[Hemi-atlas: report of five cases]. / Hemi-atlas: presentación de cinco casos,

C1 partial aplasia is a rare congenital deformity which can produce unacceptable progressive severe torticollis. Five such cases treated in two regional Pediatric Hospitals of Argentin are presented here. There were 4 girls and 1 boy, with a mean age of 6 years; four of them had formation defect of articular mass (Villa's Area 3) causing fixed torticollis in 3 who underwent surgery. In another case the defect consisted of a posterior hemi-arch (Area 2). Surgical procedures consisted on isolated posterior occipito-cervical arthrodesis in two cases, and associated with a posterior decompression by suboccipital craneotomy in the third, due to the presence of preoperative neurological deficit. Some internal fixation was achieved with sutures (non reabsorbibles in younger patient and wire suture in older ones). Average postoperative immobilisation with Halo-vest was 4.5 months, and it was followed with extended Philadelphia collar until complete consolidation. Non-operated patients responded to conservative therapy. Mean followup was 1 year 8 months. All patients presented correction of the deformity. The 3 surgically treated patients showed good arthrodesis and disappearance of preoperative delicit when present. In conclusion, the unilateral hipoplasias of C1 in children with unyielding deformity can be satisfactorily managed by means of CO-C2/C3 arthrodesis with or without decompression, always associated to external immobilization.

Hemi-Atlas: Presentación de cinco casos / Hemi-atlas: Report of five cases

La aplasia parcial del atlas es una malformación congénita rara que puede producir tortícolis grave, progresiva e incapacitante. Se presentan 5 casos de malformación de C1, tratados en dos Hospitales Pediátricos de la región Nordeste de la República Argentina. Material y métodos. Se trata de 4 mujeres y 1 varón, con una edad promedio de 6 años, cuatro presentaron defecto de formación de un macizo articular (Anea 3 de Villas) condicionante de tortícolis fijo, siendo en 3 de ellos irreductible y tratados col cirugía, y en un caso el hemiarco posterior (Area 2).Cuatro pacientes fueron operados. En 3 de ellos se realizó Artrodesis Occipito-Cervical posterior, pura en dos casos, y asociada a descompresión posterior por craneotomía suboccipital en el tercero, debido a la existencia de déficit neurológico. Estos 3 pacientes fueron equipados con Halo-Chaleco postoperatorio por 4 '/z meses, continuando con collarín hasta la consolidación. El cuarto caso fue operado con Artrodesis Posterior in situ, por una hemivértebra cérvico-dorsal asociada. Un caso recibió sólo terapia de reeducación. Resultados. El seguimiento promedio fue de 1 año 8 meses. Los 5 pacientes presentaron corrección de la deformidad. Los 4 operados mostraron una sólida artrodesis, y desaparición del déficit preoperatorio cuando el mismo estaba presente. Conclusión. Las hipoplasias de C1 con agenesia unilateral de macizo articular en niños pueden tratarse satisfactoriamente, en caso de deformidad irreductible, con Artrodesis CO-C2/C3 con o sin descompresión y siempre asociadas a inmovilización externa. Es importante valorar y tratar otras malformaciones raquídeas asociadas cuando existen, como las hemivértebras de diferentes localizaciones (AU)

Stab injury of the spinal cord surgically treated.

The authors report a case of thoracic spinal cord stab injury with neurologic impairment that was treated surgically after injury. A literature review and case analysis indicate that surgical extraction of foreign bodies retained within the spinal canal is indicated to avoid infection, delayed myelopathy, and neurologic loss. The amount of motor and functional recovery for incomplete injuries after spinal cord stab wound can be strikingly good despite pathologic changes to severely damaged areas, and removal of retained intraspinal metallic fragment can improve this neurologic outcome. Open removal of the knife seems preferable to avoid bleeding and infection.

Clubfoot surgical treatment: preliminary results of a prospective comparative study of two techniques.

Twenty patients with 30 idiopathic resistant clubfeet were operated on by the same surgeon. The mean patient age was 7.7 months (range, 3.5-19 months). Two different surgical techniques (15 posteromedial release and 15 complete circumferential subtalar release) were used during a prospective randomized study. Average follow-up was 2 years 3 months. None of the children had received previous conservative treatment. Radiologic assessment on lateral and anteroposterior radiographs included preoperative and follow-up measurements of tibiotalar, tibiocalcaneal, talocalcaneal, talo-I meta, and calcaneo-V meta angles, as well as physis morphology, talocalcaneal divergence, and location of the navicular. Before surgery, both groups were statistically similar as assessed by the Student t test. Follow-up results were also statistically similar between the groups. Functional assessment, according to Magone's score, showed global average excellent and good results in 23 feet (76.7%), with a slight but not significant difference (P = 0.77) between the two techniques. At short-term follow-up, no significant differences were found in radiologic and functional results between the two surgical procedures for idiopathic clubfoot.

Chordoma of the lumbar L2 vertebra: case report and review of the literature.

We report four new cases of chordoma of "the mobile spine", all at the L2 level. Diagnosis was often delayed due to predominantly nonspecific low back symptoms; however, neurological involvement is more frequent than in chordoma with a sacrococcygeal localization. No pathognomonic images have been described for any imaging modality, and differential diagnosis should include metastases, chondrosarcoma, and giant-cell tumor. Histopathological analysis can be performed on CT-guided puncture biopsy samples, but a high level of suspicion must be present and, if there is any doubt, immunohistochemical studies should be carried out. Despite being the treatment of choice, complete tumor resection by a double-approach spondylectomy is barely feasible at the L2 level.

DECIDE: a software for computer-assisted evaluation of diagnostic test performance.

The evaluation of the performance of clinical tests is a complex problem involving different steps and many statistical tools, not always structured in an organic and rational system. This paper presents a software which provides an organic system of statistical tools helping evaluation of clinical test performance. The program allows (a) the building and the organization of a working database, (b) the selection of the minimal set of tests with the maximum information content, (c) the search of the model best fitting the distribution of the test values, (d) the selection of optimal diagnostic cut-off value of the test for every positive/negative situation, (e) the evaluation of performance of the combinations of correlated and uncorrelated tests. The uncertainty associated with all the variables involved is evaluated. The program works in a MS-DOS environment with EGA or higher performing graphic card.

[Prevention of hip dislocation in children with cerebral palsy by early tenotomy of the adductor and psoas muscles]. / La prévention de la luxation de hanche, chez l'enfant infirme moteur d'origine cérébrale, par ténotomie précoce des adducteurs et du psoas.

The effectiveness of early tenotomy of the psoas and adductor muscles for the prevention of dislocation of the hip dislocation in children with cerebral palsy precluding walking was studied in 40 hips in 24 children with severe disability. Age at the time of the procedure ranged from 1 1/2 years to 10 years. Results were evaluated by measuring Reimers' migration percentage (MP). Mean follow-up was three years. A satisfactory outcome (at least 10% improvement in MP at last follow-up) was seen in 67% of cases. The study of correlations with age and degree of displacement at surgery showed that results were satisfactory in 90% of children who had surgery before 4 years of age and whose MP was under 33%. To have preventive value, this procedure should be carried out at 2 years of age, before development of dislocation of the hip.

The imprecision profile in immunoassay. A study using a resampling technique.

A resampling ('bootstrap') technique was applied to assess the reliability of the calculated imprecision profile (IP), as obtained from the dose/response curve and the response/error relationship (RER) using the cumulative data relative to two assays, i.e. a T4 radioimmunoassay (RIA) and a TSH immunofluorometric assay (IFMA), both run in duplicate. Mean values and the related uncertainty of the estimated dose errors were compared for different RER fitting conditions and different sizes of the duplicate response sets. The following observations were made: (a) compared to the maximum-likelihood procedure, the least-square fit proved to be unsuitable for estimating the parameters in the general RER equation variance(R) = aRb (where R indicates the response), (b) the simplifying assumption of a within-method constancy of the exponent in the RER equation, while acceptable for the T4 RIA, did not hold in the case of the TSH IFMA implying a much wider response range, (c) for both assays, response sets of ca. 100 duplicates were apparently compatible with an acceptable definition of the IP (+/- 10 to +/- 20% uncertainty).

[Surgical treatment of dislocations and subdislocations of the hip in patients with cerebral palsy by femoral and pelvic osteotomy]. / Le traitement chirurgical des luxations et subluxations de hanche chez l'IMC par ostétomie fémorale et pelvienne.

Fifty-one skeletally immature cerebral palsied (C.P.) children with 70 subluxated or dislocated hips were treated by conservative methods: femoral osteotomy (65 hips), pelvic osteotomy (52 hips) and arthrotomy when necessary (19 cases). 31 children were less than 10 years of age when operated on (mean 6 years, 6 months), 20 children were more than 10 years of age (mean 13 years, 13 months); mean follow-up was 4 years. Reduction and coverage were achieved and maintained in all patients, except for 6 redislocations: a pelvic obliquity was neglected in 3 cases; femoral shortening was not performed in 2 cases. Post-operative course was difficult in eldest patients with pain and stiffness but functional result was acceptable at follow-up in all cases except redislocations. Open reduction was related to a higher rate of postoperative rehabilitation problems. Modeling of previously deformed femoral heads and improvement of hip mobility were consistently seen at last follow-up, except for 3 redislocations. It is concluded that conservative methods are quite advisable in CP children and adolescents. Hip reduction should be preferred to femoral resection even in adolescent.

[Surgical treatment of scoliosis in bed-ridden patients with cerebral palsy]. / Le traitement chirurgical des scolioses de l'IMC grabataire.

Thirty-two scoliosis in total body involved children with cerebral palsy (CP) were reviewed. Mean preoperative angle was 13. Average follow-up was four years. Surgery included a single posterior (11 cases) or anterior (3 cases) approach and a double stage anterior and posterior procedure in 18 cases. Fusion was extended to the sacrum in 15 cases. Complications were numerous: 3 deaths, 15 postoperative complications in 10 patients. Most of them were septic and cutaneous. Cobb angle was 78 degrees before surgery, 28 degrees after surgery and 32 degrees at follow-up. Functional status was improved in most of cases. Pain disappeared in 2/3 of cases. Sitting position was acquired in all cases at follow-up; motor possibilities were improved in 1/4 of cases; associated medical pathologies (mainly respiratory) were reduced in 2/3 of cases.

Prevention of hip dislocation in cerebral palsy by early psoas and adductors tenotomies.

The effectiveness of psoas and adductor tenotomies for the prevention of hip dislocation was investigated in 40 hips of 24 total-body-involved children. Age at operation ranged from 1.6 to 10 years. Results were evaluated by the Reimers migration percentage (MP). Average follow-up was 3 years. An overall good result was observed in 67% of cases. Results were correlated with age and MP at operation. Successful results were obtained in 90% of patients under age 4 who had an MP less than 33%. Preventive surgery should be performed at 2 or 3 years of age, before the onset of hip dysplasia.

Assessment of response/error relationship and imprecision profile in immunoassay using computer simulation procedures.

Simulation procedures were applied to assess the response/error relationship (RER) and the imprecision profile (IP) for two model assays, a T4 RIA and a TSH IFMA both using duplicate samples. In order to define the reference functions, the mean data obtained in 10 successive experiments for dose/response curve (DR), RER and IP were employed. The following conclusions emerged from the study: (a) run sizes of ca. 100 duplicates can acceptably describe within-assay IPs, irrespective of the data distribution through the dose range; (b) the contribution of DR fitting error to the total variability of estimate can be disregarded in the case of small series but not for the larger ones; (c) the variability components related to the response error can be efficiently controlled by applying criteria based on RER parameters.

[The Chernobyl accident. Evaluation of the doses absorbed by the thyroid gland in children of a mountain community from the measurement of I131 retained activity]. / Incidente di Chernobyl. Valutazione della dose assorbita dall tiroide nei bambini di una Comunità Montana a partire dalle misure di attività ritenuta di I131.

I131 thyroid uptake after the Chernobyl's accident was sampled in a Val Pellice school. Children were grouped according to sex, age and area of residence. The procedure used in collecting data and calculating the transformation coefficients from activity counts by computer simulation is analysed, as are the errors and sensitivity of the method. The activities were then converted into doses using an intake model. The dose levels identified are lower than the estimates based on the measurement of environmental matrices. Statistical analysis revealed certain subgroups with significantly different levels of absorption: particularly groups accustomed to a different diet or living in particular areas.