Validación de test de flexión-relajación para definir un déficit lumbar con electrodos tetrapolares / Validation of the flexion-relaxation test to define a lumbar deficit with tetrapolar electrodes

Introducción y objetivo: Obtener un nuevo punto de corte (PC) para un test de flexión-relajación (FR) lumbar efectuado con electrodos (e.) tetrapolares, desde valores ya definidos con dispositivos bipolares.Materiales y métodosLa muestra del estudio consta de 47 pacientes en situación de incapacidad temporal por dolor lumbar (DL). Fueron evaluados mediante un test de dinamometría isométrica, una prueba cinemática y una valoración del fenómeno FR.Se plantean dos experimentos con curvas ROC. El primero, con 47 pacientes que efectuaron de modo consecutivo el test FR con ambos tipos de electrodos, utilizándose como variable de clasificación el punto de corte conocido para los e. bipolares (2,49uV). En el segundo, con los datos de la EMGs registrados con e. tetrapolares en 17 pacientes, se efectúa un test de DeLong que compara las 2 curvas ROC que construimos, por un lado, al clasificar la muestra desde pruebas de dinamometría y cinemática, y por el otro, al clasificarlos con los valores de la EMGs bipolar.ResultadosUn total de 34 pacientes completaron adecuadamente las valoraciones del primer experimento y 17 pacientes el segundo. El primer estudio arroja un punto de corte de 1,2uV, con un AUC del 87,7%; sensibilidad 84,2% y especificidad 80%. El segundo muestra un PC para los e. bipolares de 1,21uV (AUC 87,5%) y para los e. tetrapolares de 1,43 (AUC 82,5%) con un test de DeLong sin diferencias significativas entre ambas curvas (p>0,4065).ConclusionesLa metodología de validación con curvas ROC ha permitido obtener un nuevo PC para la prueba FR de modo práctico, simplemente simultaneando ambos test sobre el mismo grupo de pacientes hasta obtener una muestra significativa. (AU)

Introduction and objective: To obtain a new cut-off point (CP) for a lumbar flexion-relaxation (RF) test established with tetrapolar (e.) electrodes, from values already defined with bipolar devices.Materials and methodsThe study sample consists of 47 patients in a situation of temporary disability due to low back pain (DL). They were evaluated by means of an isometric dynamometry test, a kinematic test and an assessment of the FR phenomenon.Two experiments with ROC curves are proposed. The first, with 47 patients who consecutively performed the RF test with both types of electrodes, using the cut-off point (CP) known for the e. bipolar (2.49μV). In the second, with the EMG data recorded with e. tetrapolar in 17 patients, a DeLong test was performed that compares the 2 ROC curves that were constructed on the one hand, by classifying the sample from dynamometry and kinematic tests, and on the other, by classifying them with the bipolar EMG values.ResultsA total of 34 patients adequately completed the evaluations of the first experiment and 17 patients the second. The first study shows a cut-off point of 1.2μV, with an AUC of 87.7%; Sensitivity 84.2% and Specificity 80%. The second shows a PC for e. bipolars of 1.21μV (AUC 87.5%) and for e. tetrapolar values of 1.43 (AUC 82.5%) with a DeLong test without significant differences between both curves (p>0.4065).ConclusionsThe validation methodology with ROC curves has made it possible to obtain a new PC for the RF test in a practical way, simply by simultaneously performing both tests on the same group of patients until a significant sample is obtained. (AU)

[Validation of the flexion-relaxation test to define a lumbar deficit with tetrapolar electrodes]. / Validación de test de flexión-relajación para definir un déficit lumbar con electrodos tetrapolares.

INTRODUCTION AND OBJECTIVE: To obtain a new cut-off point (CP) for a lumbar flexion-relaxation (RF) test established with tetrapolar (e.) electrodes, from values already defined with bipolar devices. MATERIALS AND METHODS: The study sample consists of 47 patients in a situation of temporary disability due to low back pain (DL). They were evaluated by means of an isometric dynamometry test, a kinematic test and an assessment of the FR phenomenon. Two experiments with ROC curves are proposed. The first, with 47 patients who consecutively performed the RF test with both types of electrodes, using the cut-off point (CP) known for the e. bipolar (2.49µV). In the second, with the EMG data recorded with e. tetrapolar in 17 patients, a DeLong test was performed that compares the 2 ROC curves that were constructed on the one hand, by classifying the sample from dynamometry and kinematic tests, and on the other, by classifying them with the bipolar EMG values. RESULTS: A total of 34 patients adequately completed the evaluations of the first experiment and 17 patients the second. The first study shows a cut-off point of 1.2µV, with an AUC of 87.7%; Sensitivity 84.2% and Specificity 80%. The second shows a PC for e. bipolars of 1.21µV (AUC 87.5%) and for e. tetrapolar values of 1.43 (AUC 82.5%) with a DeLong test without significant differences between both curves (p>0.4065). CONCLUSIONS: The validation methodology with ROC curves has made it possible to obtain a new PC for the RF test in a practical way, simply by simultaneously performing both tests on the same group of patients until a significant sample is obtained.

Anatomía y diseño de colgajos musculocutáneos en reconstrucción nasal / Anatomy and Design of Musculocutaneous Flaps in Nasal Reconstruction

La nariz es una localización habitual de asiento de tumores cutáneos. Las arterias principales que vascularizan la nariz discurren en el espesor del tejido celular subcutáneo. La disección en el plano submuscular permite diseñar colgajos musculocutáneos fiables y seguros, adaptados a la morfología del defecto. Su gran versatilidad los convierte en colgajos de primera elección para la cobertura de defectos ubicados en localizaciones más complejas, como el canto interno del ojo o el ala nasal. Presentamos la técnica quirúrgica de los colgajos musculocutáneos procerus, nasalis de morfología V-Y y colgajo nasalis de pared lateral empleados tras exéresis tumorales. La descripción se acompaña de imágenes realizadas por los autores en pacientes y en disecciones cadavéricas para la mejor comprensión de dichos colgajos (AU)

The nose is a common site for skin tumors. The main arteries that supply the nose extend through the subcutaneous tissue. Submuscular dissection facilitates the design of safe, reliable musculocutaneous flaps that adapt well to the morphology of nasal defects. The diversity of these flaps makes them the first choice for reconstructing defects in more complex regions, such as the inner canthus of the eye and the nasal ala. We describe the surgical design of the procerus, V-Y nasalis, and lateral wall nasalis musculocutaneous flaps used to repair defects following tumor excision. The descriptions are illustrated by photographs taken by the authors during procedures and in cadaveric dissections (AU)

[Translated article] Anatomy and Design of Musculocutaneous Flaps in Nasal Reconstruction / Anatomía y diseño de colgajos musculocutáneos en reconstrucción nasal

The nose is a common site for skin tumors. The main arteries that supply the nose extend through the subcutaneous tissue. Submuscular dissection facilitates the design of safe, reliable musculocutaneous flaps that adapt well to the morphology of nasal defects. The diversity of these flaps makes them the first choice for reconstructing defects in more complex regions, such as the inner canthus of the eye and the nasal ala. We describe the surgical design of the procerus, V-Y nasalis, and lateral wall nasalis musculocutaneous flaps used to repair defects following tumor excision. The descriptions are illustrated by photographs taken by the authors during procedures and in cadaveric dissections (AU)

La nariz es una localización habitual de asiento de tumores cutáneos. Las arterias principales que vascularizan la nariz discurren en el espesor del tejido celular subcutáneo. La disección en el plano submuscular permite diseñar colgajos musculocutáneos fiables y seguros, adaptados a la morfología del defecto. Su gran versatilidad los convierte en colgajos de primera elección para la cobertura de defectos ubicados en localizaciones más complejas, como el canto interno del ojo o el ala nasal. Presentamos la técnica quirúrgica de los colgajos musculocutáneos procerus, nasalis de morfología V-Y y colgajo nasalis de pared lateral empleados tras exéresis tumorales. La descripción se acompaña de imágenes realizadas por los autores en pacientes y en disecciones cadavéricas para la mejor comprensión de dichos colgajos (AU)

Anatomy and Design of Musculocutaneous Flaps in Nasal Reconstruction. / Anatomía y diseño de colgajos musculocutáneos en reconstrucción nasal.

The nose is a common site for skin tumors. The main arteries that supply the nose extend through the subcutaneous tissue. Submuscular dissection facilitates the design of safe, reliable musculocutaneous flaps that adapt well to the morphology of nasal defects. The diversity of these flaps makes them the first choice for reconstructing defects in more complex regions, such as the inner canthus of the eye and the nasal ala. We describe the surgical design of the procerus, V-Y nasalis, and lateral wall nasalis musculocutaneous flaps used to repair defects following tumor excision. The descriptions are illustrated by photographs taken by the authors during procedures and in cadaveric dissections.

Bilateral subtrochanteric femoral fracture due to a very rare disease: Pycnodisostosis. / Fractura bilateral subtrocantérica de fémur debido a una enfermedad rara: la picnodisostosis.

Pycnodysostosis is a rare autosomal recessive disease caused by a mutation in the cathepsin K enzyme gene, a protease that is expressed primarily in osteoclasts and is responsible for bone matrix degradation. The presentation is usually accompanied by short stature, osteoesclerosis, craniofacial dysmorphia and bone fragility. Some papers provide surgical options for fractures of long bones in this type of patients, but none are presenten in European Caucasian patients. The case presented is of a Spanish Caucasian European male with bilateral femoral fracture treated by endomedular nailing.

[The lumbar flexion-relaxation phenomen as a diagnostic test in assessment of lumbar impairment. Sensitivity and specificity]. / El fenómeno de flexión-relajación lumbar como test diagnóstico en la evaluación de un déficit lumbar. Sensibilidad y especificidad.

OBJECTIVE: To define the role of the flexion-relaxation phenomenon (FRP), assessed through ratios (FRR), as a diagnostic test to define impairment in patients with chronic low back pain (CLBP). MATERIAL AND METHOD: The study sample consisted of 180 participants (16 healthy volunteers and 164 patients on work disability due to CLBP), who were consecutively referred for evaluation at the Biomechanics Laboratory of a workplace accident insurance company from January 2012 to December 2017. The evaluations consisted of an isometric dynamometry test, a kinematic test and assessment of the FRP phenomenon. Minimum criteria were established in the performance of the tests for their acceptance as valid for the study. Lumbar impairment or clinical recovery was defined on the basis of the results of the dynamometry and kinematic tests. The FRP response was assessed with FRRs. A total of 4 different ratios were taken for analysis with ROC curves. RESULTS: A total of 86 valid tests were obtained (16 classified as lumbar impairment and 71 as recovered cases). The best ratio obtained an area under the ROC curve of 0.87, with a sensitivity of 0.84, a specificity of 0.87, and a positive predictive value of 97%. CONCLUSIONS: The FRP test, along with dynamometry and kinematic evaluations, is effective in identifying lumbar impairment and is the easiest test for patients with CLBP to perform.

Morphology and molecular systematic of marine gregarines (Apicomplexa) from Southwestern Atlantic spionid polychaetes.

Gregarines are a common group of parasites that infect the intestines of marine invertebrates, and particularly polychaetes. Here, we describe for the first time four gregarine species that inhabit the intestines of three spionid species: Dipolydora cf. flava, Spio quadrisetosa and Boccardia proboscidea from the Patagonian coast, Argentina, using light and scanning electron microscopy and molecular phylogenetic analyses of small subunit (SSU) rDNA sequences. Even though the spionid species thrive in the same environments, our results showed a high host specificity of the gregarine species. Selenidium cf. axiferens and Polyrhabdina aff. polydorae were both identified from the intestine of D. cf. flava. The new species, Polyrhabdina madrynense sp. n. and Selenidium patagonica sp. n., were described from the intestines of S. quadrisetosa and the invasive species B. proboscidea, respectively. All specimens of D. cf. flava and S. quadrisetosa were infected by gregarines (P = 100%), recording the highest mean intensity values of infection (MI = 80; 60 respectively), in contrast to B. proboscidea (P = 60%; MI = 38). We associated this finding with the recent invasion of this host. It is expected that in the future, an increase of its population density might favour a rising intensity of this gregarine infection.

Pearls in the ribbed mussel Aulacomya atra caused by polydorin polychaetes (Spionidae) infestation.

Aulacomya atra populations of the San Jose gulf, Northern Patagonia, Southwestern Atlantic Ocean, are infested by two polydorin species, Polydora rickettsi and Dipolydora cf. giardi. The infestation by these boring polychaetes causes the formation of pearls which is evidenced by the presence of capsules containing polydorin tissue debris and the elemental composition of organic material inside the pearls. Moreover, a positive relationship between the abundance of perforations of polydorin polychaetes and abundance of pearls was found by applying generalized lineal model analysis. These results constitute the first evidence of pearls formation due to infestation by polychaete.

Shell damage in the Tehuelche scallop Aequipecten tehuelchus caused by Polydora rickettsi (Polychaeta: Spionidae) infestation.

The different types of shell damage caused to the commercially valuable Tehuelche scallop (Aequipecten tehuelchus) by the polychaete Polydora rickettsi are described. X-rays, computerized tomography, shell sections, scanning electron microscopy, Energy Dispersive X-ray analysis (EDAX), mineralogical analyses and geometric morphometrics were applied to that end. Scallop shells presented three types of damage: (1) spots, (2) calcareous alterations, and (3) mud blisters. Microstructural alterations consisted of a simple conchiolin membranous layer in the case of spots, a series of interleaved layers of different degree of calcifications in calcareous alterations, and two different surface morphologies (muddy and mucous layers) in mud blisters. Damage was localized mainly along concentric growth rings, coincidentally with the location of most burrows, as shown by X-ray. Mineralogical analysis showed that in all cases (including non-infested shells) calcite was the calcium carbonate polymorph present. Geometric morphometrics showed that only 5% of shape variation was explained by infestation with P. rickettsi, irrespective of the type of damage. Number of worms per infested shell varied significantly among four beds. Left shells (upward-oriented) were significantly more affected than right shells, which are in closer contact with the bottom.