Emergent "core communities" of microbes, meiofauna and macrofauna at hydrothermal vents.

Assessment of ecosystem health entails consideration of species interactions within and between size classes to determine their contributions to ecosystem function. Elucidating microbial involvement in these interactions requires tools to distil diverse microbial information down to relevant, manageable elements. We used covariance ratios (proportionality) between pairs of species and patterns of enrichment to identify "core communities" of likely interacting microbial (<64 µm), meiofaunal (64 µm to 1 mm) and macrofaunal (>1 mm) taxa within assemblages hosted by a foundation species, the hydrothermal vent tubeworm Ridgeia piscesae. Compared with samples from co-located hydrothermal fluids, microbial communities within R. piscesae assemblages are hotspots of taxonomic richness and are high in novelty (unclassified OTUs) and in relative abundance of Bacteroidetes. We also observed a robust temperature-driven distinction in assemblage composition above and below ~25 °C that spanned micro to macro size classes. The core high-temperature community included eight macro- and meiofaunal taxa and members of the Bacteroidetes and Epsilonbacteraeota, particularly the genera Carboxylicivirga, Nitratifractor and Arcobacter. The core low-temperature community included more meiofaunal species in addition to Alpha- and Gammaproteobacteria, and Actinobacteria. Inferred associations among high-temperature core community taxa suggest increased reliance on species interactions under more severe hydrothermal conditions. We propose refinement of species diversity to "core communities" as a tool to simplify investigations of relationships between taxonomic and functional diversity across domains and scales by narrowing the taxonomic scope.

Fluoroscopy-guided Sacroiliac Joint Steroid Injection for Low Back Pain in a Patient with Osteogenesis Imperfecta.

BACKGROUND: Osteogenesis imperfecta, also known as 'brittle bone disease', is a genetic connective tissue disease. It is characterized by bone fragility and osteopenia (low bone density). In this case, a 57-year old female presented to the University Hospital of the West Indies (UHWI), Physical Medicine and Rehabilitation Clinic with left low back pain rated 6/10 on the numeric rating scale (NRS). Clinically, the patient had sacroiliac joint mediated pain although X-rays did not show the sacroiliac joint changes. Fluoroscopy-guided left sacroiliac joint steroid injection was done. METHODS: Numeric rating scale and Oswestry Disability Index (ODI) questionnaire were used to evaluate outcome. This was completed at baseline, one week follow-up and at eight weeks post fluoroscopy-guided sacroiliac joint steroid injection. RESULTS: Numeric rating scale improved from 6/10 before the procedure to 0/10 post procedure, and ODI questionnaire score improved from a moderate disability score of 40% to a minimal disability score of 13%. Up to eight weeks, the NRS was 0/10 and ODI remained at minimal disability of 15%. CONCLUSION: Fluoroscopy-guided sacroiliac joint injection is a known diagnostic and treatment method for sacroiliac joint mediated pain. To our knowledge, this is the first case published on the use of fluoroscopy-guided sacroiliac joint steroid injection in the treatment of sacroiliac joint mediated low back pain in a patient with osteogenesis imperfecta.

Extravasation injuries.

OBJECTIVES: To evaluate the time and type of treatment following extravasation from intravenous infusion and the sequelae of the injuries. METHOD: The charts of 12 patients who were referred to the Plastic and Orthopaedic Services at the University Hospital of the West Indies were reviewed. The study period was between May 2003 and January 2007. Data were collected on age, gender, site of extravasation, extravasated agent, treatment of the extravasation, necrosis interval, duration of hospital stay for treatment of injury and whether the intravenous line was resited and at what site in relation to the injury. RESULTS: The age of patients ranged from three days to 67 years. The female-to-male ratio was 2:1. In five patients, the intravenous infusion was discontinued immediately after the swelling was noticed. In two patients, the intravenous infusion was stopped after seven hours and in five patients it was discontinued within 12 to 22 hours. The necrosis interval ranged from 12 hours to three weeks. Immediate treatment following extravasation and discontinuation of the infusion included limb elevation in three patients and application of cold compresses in one patient. Eleven patients developed skin necrosis of varying severities. There was no skin necrosis in one patient. Ten patients spent an average of 31 extra days in hospital for treatment of the extravasation injury. Two patients were treated in an out-patient clinic. CONCLUSIONS: Extravenous leaks can cause severe tissue injuries. Morbidity is increased by delay in recognition and treatment of the extravasation. A protocol for the treatment of extravasation is recommended.

Donor site morbidity following iliac crest bone graft.

OBJECTIVES: To evaluate the complications of harvesting autogenous bone from the iliac crest. METHODS: A retrospective review of patients undergoing iliac crest bone grafting at the University Hospital of the West Indies, during the period 2000-2004, was performed. One hundred and three patients were identified. Thirty-two patients were successfully contacted and 30 completed the questionnaire. There were 18 males (60%) and 12 females (40%). Their ages ranged from 13 years to 80 years (average 45.6 years). RESULTS: Of the 30 patients, 22 (73.3%) had complications. Fourteen (46.6%) patients had temporary pain; five (16.6%) had chronic pain. Two (6.6%) changed position of clothing due to discomfort at the graft site; five (16.6%) experienced difficulty walking, one reported itching of the scar one had altered sensation and one was unhappy with the scar. Fourteen patients (46.6%) had minor complications and eight patients (26.6%) had major complications. CONCLUSION: Autogenous iliac crest bone grafting is associated with significant complications.

The Illizarov method in infected non-union of long bones.

OBJECTIVE: To review the results of the management of infected non-union of long bones using the Illizarov fixator. METHODS: Eight patients with non-union of long bones associated with current or prior infection were treated between 1998 and 2006. Seven patients were treated between 2004 and 2006. There were seven males and one female with an average age of 32 years (range 17-53 years). Four non-unions were located in the tibia, two were present in the humerus, one was present in the femur and one was intraarticular. Five non-unions were treated with acute compression, two were treated with bone transport and the frame was used in a static mode in one. RESULTS: There was one excellent, three good, one fair and three poor results. CONCLUSION: The Illizarov technique is an important treatment method for surgeons performing posttraumatic reconstructive surgery. Non-union, infection, shortening and deformity are all addressed simultaneously.

Treatment of congenital pseudarthrosis of the tibia with the Ilizarov technique. Case report and review of the literature.

Congenital pseudarthrosis of the tibia continues to pose one of the most difficult problems in paediatric orthopaedic surgery. The surgical procedures most used for treating congenital pseudarthrosis of the tibia are intramedullary nailing associated with bone grafting, vascularized fibular graft and the Ilizarov external circular fixator. Even when union is achieved, the residual deformities in the affected limb often result in significant disability. These deformities include leg-length discrepancy, angular tibial deformities, ankle mortise valgus and fibular non-union. The Ilizarov method allows simultaneous excision of the pseudarthrosis site, correction of the deformity and lengthening. However, refractures, ankle joint stiffness, fibular non-union with progressive ankle valgus are frequent sequelae with the Ilizarov technique. The surgeon should know when to abandon reconstructive procedures and create a more functional patient with an amputation. The authors discuss the indications and results of the Ilizarov external fixator in two patients with this complex problem. In addition, a critical review of the current literature is undertaken.

Treatment of congenital pseudarthrosis of the tibia with the Ilizarov technique. Case report and review of the literature

Congenital pseudarthrosis of the tibia continues to pose one of the most difficult problems in paediatric orthopaedic surgery. The surgical procedures most used for treating congenital pseudarthrosis of the tibia are intramedullary nailing associated with bone grafting, vascularized fibular graft and the Ilizarov external circular fixator. Even when union is achieved, the residual deformities in the affected limb often result in significant disability. These deformities include leg-length discrepancy, angular tibial deformities, ankle mortise valgus and fibular non-union. The Ilizarov method allows simultaneous excision of the pseudarthrosis site, correction of the deformity and lengthening. However, refractures, ankle joint stiffness, fibular non-union with progressive ankle valgus are frequent sequelae with the Ilizarov technique. The surgeon should know when to abandon reconstructive procedures and create a more functional patient with an amputation. The authors discuss the indications and results of the Ilizarov external fixator in two patients with this complex problem. In addition, a critical review of the current literature is undertaken.

The Illizarov method in infected non-union of long bones / El método Illizarov en la no unión infectada de los huesos largos

OBJECTIVE: To review the results of the management of infected non-union of long bones using the Illizarov fixator. METHODS: Eight patients with non-union of long bones associated with current or prior infection were treated between 1998 and 2006. Seven patients were treated between 2004 and 2006. There were seven males and one female with an average age of 32 years (range 17-53 years). Four non-unions were located in the tibia, two were present in the humerus, one was present in the femur and one was intraarticular. Five non-unions were treated with acute compression, two were treated with bone transport and the frame was used in a static mode in one. RESULTS: There was one excellent, three good, one fair and three poor results. CONCLUSION: The Illizarov technique is an important treatment method for surgeons performing posttraumatic reconstructive surgery. Non-union, infection, shortening and deformity are all addressed simultaneously.

Objetivo: Examinar los resultados del tratamiento de la nounión infectada de los huesos largos usando el fijador de Illizarov. Métodos: Ocho pacientes con nounión de huesos largos asociada con infecciones presentes o previas fueron tratados entre 1998 y 2006. Siete pacientes fueron tratados entre 2004 y 2006. Hubo siete varones y una hembra con edad promedio de 32 años (rango 17­53 años). Cuatro nouniones estaban localizadas en la tibia, dos se hallaban presentes en el húmero, una se encontraba en el fémur y otra era intra-articular. Cinco nouniones fueron tratadas con compresión aguda, dos fueron tratados con transporte óseo, y en uno se usó el aparato de un modo estático, Resultados: Hubo un resultado excelente, tres buenos, uno aceptable y tres resultados pobres. Conclusión: La técnica de Illizarov es un importante método de tratamiento para los cirujanos que realizan cirugía reconstructiva post-traumática. Nounión, infección, acortamiento, y deformidad, pueden ser todos abordados simultáneamente.

Femoral lengthening using the Ilizarov technique / Alargamiento Femoral Mediante la Técnica de Ilizarov

The Ilizarov method allows the surgeon to perform extended lengthening of both congenital and acquired short limbs. The technique can be difficult, time consuming and is associated with many complications. Generally, the number of complications and failures of lengthenings increases in proportion to the length of the distraction and the severity of the preoperative problems. The rate of major complications decreases substantially as the experience of the surgeon increases.

The accuracy of joint line tenderness in the diagnosis of meniscal tears / Precisión del dolor en la línea de la articulación en el diagnóstico del desgarro meniscal

The accuracy of joint line tenderness in the diagnosis of meniscal tears was assessed in 129 knees. Arthroscopy was performed in each case to establish the diagnosis. The diagnosis was correct in 100 knees (77.5%) and incorrect in 29 (22.5%). A preoperative diagnosis of a medial meniscal tear was made in 63 knees and confirmed in 46 (73%) at arthroscopy. There were 46 true-positive, 17 false-positive, four false-negative and 62 true-negative results for the medial side. A lateral meniscal tear was suspected in 45 knees and confirmed in 39 (86.7%). Thus, 39 true-positive, six false-positive, two false-negative, and 82 true-negative interpretations were found. In this study, joint line tenderness as a test for lateral meniscal tears was accurate (93%), sensitive (95%), and specific (93%), but for medial tears the rates were lower.

La precisión del dolor en la línea de la articulación a la hora de hacer el diagnóstico del desgarro meniscal fue evaluada en 129 rodillas. En cada uno de los casos se realizó una artroscopia a fin de determinar el diagnóstico. El diagnóstico fue correcto en 100 rodillas (77.5%) e incorrecto en 29 (22.5%). Se llevó a cabo un diagnóstico preoperatorio del desgarramiento meniscal medial en 63 rodillas, confirmado en 46 (73%) por artroscopia. Hubo 46 resultados verdadero-positivos, 17 falsopositivos, 4 falso-negativos y 62 verdadero-negativos para el lado medial. Se sospechó un desgarro meniscal lateral en 45 rodillas, y se confirmó en 39 (86.7%). Por consiguiente, se hallaron 39 interpretaciones verdadero-positivas, 6 falso-positivas, 2 falso-negativas, y 82 verdadero-negativas. En este estudio, el dolor en la línea de la articulación como prueba para el desgarro meniscal lateral fue preciso (93%), sensible (95%), y específico (93%), pero para el desgarro medial los índices fueron más bajos.

Femoral lengthening using the Ilizarov technique.

The Ilizarov method allows the surgeon to perform extended lengthening of both congenital and acquired short limbs. The technique can be difficult, time consuming and is associated with many complications. Generally, the number of complications and failures of lengthenings increases in proportion to the length of the distraction and the severity of the preoperative problems. The rate of major complications decreases substantially as the experience of the surgeon increases.

The accuracy of joint line tenderness in the diagnosis of meniscal tears.

The accuracy of joint line tenderness in the diagnosis of meniscal tears was assessed in 129 knees. Arthroscopy was performed in each case to establish the diagnosis. The diagnosis was correct in 100 knees (77.5%) and incorrect in 29 (22.5%). A preoperative diagnosis of a medial meniscal tear was made in 63 knees and confirmed in 46 (73%) at arthroscopy. There were 46 true-positive, 17 false-positive, four false-negative and 62 true-negative results for the medial side. A lateral meniscal tear was suspected in 45 knees and confirmed in 39 (86.7%). Thus, 39 true-positive, six false-positive, two false-negative, and 82 true-negative interpretations were found. In this study, joint line tenderness as a test for lateral meniscal tears was accurate (93%), sensitive (95%), and specific (93%), but for medial tears the rates were lower.

Judet quadricepsplasty for extension contracture of the knee.

Extension contracture of the knee is a well known complication of severe femoral fractures, especially in the supracondylar region. Traditional management by the Thompson quadricepsplasty may result in a variable return of knee flexion and the possibility of significant extension lag. The Judet technique of quadricepsplasty offers the advantages of a controlled, sequential release of the intrinsic and then the extrinsic components limiting knee flexion and a reduced potential for iatrogenic quadriceps rupture or extension lag. The modified Judet quadricepsplasty has definite advantages over the Judet technique since it usually involves less soft tissue dissection and consequently less blood loss.

Judet quadricepsplasty for extension contracture of the knee / La cuadricepsplastia operación Judet para la contractura en extensión de la rodilla

Extension contracture of the knee is a well known complication of severe femoral fractures, especially in the supracondylar region. Traditional management by the Thompson quadricepsplasty may result in a variable return of knee flexion and the possibility of significant extension lag. The Judet technique of quadricepsplasty offers the advantages of a controlled, sequential release of the intrinsic and then the extrinsic components limiting knee flexion and a reduced potential for iatrogenic quadriceps rupture or extension lag. The modified Judet quadricepsplasty has definite advantages over the Judet technique since it usually involves less soft tissue dissection and consequently less blood loss.

La contractura en extensión de la rodilla es una complicación bien conocida de las fracturas femorales severas, sobre todo en la región supracondilar. El tratamiento tradicional mediante la cuadricepsplastia de Thompson, puede traer como resultado un retorno variable de la flexión de la rodilla y la posibilidad de un intervalo de extensión significativo. La técnica de cuadricepsplastia de Judet ofrece como ventajas un accionar secuencial y controlado de los componentes intrínsecos y extrínsecos que limitan la flexión de la rodilla, así como un potencial reducido para la ruptura de los cuadriceps iatrogénicos y el intervalo de extensión. La cuadripcepsplastia de Judet modificada tiene ventajas definidas sobre la técnica de Judet, ya que usualmente involucra menos disección de tejido blando, y por consiguiente menos pérdida de sangre.

Clinical emergence of entecavir-resistant hepatitis B virus requires additional substitutions in virus already resistant to Lamivudine.

Entecavir (ETV) exhibits potent antiviral activity in patients chronically infected with wild-type or lamivudine (3TC)-resistant (3TC(r)) hepatitis B virus (HBV). Among the patients treated in phase II ETV clinical trials, two patients for whom previous therapies had failed exhibited virologic breakthrough while on ETV. Isolates from these patients (arbitrarily designated patients A and B) were analyzed genotypically for emergent substitutions in HBV reverse transcriptase (RT) and phenotypically for reduced susceptibility in cultures and in HBV polymerase assays. After 54 weeks of 3TC therapy, patient A (AI463901-A) received 0.5 mg of ETV for 52 weeks followed by a combination of ETV and 100 mg of 3TC for 89 weeks. Viral rebound occurred at 133 weeks after ETV was started. The 3TC(r) RT substitutions rtV173L, rtL180M, and rtM204V were present at study entry, and the additional substitutions rtI169T and rtM250V emerged during ETV-3TC combination treatment. Reduced ETV susceptibility in vitro required the rtM250V substitution in addition to the 3TC(r) substitutions. For liver transplant patient B (AI463015-B), previous famciclovir, ganciclovir, foscarnet, and 3TC therapies had failed, and RT changes rtS78S/T, rtV173L, rtL180M, rtT184S, and rtM204V were present at study entry. Viral rebound occurred after 76 weeks of therapy with ETV at 1.0 mg, with the emergence of rtT184G, rtI169T, and rtS202I substitutions within the preexisting 3TC(r) background. Reduced susceptibility in vitro was highest when both the rtT184G and the rtS202I changes were combined with the 3TC(r) substitutions. In summary, infrequent ETV resistance can emerge during prolonged therapy, with selection of additional RT substitutions within a 3TC(r) HBV background, leading to reduced ETV susceptibility and treatment failure.

Routine prophylactic antibiotics for arthroplasty patients receiving dental care. Is it necessary?

Much of the debate regarding the prophylactic use of antibiotics for patients who have had a total joint replacement has focussed on their use before dental procedures. Despite the fact that almost all orthopaedic surgeons routinely recommend antibiotics for patients with prosthetic joints who require dental treatment, there is little evidence of a definitive link between transient bacteraemia occurring during dental procedures and late infections around prosthetic joints. An extensive review of the literature reveals that most authors recommend prophylactic antibiotics in high-risk patients or in those who undergo extensive dental surgery

Routine prophylactic antibiotics for arthroplasty patients receiving dental care. Is it necessary?

Much of the debate regarding the prophylactic use of antibiotics for patients who have had a total joint replacement has focussed on their use before dental procedures. Despite the fact that almost all orthopaedic surgeons routinely recommend antibiotics for patients with prosthetic joints who require dental treatment, there is little evidence of a definitive link between transient bacteraemia occurring during dental procedures and late infections around prosthetic joints. An extensive review of the literature reveals that most authors recommend prophylactic antibiotics in high-risk patients or in those who undergo extensive dental surgery.

Chondro-epiphyseal separation of the distal humerus in the newborn. A case report and review of the literature

Chondro-epiphyseal separation of the distal humerus is a rare injury, and when it occurs in the newborn, it may be difficult to diagnose and is easily mistaken for a dislocation of the elbow. The unimpressive clinical appearance of such an injury of the elbow in an infant, as well as the absence of ossific nuclei of the distal humerus in the newborn, are responsible for the dilemma in making the diagnosis. Ultrasonography, a readily available, non-invasive technique, can be used to evaluate the non-ossified epiphysis about the elbow of infants to demonstrate dislocations, fractures, and physeal separations. Closed reduction with or without percutaneous Kirschner wire fixation is the treatment of choice for these injuries. In this article, we report on a case of complete epiphyseal separation in a neonate and discuss the problems arising in its diagnosis