Influencia de la posición de la cabeza femoral en el desarrollo acetabular / Influence of femoral head positioning upon acetabular development

Objetivo: Analizar las alteraciones que las diferentes osteotomías femorales proximales provocan sobre la morfología acetabular. Material y método: Se intervinieron 30 corderos, de tres meses de edad, divididos en cinco grupos: grupo 1, se efectuó una osteotomía varizante de fémur sin modificar la versión femoral; grupo 2, una osteotomía valguizante de fémur sin modificar la versión femoral; grupo 3, una osteotomía derrotatoria de fémur, disminuyendo la anteversión femoral sin modificar el ángulo cérvico-diafisario; grupo 4, una osteotomía derrotatoria de fémur, aumentando la anteversión femoral sin modificar el ángulo cérvico-diafisario; y grupo 5 o control. El sacrificio se realizó a los tres meses de la intervención y se midió la morfología acetabulo-femoral. Resultados: La versión femoral del lado intervenido no se correlacionó ni con la diferencia entre el diámetro acetabular antero-posterior derecho e izquierdo, ni con la diferencia entre el diámetro acetabular infero-superior derecho e izquierdo, ni con la diferencia entre el volumen acetabular derecho e izquierdo. El ángulo cérvico-diafisario intervenido se correlacionó con la diferencia entre el volumen acetabular derecho e izquierdo (p=0,023), siendo menor la diferencia entre el volumen acetabular derecho e izquierdo cuanto mayor era el ángulo cérvico-diafisario. Conclusión: Un ángulo cérvico-diafisario disminuido provoca un aumento del volumen acetabular. Por lo tanto, la osteotomía varizante de fémur podría utilizarse para mejorar el volumen acetabular (AU)

Objective: To analyze the alterations produced by the different proximal femoral osteotomies upon acetabular morphology. Material and methods: Thirty 3-month-old lambs were divided into 5 groups: group 1 (varus osteotomy of the femur without modifying femoral version), group 2 (valgus osteotomy of the femur without modifying femoral version), group 3 (derotation osteotomy of the femur, reducing femoral anteversion without modifying the neck-diaphyseal angle), group 4 (derotation osteotomy of the femur, increasing femoral anteversion without modifying the neck-diaphyseal angle), and group 5 (control). The animals were sacrificed three months after the operation and the acetabular and femoral morphology was measured. Results: Femoral version on the operated side was not correlated to the difference between the right and left anteroposterior acetabular diameter, the difference between the right and left inferosuperior acetabular diameter, or the difference between the right and left acetabular volume. The operated neck-diaphyseal angle was correlated to the difference between the right and left acetabular volume (p = 0.023) - the difference in volume decreasing with increasing neck-diaphyseal angle. Conclusion: A diminished neck-diaphyseal angle results in an increased acetabular volume. Therefore, varus osteotomy of the femur could be used to improve the acetabular volume (AU)

[Dysplasia in the development of the hip]. / Displasia del desarrollo de la cadera.

Developmental dysplasia of the hip (DDH) causes anatomical changes that cause early coxarthrosis. Although risf factors have been determined, the aetiology and physiopathology remains exactly unknown. Neonatal screening with physical examination and ultrasound have been stablished in order to diagnose this disease early in life. A diagnosis in the first months of life is essential as it enables a normal hip to form and prevent the appearance of early coxarthrosis. Treatment principles are to be able to reduce the hip without provoking avascular necrosis of the femoral head, and to normalize the acetabular development. Knowledge of the orthopaedic and surgical options is essential in order to achieve success in the treatment.

Displasia del desarrollo de la cadera / Dysplasia in the development of the hip

La displasia del desarrollo de la cadera provoca cambios anatómicos que dan lugar a una coxartrosis precoz. La etiología y la patofisiología de la displasia de cadera no se conocen con exactitud, aunque se han determinado factores de riesgo. Se han establecido programas de despitaje neonatal clínicos y ecográficos que lleven a un diagnóstico precoz de esta afección. Un diagnóstico en los primeros meses de vida es fundamental porque permite obtener una cadera normal y evitar la aparición de una coxartrosis precoz. El tratamiento debe conseguir reducir la cadera, evitando la aparición de una necrosis avascular de la cabeza femoral, y normalizar el desarrollo del acetábulo. Existen opciones ortopédicas y quirúrgicas que deben ser conocidas para lograr un éxito en el tratamiento (AU)

Developmental dysplasia of the hip (DDH) causes anatomical changes that cause early coxarthrosis. Although risf factors have been determined, the aetiology and physiopathology remains exactly unknown. Neonatal screening with physical examination and ultrasound have been stablished in order to diagnose this disease early in life. A diagnosis in the first months of life is essential as it enables a normal hip to form and prevent the appearance of early coxarthrosis. Treatment principles are to be able to reduce the hip without provoking avascular necrosis of the femoral head, and to normalize the acetabular development. Knowledge of the orthopaedic and surgical options is essential in order to achieve success in the treatment (AU)

On-line strategies for determining trace levels of nitroaromatic explosives and related compounds in water.

We report the development and tests of several systems for the simultaneous determination of 18 energetic compounds and related congeners in untreated water samples. In these systems a Restricted Access Material trap or liquid-chromatography precolumn (with a C(18) or porous graphitic carbon, PGC, stationary phase) followed by a PGC analytical column are used for sample clean-up, enrichment and separation of the trace level analytes, which are then analyzed by mass spectrometry (MS). The relative merits of two MS ionization interfaces (atmospheric pressure chemical ionization, APCI, and atmospheric pressure photoionization, APPI) were also compared for the MS identification and quantification of these analytes. APCI was found to be superior in cases where both alternatives are applicable. A major drawback when applying APPI is that no signal is obtained for the cyclic nitramines and nitrate esters. Using APCI, a wide spectrum of unstable compounds can be determined in a single analysis, and the feasibility of using large volume samples (up to 100 mL) in combination with the sensitivity of the MS detection system provide method detection limits ranging from 2.5 pg/mL (for 2,4-dinitrotoluene and 2,6-diamino-6-nitrotoluene) to 563 pg/mL (for pentaerythritol tetranitrate, PETN), with repeatability ranging from 2 to 7%. Other chemometric parameters such as robustness, selectivity, repeatability, and intermediate precision were also evaluated in the validation of the extraction methods for use in water analysis. Tests with untreated groundwater and drinking water samples, spiked with 20 ng of the analytes, yielded results similar to those obtained with high purity water samples.

Acetabular dysplasia after treatment for developmental dysplasia of the hip. Implications for secondary procedures.

Untreated acetabular dysplasia following treatment for developmental dysplasia of the hip (DDH) leads to early degenerative joint disease. Clinicians must accurately and reliably recognise dysplasia in order to intervene appropriately with secondary acetabular or femoral procedures. This study sought early predictors of residual dysplasia in order to establish empirically-based indications for treatment. DDH treated by closed or open reduction alone was reviewed. Residual hip dysplasia was defined according to the Severin classification at skeletal maturity. Future hip replacement in a subset of these patients was compared with the Severin classification. Serial measurements of acetabular development and subluxation of the femoral head were collected, as were the age at reduction, type of reduction, and Tonnis grade prior to reduction. These variables were used to predict the Severin classification. The mean age at reduction in 72 hips was 16 months (1 to 46). On the final radiograph, 47 hips (65%) were classified as Severin I/II, and 25 as Severin III/IV (35%). At 40 years after reduction, five of 43 hips (21%) had had a total hip replacement (THR). The Severin grade was predictive for THR. Early measurements of the acetabular index (AI) were predictive for Severin grade. For example, an AI of 35 degrees or more at two years after reduction was associated with an 80% probability of becoming a Severin grade III/IV hip. This study links early acetabular remodelling, residual dysplasia at skeletal maturity and the long-term risk of THR. It presents evidence describing the diagnostic value of early predictors of residual dysplasia, and therefore, of the long-term risk of degenerative change.

Contribución al estudio de la luxación congénita de la rótula. Comentario / Contribution to the study of congenital patellar dislocation. Comment

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Evaluation of some screening methods for the analysis of contaminants in recycled polyethylene terephthalate flakes.

A range of different analytical techniques were used to test recycled polyethylene terephthalate (PET) flakes for potential chemical contaminants. The techniques used were headspace gas chromatography coupled to mass spectrometry (GC-MS), liquid extraction followed by GC-MS, supercritical-fluid extraction followed by GC-MS, and migration testing followed by elemental analysis using inductively coupled plasma mass spectroscopy (ICP-MS). The PET samples were 50 representative samples taken from 600 that had been collected throughout Europe and which had been screened for potential contaminants using a single technique of high-temperature GC-MS. Six of the 50 samples tested had been spiked with a selection of model contaminants, three samples were virgin PET flakes and two of the samples were from supercleaning processes. All samples were analysed 'blind' in this exercise. The qualitative results showed that most of the contaminants came from the first use, being flavour-aroma compounds from soft drinks. The quantitative analysis found concentrations under a few mg kg(-1) in the polymer, except for the spiked samples. Element migrations were low and only calcium, silicon and sodium had median migrations above 50 microg l(-1). This in-depth analysis of recycled PET flakes did not identify any significant contaminants that had not already been detected by the high-temperature static GC-MS screening method, thus demonstrating its utility.

Femoral fractures in children from 4 years to 10 years: conservative treatment.

Some authors have widened the indications for surgical management of isolated femoral shaft fractures in children between 4 years and 10 years of age. We address this study to evaluate the results of such femoral fractures treated conservatively in 41 children. All fractures were closed, isolated, and diaphyseal. The mean age was 6.5 years (standard deviation, 1.7 years) and the mean follow-up was 2.3 years (standard deviation, 1.7 years). All fractures were managed conservatively with skin traction (mean hospitalization time, 20.7 days), alignment of the fragments was serially followed by X-ray, and a spica cast was applied (9.7 weeks), usually without a general anesthesia. Angular deformity was assessed by measurement of the fracture-site diaphyseal angle as well as by measurement of the interphyseal angle described by Wallace and Hoffman. No significant complications were recorded regarding leg-length discrepancy, deformity, refractures, etc. Mean cost is not a factor in determining method of treatment at our hospital. We feel that this type of fracture in the 4 years to 10 years age group can be safely treated with a conservative approach.

Osteotomías de cadera en la parálisis cerebral / Hip osteotomy in cerebral palsy

Se han revisado 49 casos de subluxación o luxación de cadera espástica en pacientes tetraparéticos mayoritariamente, tratados mediante osteotomías femorales, femorales y pélvicas u osteotomía femoral con reducción abierta. Se evaluó radiológicamente cada cadera antes y después de la cirugía con un seguimiento medio de 31 meses, valorando el valgo femoral, el grado de cobertura, el porcentaje de epífisis femoral descubierta y el grado de displasia acetabular. Los pacientes menores fueron tratados con una osteotomía femoral que mejoró la cobertura pero no la displasia acetabular (n = 23). Los casos tratados con ambas osteotomías, mejoraron ambas variables (n = 21). La reducción abierta se indicó en aquellos casos en los que la cadera estaba completamente luxada (n = 5) (AU)

Pediatric stress fractures.

Stress fractures in children are uncommon. This report describes the findings of 8 cases in 6 children. One patient had 3 stress fractures: 2 consecutive midshaft stress fractures of the same tibia associated with one of the fibula. Signs and symptoms may be misdiagnosed as malignant tumors or osteomyelitis. Serial radiographs and computed tomography scans are the key to the diagnosis, although bone scan and magnetic resonance imaging can be helpful. Biopsy is unnecessary and might even be misleading.

Unusual finding after contrast injection of a solitary bone cyst. A case report.

Injection of radiopaque contrast into a solitary bone cyst (SBC) prior to methylprednisolone acetate (MPA) injection has been previously reported. We report an unusual finding during the injection of radiopaque contrast in the treatment of one case of SBC of the femur: a bicameral appearance of the cyst was observed; no filling of the proximal cavity occurred and immediate perfusion of the femoral vein with contrast was noted. In cases of SBC such as this one, percutaneous autologous marrow or corticosteroid injection may fail to be effective. Furthermore there exists the potential risk of fat embolus secondary to bone marrow injection. Based on these findings in the case reported, we suggest that contrast injection should be performed prior to bone marrow or corticosteroid injection in order to evaluate both the venous drainage of the cyst and its degree of loculation.

Patellar height ratios in children: an interobserver study of three methods.

Several indices for patellar height measurement have been described to relate patellofemoral instability and maltracking. No known study has proved interobserver reliability of these indices when applied to growing knees. This study included comparisons of three of these indices: Caton-Deschamps, Blackburne-Peel, and Koshino. Three observers measured patellar height on 36 lateral radiographs of children's knees. The best interobserver agreement was achieved by the Caton-Deschamps method, a simple, reliable, and reproducible index that is not affected by skeletal maturation.

Results after preoperative traction and pinning in slipped capital femoral epiphysis: K wires versus cannulated screws.

We have retrospectively reviewed 53 cases (62 hips) with a diagnosis of slipped capital wedge epiphysis. After admission to our Hospital, a skin longitudinal traction was applied for 2 weeks, All patients were treated afterward with pinning in situ without manipulation in the operating room. Group A (31 hips) consisted of patients treated with smooth K wires and group B (31 hips) of patients treated with cannulated screws. We found a high incidence of pin penetration in group A (27 hips), whereas there was just one case in group B. Physical closure was considered when 75% of proximal growth plate disappeared in the frog lateral view and both groups showed similar values (7 months). Chondrolysis was observed in just three cases in group A, and one case had an avascular necrosis. Few complications were observed compared with the high rate of pin penetration, and we suggest that preoperative traction may be a relevant factor contributing to the low incidence of avascular necrosis (1.6%).

Correlative study between arthrograms and surgical findings in congenital dislocation of the hip.

The arthrogram plays an important role in the diagnosis and treatment of congenital dislocation of the hip (CDH), because congrous reduction has been related with hip outcome. We have reviewed 29 children younger than 1 year of age (34 hips) diagnosed and treated in our hospital for CDH, and we have recorded three radiologic parameters: acetabular index, acetabular floor thickness, and grade of dislocation. We also have evaluated three surgical and arthrogram findings (limbus, ligamentun teres, and transverse ligament) in order to study their statistical correlation, and consequently, to evaluate arthrogram usefulness. Results show a significantly high acetabular index and floor thickness as secondary to absence of femoral head.

Five additional cases of local fibrocartilaginous dysplasia.

Focal fibrocartilaginous dysplasia has previously been described as an etiology of genu varum deformity in children at about walking age. We have found 20 cases in the literature, and all of them were located in the medial proximal tibial metaphysis. We report five additional cases of this entity. The patients had a genu varum deformity, and the angulation was at the site of the bone lesion. Four cases were in the tibia, and one case was in the distal medial femoral metaphysis. Age at diagnosis ranged from 13 to 24 months. A cortical defect with surrounding sclerosis was observed on radiographs. The angulation usually progressed initially, and spontaneous resolution was observed in two cases at last follow-up. Open biopsy and tibial valgus osteotomy were performed in two cases. The unusual femoral case was also treated with open biopsy and medial hemicircumferential periosteal release. Spontaneous remodeling of varus angulation and resolution of bony defect may be expected in most cases, and osteotomy can be avoided.

The teardrop in congenital dislocation of the hip diagnosed late. A quantitative study.

We retrospectively reviewed the radiographs of the pelvis and hips of forty-five patients who had unilateral congenital dislocation of the hip treated with closed reduction and application of a cast without subsequent operations. The radiographs were made at the time of the initial diagnosis, two years after the reduction, when the child was ten years old, and at skeletal maturity. The width, shape, and type of the teardrop; the thickness of the acetabular floor; the acetabular index; the center-edge angle; the articulotrochanteric distance; and the Severin class at maturity were measured in the dislocated and contralateral, normal hips. At the time of the initial diagnosis, a well defined teardrop was seen in thirty-six (80 per cent) of the normal hips and in seven (16 per cent) of the dislocated hips. There was no difference in the width of the teardrop in the seven dislocated hips compared with that in the normal hips, although the v-shaped and crossed types of teardrops were more frequent in the dislocated hips. The v shape was not observed in the normal hips but was seen in sixteen dislocated hips two years after the reduction and in twelve dislocated hips when the children were ten years old. The superior and inferior widths of the teardrop of the dislocated hips were significantly greater than those of the normal hips (p < 0.001 and p < 0.05, respectively) when the children were ten years old. The hips with residual acetabular dysplasia had a v-shaped teardrop, widening of the superior width of the teardrop, and thickening of the acetabular floor. These hips, which were usually Severin class IV at the time of skeletal maturity, had a poor prognosis in adult life.

Congenital hypoplasia of the fibula: clinical manifestations.

We describe five cases of congenital hypoplasia of the fibula and the clinical appearance of the patients. The more relevant clinical manifestation is leg length discrepancy, which is usually < 6 cm. The management of this problem has been approached with predictive tables and timing of the epiphyseodesis. Some cases have been treated with tibial lengthening to correct the associated valgus deformity simultaneously. The valgus deformity is secondary to the hypoplasia of the lateral femoral condyle, which can be treated with medial hemiepiphysiodesis of the distal femur. Anterior instability of the knee usually exists due to congenital absence of the anterior cruciate ligament and can complicate lengthening procedures. The hip joint is not involved, but mild shortening of the femur was observed in four cases. Ball and socket joint at the ankle and tarsal coalitions with absent lateral rays of the foot can occur. Management of the leg length discrepancy must be considered in light of all these possible associated defects.

Early posttraumatic physeal arrest in distal radius after a compression injury.

Early posttraumatic arrest of the distal radial physis is an uncommon complication and usually appears after type II physeal injury. We report a 13-year-old boy who sustained an injury to his right wrist, incurring an avulsion fracture of ulnar styloid process. Twenty-one months later, a uniform closure of the distal radial physis was observed. An ulnar shortening osteotomy and distal ulnar epiphysiodesis were performed. We discuss different factors of this complication, but crush injury of germinal cells of the growthplate is considered the main etiology.

Radiologic pelvic asymmetry in unilateral late-diagnosed developmental dysplasia of the hip.

Eighty-three cases of unilateral late-diagnosed (older than 4 months of age) developmental dysplasia of the hip (DDH) were studied to evaluate pelvic shape and innominate bone relationships in the initial anteroposterior radiograph. To be included, each initial radiograph had to have no lumbar pedicle rotation, lumbar scoliosis, gas shadows, or metallic protectors. Measurements were done using as reference a medial pelvic line, which divides the pelvis into two innominate bones. Lineal parameters were defined to assess pelvic radiologic shape; angular parameters defined the relationship between the ilium, ischium and pubis, and sacrum. Statistically significant differences were observed in most cases, and pelvis asymmetry was evident. The asymmetry was more obvious in cases in which the teardrop had a negative value and in low dislocations. Similar changes have been observed in experimental dislocation of the hip secondary to a triplane pelvic deformity. We suggest that similar alterations of pelvic shape occur in DDH, possibly secondary to growth disturbance in the triradiate cartilage.

Femoral head avascular necrosis associated with metaphyseal aneurysmal bone cyst.

A 12-year-old girl had an aneurysmal bone cyst in the proximal femoral metaphysis simultaneously with an avascular necrosis of the femoral head, as seen on radiological examination. No extension of the lesion across the growth plate into the femoral epiphysis was observed. The expansive behavior of this lesion (ABC) could have compromised the posterosuperior vascular supply of the femoral epiphysis, since no radiographic signs of fractures could be found. Vascular anomalies within the lesion that increase venous pressure could be another factor responsible for the decrease in the blood supply of the femoral epiphysis and could cause necrosis, hence compromising the morphology of the hip joint at maturity.