[Evaluation of factors associated with major hemorrhage in patients undergoing primary total hip arthroplasty]. / Evaluación de factores asociados a hemorragia mayor en pacientes sometidos a artroplastía total de cadera primaria.

INTRODUCTION: the use of blood transfusions leads to increased hospital costs and an increased risk of medical complications and death. Therefore, it is necessary to study the incidence of major bleeding events and the factors associated with these outcomes in patients undergoing primary total hip arthroplasty (THA). MATERIAL AND METHODS: observational, longitudinal and prospective study, carried out at the High Specialty Medical Unit of Traumatology and Orthopedics of Lomas Verdes of the Mexican Institute of Social Security, in the Joint Replacement Service, in the period from March 1, 2020 to July 1, 2020. RESULTS: the incidence of major bleeding in patients undergoing primary THA was 84.8%, when considering two criteria: a decrease in hemoglobin 2 g/dl and the need for transfusion 2 units of red blood cells. This figure increased to 87.1% when also including trans-surgical bleeding at its 75th percentile, equivalent to 500 ml. Transfusion of at least one unit of red blood cells during surgery was performed in 68% of patients. Trans-surgical bleeding reached a maximum of 1,900 ml, with a 75th percentile of 500 ml. Unlike other studies, in our institution, female gender did not prove to be a significant risk factor for major bleeding. CONCLUSION: it is advisable to analyze the procedures and particularities of THA surgery that may be associated with a lower risk of bleeding in older patients.

INTRODUCCIÓN: el uso de transfusiones sanguíneas conlleva aumentos en los costos hospitalarios y un mayor riesgo de complicaciones médicas y fallecimientos; por lo que es necesario el estudio de la incidencia de eventos de hemorragia mayor y de los factores que se asocien a estos desenlaces en los pacientes que se someten a una artroplastía total de cadera (ATC) primaria. MATERIAL Y MÉTODOS: estudio observacional, longitudinal y prospectivo, llevado a cabo en la Unidad Médica de Alta Especialidad de Traumatología y Ortopedia de Lomas Verdes del Instituto Mexicano del Seguro Social, en el Servicio de Reemplazo Articular, en el período comprendido entre el 01 Marzo 2020 al 01 Julio 2020. RESULTADOS: la incidencia de hemorragia mayor en pacientes sometidos a ATC primaria fue de 84.8%, al considerarse dos criterios: una disminución de hemoglobina 2 g/dl y la necesidad de transfusión 2 unidades de glóbulos rojos. Esta cifra aumentó a 87.1% al incluir también el sangrado transquirúrgico en su percentil 75, equivalente a 500 ml. La transfusión de al menos una unidad de glóbulos rojos durante la cirugía se realizó en 68% de los pacientes. El sangrado transquirúrgico alcanzó un máximo de 1,900 ml, con un percentil 75 de 500 ml. A diferencia de otros estudios, en nuestra institución, el género femenino no demostró ser un factor de riesgo significativo para la hemorragia mayor. CONCLUSIÓN: es aconsejable analizar los procedimientos y las particularidades de la cirugía de ATC que puedan estar asociados con un menor riesgo de hemorragia en los pacientes mayores.

Multiple deep tissue cultures in primary total hip arthroplasty: prognostic value for periprosthetic infection.

BACKGROUND: The risk of infection after total hip replacement (THR) is significant, with negative impact on quality of life and high costs. Bacteria can contaminate the surgical site despite aseptic techniques; however, there is debate regarding the benefit of identifying bacteria during the primary procedure. Although taking multiple samples for culture is a well-established practice in revision arthroplasty, doing so in primary cases remains controversial. We aimed to investigate whether there is a prognostic value in the culture of samples taken during primary THR, seeking a correlation between the positivity of the cultures and subsequent prosthetic joint infection (PJI). METHODS: Deep samples (capsule, femoral and acetabular bone) were collected from 426 patients undergoing elective primary THR. Follow-up was at least 3 years. Microbiological profiles of cultures were analysed. Patient data were reviewed for the identification of risk factors presumably associated with a higher risk of PJI. RESULTS: 54 surgeries (12.6%) had positive cultures. 16 cases (3.8%) developed infection, of which 5 had a positive culture in the primary surgery. Infection rate was 9.3% in patients with positive culture and 3% in those with negative culture (p < 0.05), with an odds ratio of 3.34 (95% CI, 1.09-10.24). Patients with previous hip surgery had an infection rate of 8.5%, compared to 2.9% in patients with no previous surgery (p < 0.05). CONCLUSIONS: Routinely harvesting microbiologic samples in primary THR is not justified, as it has no consequence in clinical decision for most patients. It might be recommended in selected cases that are suspected to be at high risk for infection, especially previously operated patients (conversion arthroplasty).

Are Ceramic Bearings Becoming Cost-Effective for All Patients Within a 90-Day Bundled Payment Period?

BACKGROUND: We analyzed whether the total hospital cost in a 90-day bundled payment period for ceramic-on-polyethylene (C-PE) and ceramic-on-ceramic (COC) total hip arthroplasty (THA) bearings was changing over time, and whether the cost differential between ceramic bearings and metal-on-polyethylene (M-PE) bearings was approaching the previously published tipping point for cost-effectiveness of US$325. METHODS: A total of 245,077 elderly Medicare patients (65+) who underwent primary THA between 2010 and 2015 were identified from the United States Medicare 100% national administrative hospital claims database. The total inpatient cost, calculated up to 90 days after index discharge, was computed using cost-to-charge ratios, and hospital payment was analyzed. The differential total inpatient cost of C-PE and COC bearings, compared to metal-on-polyethylene (M-PE), was evaluated using parametric and nonparametric models. RESULTS: After adjustment for patient and clinical factors, and the year of surgery, the mean hospital cost up to 90 days for primary THA with C-PE or COC was within ±1% of the cost for primary THA with M-PE bearings (P < .001). From the nonparametric analysis, the median total hospital cost was US$296-US$353 more for C-PE and COC than M-PE. Cost differentials were found to decrease significantly over time (P < .001). CONCLUSION: Patient and clinical factors had a far greater impact on the total cost of inpatient THA surgery than bearing selection, even when including readmission costs up to 90 days after discharge. Our findings indicate that the cost-effectiveness thresholds for ceramic bearings relative to M-PE are changing over time and increasingly achievable for the Medicare population.

Preservación ósea femoral con tallos cortos de fijación cervicometafisaria. Estudio radiográfico comparativo con tallos no cementados de fijación metafisaria / Femoral bone presevation using short stems with metaphyseal fixation

Introducción: Los tallos no cementados recubiertos con hidroxiapatita de fijación metafisaria han logrado excelentes resultados a largo plazo. La segunda generación de tallos cortos de fijación cervicometafisaria ha surgido a principios de la década de 1990, con el objetivo de preservar capital óseo femoral. Sin embargo, la preservación ósea femoral teóricamente propuesta no ha sido comprobada. El objetivo de este trabajo es determinar radiográficamente la preservación del capital óseo femoral cuando se utilizó un tallo corto de fijación cervicometafisaria, comparando las radiografías posoperatorias con la programación del tallo que se debería haber utilizado en caso de ser un diseño convencional con fijación metafisaria. Materiales y Métodos: Los primeros 50 tallos cortos de fijación cervicometafisaria (MiniHip TM, Corin, Cirencester, Reino Unido) fueron analizados por dos observadores independientes, con radiografías de frente, en cuanto a nivel de resección cervical y longitud del tallo, comparándolos con las filminas de un tallo convencional de fijación metafisodiafisaria (MetaFix TM, Corin, Cirencester, Reino Unido). Resultados: Según el análisis radiográfico, los tallos cortos de fijación cervicometafisaria ocuparon una longitud femoral promedio de 79 mm (rango 68-102). Los tallos convencionales de fijación metafisaria hubiesen ocupado, en promedio, 73 mm más que los tallos cortos (rango 47-94). Esta distribución se observó en el corte de cuello (promedio 10 mm más distal) y en la longitud del implante (promedio 66 mm mayor longitud) (p <0,001). Esta diferencia permite preservar un 42% el capital óseo femoral. Conclusión: La preservación ósea relacionada con el uso de tallos cortos de fijación cervicometafisaria podría traer beneficios a largo plazo en pacientes jóvenes con alta demanda funcional.

Background: Uncemented hydroxyapatite-coated stems with methaphyseal fixation have demonstrated excellent long-term results. Second generation of short stems has been developed in the 90’s with the purpose to preserve femoral bone at the femoral neck and diaphysis. However, the amount of bone that would be theoretically saved has not been well-established. To radiographically determine femoral bone preservation in a series of patients operated on with a short, neck preserving stem, we compared these results with the length of a templated conventional length, uncemented hydroxyapatite-coated stem. Methods: The first 50 short hydroxyapatite-coated uncemented stems (MiniHip TM, Corin, Cirencester, UK) were radiographically analyzed by two independent observers measuring the level of neck cut and the stem length. Then, these results were compared with the level of neck cut and stem length when a conventional, metaphysodiaphyseal stem (MetaFix TM, Corin, Cirencester, UK) was implanted using templates. Results: According to the radiographic results, short stems measured an average length of 79 mm (range 68-102). Conventional stems would have required 78 mm (range 47-94) more bone for fixation than short stems. This difference was observed in the neck cut (average 10 mm more distal with a conventional stems), as well as in the diaphysis (average 66 mm more distal with a conventional stems) (p <0.001). Conclusion: Femoral bone preservation may be related to long-term benefits especially in young patients.