Aflojamiento del componente femoral de prótesis de cadera cementada en el postoperatorio precoz.: a propósito de un caso.

Presentamos el caso clínico de una complicación extremadamente rara de aflojamiento precoz del componente femoral de una prótesis de cadera cementada. Este acontecimiento es consecuencia de la pérdida de adherencia entre la interfaz metal-cemento y tuvo lugar 14 días después de la colocación de una prótesis total de cadera cementada. En la literatura sólo se encuentra descrito un caso similar. Las causas atribuidas son el biomaterial y diseño de la prótesis, y la técnica de cementación.We report a case of an extremely rare complication of early loosening of the femoral component of a hip arthroplasty. This event is a consequence of the loss of adhesion between the metal-cement interface and took place 14 days after the placement of cemented total hip prosthesis. There was only described a similar case in the literature. The causes attributed are the biomaterial and design of the prosthesis, and cementation technique

Complicaciones en el uso de aloinjertos intercalares tras resección de tumores óseos

La reconstrucción ósea mediante aloinjertos intercalares es una técnica de uso frecuente tras resecciones tumorales, que presenta -a largo plazo- mejores resultados que las endoprótesis diafisarias o los autoinjertos vascularizados. Sin embargo, entre las complicaciones más frecuentes destacan las infecciones y las fracturas del aloinjero asociadas a roturas o aflojamientos de la osteosíntesis. Se presentan dos casos tratados con reconstrucciones de este tipo en los que el sistema de osteosíntesis utilizado fracasó, en uno de ellos de forma repetida.The reconstruction of skeletal defects using bone allografts is a frequent procedure after tumoral resections associated to good long-term results, usually better than diaphyseal endoprostheses or autologous grafts. Nevertheless, there are some complications: infection and allograft fracture associated with failure or broken fixation. We report two cases of bone reconstruction in who the fixation failed, twice in one of them

Necrosis de la cabeza femoral tras fractura del cuello femoral tratada mediante osteosíntesis

Se presenta un análisis retrospectivo de las necrosis aparecidas en 233 pacientes con fractura de cuello femoral fijada con tornillos de esponjosa. La edad media fue de 80,6 años. Setenta y un pacientes (26%) tuvieron una fractura no desplazada (Garden I o II) y 172 (74%) una fractura desplazada (Garden III o IV). Seis meses tras la cirugía 170 pacientes sobrevivían (72,9%). Treinta y cuatro de ellos (20%) habían desarrollado necrosis y 10 (5,9%) colapso. Tras un seguimiento de 12 meses 114 pacientes sobrevivían (48,9%). Veinticuatro de ellos (21%) tenía una necrosis y 18 (15,7%) un colapso. Dos años tras la intervención, 103 pacientes sobrevivían (44,2%). Siete de ellos habían desarrollado una necrosis (7,6%) y 25 un colapso (27,2%). En el último seguimiento (a los 3 años) 84 pacientes sobrevivían (36%). Se halló un colapso en 8 de ellos (9,5%). Observamos una relación significativa entre los pacientes que tenían una fractura desplazada, una mala reducción, una fijación inestable, y el desarrollo posterior de necrosis o colapso tardío.We report a retrospective analysis of the incident of osteonecrosis in 233 patients with femoral neck fractures treated with cancellous screws. The average age was 80.6 years. Seventy-one patients (26%) had a displaced fracture (Garden I-II). Six months after surgery 170 patients survived (73%). Thirty-four of them (20%) had developed osteonecrosis and 10 (5,9%) collapse. After a follow-up of 12 months 114 patients (49%) survived. Twenty-four of these patients (21%) had an osteonecrosis and 18 (16%) a collapse. Two years after surgery 103 patients (44%) survived. Seven of them had developed an osteonecrosis (8%) and 25 a collapse (27%). At the time of most recent follow-up (three years) 84 patients survived (36%). There was a collapse in 8 of them (10%). We observed a significant relation between patients who had a displaced fracture, a failed reduction, an unstable fixation, and the later development of necrosis and late collapse

Bone Remodeling of Two Anatomic Stems: Densitometric Study of the Redesign of the ABG-II Stem

Background: Periprosthetic bone remodeling, which is a phenomenon observed in all femoral stems, has a multifactorial origin as it depends on factors related to the patient, the surgical technique, and the design of the implant. To determine the pattern of remodeling produced by 2 models of anatomic cementless implants, we quantified the changes in bone mineral density (BMD) in the 7 areas of Gruen observed at different moments after surgery during the first postoperative year. Methods: A prospective, comparative, controlled, 1-year follow-up densitometric study was carried out in 2 groups of patients suffering from primary unilateral hip osteoarthritis. In the first group, with 68 patients, an ABG-II stem was implanted. In the second, with 66 patients, the ANATO stem was used. The contralateral, healthy hip was taken as a control. Results: Both groups showed a decrease in BMD at 3 months in all the areas, which recovered at the end of the study, except in zone 7: there was a 17.7% decrease in the ABG-II group and a 5.9% decrease in the ANATO group. In zones 2 and 6, where more loads are transmitted, conservation of BMD is observed in response to Wolff''s law. The differences in the pattern of remodeling between groups were maintained despite the age, gender, and BMI of the patients or the size of the implants. Conclusion: The ANATO stem achieved a more efficient transmission of loads at the metaphyseal level, which promotes bone preservation at the proximal femur, than the ABG-II stem

Osteoartritis luética de rodilla

Se presenta el caso de un varón de 59 años, con antecedente de contacto sexual sospechoso entre 3 y 5 años antes, que desarrolló episodios de derrame articular indoloro en rodilla izquierda con una lesión osteítica destructiva en meseta tibial interna. Tras descartar otras patologías, el diagnóstico se efectuó por la intensa actividad treponéndca demostrada en la serología específica y la buena respuesta al tratamiento antibiótico. Los derrames desaparecieron, persistiendo únicamente la deformidad residual. No conseguimos identificar espiroquetas en el material obtenido por biopsia osteoarticular.We report a 59 years old man with a suspicious sexual contact between 3-5 years ago, who developed repeated painless swelling in his left knee, and a progressive destructive osteitis in his tibia. After rejecting other pathologies, the diagnosis arrived by the high treponemic activity proved by specific serology and the clinical recovery with antibiotic treatment. The swelling disappeared and only the residual deformity persisted. We didn't find any treponema in the biopsy

Influencia biomecánica de la artroplastia total de rodilla en el apoyo metatarsal

Las articulaciones de la extremidad inferior forman una cadena cinemática y tanto desde el punto de vista normal como patológico se influyen mutuamente. El objetivo de nuestro trabajo es analizar las características del apoyo plantar en 100 pacientes subsidiarios de prótesis total de rodilla que presentan trastornos en la alineación del miembro antes y después de la corrección del eje de la extremidad que supone la cirugía. Además se compara el patrón de apoyo metatarsal con sujetos sanos de características antropométricas similares (grupo control).El genu varo preoperatorio se relaciona con un hiperapoyo de la paleta externa y un hipoapoyo de las paletas central e interna del antepié. En cambio el valgo fisiológico conseguido en el postoperatorio se corresponde con un patrón de apoyo metatarsal al año y a los dos años similar al del grupo control con pequeñas variaciones.Peer Reviewe

Adaptive Bone Remodeling With New Design of the ABG Stem. Densitometric Study

To establish the pattern of bone remodeling caused by a cementless, anatomic implant, we intend to evaluate the changes in bone mineral density observed after surgery in the Gruen zones. A controlled, prospective study was carried out, in which a group of 37 patients with primary coxarthrosis were densitrometrically analyzed over the 1 year period following the implant of an ANATO stem (Stryker). The patient's healthy hip was taken as the control. Any differences in the remodeling pattern were compared according to age, body mass index, and implant size. Decreases in bone mineral density were observed after 3 months in all of the zones studied. However, this bone mineral density loss was recovered in all zones by the end of the study, except in zone 7 where a decrease of 7.2% in bone mass was observed. In zones 2 and 6, where more loads are transmitted, bone mass preservation, in accordance with Wolff's law, can be seen. No differences were found in the remodeling pattern in relation to age and body mass index. There were also no differences related to stem size except in zones 1 and 7. The ANATO stem achieves an efficient transmission of loads between the stem and the proximal femur, providing enough mechanical loads for bone preservation. It is only in zone 7 where significant bone atrophy can be observed, attributable to the damage that this area suffers during the surgical process and the subsequent stress-shielding caused by the implant design

Study of bone remodeling of two models of femoral cementless stems by means of DEXA and finite elements

<p>Abstract</p> <p>Background</p> <p>A hip replacement with a cemented or cementless femoral stem produces an effect on the bone called adaptive remodelling, attributable to mechanical and biological factors. All of the cementless prostheses designs try to achieve an optimal load transfer in order to avoid stress-shielding, which produces an osteopenia.</p> <p>Long-term densitometric studies taken after implanting ABG-I and ABG-II stems confirm that the changes made to the design and alloy of the ABG-II stem help produce less proximal atrophy of the femur. The simulation with FE allowed us to study the biomechanical behaviour of two stems. The aim of this study was, if possible, to correlate the biological and mechanical findings.</p> <p>Methods</p> <p>Both models with prostheses ABG-I and II have been simulated in five different moments of time which coincide with the DEXA measurements: postoperative, 6 months, 1, 3 and 5 years, in addition to the healthy femur as the initial reference. For the complete comparative analysis of both stems, all of the possible combinations of bone mass (group I and group II of pacients in two controlled studies for ABG-I and II stems, respectively), prosthetic geometry (ABG-I and ABG-II) and stem material (Wrought Titanium or TMZF) were simulated.</p> <p>Results and Discussion</p> <p>In both groups of bone mass an increase of stress in the area of the cancellous bone is produced, which coincides with the end of the HA coating, as a consequence of the bottleneck effect which is produced in the transmission of loads, and corresponds to Gruen zones 2 and 6, where no osteopenia can be seen in contrast to zones 1 and 7.</p> <p>Conclusions</p> <p>In this study it is shown that the ABG-II stem is more effective than the ABG-I given that it generates higher tensional values on the bone, due to which proximal bone atrophy diminishes. This biomechanical behaviour with an improved transmission of loads confirmed by means of FE simulation corresponds to the biological findings obtained with Dual-Energy X-Ray Absorptiometry (DEXA).</p

Efectividad de un programa de ahorro de sangre en prótesis total de cadera electiva

En el ámbito de la Cirugía Ortopédica, la implantación de una prótesis total de cadera es uno de los procesos que más frecuentemente requiere reposición hemática en el postoperatorio inmediato. La autodonación preoperatorio se contempla como uno de los procedimientos más eficaces y seguros, aunque no puede llevarse a cabo en todos los pacientes y deben considerarse otras alternativas como los recuperadores de sangre a partir de los drenajes quirúrgicos o el uso pre-operatorio de eritropoyetina. La experiencia de la autodonación en nuestro hospital en el período 1996-2001 ha permitido reducir las necesidades de sangre alogénica en estos pacientes, y ha clarificado el perfil de pacientes que con mayor probabilidad completarán el programa de autodonación y no precisarán sangre alogénica; y, por el contrario, aquellos que serían candidatos a otras técnicas de reposición hematica.In the field of Orthopaedic Surgery, total hip replacement is one of the procedures that most frequently need post operative blood transfusion. Predeposit autologous transfusión is considered a safety an efficient procedure that virtually eliminates the risk of viral transmission and immunological reactions, but this method can not be use in all the patients and other techniques -like intraoperative and postoperative blood salvage, use of epoetin alfa-, must be considered. Our experience with predeposit autologous transfusión from 1996 to 2001 has allowed use to reduce the need of allogenic blood tranfusion. We defined in what patients we can suggests this technique or consider other alternatives

Tratamiento de las fracturas del fémur distal en ancianos

Presentamos los resultados comparativos del tratamiento con dos métodos diferentes de 55 casos de fractura del fémur distal en pacientes ancianos. Hugo 27 pacientes que fueron tratados con el tornillo dinámico condilar (grupo A) y 28 con tracción esquelética (grupo B). Se obtuvieron resultados excelentes y buenos en el 70% del grupo quirúrgico y en el 30% del grupo no intervenido. Hubo más complicaciones en este último. Cinco pacientes fallecieron, todos ellos en el grupo B.We report the comparative results of treatment of 55 cases of fractures of the distal femur in elderly patients using two different methods. There were 27 patients treated with the dynamic condylar screw (group A), and 28 with skeletal traction (group B). excellent or good results were achieved in 70% of the operated and in 30% of the non-operated group. There were more complications in the latter. Five patients died, all of them in group B