Frozen cancellous bone allografts: positive cultures of implanted grafts in posterior fusions of the spine.

We have carried out a study on the behaviour pattern of implanted allografts initially stored in perfect conditions (aseptically processed, culture-negative and stored at -80 degrees C) but which presented positive cultures at the implantation stage. There is no information available on how to deal with this type of situation, so our aim was to set guidelines on the course of action which would be required in such a case. This was a retrospective study of 112 patients who underwent a spinal arthrodesis and in whom a total of 189 allograft pieces were used. All previous bone and blood cultures and tests for hepatitis B and C, syphilis and HIV (via PCR techniques) were negative. The allografts were stored by freezing them at -80 degrees C. A sample of the allograft was taken for culture in the operating theatre just before its implantation in all cases. The results of the cultures were obtained 3-5 days after the operation. There were 22 allografts with positive culture results (12%) after implantation. These allografts were implanted in 16 patients (14%). Cultures were positive for staphylococci coagulase negative (ECN) in 10 grafts (46%), Pseudomonas stutzeri in two grafts (9%), Corynebacterium jeikeium in two grafts (9%), staphylococci coagulase positive in two grafts (9%) and for each of the following organisms in one case each (4%): Corynebacterium spp., Actinomyces odontolyticus, Streptococcus mitis, Peptostreptococcus spp., Rhodococcus equi and Bacillus spp. No clinical infection was seen in any of these patients. Positive cultures could be caused by non-detected contamination at harvesting, storing or during manipulation before implantation. The lack of clinical signs of infection during the follow-up of our patients may indicate that no specific treatment different from our antibiotic protocol is required in the case of positive culture results of a graft piece after implantation.

Positive culture in allograft ACL-reconstruction: what to do?

The transmission of disease or infection from the donor to the recipient is always a risk with the use of allografts. We carried out a research study on the behavioural pattern of implanted allografts, which were initially stored in perfect conditions (all cultures being negative) but later presented positive cultures at the implantation stage. Because there is no information available on how to deal with this type of situation, our aim was to set guidelines on the course of action which would be required in such a case. We conducted a retrospective study of 181 patients who underwent an ACL reconstruction using BPTB allografts. All previous bone and blood cultures and tests for hepatitis B and C, syphilis and HIV were negative. An allograft sample was taken for culture in the operating theatre just before its implantation. The results of the cultures were obtained 3-5 days after the operation. We had 24 allografts with positive culture (13.25%) after the implantation with no clinical infection in any of these patients. Positive cultures could be caused by undetected contamination while harvesting, storing or during manipulation before implantation. The lack of clinical signs of infection during the follow-up of our patients may indicate that no specific treatment-other than an antibiotic protocol-would be required when facing a case of positive culture of a graft piece after its implantation.

Espondilodiscitis cervicales / Cervical spondylodiscitis

Se revisaron nueve casos de discitis infecciosas de localización cervical de una serie de ochenta pacientes con espondilodiscitis (10 por ciento). Se valoraron mediante historia clínica, analítica y radiología simple todos ellos. Además, seis de ellos se valoraron por Resonancia Magnética, tres por gammagrafía ósea, y un caso por punción-biopsia. Los factores predisponentes eran claros en seis de los pacientes, encontrando entre ellos tres sepsis por Stafilococcus aureus, dos intervenciones quirúrgicas previas sobre columna cervical y una insuficiencia renal crónica terminal en tratamiento con hemodiálisis. Sólo uno de los pacientes se complicó al presentar secundariamente afectación neurológica con resultado de tetraplejía flácida. Se llevó a cabo tratamiento médico con antibioterapia e inmovilización con collarín en siete casos; en dos casos se realizó tratamiento quirúrgico mediante limpieza del foco y artrodesis (uno de ellos con descompresión medular) además del tratamiento médico. En aquellos pacientes tratados conservado ramente mediante tratamiento médico y ortopédico la evolución fue hacia la curación con anquilosis vertebral (fusión) en cinco de ellos, y en uno hacia discopatía artrósica crónica. Los pacientes tratados quirurgicamente evolucionaron hacia artrodesis estable, aunque uno de ellos, el que tenía comprometida la función neurológica con tetraplejía, no la recuperó.Mediante esta revisión pretendemos plantear la dificultad diagnóstica y el riesgo potencial de las infecciones cervicales (AU)

[Congenital synostoses of the tarsus. Concept, classification, diagnosis and therapeutic approach]. / Sinostosis congénitas del tarso. Concepto, clasificación, diagnóstico y planteamiento terapéutico.

The incidence of congenital tarsal coalition is about 1%. It is recognized as the main etiology of painful, rigid flatfoot in the pediatric population. Talonavicular (50%) and talocalcaneal (40%) coalition are the most common presentation. We must suspect a tarsal coalition in a child with mechanical pain and shoes deformity. Rigid and painful planovalgus deformity are found in physical exam which led to describe in the pass this entity as peroneal spastic flatfoot. Lateral and oblique (35 degrees-45 degrees) radiographs must be practice to observe the coalition. The presence of a beak in the head of the talus or a half moon condensation image as the result of the superposition of the talus over the calcaneus are commonly described. CT-scan is also useful to delineate the size of the coalition and its location. Resection of the bar is the surgical treatment of choice. Excision of the coalition and interposition of fat or a graft must be tried in young patients in order to preserve foot biomechanical properties and to avoid long term problems associated with arthrodesis. Triple arthrodesis or subtalar arthrodesis must be used in older patients with degenerative signs in radiographs or in those cases of multiple coalition or if resection has failed.

Sinostosis congénitas del tarso Concepto, clasificación, diagnóstico y planteamiento terapéutico / Congenital tarsal coalition. Concept, classification, diagnostic and therapy

La incidencia de las sinostosis congénitas del tarso se estima en torno al 1 por ciento de la población, siendo una de las causas más comunes de pie plano rígido doloroso en la población pediátrica. La barra calcáneoescafoidea (50 por ciento) y el puente astragalocalcáneo (40 por ciento) son las formas de presentación más frecuentes. La restricción de la movilidad, el dolor mecánico en el lugar de la fusión y la deformidad del calzado referida en la anamnesis deben hacernos sospechar esta entidad. En la exploración física destaca la rigidez del retropió con limitación dolorosa característica de la pronosupinación que ha motivado clásicamente la errónea denominación de pie plano peroneo espástico. El diagnóstico radiológico se hace normalmente con radiografías simples (proyecciones laterales y oblicuas entre 35 y 45°), en las que observamos el osteofito anterior de la cabeza del astrágalo o la imagen de condensación en "media luna" del astrágalo superpuesto con el calcáneo, siendo necesario en ocasiones recurrir al TAC. Entre las posibilidades terapéuticas, el tratamiento quirúrgico es el único resolutivo del problema de base. La resección-artroplastia de interposición debe intentarse en pacientes jóvenes en los que se quiera preservar la biomecánica normal del pie, evitándose los problemas a largo plazo de la artrodesis. La triple artrodesis o la artrodesis subastragalina, se reservan para pacientes mayores con signos degenerativos, en casos de fusiones tarsianas múltiples y tras fracaso de la resección-artroplastia (AU)

[Cervical spondylodiscitis]. / Espondilodiscitis cervicales.

Eighty patients were treated for spondylodiscitis with the cervical spine involved in nine cases. Conservative treatment was applied in seven cases with Minerva jacket and antibiotics, and surgical treatment was applied in severe, rapidly, progressive, complicated cases and in patients with involvement of nervous system (two cases). The good and satisfactory results in both group were similar. These results show that when the indications are properly established, both conservative and operative methods have satisfactory results.

Radiofrequency ablation of the inferior vena cava-tricuspid valve isthmus in common atrial flutter.

Endocardial mapping has suggested that common atrial flutter (AF) is based on right atrial reentry surrounding the inferior vena cava (IVC). The isthmus between the IVC and the tricuspid valve (TV) appears essential to close the circuit. To test this hypothesis, radiofrequency was applied to the IVC-TV isthmus, with catheter electrodes, in 9 patients with AF. Mapping confirmed a right atrial circuit surrounding the IVC in all. In 4 patients another type of AF was induced that followed the circuit in the opposite direction. Radiofrequency interrupted AF in all patients. Multiple endocardial recordings showed that interruption was due to activation block at the point of application. Radiofrequency produced very brief or sustained, atrial fibrillation in 2 patients, which resulted in sinus rhythm. AF recurred in 4 patients with the same activation pattern and was interrupted again with radiofrequency in the IVC-TV isthmus in 3. AF was noninducible in 7 patients after 1 to 4 sessions. AF-free periods of 2 to 18 months without drugs were observed after radiofrequency, but 2 patients had paroxysmal atrial fibrillation. These results confirm that the IVC-TV isthmus is an essential part of the AF circuit. Ablation of this area may be of therapeutic value, but technical improvements are needed. Long-term efficacy of the procedure is uncertain.

[Severe hypoxemia due to a right-left shunt at the level of the foramen ovale. A complication of right ventricular infarct]. / Hipoxemia grave por cortocircuito derecha-izquierda a nivel del foramen oval. Una complicación del infarto de ventrículo derecho.

A 76-year-old woman with an inferior wall myocardial infarction, with right ventricular involvement, developed severe arterial hypoxemia with neurological involvement. Pulmonary edema or embolism and chronic obstructive pulmonary disease were ruled-out, and a right-to-left shunt was demonstrated by contrast echocardiography at the level of the foramen ovale. After inotropic support and oxygen supplementation, the patient recovered, although with significant neurological sequelae. No focal lesions were detected in the central nervous system by computerized tomography. Hypoxemia improved, coinciding with the disappearance of right-to-left shunt by contrast echocardiography.

Suppression of Torsades de Pointes with verapamil in patients with atrio-ventricular block.

Experimental data have suggested a relation between Torsades de Pointes and early post-depolarization (EPD). We have studied the effect of intravenous verapamil in three patients with atrioventricular block (AVB) and Torsades de Pointes (TP), to obtain indirect evidence of slow membrane channel involvement in the TP mechanism. In two cases TP were completely suppressed and in one there was marked, albeit partial, suppression. In two cases verapamil did not shorten QT, while in the third suppression verapamil was related to junctional escape acceleration and QT shortening. In one of the cases where QT was not changed, the abolition of long pauses may have played a role in TP suppression. The affect of verapamil on TP in our patients is consistent with a combination of mechanisms, including direct membrane effects (EPD inhibition) and junctional pacemaker acceleration. Verapamil might be of therapeutic value in this clinical setting.

Atrial endocardial mapping in the rare form of atrial flutter.

Endocardial atrial activation mapping was performed in 7 patients with rare atrial flutter (AF), inscribing predominantly positive deflections on leads II, III and aVF. In 2 cases both a rare and a common AF were mapped on different occasions. Every case displayed circular right atrial activation. In 5 of the 7 cases rare AF direction was clockwise (craniocaudal in the septum and posterior wall and caudocranial on the lateral and anterior walls). In 2 cases rare AF direction was counterclockwise (caudocranial in the septum and posterior wall and craniocaudal in the lateral and anterior walls). Both common AF rotated counterclockwise. A "line" of conduction delay or block was present in both clockwise and counterclockwise circuits between the posterior and lateral walls, in the probable location of the crista terminalis. This line of block extended the central obstacle made by the inferior vena cava toward, but perhaps not all the way to, the superior vena cava, making activation rotate roughly around the tricuspid ring. The ridge between the inferior vena cava and the tricuspid ring was a critical anatomic "closing" point in all clockwise and counterclockwise circuits. Right atrial macroreentry underlies rare AF. Direction of activation tends to be opposite to that in common AF. The cause of the positive deflection is unclear.

[Post-infarction thrombosis of the right ventricle]. / Trombosis ventricular derecha postinfarto.

Right ventricular mural thrombosis is not commonly detected and in most cases is related to the use of monitoring, infusion, or pacing catheters. We report right ventricular mural thrombosis, complicated by pulmonary embolism, in 2 cases of inferior wall myocardial infarction with right ventricular involvement. None of the patients had been monitored by means of right ventricular catheterization. Bidimensional echocardiography allowed visualization of the thrombi, and demonstrated their resolution after anticoagulant treatment.

Junctional echoes with slow retrograde conduction without His bundle depolarization: further evidence of reentry within the atrioventricular node.

We report a case of intranodal reentry with slow retrograde conduction and atrial echoes in the absence of His bundle activation. Echoes were related to delay in intranodal conduction. Reentry using anomalous atrioventricular connexions is impossible without ventricular activation. This observation suggests reentry within the node without participation of neighboring structures.