number of failed treatments. The secondary outcomes were the number of blood samples and weight gain during treatment. One hundred forty-seven patients were recruited, 69 patients randomized to conventional phototherapy and 78 to home phototherapy. The results showed that no patients needed blood exchange and only 4% of the patients allocated to home phototherapy were admitted to the hospital. The duration of phototherapy, length of stay, amount of blood tests and weight change showed no statically significant differences.Conclusion: Home phototherapy could be a safe alternative to inpatient phototherapy for otherwise healthy newborns with hyperbilirubinemia if daily checkups and 24/7 telephone support can be provided. The parents should be informed to contact the hospital immediately if they fail to perform the treatment at home.Trial registration: Clinicaltrials.gov NCT03536078 What is Known: • Phototherapy in the hospital is a safe and effective treatment without major side effects. • Fibre optic equipment has made the choice of home phototherapy possible. What is New: • This is the first randomized controlled trial comparing home phototherapy with hospital phototherapy. • Results indicate that home phototherapy could be considered as a safe and feasible alternative when performed according to instructions given, to hospital treatment for otherwise healthy term newborns.

CELSR2 is a candidate susceptibility gene in idiopathic scoliosis

A Swedish pedigree with an autosomal dominant inheritance of idiopathic scoliosis was initially studied by genetic linkage analysis, prioritising genomic regions for further analysis. This revealed a locus on chromosome 1 with a putative risk haplotype shared by all affected individuals. Two affected individuals were subsequently exome-sequenced, identifying a rare, non-synonymous variant in the CELSR2 gene. This variant is rs141489111, a c.G6859A change in exon 21 (NM_001408), leading to a predicted p.V2287I (NP_001399.1) change. This variant was found in all affected members of the pedigree, but showed reduced penetrance. Analysis of tagging variants in CELSR1-3 in a set of 1739 Swedish-Danish scoliosis cases and 1812 controls revealed significant association (p = 0.0001) to rs2281894, a common synonymous variant in CELSR2. This association was not replicated in case-control cohorts from Japan and the US. No association was found to variants in CELSR1 or CELSR3. Our findings suggest a rare variant in CELSR2 as causative for idiopathic scoliosis in a family with dominant segregation and further highlight common variation in CELSR2 in general susceptibility to idiopathic scoliosis in the Swedish-Danish population. Both variants are located in the highly conserved GAIN protein domain, which is necessary for the auto-proteolysis of CELSR2, suggesting its functional importance.

Position, Orientation and Component Interaction in Dislocation of the Total Hip Prosthesis

The position, orientation in space and interaction of prosthetic components was determined in 15 patients with known episodes of dislocation after total hip replacement. The same calculations were performed in a reference group of 44 patients without dislocation. In the group with dislocations, there was a significantly decreased femoral anteversion, and a decreased femoral flexion permitted by the prosthetic components. There were no further significant differences of clinical relevance between the groups concerning all other examined parameters of component position, orientation and interaction. It is concluded that the decreased range of flexion, caused by impingement of the prosthetic components with ensuing leverage effect is one cause of dislocation.

Candidate gene analysis and exome sequencing confirm LBX1 as a susceptibility gene for idiopathic scoliosis

BACKGROUND CONTEXT

Idiopathic scoliosis is a spinal deformity affecting approximately 3% of otherwise healthy children or adolescents. The etiology is still largely unknown but has an important genetic component. Genome-wide association studies have identified a number of common genetic variants that are significantly associated with idiopathic scoliosis in Asian and Caucasian populations, rs11190870 close to the LBX1 gene being the most replicated finding.

PURPOSE

The aim of the present study was to investigate the genetics of idiopathic scoliosis in a Scandinavian cohort by performing a candidate gene study of four variants previously shown to be associated with idiopathic scoliosis and exome sequencing of idiopathic scoliosis patients with a severe phenotype to identify possible novel scoliosis risk variants.

STUDY DESIGN

This was a case control study.

PATIENT SAMPLE

A total of 1,739 patients with idiopathic scoliosis and 1,812 controls were included.

OUTCOME MEASURE

The outcome measure was idiopathic scoliosis.

METHODS

The variants rs10510181, rs11190870, rs12946942, and rs6570507 were genotyped in 1,739 patients with idiopathic scoliosis and 1,812 controls. Exome sequencing was performed on pooled samples from 100 surgically treated idiopathic scoliosis patients. Novel or rare missense, nonsense, or splice site variants were selected for individual genotyping in the 1,739 cases and 1,812 controls. In addition, the 5'UTR, noncoding exon and promoter regions of LBX1, not covered by exome sequencing, were Sanger sequenced in the 100 pooled samples.

RESULTS

Of the four candidate genes, an intergenic variant, rs11190870, downstream of the LBX1 gene, showed a highly significant association to idiopathic scoliosis in 1,739 cases and 1,812 controls (p=7.0×10(-18)). We identified 20 novel variants by exome sequencing after filtration and an initial genotyping validation. However, we could not verify any association to idiopathic scoliosis in the large cohort of 1,739 cases and 1,812 controls. We did not find any variants in the 5'UTR, noncoding exon and promoter regions of LBX1.

CONCLUSIONS

Here, we confirm LBX1 as a susceptibility gene for idiopathic scoliosis in a Scandinavian population and report that we are unable to find evidence of other genes of similar or stronger effect.

Evaluation of implant loosening following segmental pedicle screw fixation in adolescent idiopathic scoliosis: a 2 year follow-up with low-dose CT

Background

The long term radiological status of screw fixation following scoliosis surgery with all pedicle screw construct is not previously studied.

Aim

To evaluate the incidence of loosening (implant failure) evaluated with low-dose CT two years following scoliosis surgery.

Study design

Retrospective study.

Methods

81 consecutive patients with adolescent idiopathic scoliosis (AIS), aged 18 ± 3 years at 2 years follow-up (83% were female), subjected for scoliosis corrective surgery with all pedicle screw construct (total of 1666 screws) has been examined with plain radiography and with low dose CT 6 weeks and 2 years postoperatively.

Results

In 26 out of 81 (32%) patients there were signs of loosening of one or more screws, a maximum 3 screws. 47 out of 1666 (2.8%) screws showed evidence of loosening. Preoperative Cobb angle was 56° among patients with loosening compared with 53° among patients with no evidence of loosening (P = 0.288). In males there were signs of loosening in 8 out of 14 (57%) and in females 18 out of 67 (27%), (P = 0.027). Among cases with loosening, 14% had suboptimal screw placement at the first postoperative CT compared with 11% among patients with no evidence of loosening (P = 0.254). One patient with a loosened L4 screw had neurological deficit and subjected for revision of the construct. Out of 26 patients with evidence of loosening, 5 patients reported minor pain or discomfort, 1 patient had a minor proximal junctional kyphosis of about 15° and 3 patients showed evidence of pull-out of 3–5 mm at the upper end of the construct but no clinical complaint. With plain radiography loosening could be observed only in 11 out of 26 cases, 5 were in the lumbar region.

Conclusions

In a consecutive series of 81 cases with AIS who had underwent scoliosis surgery, one third showed, 2 years after the intervention, minor screw loosening. Males were more prone to develop screw loosening. In CT system that enables low-dose protocol, CT is recommended for the evaluation of evidence of screw loosening.

Family history and its association to curve size and treatment in 1,463 patients with idiopathic scoliosis

PURPOSE

To study family history in relation to curve severity, gender, age at diagnosis and treatment in idiopathic scoliosis.

METHODS

A self-assessment questionnaire on family history of scoliosis was administered to 1,463 untreated, brace or surgically treated idiopathic scoliosis patients.

RESULTS

Out of the 1,463 patients, 51 % had one or more relatives with scoliosis. There was no significant difference between females and males, nor between juvenile and adolescent study participants in this respect (p = 0.939 and 0.110, respectively). There was a significant difference in maximum curve size between patients with one or more relatives with scoliosis (median 35°, interquartile range 25) and patients without any relative with scoliosis (median 32°, interquartile range 23) (p = 0.022). When stratifying patients according to treatment (observation, brace treatment or surgery), we found that it was more common to have a relative with scoliosis among the treated patients (p = 0.011). The OR for being treated was 1.32 (95% CI 1.06-1.64) when the patient had a relative with scoliosis, compared to not having.

CONCLUSIONS

Larger curve sizes were found in patients with a family history of scoliosis than in the ones without. No relation between family history and gender or between family history and age at onset of idiopathic scoliosis was found. Although the presence of a family history of scoliosis may not be a strong prognostic risk factor, it indicates that these patients are at higher risk of developing a more severe curve.

Patients with adolescent idiopathic scoliosis of Lenke type-1 curve exhibit specific pedicle width pattern

INTRODUCTION

Study aim was to find out if patients with Lenke type 1 curve exhibit smaller pedicles and specific pedicle width pattern compared with individuals with no scoliosis.

MATERIALS AND METHODS

4,828 pedicle width measurements (T1-L5) in 61 consecutive patients with adolescent idiopathic scoliosis of Lenke type 1 curve, 61 control subjects, and 20 patients with Lenke type 5 curve, were retrospectively performed by an experienced neuroradiologist.

RESULTS

Among patients with Lenke type 1 curve, the differences between the width of right and left upper thoracic pedicles were statistically significant; smallest at right T4 (2.6 mm). At scoliotic apex, the pedicles on the concave (left) side were significantly smaller than those on the convex (right) side; smallest at left T7 (3.2 mm). Among patients with Lenke type 1 curve, 97% had pedicle width <4 mm.

CONCLUSIONS

Our study showed that patients with Lenke type 1 curve exhibit smaller pedicles and asymmetric pedicle width compared with control subjects.

Increased rod stiffness improves the degree of deformity correction by segmental pedicle screw fixation in adolescent idiopathic scoliosis

Background

There are limited reports in literature studying the impact of rod diameter and stiffness on the degree of deformity correction in patients with AIS.

Aims

The aims of this study were to evaluate the 3-dimentional deformity correction achieved by segmental pedicle screw fixation in patients with adolescent idiopathic scoliosis, and to find out if learning or the change to stiffer rods had any positive impact on deformity correction.

Study design

Retrospective study.

Methods

Plain radiographs and low-dose spine CTs of 116 consecutive patients (aged 15.9 ± 2.8 years) operated during the period 2005-2009 (group 1: patients operated autumn 2005-2006; group 2: 2007; group 3: 2008; group 4: 2009) were retrospectively evaluated.

Results

There was no statistically significant difference between the correction of the Cobb angle (P = 0.425) or lower end vertebra tilt (P = 0.298) in patients operated during the first versus the remaining periods of the study. No restoration of the sagittal kyphosis was reported in the first period compared with 5.9° in the last study period (P < 0.001). The correction of vertebral rotation was also improved from 4.2° to 7.8° (P < 0.001) for the same periods. For the whole study population, there was statistically significant correlation between the order of the operation (patient number) and the restoration of sagittal kyphosis (r = -0.344, P = 0.001), and the correction of vertebral rotation (r = 0.370, P < 0.001), but not for the Cobb angle or LEVT. However, there was no significant difference in restoration of sagittal kyphosis and the vertebral rotation in the first 17 patients compared with the last 17 patients operated with rods of 5.5 mm diameter (P = 0.621, and 0.941, respectively), indicating that rod stiffness had more impact on the deformity correction than did learning.

Conclusions

This study showed that rod stiffness had more impact on the deformity correction than did learning.

Evaluation of a commercial multiplex PCR test (SeptiFast) in the etiological diagnosis of community-onset bloodstream infections

The commercial polymerase chain reaction (PCR) test, SeptiFast, is designed to identify the DNA of individual bacterial and fungal pathogens in whole blood. We aimed to evaluate the usefulness of the test for the detection of community-onset bloodstream infections. We prospectively included adult patients who were subjected to blood culture (BC) at an infectious diseases department. For the evaluation, one BC/PCR set (two BC bottles and one PCR tube) per patient was used. When several sets were obtained and analyzed, the first set with any positive result was evaluated. Among 1,093 consecutively included patients, BC was positive in 138 and PCR was positive in 107. Fifty positive PCR results were supported by BC in the same BC/PCR set, ten were supported by other cultures, and, additionally, ten were supported by the clinical presentation. Compared with BC, PCR showed specificities and negative predictive values of >97% for all detectable pathogens. The following sensitivities and positive predictive values (PPVs) were noted: Staphylococcus aureus, 67% and 43%; Streptococcus pneumoniae, 12% and 67%; other Streptococcus species, 43% and 77%; Escherichia coli, 53% and 56%; and Klebsiella species, 43% and 23%. If support from other cultures and the clinical presentation were included in the reference standard, the PPVs for the detection of these bacteria were 57%, 100%, 92%, 75%, and 69%, respectively. Although the specificities were high, the low sensitivities and suboptimal PPVs noted in the present study discourage routine use of the test in its present form for the detection of community-onset bloodstream infections.

The rate of screw misplacement in segmental pedicle screw fixation in adolescent idiopathic scoliosis

BACKGROUND AND PURPOSE

There are no reports in the literature on the influence of learning on the pedicle screw insertion. We studied the effect of learning on the rate of screw misplacement in patients with adolescent idiopathic scoliosis treated with segmental pedicle screw fixation.

METHOD

We retrospectively evaluated low-dose spine computed tomography of 116 consecutive patients (aged 16 (12-24) years, 94 females) who were operated during 4 periods over 2005-2009 (group 1: patients operated autumn 2005-2006; group 2: 2007; group 3: 2008; and group 4: 2009). 5 types of misplacement were recorded: medial cortical perforation, lateral cortical perforation, anterior cortical perforation of the vertebral body, endplate perforation, and perforation of the neural foramen.

RESULTS

2,201 pedicle screws were evaluated, with an average of 19 screws per patient. The rate of screw misplacement for the whole study was 14%. The rate of lateral and medial cortical perforation was 7% and 5%. There was an inverse correlation between the occurrence of misplacement and the patient number, i.e. the date of operation (r = -0.35; p < 0.001). The skillfulness of screw insertion improved with reduction of the rate of screw misplacement from 20% in 2005-2006 to 11% in 2009, with a breakpoint at the end of the first study period (34 patients).

INTERPRETATION

We found a substantial learning curve; cumulative experience may have contributed to continued reduction of misplacement rate.

Rapid typing of neonatal Staphylococcus epidermidis isolates using polymerase chain reaction for repeat regions in surface protein genes

Staphylococcus epidermidis is a significant pathogen in neonatal sepsis and other nosocomial infections. For further investigations of the colonisation patterns and invasive pathways, typing methods that are applicable on large populations of bacterial isolates are warranted. In the present study, a genotyping method based on polymerase chain reaction (PCR) for the repeat regions of four genes (sdrG, sdrF, aap and sesE) that encode for bacterial surface proteins was developed and applied to a sample of well-characterised neonatal blood isolates of S. epidermidis (n = 49). The PCR products were visualised on agarose gel (sdrG, sdrF and sesE) or by fragment analysis (aap). The discriminatory index (D-index) for genotyping of the different genes was compared to genotyping by pulsed-field gel electrophoresis (PFGE). The highest D-index for the PCR-based typing methods was found for the combination of sdrF, sdrG and aap (D-index 0.94), whereas the optimal two-gene combination (sdrF and aap) resulted in a D-index of 0.92. We conclude that the described method can be used for the genotyping of large populations of S. epidermidis isolates with a sufficient discriminatory capacity, and we suggest that the combination of sdrF and aap is the most suitable to use.

Curve length, curve form, and location of lower-end vertebra as a means of identifying the type of scoliosis

PURPOSE

To determine if the curve length, curve form, and location of the lower-end vertebra can identify the type of scoliosis.

METHODS

Standing posteroanterior and lateral radiographs of 78 women and 27 men with scoliosis aged 8 to 32 years were retrospectively analysed. Parameters measured were (1) the curve length (the number of vertebrae in the main curve), (2) the curve form (C-form, inverted C-form, or S-form), (3) the curve apex (the vertebral body at the apex of each curve), (4) the site of the scoliosis (thoracic, thoracolumbar, or lumbar), and (5) the location of the lower-end vertebra.

RESULTS

Only 3 (4%) of 77 patients with idiopathic scoliosis had a curve length of >8 vertebrae, compared with 19 (90%) of 21 patients with neuromuscular/neuropathic scoliosis (p<0.001, Fisher's exact test). 14 (18%) of the patients with idiopathic scoliosis had an S-form curve, compared with none in those with neuromuscular/neuropathic or congenital/osteogenic scoliosis (p=0.035, Fisher's exact test). No patient with idiopathic scoliosis had the lower- end vertebra located at L5, compared with 8 (38%) patients with neuromuscular scoliosis (p<0.001, Fisher's exact test). The criteria for neuromuscular/neuropathic scoliosis (a curve length of >8 vertebrae, a C-form or inverted C-form curve, and a lower-end vertebra located at L4 or L5) had 81% specificity, 76% sensitivity, 100% positive and 93% negative predictive values.

CONCLUSION

These criteria may help identify patients with neuromuscular/neuropathic scoliosis for further investigation by magnetic resonance imaging or computed tomography before they undergo corrective surgery.

Dural ectasia in adolescent idiopathic scoliosis: quantitative assessment on magnetic resonance imaging

To our knowledge, the assessment of dural sac diameters in patients with adolescent idiopathic scoliosis (AIS) is not reported in the literature. The aim of this study was to find out if, dural ectasia occurs more frequently among patients with AIS, to define cut-off values for dural sac ratio and test the validity of such values. A total of 126 spine MRIs (79 patients with AIS and 47 control subjects) were included in this retrospective analysis (age range 7-25 years, 62% were females). Dural sac diameter (DSD) and vertebral body diameter (VBD) were estimated and dural sac ratio (DSR = DSD/VBD) was calculated at T5 and L3. DSR at T5 and L3 were 0.69 +/- 0.12, and 0.52 +/- 0.10, respectively, in patients with AIS compared with 0.62 +/- 0.11, and 0.44 +/- 0.07, respectively, in controls (P = 0.001 at T5 and <0.001 at L3). Our estimated cut-off values for DSR were 0.84 and 0.58 at T5 and L3, respectively. This resulted in 100% sensitivity compared with 74% when using the cut-off values proposed by Oosterhof et al. No statistically significant association was found between the occurrence of dural sac enlargement in patients with AIS and the severity of scoliotic deformity, the apical vertebral rotation, epidural fat thickness, occurrence of pain, neurological deficit, atypical scoliosis or rapid curve progression. Females were affected more frequently than males. As dural sac enlargement means thinning of the pedicles, we believe that the findings of this study have important clinical implications on the preoperative workup of AIS.

Measurement of vertebral rotation in adolescent idiopathic scoliosis with low-dose CT in prone position - method description and reliability analysis

BACKGROUND

To our knowledge there is no report in the literature on measurements of vertebral rotation with low-dose computed tomography (CT) in prone position.

AIMS

To describe and test the reliability of this new method, compare it with other methods in use and evaluate the influence of body position on the degree of vertebral rotation measured by different radiological methods.

STUDY DESIGN

Retrospective study.

METHODS

25 consecutive patients with adolescent idiopathic scoliosis scheduled for surgery (17 girls, 8 boys) aged 15 +/- 2 years (mean +/- SD) were included in the analysis of this study. The degree of the vertebral rotation was in all patients measured according to the method of Perdriolle on standing plain radiographs and on supine CT scanogram, and according to the method of Aaro and Dahlborn on axial CT images in prone position and on magnetic resonance imaging (MRI) in supine position. The measurements were done by one neuroradiologist at two different occasions. Bland and Altman statistical approach was used in the reliability assessment.

RESULTS

The reliability of measuring vertebral rotation by axial CT images in prone position was almost perfect with an intraclass correlation coefficient of 0.95, a random error of the intraobserver differences of 2.3 degrees , a repeatability coefficient of 3.2 degrees and a coefficient of variation of 18.4%. Corresponding values for measurements on CT scanogram were 0.83, 5.1 degrees , 7.2 degrees , and 32.8%, respectively, indicating lower reliability of the latter modality and method. The degree of vertebral rotation measured on standing plain radiographs, prone CT scanogram, axial images on CT in prone position and on MRI in supine position were 25.7 +/- 9.8 degrees , 21.9 +/- 8.3 degrees , 17.4 +/- 7.1 degrees , and 16.1 +/- 6.5 degrees , respectively. The vertebral rotation measured on axial CT images in prone position was in average 7.5% larger than that measured on axial MRI in supine position.

CONCLUSIONS

This study has shown that measurements of vertebral rotation in prone position were more reliable on axial CT images than on CT scanogram. The measurement of vertebral rotation on CT (corrected to the pelvic tilt) in prone position imposes lower impact of the recumbent position on the vertebral rotation than did MRI in supine position. However, the magnitude of differences is of doubtful clinical significance.

Radiological and clinical outcome of screw placement in adolescent idiopathic scoliosis: evaluation with low-dose computed tomography

Posterior corrective surgery using "all pedicle screw construct" carries risk of neurovascular complications. The study aims were to assess the screw placement in patients with adolescent idiopathic scoliosis using CT with low-radiation dose, and to evaluate the clinical outcome in patients with misplaced pedicle screws. CTs of 49 consecutive patients (873 screws, 79% thoracic) were retrospectively evaluated by two independent radiologists. A new grading system was developed to distinguish between lateral, medial and anterior cortical perforations, endplate perforation and foraminal perforation. The grading system is based on whether the cortical violation is partial or total rather than on mm-basis. The overall rate of screw misplacement was 17% (n = 149): 8% were laterally placed and 6.1% were medially placed. The rates of anterior cortical, endplate and foraminal perforation were 1.5, 0.9, and 0.5%, respectively. Lateral cortical perforation was more frequent in the thoracic spine (P = 0.005), whereas other types of misplacement including medial cortical perforation were more frequent on the left and the concave side of scoliotic curves (P = 0.002 and 0.003). No neurovascular complications were reported. The association between the occurrence of screw misplacement and the Cobb angle was statistically significant (P = 0.037). Misplacements exceeding half screw diameter should be classified as unacceptable. Low-dose CT implies exposing these young individuals to a significantly lower radiation dose than do other protocols used in daily clinical practice. We recommend using low-dose CT and the grading system proposed here in the postoperative assessment of screw placement.

Tonsillar ectopia in idiopathic scoliosis: does it play a role in the pathogenesis and prognosis or is it only an incidental finding?

Background

There is an ongoing controversy about the significance of tonsillar ectopia among patients with idiopathic scoliosis (IS).

Aim

To find out if tonsillar ectopia occurs more frequently among patients with IS and if it plays any etiological or prognostic role in IS.

Study design

Retrospective study.

Methods

Retrospective analysis of 155 consecutive spine MRIs (79 patients with IS and 76 controls; aged 7-25 years; 55% were female) with regard to the position of the cerebellar tonsils in relation to foramen magnum and the sagittal diameter of foramen magnum. All images were evaluated independently by two neuroradiologists. Interobserver and intraobserver reliability analysis was performed by calculation of κ-value, intraclass correlation coefficient, and systematic and random errors. The occurrence of tonsillar ectopia among patients with IS and controls was estimated and the association of tonsillar ectopia with different predictors has been tested. Statistical significance was set to P ≤ 0.05.

Results

The interobserver and intraobserver agreement with regard to the occurrence of tonsillar ectopia was almost perfect (κ 0.84 and 0.89, respectively). Tonsillar ectopia was found in 37% of patients with IS compared with 13% among controls (p < 0.001 and odds ratio of 3.8, 95% CI 1.7-8.5). The occurrence of tonsillar ectopia was not associated with the severity of scoliotic deformity (p = 0.85), or rapid progression of scoliosis (p = 0.76). Neurological deficit occurs twice as frequently in patients with tonsillar ectopia as in those with no tonsillar ectopia. Two of five patients with tonsillar ectopia showed improvement of their neurological deficit after the surgical correction of scoliosis.

Conclusion

As tonsillar ectopia is significantly more frequent among patients with IS and may exhibit some prognostic utility in patients with neurological deficit, we forward the hypothesis that tonsillar ectopia may play a role in the development of the deformity in some patients with IS. However, occurrence of tonsillar ectopia among 13% of controls precludes stating a definitive role of tonsillar ectopia in the pathogenesis of IS. Some patients with IS, tonsillar ectopia and neurological deficit showed neurological improvement following the surgical correction of scoliosis.

Radiation Dose Optimization in CT Planning of Corrective Scoliosis Surgery. A Phantom Study

The aim of the study was to explore the possibility of obtaining a helical CT scan of a long segment of vertebral column, optimally reduce the radiation dose, compare the radiation dose of the low dose helical CT with that of some of the CT protocols used in clinical practice and finally assess the impact of such a dose reduction on the image quality. A chest phantom was examined with a 16-slice CT scanner. Six scans were performed with different radiation doses. The lowest radiation dose which had no impact on image quality with regard to the information required for surgical planning of patients with scoliosis, was 20 times lower than that of routinely used protocol for CT examination of the spine in children (0.38 mSv vs 7.76 mSv). Patients with scoliosis planned for corrective spinal surgery can be examined with low dose helical CT scan. The dose reduction systems (DRS) available in modern CT scanners contribute to dose reduction and should be used.

A prospective study of brace treatment versus observation alone in adolescent idiopathic scoliosis: a follow-up mean of 16 years after maturity

STUDY DESIGN

The Swedish patients included in the previous SRS brace study were invited to take part in a long-term follow-up.

OBJECTIVE

To investigate the rate of scoliosis surgery and progression of curves from baseline as well as after maturity.

SUMMARY OF BACKGROUND DATA

Brace treatment was shown to be superior to electrical muscle stimulation, as well as observation alone, in the original SRS brace study. Few other studies have shown that brace treatment is effective in the treatment of scoliosis.

METHODS

Of 106 patients, 41 in Malmö (all Boston brace treatment) and 65 in Göteborg (observation alone as the intention to treat), 87% attended the follow-up, including radiography and chart review. All radiographs were (re)measured for curve size (Cobb method) by an unbiased examiner. Searching in the mandatory national database for performed surgery identified patients who had undergone surgery after maturity.

RESULTS

The mean follow-up time was 16 years and the mean age at follow-up was 32 years The 2 treatment groups had equal curve size at inclusion. The curve size of patients who were treated with a brace from the start was reduced by 6 degrees during treatment, but the curve size returned to the same level during the follow-up period. No patients who were primarily braced went on to undergo surgery. In patients with observation alone as the intention to treat, 20% were braced during adolescence due to progression and another 10% underwent surgery. Seventy percent were only observed and increased by 6 degrees from inclusion until now. No patients underwent surgery after maturity. Progression was related to premenarchal status.

CONCLUSION

The curves of patients with adolescent idiopathic scoliosis with a moderate or smaller size at maturity did not deteriorate beyond their original curve size at the 16-year follow-up. No patients treated primarily with a brace went on to undergo surgery, whereas 6 patients (10%) in the observation group required surgery during adolescence compared with none after maturity. Curve progression was related to immaturity.

Effects on osteoclast and osteoblast activities in cultured mouse calvarial bones by synovial fluids from patients with a loose joint prosthesis and from osteoarthritis patients

Aseptic loosening of a joint prosthesis is associated with remodelling of bone tissue in the vicinity of the prosthesis. In the present study, we investigated the effects of synovial fluid (SF) from patients with a loose prosthetic component and periprosthetic osteolysis on osteoclast and osteoblast activities in vitro and made comparisons with the effects of SF from patients with osteoarthritis (OA). Bone resorption was assessed by the release of calcium 45 (⁴⁵Ca) from cultured calvariae. The mRNA expression in calvarial bones of molecules known to be involved in osteoclast and osteoblast differentiation was assessed using semi-quantitative reverse transcription-polymerase chain reaction (PCR) and real-time PCR. SFs from patients with a loose joint prosthesis and patients with OA, but not SFs from healthy subjects, significantly enhanced ⁴⁵Ca release, effects associated with increased mRNA expression of calcitonin receptor and tartrate-resistant acid phosphatase. The mRNA expression of receptor activator of nuclear factor-kappa-B ligand (rankl) and osteoprotegerin (opg) was enhanced by SFs from both patient categories. The mRNA expressions of nfat2 (nuclear factor of activated T cells 2) and oscar (osteoclast-associated receptor) were enhanced only by SFs from patients with OA, whereas the mRNA expressions of dap12 (DNAX-activating protein 12) and fcrγ (Fc receptor common gamma subunit) were not affected by either of the two SF types. Bone resorption induced by SFs was inhibited by addition of OPG. Antibodies neutralising interleukin (IL)-1α, IL-1β, soluble IL-6 receptor, IL-17, or tumour necrosis factor-α, when added to individual SFs, only occasionally decreased the bone-resorbing activity. The mRNA expression of alkaline phosphatase and osteocalcin was increased by SFs from patients with OA, whereas only osteocalcin mRNA was increased by SFs from patients with a loose prosthesis. Our findings demonstrate the presence of a factor (or factors) stimulating both osteoclast and osteoblast activities in SFs from patients with a loose joint prosthesis and periprosthetic osteolysis as well as in SFs from patients with OA. SF-induced bone resorption was dependent on activation of the RANKL/RANK/OPG pathway. The bone-resorbing activity could not be attributed solely to any of the known pro-inflammatory cytokines, well known to stimulate bone resorption, or to RANKL or prostaglandin E₂ in SFs. The data indicate that SFs from patients with a loose prosthesis or with OA stimulate bone resorption and that SFs from patients with OA are more prone to enhance bone formation.

Vertebral fractures in late adolescence: a 27 to 47-year follow-up

The long-term outcome of thoracic and lumbar fractures in late adolescence is sparsely described and it is unclear whether a fractured vertebral body in these years, as in young children, can be resituated in height. The purpose of this study was to in late adolescence determine the incidence, the long-term outcome and the modelling capacity in fractures of the thoracic and lumbar region. The incidence of vertebral fractures 1950-1971 in individuals aged 16-18 years was through the radiological archives evaluated in a city cohort of 228,878 citizens, of whom 13,893 were aged 16-18. A follow-up, 27-47 years after the injury, including subjective, objective and radiological evaluation was conducted in 18 boys and 5 girls. Twenty-nine boys and 11 girls were registered with a thoracic or lumbar vertebral fracture during the study period conferring an annual incidence of 0.14 per thousand. Of the 23 individuals that attended the follow-up, 14 had one-column compression fractures, one a Denis type A, six a Denis type B, one a Denis type D and one a Chance fracture. At injury, one had a partial paresis in one leg and one developed a transient paraparesis during the first week. All were treated non-operatively. At follow-up, 18 individuals had no complaints while 5 had occasional back pain, 20 were classified as Frankel E and 3 as Frankel D. The radiographic ratio of anterior height to posterior height of the fractured vertebral body was unchanged during the study period. Thoracic and lumbar vertebral fractures in late adolescence with no or minor neurological deficits have a predominantly favourable long-term outcome, even if no modelling capacity of the fractured vertebral body remains in late adolescence.

Vertebroplasty and kyphoplasty: New treatment strategies for fractures in the osteoporotic spine

During the last decade, two new treatment modalities for osteoporotic vertebral fractures have gained more interest: percutaneous vertebroplasty and kyphoplasty. The techniques and the short-term clinical results and complications have been presented but there is no scientific evidence-based information regarding the efficacy of the procedures, such as randomized controlled trials (RCT). Instead, we have to rely on prospective and retrospective uncontrolled short-term observational studies and case-control studies. These studies have shown consistently that the short-term results after the procedures are favorable as regards both pain relief and functional status. It is currently unknown, however, whether a vertebroplasty or a kyphoplasty gives a better outcome than nonoperative treatment, and whether the long-term results are as favorable as the short-term results.

[Treatment of osteoporotic vertebral compression. Explosive interest for vertebroplasty and kyphoplasty]

During the last 15 years, two new treatment strategies have gained worldwide attention in the treatment of osteoporotic vertebral fractures. The exponential increase in the use of percutaneous vertebro- or kyphoplasty has up to now not been supported by scientific sound evidence-based data. There exist no prospective randomised controlled trials (RCT) that support the efficacy of the treatments, not even adequate controlled studies. Instead we have to rely on prospective and retrospective uncontrolled short-term observational studies and case-control studies. These studies consistently indicate that the short-term results after the procedures in the treatment of osteoporotic vertebral fractures are favourable, regarding both pain relief and functional status. However, if a vertebro- or a kyphoplasty produces a better outcome than conservative treatment, and if the long-term results are as favourable as the short-term results in the treatment of osteoporotic vertebral fractures, is currently unknown.

Grisel syndrome after velopharyngoplasty

We describe two patients with Grisel syndrome (atlantoaxial dislocation) after velopharyngoplasty. One required open fixation, while the other was treated with closed reduction and skull traction. Both patients recovered well after long-term follow-up. Early detection and appropiate treatment improve the prognosis.

Vertebroplasty and kyphoplasty in the fractured osteoporotic spine

Percutaneous vertebroplasty and kyphoplasty have during the last decade gained an increasing popularity in the treatment of osteoporotic fractures of the spine. The techniques, clinical results and complications are described. There is however a disturbing lack of scientific evidence regarding the efficacy of the procedures, no controlled studies are published. An ongoing prospective randomised study is presented.

A modeling capacity of vertebral fractures exists during growth: an up-to-47-year follow-up

STUDY DESIGN

The study is an observational cohort study.

OBJECTIVES

To determine the incidence and the long-term outcome of thoracic or lumbar vertebral fractures in children.

SUMMARY OF BACKGROUND DATA

The incidence of vertebral fractures in children is described as rare and the outcome as favorable. However, no studies evaluate the clinical and radiographic long-term outcome and if a fractured vertebra could be rebuilt during growth.

METHOD

The incidence of vertebral fractures in children was evaluated through the radiographic archives. Twelve boys and 12 girls, aged 7-16 when sustaining the fracture, 21 one-column compression fractures and 3 burst fractures Denis type B, all without neurologic deficits, attended the follow-up. Primary treatment consisted of immediate mobilization without brace. Clinical and radiographic examinations were performed 27-47 years after the injury.

RESULTS

The annual incidence of thoracic and lumbar vertebral body fractures in individuals below age 16 was 0.07%. Twenty-one individuals had, at follow-up, no subjective complaints, 3 had occasional back pain (Oswestry Scores 8, 22, and 26), 23 were classified as Frankel E, and 1 as Frankel D. The radiographic ratio anterior height/posterior height of the fractured vertebral body increased from 0.75 after injury to 0.87 at follow-up (P < 0.001). The posttraumatic kyphosis in the fractured region decreased in 8 individuals (33%), all aged 13 or less at fracture. No increased disc degeneration was observed.

CONCLUSION

Thoracolumbar vertebral fractures without neurologic deficits, sustained during growth, have a favorable long-term outcome. A modeling capacity, reducing the fracture deformity, exists at least in the youngest patients.

Posterior transpedicular stabilisation of the infected spine

BACKGROUND

Six men and seven women, aged 62 years, bedridden due to back pain from a septic spondylitis in the thoracolumbar region and not responding to conservative treatment, were operated on with transpedicular stabilisation of the affected segments to enhance mobilisation. All patients experienced immediately reduced back pain, allowing them to leave their bed and start mobilisation during the first postoperative day. At follow-up after a mean of 29 months (range 13-60 months) only one was using analgesics.

RESULTS

Nine of the 11 patients with pathological neurology at surgery had improved, none had deteriorated, and all were ambulatory without bladder or bowel disturbances. Seven had achieved a solid interbody fusion, with a continued radiographic decrease in the spondylitic change in the rest, indicating that a progressive interbody fusion was in progress. Three individuals had increased kyphosis, a mean of 11 deg compared with the postoperative radiographs.

Spatial facilitation of motor evoked responses in monitoring during spinal surgery

During spinal cord monitoring, motor responses in the tibialis anterior muscles were recorded on transcranial electrical stimulation of the motor cortex. In order to facilitate the responses, the cortical stimulus was preceded by a train of stimuli to the foot sole within the receptive field of the withdrawal reflex of the tibialis anterior muscle. This cutaneous input provides a spatial facilitation of the cortically elicited response. When the stimulus interval was 50-100 ms, large and reliable responses were seen in most cases.

Bone resorbing activity released from zymosan-activated mouse peritoneal macrophages--the role of prostanoids and interleukin-1

OBJECTIVE

To study the effect of zymosan on the release of osteoclast stimulating activity from macrophages.

MATERIALS

Calvarial bones from neonatal mice and peritoneal macrophages were incubated in the absence and presence of zymosan for 72 h and supernatants harvested for subsequent analysis of bone resorbing activities and prostaglandin concentration.

METHODS

Bone resorption was assessed in vitro by analysing the release of 45Ca and 3H from neonatal mouse calvarial bones prelabelled in vivo by injections of [45Ca]CaCl2 or [3H]-proline. Prostaglandin E2 (PGE2) and I2 (PGI2) were analyzed using radioimmunoassays.

RESULTS

Supernatants from macrophages treated with zymosan stimulated the release of 45Ca and 3H. The amount of bone resorbing activity present in the macrophage supernatants was dependent on the concentration of zymosan (0.1-100 microg/ml), as well as the number of macrophages present. The 45Ca release induced by zymosan treated macrophages was inhibited by three different inhibitors of osteoclastic bone resorption (calcitonin, acetazolamide, amino bisphosphonate). The bone resorbing activity released by the zymosan-activated macrophages was lost after ultrafiltration using a filter with a molecular weight cut off of 30,000 Daltons, but retained when using a filter with a cut off of 3000 Daltons. Time-course studies of the production of bone resorbing activity in macrophages showed that activity increased during the first hour of exposure to zymosan and then reached a plateau for 96 h. PGE2 and PGI2 release from macrophages was increased during the first three hours of exposure to zymosan. This prostanoid production, together with bone resorbing activity, was abolished by indomethacin. The bone resorbing activity present 3-72 h after zymosan exposure, however, was not inhibited by indomethacin. Bone resorption stimulated by conditioned media from zymosan treated macrophages after 3 h was inhibited by 60-75% in the presence of anti IL-1alpha, 0-20% by anti IL-1beta, and completely by antisera neutralizing both IL-1alpha and IL-1beta. In addition, an IL-1 receptor antagonist abolished the stimulatory effect of conditioned media from zymosan treated macrophages.

CONCLUSIONS

These data indicate that treatment of mouse peritoneal macrophages with zymosan results in production of activities capable of stimulating bone resorption in vitro. The activity released initially appears to be due to a zymosan induced burst of prostanoid production, while the activity released during prolonged exposure to zymosan is due primarily to IL-1alpha.

Gutta-percha-stimulated mouse macrophages release factors that activate the bone resorptive system of mouse calvarial bone

This study investigated the capacity of macrophages exposed to gutta-percha particles to produce factors affecting bone metabolism. Peritoneal mouse macrophages were isolated and incubated with and without gutta-percha particles, and the supernatants were assessed for bone resorbing activity by adding macrophage-conditioned media to cultures of neonatal mouse calvarial bones. Bone resorption was measured by mineral mobilization (45Ca release) and matrix degradation (3H from [3H]proline labelled bones). The results showed that supernatant from gutta-percha-stimulated macrophages enhanced bone resorption. This effect was related to the amount of gutta-percha, and the concentration and time of exposure to the conditioned media. Stimulated macrophages released enhanced amounts of prostaglandins E2 and I2; however, indomethacin, which inhibits the prostanoid response, had no effect on bone resorbing activity. The stimulatory effect on bone resorption was inhibited by calcitonin, interleukin-1 receptor antagonistic protein, and by antiserum neutralizing mouse interleukin-1alpha(IL-1alpha), but not by anti-IL-1beta. Filtration experiments revealed that the molecules involved in the resorption activity had an apparent molecular weight between 3000 and 30,000 Da. These experiments show that mouse peritoneal macrophages, when exposed to gutta-percha particles, release factors which have a bone resorbing activity that is primarily due to enhanced production of IL-1alpha.

Bacteria inhibit biosynthesis of bone matrix proteins in human osteoblasts

The effect of extracts from Staphylococcus aureus and Staphylococcus epidermidis on bone matrix production were assessed by analyzing the biosynthesis of osteocalcin and Type I collagen in a human osteoblastic osteosarcoma cell line (MG-63). In MG-63 cells, extracts from Staphylococcus aureus and Staphylococcus epidermidis decreased 1,25(OH)2-vitamin D3 stimulated osteocalcin biosynthesis, and insulin-like growth factor I induced production of Type I collagen in a concentration dependent manner. The basal rate of osteocalcin and Type I collagen formation was unaffected by the bacterial extracts. The inhibitory effect of the bacteria on osteocalcin biosynthesis was seen after 24 hours of treatment and was maintained for at least 96 hours. The extracts of Staphylococcus aureus and Staphylococcus epidermidis enhanced prostaglandin E2 formation in the MG-63 cells. Abolition of the prostaglandin E2 response by treatment with indomethacin and flurbiprofen did not affect bacteria induced inhibition of osteocalcin production. Stimulation of osteocalcin biosynthesis by 1,25(OH)2-vitamin D3 was associated with a decreased rate of cell proliferation. The inhibitory action of the bacterial extracts was not linked to any inhibition of [3H]-thymidine incorporation into deoxyribonucleic acid. These data show that extracts of Staphylococcus aureus and Staphylococcus epidermidis have the ability to inhibit the biosynthesis of bone matrix proteins by a nonprostaglandin and noncytotoxic dependent mechanism and suggest that bone loss in inflammatory processes containing Staphylococcus aureus or Staphylococcus epidermidis may not be caused only by enhanced bone resorption but also by decreased bone formation.

Remodeling of the spinal canal deformed by trauma

Computed tomography (CT) examinations and functional scores were evaluated in 28 patients with thoracolumbar fractures with intraspinal fragments, of whom 20 underwent operation. The cross-sectional area and the sagittal and frontal diameters of the spinal canal were measured after the injury, postoperatively, and at follow-up (mean, 6 years). The operative reduction significantly increased both diameter and area of the spinal canal. During follow-up, a further significant increase of the sagittal diameter and the area was noted, in both surgically and conservatively treated patients. There was no difference in remodeling between the groups. Six patients in the surgically treated group had neurologic deficits at admission, five had improved, and one remained unchanged at follow-up. The presence or absence of intraspinal fragments should not influence the treatment strategy per se in cases without neurologic signs.

Cytokine-induced inhibition of bone matrix proteins is not mediated by prostaglandins

Interleukin-1 (IL-1) and tumor necrosis factor (TNF), two pleiotropic cytokines produced in inflammatory processes, inhibit bone matrix biosynthesis and stimulate prostanoid formation in osteoblasts. In the present study, the importance of prostaglandin formation in IL-1 and TNF-induced inhibition of osteocalcin and type I collagen formation has been examined. In the human osteoblastic cell line MG-63, IL-1 alpha (10-1000 pg/ml), IL-1 beta (3-300 pg/ml) and TNF-alpha (1-30 ng/ml) stimulated prostaglandin E2 (PGE2) formation and inhibited 1,25(OH)2-vitamin D3-induced osteocalcin biosynthesis as well as basal production of type I collagen. Addition of PGE2 or increasing the endogenous formation of PGE2 by treating the cells with arachidonic acid, bradykinin, Lys-bradykinin or des-Arg9-bradykinin, did not affect osteocalcin and type I collagen formation in unstimulated or 1,25(OH)2-vitamin D3-stimulated osteoblasts. Four non-steroidal antiinflammatory drugs, indomethacin, flurbiprofen, naproxen and meclofenamic acid, inhibited basal, IL-1 beta- and TNF-alpha-stimulated PGE2 formation in the MG-63 cells without affecting IL-1 beta- or TNF-alpha-induced inhibition of osteocalcin and type I collagen formation. In isolated, non-transformed, human osteoblast-like cells, IL-1 beta and TNF-alpha stimulated PGE2 formation and concomitantly inhibited 1,25(OH)2-vitamin D3-stimulated osteocalcin biosynthesis, without affecting type I collagen formation. In these cells, indomethacin and flurbiprofen abolished the effects of IL-1 beta and TNF-alpha on prostaglandin formation without affecting the inhibitory effects of the cytokines on osteocalcin biosynthesis. These data show that IL-1 and TNF inhibit osteocalcin and type I collagen formation in osteoblasts independently of prostaglandin biosynthesis and that non-steroidal antiinflammatory drugs do not affect the effects of IL-1 and TNF on bone matrix biosynthesis.

Factors related to body weight changes during and after pregnancy: the Stockholm Pregnancy and Weight Development Study

The Stockholm Pregnancy and Weight Development Study is a prospective study of body weight changes in women, whose maternity unit charts were reviewed and who were then invited for a 1-year follow-up, including weigh-in sessions and questionnaires on dietary habits, physical activity and socio-demographic factors. Total weight gain during pregnancy was related to weight gain already during the first trimester. Women reporting previous weight cycling had slightly higher weight gain during pregnancy. Successful return towards pre-pregnancy weight was found more often in women with regular breakfast and lunch habits. Lactation had only a small effect on weight loss after delivery, independent of eating habits. Lack of physical activity was more common in women who had low lactation scores. Twenty-eight percent reported an increased interest in sweets during pregnancy; these women increased 1 to 2 kg more than others in weight during pregnancy. Postpartum weight retention was more affected by lifestyle changes during and after pregnancy than by factors before pregnancy.

Comparative susceptibilities of human embryonic fibroblasts and HeLa cells for isolation of human rhinoviruses

The recovery of human rhinovirus (HRV) from nasal washings and nasal and pharyngeal swabs from volunteers with naturally acquired colds was compared in different cell types. Human embryonic lung fibroblast (HELF) strain WI-38 (sensitivity, 61 to 84%) and HeLa-I, an HRV-susceptible HeLa clone (sensitivity, 86 to 94%), were the most sensitive cell types used. HELF-WI-38 cells showed a cytopathic effect earlier than the other cells used, and the different strains of HRV-susceptible HeLa cells varied in their sensitivities for HRV isolation. HRV was detected in a single cell type in 20 to 35% of the positive samples, suggesting that use of a combination of different HRV-susceptible cell lines is the best approach for the recovery of HRV. Although nasal washings tended to yield more HRV isolates than nasal and pharyngeal swabs, the two sampling methods were not found to be significantly different.

Pregnancy as a risk factor for obesity: lessons from the Stockholm Pregnancy and Weight Development Study

Pregnancy and maternal body weight development are intertwined in complicated patterns. In most studies, an increase in maternal body weight with age and parity has been reported. For women who develop obesity, pregnancies can, in retrospect, be identified as important triggering life events. In a retrospective analysis of 128 women at our Obesity Unit, 73% of these severely obese patients had retained more than 10 kg in connection with a pregnancy. For the general population, the effect of a pregnancy on future weight development is surprisingly difficult to predict. In The Stockholm Pregnancy and Weight Development Study, the effects of pregnancy on weight retention one year after delivery were studied in 1423 women. Data were collected retrospectively from routine pregnancy records and then extended prospectively 6 and 12 months after delivery. The mean weight retention associated with a pregnancy one year after delivery was estimated to about 0.5 kg, with a range of -12 to +26 kg. Fourteen percent of the women gained more than 5 kg. Weight increase during pregnancy was the strongest predictor for sustained weight retention 1 year later. Prepregnancy weight did not predict the weight development outcome. The lactation pattern had only a minor influence on weight development. Smoking cessation was an important predictor for sustained weight increase. More weight retention was observed in those women who reported a change in lifestyle as regarded eating habits, meal patterns, and physical activity, suggesting that eventual body weight after pregnancy is more determined by the changes in association with that particular pregnancy than with the lifestyle before.

Complications after transpedicular stabilization of the spine. A survivorship analysis of 163 cases

OBJECTIVES

The authors studied complications of transpedicular stabilization methods.

SUMMARY OF BACKGROUND DATA

One hundred and sixty-three consecutive transpedicular stabilization procedures were performed between January 1987 and December 1991. The indications for stabilization were trauma (33 cases), metastatic spinal disorder (30 cases), spinal stenosis (33 cases), spondylolisthesis (27 cases), ankylosing spondylitis (6 cases), low back pain (22 cases), and miscellaneous (12 cases).

METHODS

Patients records and the entire series of radiographs for each case were scrutinized by independent observers. All per- and postoperative complications, including implant loosening and fatigue, were recorded. Clinical and radiographic survivorship analyses of the implants were performed.

RESULTS

Early complications were unusual and none were associated with permanent morbidity. The probability of not having the implant removed in the first postoperative year was 85%. There was a 40% risk of radiographic failure, defined as loosening or implant fatigue, at 6 months. The outcome was more favorable in cases in which anterior vertebral interbody fusion was also performed.

CONCLUSIONS

Transpedicular fixation is a safe procedure with a low incidence of serious per- and early postoperative complications. The mechanical durability of transpedicular fixators used alone is a cause for concern.

Spectrum of activity of soluble intercellular adhesion molecule-1 against rhinovirus reference strains and field isolates

The antiviral potency of soluble intercellular adhesion molecule-1 (ICAM-1; the major receptor for human rhinoviruses) was determined for a subset of American Type Culture Collection reference serotypes and field isolates of rhinovirus. The results indicate that soluble ICAM-1 exhibits a broad spectrum of activity against rhinoviruses and that field isolates have a sensitivity indistinguishable from that of laboratory strains.

Trends in eating patterns, physical activity and socio-demographic factors in relation to postpartum body weight development

'The Stockholm Pregnancy and Weight Development Study' was conducted to identify risk factors for postpartum weight retention, such as dietary habits, physical activity and socio-demographic factors. The body weight development of 1423 pregnant women was studied prospectively from the beginning of the pregnancy until 1 year postpartum. Data were collected from routine pregnancy records and from questionnaires 6 and 12 months postpartum. Mean weight retention 1 year postpartum was 0.5 kg compared with the prepregnancy body weight. A 'trend method' was constructed to identify a number of pre-defined major patterns of behaviour. The weight retention 1 year postpartum was greater in women who (a) increased their energy intake during and after pregnancy, (b) increased their snack eating after pregnancy to three or more snacks/d, and (c) decreased their lunch frequency starting during or after the pregnancy. Women who had retained > or = 5 kg 1 year postpartum were more seldom physically active in their leisure time throughout the study period compared with women with a smaller weight gain. Postpartum weight retention correlated negatively with the degree of physical activity in the second half year postpartum. These results indicate that postpartum weight retention is more affected by a change in lifestyle during, and above all after, pregnancy than by factors before pregnancy.

Migration of acetabular components, inserted with and without cement, in one-stage bilateral hip arthroplasty. A controlled, randomized study using roentgenstereophotogrammetric analysis

Twenty-one patients who had primary osteoarthrosis were managed with a bilateral total hip arthroplasty with insertion of a Charnley femoral component. In each patient, one hip was randomly allocated to have a Harris-Galante acetabular component inserted without cement, and the contralateral hip was treated with an all-polyethylene Charnley acetabular component fixed with cement. The clinical result was satisfactory in all patients. All forty-two hips were followed, with respect to migration of the acetabular component, with use of roentgenstereophotogrammetric analysis for a median of twenty-seven months (range, twenty-three to forty-nine months). Each patient served as his or her own control. Maximum migration in any direction was 1.7 and 2.1 millimeters, and maximum rotation was 2.2 and 2.0 degrees for the Harris-Galante and Charnley acetabular components, respectively. There was no significant difference in migration between the two designs of acetabular components (p = 0.98, p = 0.75, and p = 0.06 for the transverse, longitudinal, and sagittal axes, respectively). However, the Harris-Galante acetabular components rotated significantly more than the Charnley acetabular components around two of the three axes (p = 0.008, p = 0.08, and p = 0.03 for the transverse, longitudinal, and sagittal axes, respectively). The Charnley hip implant has been used clinically for a long time, with successful results. Comparison of new designs of implants with the Charnley prosthesis is therefore important. Roentgenstereophotogrammetric analysis provides a potential for detection of problems with fixation at an early stage rather than after long-term follow-up. No major difference in terms of skeletal fixation was found between the two designs of components after short to medium-term follow-up.