Correlation between curve severity, somatosensory evoked potentials, and magnetic resonance imaging in adolescent idiopathic scoliosis

STUDY DESIGN

A prospective study in patients with adolescent idiopathic scoliosis of different clinical severity using whole-spine magnetic resonance imaging and somatosensory evoked potentials.

OBJECTIVES

To correlate the presence of magnetic resonance imaging structural abnormalities with somatosensory evoked potential-detected functional disorders in the hind brain and spinal cord and the Cobb's angle in patients with adolescent idiopathic scoliosis and to compare the result with those in healthy matched control subjects.

SUMMARY OF BACKGROUND DATA

Many different types of neurologic dysfunction have been reported in scoliosis. With the advent of magnetic resonance imaging, there are increased reports on the association of idiopathic scoliosis and syringomyelia, Chiari I malformation, or tonsillar ectopia. The actual link between structural and functional disorder in idiopathic scoliosis is, however, unclear.

METHODS

Posterior tibial nerve evoked potentials and whole-spine magnetic resonance imaging were performed in 36 healthy control subjects, 135 patients with adolescent idiopathic scoliosis with Cobb's angle less than 45 degrees, and 29 patients with Cobb's angle more than 45 degrees.

RESULTS

Tonsillar ectopia or syringomyelia, detected by magnetic resonance imaging, or functional disturbance in the somatosensory pathway, detected by somatosensory evoked potentials, was found to be significantly more frequent in the group of patients with severe scoliosis curvature, with an incidence of 31% and 27.6%, respectively. Incidence of tonsillar ectopia was 33.3% in patients with abnormal somatosensory evoked potentials in contrast to the much lower incidence of 2.9% in patients with normal somatosensory evoked potentials. There was a significant structural and functional link. The incidence of syringomyelia in patients with and without tonsillar ectopia was 33.3% and 0.7%, respectively.

CONCLUSIONS

In patients with adolescent idiopathic scoliosis with severe curve, the significant association with tonsillar ectopia and abnormal somatosensory function points to a neural origin. Disorders in the somatosensory function may be one of the mechanisms linking tonsillar ectopia to scoliosis. Somatosensory evoked potentials and magnetic resonance imaging may have important diagnostic and predictive value and may help in the management of adolescent idiopathic scoliosis.

Specific interaction between the hepatitis C virus NS5B RNA polymerase and the 3' end of the viral RNA

Hepatitis C virus (HCV) NS5B protein is the viral RNA-dependent RNA polymerase capable of directing RNA synthesis. In this study, an electrophoretic mobility shift assay demonstrated the interaction between a partially purified recombinant NS5B protein and a 3' viral genomic RNA with or without the conserved 98-nucleotide tail. The NS5B-RNA complexes were specifically competed away by the unlabeled homologous RNA but not by the viral 5' noncoding region and very poorly by the 3' conserved 98-nucleotide tail. A 3' coding region with conserved stem-loop structures rather than the 3' noncoding region of the HCV genome is critical for the specific binding of NS5B. Nevertheless, no direct interaction between the 3' coding region and the HCV NS5A protein was detected. Furthermore, two independent RNA-binding domains (RBDs) of NS5B were identified, RBD1, from amino acid residues 83 to 194, and RBD2, from residues 196 to 298. Interestingly, the conserved motifs of RNA-dependent RNA polymerase for putative RNA binding (220-DxxxxD-225) and template/primer position (282-S/TGxxxTxxxNS/T-292) are present in the RBD2. Nevertheless, the RNA-binding activity of RBD2 was abolished when it was linked to the carboxy-terminal half of the NS5B. These results provide some clues to understanding the initiation of HCV replication.

Persistent osteopenia in adolescent idiopathic scoliosis. A longitudinal follow up study

STUDY DESIGN

A follow-up study assessing the bone mineral dynamics in adolescent patients with idiopathic scoliosis and associated osteopenia.

OBJECTIVES

To investigate whether osteopenia in patients with adolescent idiopathic scoliosis is a transient phenomenon or a persistent problem.

SUMMARY OF BACKGROUND DATA

Investigators have suggested a significant correlation of osteopenia with adolescent idiopathic scoliosis. Because one half of the skeletal mass is acquired during the adolescent years, it is of importance to know whether the osteopenia is transient or persistent.

METHODS

Using dual-energy x-ray absorptiometry, bone mineral density of bilateral proximal femurs was studied longitudinally in 70 healthy control subjects and 14 patients with adolescent idiopathic scoliosis with significant osteopenia more than 2 standard deviations below the mean normal value.

RESULTS

The 14 girls with osteopenic adolescent idiopathic scoliosis who were followed up longitudinally for up to 3 years showed persistent and significantly lower bone mineral density when compared with normal age-, sex- and maturity-matched control subjects.

CONCLUSIONS

Patients with adolescent idiopathic scoliosis are at increased risk of osteoporosis than are healthy adolescents. The lower rate of increase of bone mineral density in patients with adolescent idiopathic scoliosis who have low bone mineral density could predict a significantly lower peak bone mass in adulthood, with all the associated problems of osteoporosis. Further investigation is needed to define whether osteopenia-associated scoliosis has the same cause, pathogenetic mechanism, and risk of progression when compared with adolescent scoliosis without osteopenia.

Axial and peripheral bone mineral acquisition: a 3-year longitudinal study in Chinese adolescents

We performed a 3-year longitudinal study of a group of 179 healthy Chinese adolescents (92 boys and 87 girls) aged from 12 to 16 years to determine the effects of puberty, physical activity, physical fitness, and calcium intake on the acquisition of bone mass. At yearly intervals for 3 consecutive years we recorded nutrition, calcium intake and anthropometric measurements, and assessed pubertal status according to Tanner. Bone mass of the lumbar spine was determined by dual-energy X-ray absorptiometry and radial bone mass by single-photon absorptiometry. Physical fitness and level of physical activity were assessed and muscle strength and power determined by isokinetic testing. Peripheral bone mass correlated with axial skeleton bone mass. Age, pubertal staging, physical fitness and muscle strength were significantly associated with bone mass increments on cross-sectional univariate and regression analysis. Longitudinal regression analysis showed that the most important factor affecting bone mass accretion in adolescents in both sexes was their pubertal stage. In boys, bone mass increment throughout the study was greater in children who were already in the advanced pubertal stages on entering the study than in those who started puberty in year 2 or 3 of the study. The percentage change in bone mineral content of the forearm and in bone mineral density of the lumbar spine was greater than 25% in the advanced pubertal group as compared to around 20% in the less mature group. For girls, the reverse was true. The increment of bone mass during the study period was significantly greater in those who presented in the earlier pubertal stages than in those who were at the more advanced stage of puberty on entry into the study. There was no significant effect of calcium intake and physical activities on the bone mass accretion.

CONCLUSION

In Chinese adolescents, bone mineral accretion at adolescence is not influenced by exercise, level of physical fitness and calcium intake. In both sexes, and especially in girls, to optimally increase bone mass, regular physical exercise programmes should be instituted well before the onset of puberty rather than at or after it. Once puberty starts, these interventions may have no or only limited effect.

Sternocleidomastoid pseudotumor and congenital muscular torticollis in infants: a prospective study of 510 cases

OBJECTIVES

Congenital muscular torticollis is a common and controversial condition in infancy. We studied prospectively a group of infants with clearly defined sternomastoid tumor treated with a well-defined protocol.

STUDY DESIGN

A total of 510 cases of sternomastoid tumor in infants over a 10-year period were studied prospectively with a mean follow-up of 3.5 years and a range from 1. 5 years to 13 years. The clinical presentations, associated abnormalities, treatments, and outcomes of the overall group and subgroups were evaluated to determine the most important prognostic factors.

RESULTS

The mean age of presentation was day 24, with most (92.7%) presenting before the age of 3 months. There was a high correlation with breech presentation and assisted delivery. Clinical subgroups according to the deficit in passive rotation of the neck correlated with the incidence of hip dysplasia (up to 11.6%), mode of delivery, time of presentation, degree of craniofacial asymmetry, head tilt, and the size and extent of the pseudotumor (P <.05). With an early and prolonged manual stretching program, 90.7% had excellent and good overall results. The 6.7% of patients in the poor outcome group requiring surgical treatment all belonged to the more severe rotation limitation groups.

CONCLUSIONS

Subgrouping patients with sternomastoid tumor according to the passive limitation of rotation of the neck has prognostic significance, with good overall results of conservative treatment with manual stretching.

A 10-year study of the changes in the pattern and treatment of 6,493 fractures

A total of 6,493 fractures was studied from 6,389 children younger than 16 years admitted as inpatients to one center in a 10-year period. The boy-to-girl ratio increased from 1.4:1 in the infants to 4.9:1 in the adolescents. The most common fractures were the distal radius (20.2%), supracondylar fracture of the humerus (17.9%), forearm shaft (14.9%), and the tibial shaft (11.9%). A distinct age-specific fracture pattern also was found, with supracondylar fracture of the humerus being the most common fracture in the age 0- to 3-year (26.7%) and the 4- to 7-year (31.6%) groups and distal radius in the 8- to 11-year and the 12- to 16-year groups (24.3 and 25.7%, respectively). Although the overall pattern of the major fractures had not changed over the 10-year period, significant changes in the treatment pattern were observed. The closed-reduction and percutaneous pinning rates increased from 9.5 to 38.7% in fracture of the distal radius, 4.3 to 40% in the supracondylar humerus, and 1.8 to 22% in the forearm shaft. The changes in treatment pattern were also accompanied by a corresponding decrease in the open-reduction rate and hospital stay periods from <10% to 38% of patients being discharged within 1 day of admission in the 10-year period.

MRI evaluation of multifidus muscles in adolescent idiopathic scoliosis

BACKGROUND

The role of the multifidus muscles in the initiation and progression of curve in adolescent idiopathic scoliosis is not fully understood and controversy exists as to the side of the abnormality.

OBJECTIVE

To evaluate on MRI the multifidus muscles at the apex of the major curve in adolescent idiopathic scoliosis to ascertain if the multifidus muscles on the convex or concave side are abnormal and the relationship to curve severity.

MATERIALS AND METHODS

Forty-six patients with adolescent idiopathic scoliosis, separated into two groups, were studied using a 1.5-T MR scanner with the synergy spine coil, employing a modified STIR (short tau inversion recovery) axial sequence obtained at the apex of the major scoliotic curve.

RESULTS

No hyperintense signal change was demonstrated in the convex side multifidus muscles in any patient. In group I, 16 of 18 patients with severe or rapidly progressive curve showed increase in signal intensity in the multifidus muscle on the concave side of the apex of the curve. In group II, of the 15 patients with mild curve (Cobb angle 10-30 degrees), 4 had increased signal intensity in the multifidus muscle on the concave side; of the 13 with more severe curve (Cobb angle greater than 30 degrees), 10 had increase in multifidus signal intensity on the concave side.

CONCLUSIONS

The concave-side multifidus muscle at the apex of a scoliotic curve was morphologically abnormal. A significant association between abnormal signal change and curve severity was also established.

Decompression and stable internal fixation of femoral neck fractures in children can affect the outcome

Pediatric femoral neck fracture is rare and known to be associated with a high complication rate. The effect of early decompression and operative fixation is not frequently reported in the literature. This is a retrospective study of 14 patients younger than 16 years with traumatic fractures of the femoral neck and intertrochanteric region over a 10-year period with a follow-up of 2-11 years (mean, 4.6 years). Road traffic accidents and falls from a height were the main causative factors, and the fractures were subclassified into transcervical, 58%; intertrochanteric, 29%; transepiphyseal, 7%; and cervicotrochanteric, 7%. Of all the fractures, 10 (71%) were displaced. Decompression of the hip by aspiration and closed reduction and internal fixation was performed for all the displaced fractures within 24 h after admission. Three cases required open reduction. Complete fracture healing and functional recovery was achieved in 13 patients with only one delayed union. No patient had radiographic evidence of avascular necrosis. When compared with earlier studies, the current aggressive management protocol for displaced fracture significantly minimized the complications of avascular necrosis, non-union, delayed union, and premature physeal closure.

Outcome of surgical treatment of congenital muscular torticollis

Eighty-four patients with congenital muscular torticollis were treated surgically in a 10-year period with a mean followup of 5 years (range, 2-13 years). All patients were classified into subgroups according to the type of congenital torticollis, the limitation of passive rotation of the neck, and other parameters, including head tilt and craniofacial asymmetry. Twenty-two (26.2%) patients underwent surgery before they were 1 year of age, 22.6% were between 1 and 3 years of age, 38.1% were between 3 and 10 years, and 13.1% were older than 10 years. Postoperative management included physiotherapy for 3 to 4 months and the application of a multiply adjustable torticollis brace for 10 weeks in children older than 2 years of age. Loss of the sternomastoid column was found in 82.6%, poor scar in 2.4%, lateral band in 47.2% and 1.2% required a second operation. The final overall score showed excellent results in 88.1%, good results in 8.3%, and fair to poor results in 3.6%. The most important factor affecting the overall result and outcome was found to be the age of the patient at the time of operation. However, this series also showed that for patients who were 10 years or older at the time of surgery, 63.6% had excellent results and 81.8% had good to excellent results, indicating the benefit of surgery even in the late cases.

Medical data mining using evolutionary computation

In this paper, we introduce a system for discovering medical knowledge by learning Bayesian networks and rules. Evolutionary computation is used as the search algorithm. The Bayesian networks can provide an overall structure of the relationships among the attributes. The rules can capture detailed and interesting patterns in the database. The system is applied to real-life medical databases for limb fracture and scoliosis. The knowledge discovered provides insights to and allows better understanding of these two medical domains.

Postoperative bleeding with factor VII deficiency: case report

Factor VII deficiency was diagnosed during haematological investigation of a patient with multiple occurrences of postoperative bleeding after surgical extraction of an impacted upper left canine. The bleeding was eventually stopped with local measures without resorting to blood product transfusion which may have been necessary if local measures had failed to control bleeding. Abnormalities were also found in subsequent blood profiles and coagulation tests in other members of the patient's family.

Individual differences in P3 scalp distribution in older adults, and their relationship to frontal lobe function

There is evidence that frontal lobe function may diminish in normal aging. The P3 component of the event-related brain potential (ERP) elicited by target events in an oddball paradigm becomes more frontally oriented in elderly subjects. It was hypothesized that the extent to which the P3 distribution is frontally oriented in old subjects may index less efficient frontal lobe function. In this study, bootstrapping methods were used to establish the reliability of the locations of maxima of surface brain activity obtained with ERP recordings from young and old subjects. The results indicated that brain activity maxima are reliable for a given individual. However, among the elderly only, there were also clear individual differences in the distribution of the P3 component elicited by target stimuli in an oddball paradigm. On the basis of these differences, the old subjects were divided into two groups. In line with predictions, those elderly subjects who showed frontal-maximal P3 scalp distributions had lower performance on standardized neuropsychological tests of frontal lobe function than those elderly subjects who showed posterior-maximal scalp topographies.

Telemedicine conference on a 13-year-old Chinese girl with an unusual skeletal condition

Departments of Paediatrics, Diagnostic Radiology, Orthopaedics and Traumatology and Chemical Pathology, Prince of Wales Hospital, Shatin, Hong Kong, China; Department of Paediatric Radiology, Hospital for Sick Children, Great Ormond Street Hospital, London, UK

Severe progressive deformities after limb lengthening in type-II fibular hemimelia

Until recently the accepted treatment of choice for severe type-II fibular hemimelia has been Syme's or Boyd's amputation. The alternative of distraction lengthening using the Ilizarov technique is now available. We report three patients (four limbs) with type-II fibular hemimelia who were treated by the Ilizarov technique and followed up for two to six years. Severe progressive procurvatum and valgus deformity of the tibia and valgus deformity and lateral subluxation of the ankle were found in all four limbs. Multiple additional soft-tissue and bony surgery was necessary. In view of these problems we feel that reappraisal of the indications for lengthening in type-II fibular hemimelia is necessary.

Pseudoaneurysm after high tibial osteotomy and limb lengthening

A case of a young man with anterior tibial artery rupture and pseudoaneurysm formation that occurred during lengthening of a scarred limb is presented. Leg length discrepancy occurred because of previous distal femoral and proximal tibial fractures. Two corrective operations were performed 11 and 2 years earlier at another hospital. As limb deformity persisted, distal femoral and proximal tibial osteotomies combined with limb lengthening were performed. The aim was to achieve 120 mm (70 mm femoral, 50 mm tibial) lengthening. The operative and early postoperative course was uneventful. Twenty-six days after surgery (when femoral and tibial lengthening was 13.5 mm and 5.5 mm, respectively), blood began oozing from the operative scar during limb distraction. At 70 days after surgery (when femoral and tibia lengthening was 41.5 mm and 14 mm, respectively), a rupture and pseudoaneurysm of the anterior tibial artery became apparent. Documentation of a normal pulses in the foot after surgery, the late presentation of pseudoaneurysm, and the initiation of bleeding by limb distraction indicate that limb lengthening either aggravated an unrecognized arterial injury or precipitated de novo rupture of the anterior tibial artery scarred from previous trauma. The pseudoaneurysm was treated successfully by transarterial embolization.

Lengthening of a one-bone forearm. A sequel of neonatal osteomyelitis

An 8-year-old girl presented with marked shortening of the right forearm due to destruction of both the radius and ulna secondary to neonatal osteomyelitis. A one-bone forearm operation was performed to achieve a stable forearm. Two years later, the one-bone forearm was lengthened for 6 months by callus distraction (callotasis) achieving 12 cm of extra length. The patient was last followed up at the age of 16. The appearance and functional outcome of the right upper limb had been improved and she was independent in all activities of daily living.

Diagnostic thoracic-computed tomography in radiotherapy for loco-regional recurrent breast carcinoma

PURPOSE

This study was initiated to evaluate whether pretreatment diagnostic thoracic CT scan was useful for patients with loco-regional recurrent breast carcinoma, and to assess its impact on the design of radiotherapeutic treatment.

METHODS AND MATERIALS

Between March 1991 and January 1997, 44 patients underwent thoracic CT examination with contrast material before the consideration of radiotherapy for their isolated loco-regional recurrent breast carcinoma. The CT radiographs were prospectively reviewed for additional findings clinically undetected by prior physical examination and plain-chest radiograph. The changes made in treatment design and dosage of radiation as a result of CT findings were recorded for analysis. The correlation between prognostic indicators and the CT findings was also studied.

RESULTS

Twenty-two of 44 (50%) patients were found to have additional abnormalities detected only after thoracic CT examinations were performed. The strategy of radiation therapy was altered in 17 of 22 (77%) patients as a result. Patients with shorter disease-free interval (p = 0.08) and multiple sites of recurrence (p = 0.05) tended to have greater numbers of findings on CT scan previously unsuspected. Thus, CT scan is a valuable guide to treating loco-regional recurrent disease.

CONCLUSION

Pretreatment diagnostic thoracic CT scan offers essential information that can alter treatment planning and thus optimize treatment strategy for a large proportion of patients with clinically isolated loco-regional recurrent breast carcinoma. In this population of patients we recommend that thoracic CT examination be considered before the initiation of radiation therapy.

Determinants of axial and peripheral bone mass in Chinese adolescents

OBJECTIVE

To determine the relation of puberty, physical activity, physical fitness, and calcium intake with bone mineral content (BMC) of the distal radius, and on bone mineral density (BMD) of the L2 to L4 vertebrae in a group of healthy Chinese adolescents.

DESIGN

Cross sectional survey.

SUBJECTS

A group of 179 healthy Chinese adolescents (92 boys and 87 girls) aged 12 to 13 years enrolled in the first year of the Tii Junior High School in Shatin, Hong Kong. Ninety four of the pupils enrolled were in the physical education major class (PE), and the other 85 were in the art major class (ARTS).

MAIN OUTCOME MEASURES

Correlation of BMC of the distal radius and BMD of the L2 to L4 vertebrae with level of physical activity, physical fitness (isometric and isokinetic), muscle strength of the upper and lower limb, and calcium intake.

RESULTS

BMC of the distal radius and BMD of the L2 to L4 vertebrae were significantly positively correlated. Univariate and regression analysis showed that age, pubertal staging, physical fitness, and muscle strength were significantly associated with bone mass in a positive way. Calcium intake and type of sport practised did not exert a significant influence on BMC of the distal radius and BMD of the L2 to L4 vertebrae in boys. The results for the BMD of the L2 to L4 vertebrae were similar in girls and boys; however, in girls, the BMC of the distal radius had a negative correlation with calcium intake. Physical fitness was a significant positive predictor of BMD of the L2 to L4 vertebrae.

CONCLUSIONS

Among Chinese adolescents bone mass was positively influenced by certain measures of physical fitness as well as by age, weight, and pubertal stage.

Can we predict body height from segmental bone length measurements? A study of 3,647 children

It is well known that significant differences exist in the anthropometric data of different races and ethnic groups. This is a cross-sectional study on segmental bone length based on 3,647 Chinese children of equal sex distribution aged 3-18 years. The measurements included standing height, weight, arm span, foot length, and segmental bone length of the humerus, radius, ulna, and tibia. A normality growth chart of all the measured parameters was constructed. Statistical analysis of the results showed a very high linear correlation of height with arm span, foot length, and segmental bone lengths with a correlation coefficient of 0.96-0.99 for both sexes. No differences were found between the right and left side of all the segmental bone lengths. These Chinese children were found to have a proportional limb segmental length relative to the trunk.

A new look at the sequential development of elbow-ossification centers in children

The pattern and sequence of ossification of the six secondary ossification centers around the elbow in the child were mainly derived from studies done >30 years ago. This series reexamined the sequence and pattern based on a cross-sectional study of the elbow radiographs of 1,577 Chinese children with elbow injuries; age range, from newborn to 17 years. The ratio of girls to boys was 1:2. Each child had a radiograph of the normal and the injured elbow giving a total of 3,154 radiographs. A percentile chart of ossification was constructed for each of the ossification centers in both sexes for easy reference. No differences in the timing and ossification pattern were found between the right and left elbow or between the normal and injured elbow in this study. The sequence of ossification in both boys and girls was found to be the same (i.e., the capitulum first, followed by the radial head, medial epicondyle, olecranon, trochlea, and last, the lateral epicondyle). The ages at which 50% of the girls were found to have positive radiologic ossification for each of these centers were ages 1, 5, 5, 9, 9, and 10 years, respectively. In boys, with the exception of the capitulum, an average delay of 2 years was found in each of the ossification centers, although the sequence remained similar.

The role of arthroscopy in ankle and subtalar degenerative joint disease

Treatment options for degenerative joint disease of the ankle and subtalar joints are limited. When conservative management fails, the only effective procedure is arthrodesis. With the advent of the small arthroscope and the development of better instrumentation and distraction techniques, small joint arthroscopy has gained popularity as an important diagnostic and therapeutic tool in the treatment of ankle and subtalar disorders. Although the benefits of arthroscopic ankle arthrodesis are well established, and arthroscopic subtalar arthrodesis has been described recently, the role of arthroscopic debridement for degenerative joint disease of the ankle and subtalar joints remains controversial. Traditionally, operative arthroscopy for ankle arthritis has not met with great success; however, recent studies have shown that it can provide an interim alternative to arthrodesis in early arthritis with preserved range of motion. Lesions associated with arthritis, such as impinging osteophytes and loose bodies, can be treated effectively with arthroscopy.

Posterior tibial nerve somatosensory cortical evoked potentials in adolescent idiopathic scoliosis

STUDY DESIGN

Somatosensory-evoked potentials were used to evaluate neurologic function in patients with adolescent idiopathic scoliosis.

OBJECTIVES

To compare the somatosensory-evoked potentials between patients with adolescent idiopathic scoliosis and healthy control individuals, and to determine the incidence of abnormal somatosensory function in patients with adolescent idiopathic scoliosis.

SUMMARY OF BACKGROUND DATA

Somatosensory-evoked potentials are sensitive in detecting structural lesions in the somatosensory pathway. Previous studies on somatosensory function in patients with idiopathic scoliosis have demonstrated statistical differences in somatosensory-evoked potential latency between scoliotic and normal groups. However, no documentation of the actual incidence of abnormal somatosensory-evoked potentials is available.

SUBJECTS AND METHODS

Posterior tibial nerve somatosensory cortical evoked potentials were evaluated on 147 young patients with adolescent idiopathic scoliosis and 31 healthy control individuals.

RESULTS

Seventeen patients with idiopathic scoliosis showed pathologic evoked potentials. Among them were seven with absent somatosensory-evoked potential waveform and 10 with delayed latency. The results were reproducible on repeated measurement.

CONCLUSIONS

Adolescent idiopathic scoliosis could be subdivided according to the somatosensory-evoked potential findings into two subgroups, those with and those without a somatosensory pathologic process. Potential clinical significance in predicting curve progression in idiopathic scoliosis could be pursued further.

The conservative management of acute pyogenic iliopsoas abscess in children

We describe three cases of acute pyogenic abscess of the iliopsoas in children treated conservatively. Two patients had image-guided aspiration and one was managed with antibiotics alone. All made a complete recovery. Acute pyogenic abscess of the iliopsoas in children can be treated effectively and safely with intravenous antibiotics and image-guided aspiration of the abscess.

Percutaneous intramedullary Kirschner wiring for displaced diaphyseal forearm fractures in children

Displaced fractures of the forearm in children are often treated conservatively, but there is a relatively high incidence of redisplacement, malunion and consequent limitation of function. We have performed percutaneous Kirschner (K) wire fixation in 72 such children under the age of 14 years, of which 57 were reviewed for our study. Both the radius and ulna were fractured in 45 (79%), the radius only in eight and the ulna only in four. The mean initial angulation was 19 degrees in the lateral plane and 9 degrees in the anteroposterior plane for the radius and 15 degrees and 9 degrees, respectively, for the ulna. In 42 patients (74%) we performed closed reduction. In the remaining 15 (26%) closed reduction failed and an open reduction, through a minimal approach, was required before K wiring. At a mean follow-up of 20 months all patients had good functional results with an excellent range of movement. Only five had angulation of from 10 degrees to 15 degrees and none had nonunion, premature epiphyseal closure or deep infection. Percutaneous intramedullary K wiring for forearm diaphyseal fracture is a convenient, effective and safe operation, with minimal complications.

EMF genes regulate Arabidopsis inflorescence development

Mutations in EMBRYONIC FLOWER (EMF) genes EMF1 and EMF2 abolish rosette development, and the mutants produce either a much reduced inflorescence or a transformed flower. These mutant characteristics suggest a repressive effect of EMF activities on reproductive development. To investigate the role of EMF genes in regulating reproductive development, we studied the relationship between EMF genes and the genes regulating inflorescence and flower development. We found that APETALA1 and AGAMOUS promoters were activated in germinating emf seedlings, suggesting that these genes may normally be suppressed in wild-type seedlings in which EMF activities are high. The phenotype of double mutants combining emf1-2 and apetala1, apetala2, leafy1, apetala1 cauliflower, and terminal flower1 showed that emf1-2 is epistatic in all cases, suggesting that EMF genes act downstream from these genes in mediating the inflorescence-to-flower transition. Constitutive expression of LEAFY in weak emf1, but not emf2, mutants increased the severity of the emf phenotype, indicating an inhibition of EMF activity by LEAFY, as was deduced from double mutant analysis. These results suggest that a mechanism involving a reciprocal negative regulation between the EMF genes and the floral genes regulates Arabidopsis inflorescence development.