Controversies in orthopaedic oncology.

Chondrosarcoma is the second most common surgically treated primary bone sarcoma. Despite a large number of scientific papers in the literature, there is still significant controversy about diagnostics, treatment of the primary tumour, subtypes, and complications. Therefore, consensus on its day-to-day treatment decisions is needed. In January 2024, the Birmingham Orthopaedic Oncology Meeting (BOOM) attempted to gain global consensus from 300 delegates from over 50 countries. The meeting focused on these critical areas and aimed to generate consensus statements based on evidence amalgamation and expert opinion from diverse geographical regions. In parallel, periprosthetic joint infection (PJI) in oncological reconstructions poses unique challenges due to factors such as adjuvant treatments, large exposures, and the complexity of surgery. The meeting debated two-stage revisions, antibiotic prophylaxis, managing acute PJI in patients undergoing chemotherapy, and defining the best strategies for wound management and allograft reconstruction. The objectives of the meeting extended beyond resolving immediate controversies. It sought to foster global collaboration among specialists attending the meeting, and to encourage future research projects to address unsolved dilemmas. By highlighting areas of disagreement and promoting collaborative research endeavours, this initiative aims to enhance treatment standards and potentially improve outcomes for patients globally. This paper sets out some of the controversies and questions that were debated in the meeting.

Body composition, strength static and isokinetic, and bone health: comparative study between active adults and amateur soccer players.

OBJECTIVE: To compare tissue composition, total and regional bone mineral content and bone mineral density, static hand grip and knee joint isokinetic strength between amateur soccer players and Control Group. METHODS: Cross-sectional study. Air displacement plethysmography was used to estimate body volume and, in turn, density. Body composition, bone mineral content and bone mineral density were assessed for the whole body and at standardized regions using dual energy X-ray absorptiometry. Static grip strength was assessed with an adjustable dynamometer, and peak torque derived from isokinetic strength dynamometer (concentric muscular knee actions at 60°/s). Magnitude of the differences between groups was examined using d-Cohen. RESULTS: Compared to healthy active adults, soccer players showed larger values of whole body bone mineral content (+651g; d=1.60; p<0.01). In addition, differences between groups were large for whole body bone mineral density (d=1.20 to 1.90; p<0.01): lumbar spine, i.e. L1-L4 (+19.4%), upper limbs (+8.6%) and lower limbs (+16.8%). Soccer players attained larger mean values in strength test given by static hand grip protocol (+5.6kg, d=0.99; p<0.01). CONCLUSION: Soccer adequately regulates body composition and is associated better bone health parameters (bone mineral content and density at whole-body and at particular sites exposed to mechanical loadings).

Body composition, strength static and isokinetic, and bone health: comparative study between active adults and amateur soccer players / Composição corporal, força estática e isocinética, e saúde óssea: estudo comparativo entre adultos ativos e futebolistas amadores

ABSTRACT Objective: To compare tissue composition, total and regional bone mineral content and bone mineral density, static hand grip and knee joint isokinetic strength between amateur soccer players and Control Group. Methods: Cross-sectional study. Air displacement plethysmography was used to estimate body volume and, in turn, density. Body composition, bone mineral content and bone mineral density were assessed for the whole body and at standardized regions using dual energy X-ray absorptiometry. Static grip strength was assessed with an adjustable dynamometer, and peak torque derived from isokinetic strength dynamometer (concentric muscular knee actions at 60°/s). Magnitude of the differences between groups was examined using d-Cohen. Results: Compared to healthy active adults, soccer players showed larger values of whole body bone mineral content (+651g; d=1.60; p<0.01). In addition, differences between groups were large for whole body bone mineral density (d=1.20 to 1.90; p<0.01): lumbar spine, i.e. L1-L4 (+19.4%), upper limbs (+8.6%) and lower limbs (+16.8%). Soccer players attained larger mean values in strength test given by static hand grip protocol (+5.6kg, d=0.99; p<0.01). Conclusion: Soccer adequately regulates body composition and is associated better bone health parameters (bone mineral content and density at whole-body and at particular sites exposed to mechanical loadings).

RESUMO Objetivo: Comparar a composição de tecidos, o conteúdo mineral ósseo e a densidade mineral óssea totais e por regiões do corpo, a força de preensão manual estática, e força isocinética da articulação do joelho, entre um grupo de jogadores de futebol amadores e um Grupo Controle. Métodos: Estudo transversal utilizando pletismografia de ar deslocado para estimar o volume corporal, para subsequente cálculo da densidade corporal. A composição de tecidos, o conteúdo mineral ósseo e a densidade mineral óssea foram avaliados para o corpo todo e regiões padronizadas através da absorciometria de raios-X de dupla energia. A força de preensão manual estática foi avaliada por um dinamômetro ajustável. Os momentos máximos de força das ações musculares concêntricas para os extensores e flexores do joelho foram avaliados pela dinamometria isocinética (60°/s). Foi calculado o valor d-Cohen para apreciar a magnitude do efeito das diferenças entre grupos. Resultados: Os futebolistas apresentaram níveis superiores de conteúdo mineral ósseo em comparação com os adultos ativos do Grupo Controle (+651g; d=1,60; p<0,01) e obtiveram valores superiores de densidade mineral óssea (d: 1,20 a 1,90; p<0,01) para a coluna lombar, L1-L4 (+19,4%), membros superiores (+8,6%) e membros inferiores (+16,8%). Para a força de preensão (estática) a diferença foi moderada (d=0,99; p<0,01) com valores mais elevados apresentados pelo futebolistas (+5,6kg; d=0,99; p<0,01). Conclusão: A prática de futebol promove uma regulação adequada da composição corporal (tecidos magro e gordo) e ganhos na densidade mineral óssea, mais acentuada em partes do corpo com maior exposição aos impactos mecânicos da atividade motora.

Neoadjuvant Trabectedin plus Radiotherapy in High-Grade Sarcoma of the Leg: A Case Report.

Here, we present the case of a 78-year-old male patient with undifferentiated spindle cell sarcoma on the posteromedial surface of the right leg who experienced a long-lasting progression-free survival. Due to an underlying cardiac disease, the patient was not suitable for anthracyclines. In September 2015, he received first-line chemotherapy with trabectedin (Yondelis®) at the approved dosage and regimen - concomitant with external radiotherapy (RT). After the first 9 cycles of trabectedin plus RT given in the neoadjuvant setting, the patient underwent surgical resection. At that stage, we observed a very good pathological response with 80% of necrotic area. The patient resumed the therapy with trabectedin; however, approximately 5 months later, we observed a new nodular heterogeneous lesion with ill-defined margins in the right leg and suggestive of tumor relapse. Subsequently an above-the-knee amputation was performed, and the patient resumed his trabectedin therapy with the same dosage and regimen. In January 2018, almost 2 1/2 years after the start of trabectedin treatment and 30+ cycles of trabectedin, the patient is locoregionally and distant metastatically disease-free. Currently, the treatment with trabectedin is maintained without any significant serious toxicity. Future clinical trials are needed to gain additional insights into the role of trabectedin maintenance therapy until disease progression in the neoadjuvant setting and to identify predictive and prognostic criteria for response to trabectedin in patients with advanced sarcoma.

Agreement between dual x-ray absorptiometers using pencil beam and fan beam: indicators of bone health and whole-body plus appendicular tissue composition in adult athletes.

OBJECTIVE: The current study was aimed to examine intra-individual variation on indicators of bone health in addition to whole-body plus appendicular tissue measurements using two concurrent assessments based on pencil beam and fan beam dual energy X-ray absorptiometry (DXA) systems in adult athletes from several sports. METHOD: Thirty-two male participants (27.6±10.1 years) were measured on anthropometry including multifrequency bioelectric impedance and air-displacement plethysmography. Bone mineral content (BMC), bone area, fat and lean soft tissue were derived using pencil beam (Lunar DPX-MD+) and fan beam (Lunar iDXA) absorptiometry. Bone mineral density (BMD) was obtained for the femoral neck, trochanter and triangle of ward. Finally, the right thigh was defined as a region of interest (ROI). Analyses comprised intra-class correlation (ICC), Effect size (d) from mean differences of repeated measurements, coefficient of variation (CV). RESULTS: ICC were >0.900 for all measurements. Intra-individual differences were large for BMC (d=1,312; CV=2,7%), bone area (d=1,761; CV=2,7%), fat tissue (d=1,612; CV=11%) and all indicators of appendicular lean soft tissue (d=1,237-1687; CV=2,0-4,1%). A very large difference (d=4,014; CV=8.4%) was diagnosed for lean soft tissue of the ROI. CONCLUSION: Although differences among concurrent instruments for BMC and bone area, the effect size of mean differences was negligible for BMD. Fat and lean soft tissue derived from DXA should be interpreted as reference values (not criterion) due to equipment-related variation, more apparently in the ROI values.

Total and regional bone mineral and tissue composition in female adolescent athletes: comparison between volleyball players and swimmers.

BACKGROUND: Exploring the osteogenic effect of different bone-loading sports is particular relevant to understand the interaction between skeletal muscle and bone health during growth. This study aimed to compare total and regional bone and soft-tissue composition between female adolescent swimmers (n=20, 15.71±0.93 years) and volleyball players (n=26, 16.20±0.77 years). METHODS: Dietary intake was obtained using food frequency questionnaires. Body size was given by stature, sitting height, and body mass. Six skinfolds were measured. Bone mineral content (BMC) and density (BMD), lean soft tissue, and fat tissue were assessed using dual-energy X-ray absorptiometry. Pearson's product moment correlation coefficients were calculated to examine the relationships among variables, by type of sport. Comparisons between swimmers and volleyball players were performed using student t-tests for independent samples and multivariate analysis of covariance (controlling for age, training history and body size). RESULTS: Swimmers (BMC: 2328±338 g) and volleyball players (BMC: 2656±470 g) exceeded respectively by 2.1 and 2.8 standard deviation scores the average of international standards for whole body BMC of healthy adolescents. Years of training in swimmers were positively related to the upper limbs BMC (r=+0.49, p<0.05). In volleyball players, years of training correlated significantly with lower limbs BMD (r=+0.43, p<0.05). After adjustments for potential confounders, moderate differences (ES-r=0.32) between swimmers and volleyball players were noted in BMD at the lower limbs (volleyball players: +0.098 g∙cm-2, +7.8%). CONCLUSIONS: Youth female athletes who participate in high-intensity weight-loading activities such as volleyball exhibit moderately higher levels of BMD at the lower limbs compared to non-loading sports such as swimming.

Agreement between dual x-ray absorptiometers using pencil beam and fan beam: indicators of bone health and whole-body plus appendicular tissue composition in adult athletes

SUMMARY OBJECTIVE: The current study was aimed to examine intra-individual variation on indicators of bone health in addition to whole-body plus appendicular tissue measurements using two concurrent assessments based on pencil beam and fan beam dual energy X-ray absorptiometry (DXA) systems in adult athletes from several sports. METHOD: Thirty-two male participants (27.6±10.1 years) were measured on anthropometry including multifrequency bioelectric impedance and air-displacement plethysmography. Bone mineral content (BMC), bone area, fat and lean soft tissue were derived using pencil beam (Lunar DPX-MD+) and fan beam (Lunar iDXA) absorptiometry. Bone mineral density (BMD) was obtained for the femoral neck, trochanter and triangle of ward. Finally, the right thigh was defined as a region of interest (ROI). Analyses comprised intra-class correlation (ICC), Effect size (d) from mean differences of repeated measurements, coefficient of variation (CV) RESULTS: ICC were >0.900 for all measurements. Intra-individual differences were large for BMC (d=1,312; CV=2,7%), bone area (d=1,761; CV=2,7%), fat tissue (d=1,612; CV=11%) and all indicators of appendicular lean soft tissue (d=1,237-1687; CV=2,0-4,1%). A very large difference (d=4,014; CV=8.4%) was diagnosed for lean soft tissue of the ROI. CONCLUSION: Although differences among concurrent instruments for BMC and bone area, the effect size of mean differences was negligible for BMD. Fat and lean soft tissue derived from DXA should be interpreted as reference values (not criterion) due to equipment-related variation, more apparently in the ROI values.

RESUMO OBJETIVO: O presente estudo examinou a concordância entre os indicadores de saúde óssea e composição tecidual resultantes da aplicação de equipamentos concorrentes de absorciometria de raios X de dupla energia (DXA). MÉTODO: A amostra (n = 32), com 27,6 ± 10,1 anos de idade avaliados antropometricamente, inclui impedância bioelétrica com multifrequência e pletismografia de ar deslocado. O conteúdo mineral ósseo (CMO), a área de tecido ósseo, o tecido magro e o tecido gordo de corpo inteiro foram obtidos considerando o modo pencil beam (Lunar DPX-MD+) e o fan beam (Lunar iDXA). Para cada um dos equipamentos, foi efetuado um scanner proximal do fêmur, sendo produzida informação sobre a densidade mineral óssea (DMO) do colo, nomeadamente triângulo de Ward, trocanter e haste. Na fase de processamento, foi definida uma região de interesse (ROI; coxa direita). As análises compreenderam a diferença de médias de medidas repetidas com cálculo da magnitude de efeitos (d), coeficiente de correlação intraclasse (CCI), coeficiente de variação (CV). RESULTADOS: Foram obtidos CCI>0,900 para todas as medidas, com diferenças intraindividuais largas apenas para CMO (d = 1,312; CV = 2,7%), área de tecido ósseo (d = 1,761; CV = 2,7%), tecido gordo total (d = 1,612; CV = 11%) e tecido magro em todos os segmentos (d = 1,237-1,687; CV = 2,0-41%). A massa magra da ROI apresentou uma variaçāo intraindividual muito larga (d = 4,014; CV = 8,4%). CONCLUSÃO: Foram encontradas diferenças negligenciáveis para a DMO de corpo todo. As medidas de massa gorda e massa magra obtidas por DXA nāo devem ser tidas como critério, mas antes como referenda, muito especialmente quando se delimita uma ROI.

Concurrent agreement between an anthropometric model to predict thigh volume and dual-energy X-Ray absorptiometry assessment in female volleyball players aged 14-18 years.

BACKGROUND: A variety of performance outputs are strongly determined by lower limbs volume and composition in children and adolescents. The current study aimed to examine the validity of thigh volume (TV) estimated by anthropometry in late adolescent female volleyball players. Dual-energy X-ray absorptiometry (DXA) measures were used as the reference method. METHODS: Total and regional body composition was assessed with a Lunar DPX NT/Pro/MD+/Duo/Bravo scanner in a cross-sectional sample of 42 Portuguese female volleyball players aged 14-18 years (165.2 ± 0.9 cm; 61.1 ± 1.4 kg). TV was estimated with the reference method (TV-DXA) and with the anthropometric method (TV-ANTH). Agreement between procedures was assessed with Deming regression. The analysis also considered a calibration of the anthropometric approach. RESULTS: The equation that best predicted TV-DXA was: -0.899 + 0.876 × log10 (body mass) + 0.113 × log10 (TV-ANTH). This new model (NM) was validated using the predicted residual sum of squares (PRESS) method (R2PRESS = 0.838). Correlation between the reference method and the NM was 0.934 (95%CI: 0.880-0.964, Sy∙x = 0.325 L). CONCLUSIONS: A new and accurate anthropometric method to estimate TV in adolescent female volleyball players was obtained from the equation of Jones and Pearson alongside with adjustments for body mass.

Are Complications Associated With the Repiphysis(®) Expandable Distal Femoral Prosthesis Acceptable for Its Continued Use?

BACKGROUND: Reconstruction of the distal femur after resection for malignant bone tumors in skeletally immature children is challenging. The use of megaprostheses has become increasingly popular in this patient group since the introduction of custom-made, expandable devices that do not require surgery for lengthening, such as the Repiphysis(®) Limb Salvage System. Early reports on the device were positive but more recently, a high complication rate and associated bone loss have been reported. QUESTIONS/PURPOSES: We asked: (1) what are the clinical outcomes using the Musculoskeletal Tumor Society (MSTS) scoring system after 5-year minimum followup in patients treated with this prosthesis at one center; (2) what are the problems and complications associated with the lengthening procedures of this implant; and (3) what are the specific concerns associated with revision of this implant? METHODS: At our institute, between 2002 and 2007, the Repiphysis(®) expandable prosthesis was implanted in 15 children (mean age, 8 years; range, 6-11 years) after distal femoral resection for malignant bone tumors. During this time, the general indication for use of this implant was resection of the distal femur for localized malignant bone tumors in pediatric patients. Alternative techniques used for this indication were modular prosthetic reconstruction, massive (osteoarticular or intercalary) allograft reconstruction, or rotationplasty. Age and tumor extension were the main factors to decide on the surgical indication. Of the 15 patients who had this prosthesis implanted during reconstruction surgery, five died with the implant in situ or underwent amputation before 5 years followup and the remaining 10 were evaluated at a minimum of 5 years (mean, 104 months; range, 78-140 months). No patients were lost to followup. These 10 patients were long-term survivors and underwent the lengthening program. They were included in our study analysis. The first seven lengthening procedures were attempted in an outpatient setting; however, owing to pain and burning sensations experienced by the patients, the procedures failed to achieve the desired lengthening. Therefore, other procedures were performed with the patients under general anesthesia. We reviewed clinical data at index surgery for all 15 patients. We further analyzed the lengthening procedures, implant survival, radiographic and functional results, for the 10 long-term survivors. Functional results were assessed according to the MSTS scoring system. Complications were classified according to the International Society of Limb Salvage (ISOLS) classification system. RESULTS: Nine of the 10 survivors underwent revision of the implant for mechanical failure. They had a mean MSTS score of 64% (range, 47%-87%) before revision surgery. At final followup the 10 long-term surviving patients had an average MSTS score of 81% (range, 53%-97%). In total, we obtained an average lengthening of 39 mm per patient (range, 17-67 mm). Exact expansion of the implant was unpredictable and difficult to control. Nine of 10 of the long-term surviving patients underwent revision surgery of the prosthesis-eight for implant breakage and one for stem loosening. At revision surgery, six patients had another type of expandable prosthesis implanted and three had an adult-type megaprosthesis implanted. In five cases, segmental bone grafts were used during revision surgery to compensate for loss of bone stock. CONCLUSIONS: We could not comfortably expand the Repiphysis(®) prosthesis in an outpatient setting because of pain experienced by the patients during the lengthening procedures. Furthermore, use of the prosthesis was associated with frequent failures related to implant breakage and stem loosening. Revisions of these procedures were complex and difficult. We no longer use this prosthesis and caution others against the use of this particular prosthesis design. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Tumors of the foot and ankle: a single-institution experience.

Tumors of the foot and ankle are rare, and the particular clinicopathologic features, therapeutic approach, and outcomes in this setting are not well established. From January 2000 to December 2010, 72 patients with primary musculoskeletal tumors of the foot and ankle, both benign and malignant, were treated at a single institution. Of the 72 patients, 56% were female. The median age was 52 years. Of the 72 tumors, 62 (86.11%) were located in the foot and 10 were located in the ankle; 63 (87.5%) were soft tissue tumors and 9 (12.5%) were bone tumors. Overall, 56 (78%) were benign tumors and 16 (22%) were malignant tumors. The most frequent soft tissue and bone diagnosis was giant cell tumor. The median follow-up period was 49 months. The vast majority of the tumors were located in the foot. Benign tumors were dominant, outnumbering malignant tumors by more than 3 to 1. The diversity of the histologic benign types was evident, with giant cell tumor, angiomyoma, and lipoma the most frequent. Regarding the malignant tumors, a clear male predominance was present, the median age was 45 years, and the most frequent tumor was synoviosarcoma. The 9-year overall and disease-free survival rate was 65% and 40%, respectively.

Acción del verapamil intravenoso en arritmias ventriculares experimentales / Action of intravenous Verapamil in experimental ventricular aeehythmias

Hemos estudiado la respuesta de taquicardias ventriculares (TV) exprerimentales al verapamil, inyectado en 15 ó 20 min. por la vena cava superior. Dichas taquicardias eran producidas por cristales de aconitina en la periferia de un área de infarto apical del ventrículo izquierdo, en perros anestesiados con pentobarbital sódico por vía venosa. DII a VL, las derivaciones unipolares intraventriculares derecha e izquierda y la de la vena cava superior, se registraron en condiciones de control, con la taquicardia y tras la inyección del fármaco en estudio. Esto se hizo con intervalos constantes, esperando la reaparición del ritmo sinusal (RS) y el restablecimiento sucesivo de la TV. Los experimentos, que duraban de 6 a 8 hs, se efectuaron bajo infusiones continuas de solución de Hartmann siguiendo las variaciones de la presión arterial sistólica en un manómetro de mercurio. De 75 perros tratados con 0.2 mg/kg de verapamil, se restableció transitoriamente el RS en 30 (40 por ciento), se observó una acción antiarrítmica parcial en 26 (35 por ciento) y no hubo ningún efecto favorable en los 19 restantes (25 por ciento). La presión arterial sistólica se abatió de manera importante en 10 animales (13 por ciento). En otros 3 grupos de 15 perros cada uno se probaron camparativamente verapamil vs lidocaína (I), vs mexiletina (II) y vs propafenona (III). En I, el verapamil restableció el RS en el 73 por ciento de los animales y la lidocaína sólo en el 7 por ciento; en II, el RS se debió en el 33 por ciento al verapamil y en el 7 por ciento a la mexiletina; en III, reapareció el RS en el 21 por ciento por el verapamil y en el 28 por ciento por la propafenona. El efecto positivo repetitivo del verapamil se obtuvo en el 33 por ciento de 15 experimentos, mientras que éste no tuvo ninguna acción antiarritmica en el 40 por ciento. El verapamil actúa sobre ciertas TV experimentales, probablemente relacionadas con potenciales dependientes del calcio

El cáncer broncogénico en el Hospital General de México: estudio de dos décadas / Broncogenic cancer in the General Hospital of Mexico: a estudy of two decades

De 1 855 tumores torácicos detectados entre 1971 y 1990, 923 (50 por ciento) correspondieron a cáncer broncogénetico (CaBr). La relación entre el sexo masculino y el femenino fue, en promedio, de 1.95:1. Los tipo histológico más frecuentes encontrados en hombres fueron: epidermoide 34.2 por ciento, adenocarcinoma 28.4 por ciento y de células pequeñas 13.2 por ciento; en mujeres: adenocarcinoma 38.9 por ciento, epidermoide 28.9 por ciento y mixto 7.7 por ciento, con una diferencia significativa entre los dos sexos para este tipo de tumores. considerando la relación entre fumadores y no fumadores, en el sexo masculino predominaron los tipos epidermoide, adenocarcinoma, indiferenciados de células pequeñas, indiferenciados de células grandes y tumores mixtos en los fumadores (p < 0.001); en el sexo femenino estas mismas extirpes predominaron en las no fumadoras. La comparación con el grupo sin CaBr mostró que el epidermoide, el adenocarcinoma y el de células pequeñas ocurren con más frecuencias en fumadores. El 92.2 por ciento de los casos se encontró en estadio III (Tumor Node Metastasys) y la oportunidad del tratamiento radical fue nula; la radioterapia y la quimioterapia tuvieron posibilidades muy limitadas; sólo 94 casos fueron quirúrgicos, con resección total en 36. Se requiere de los programas antitabáquicos se intensifiquen por la elevada frecuencia de CaBr en fumadores

Among 1855 thoracic neoplasms seen from 1971 to 1990, there were 923 with bronchogenic carcinoma (CaBr), 50%. The relation male: female was 1.95:1. Sixty three period thirty one percent were male. The histologic type were epidermoid 32.2%, adenocarcinoma 28.4% and small cells 13.2% in men; in women adenocarcinoma 38.9%, epidermoid 28.9% and mixed 7.7% with a significative difference for both sexes for these neoplasms. Other types were less frequent. There is significative difference between smokers and non smokers of both sexes p < 0.001. Epidermoid, adenocarcinoma, small cells, large cells and mixed were the most frequent in male smokers, in women these varieties were more frequent in nonsmokers. Comparison with the reference group with no CaBr suggests that epidermoid, adenocarcinoma and small cells carcinomas have a great possibility to be found in male smokers. Ninety two period two percent of cases were stage III (Tumor Node Metastasys) with no chance for radical treatment. Only 94 were subject to surgery with 36 total resections. CaBr is an important problem in the General Hospital of Mexico. Antismoking programmes must be stressed in relation to the frequency of CaBr in smokers.

El tratamiento de la endocarditis infecciosa: cefotaxima versus manejo médico tradicional / Treatment of infective endocarditis with cephotaxime

El objeto de éste estudio aleatorio abierto, controlado, fué comparar las eficacia y nefrotoxicidad de la cefotaxima, (CTX) con la terapéutica habitual de combinación betalactámico aminoglucósido, que se usa en el manejo médico de la endocarditis infecciosa (EI). Estudiamos 20 enfermos cuya edad osciló entre 12 y 70 años. Diez recibieron CTX 1 g cada 6 hr por 21 días más aminoglucósidos a dosis apropiadas por sólo 10 días. En el grupo de comparación se usó cualquier otro betalactámico endovenoso combinado con aminoglucósido por períodos de 21 a 50 días. Dos enfermos en el grupo CTX no respondieron; en el grupo de comparación no hubo respuesta en 3 casos. De los 8 enfermos restantes en CTX, 5 tuvieron elevación de creatinina, pero ésta no normalizó para el momento de egreso. En el grupo de comparación se observaron niveles altos de creatinina en 6 de 8 pacientes, persistieron elevados en 5 al egreso, y en 5 durante el seguimiento. El promedio de duración de la hospitalización fué menor en el grupo CTX:36.6 vs 53.6 días. Aunque la CTX es tan efectiva como el esquema habitual de tratamiento y en las condiciones del estudio parece tener menos nefrotoxicidad, su uso aumenta el costo directo del tratamiento en 38 por ciento en promedio