[Survey on the use and behaviour of metal-metal hip replacements in Spain]. / Encuesta sobre el uso y comportamiento de las prótesis de cadera metal-metal en España.

BACKGROUND: Following medical device alerts published in different countries of problems with metal-on-metal total hip replacements, the Spanish Agency of Medicines and Medical Devices (AEMPS) in collaboration with the Spanish Hip Society Surgery designed a national survey to gather information on the use and behaviour of these hip implants. METHODS: The survey consisted of a questionnaire sent by e-mail to 283 clinical centre recipients of metal-on-metal hips to be filled in by surgeons with expertise in the field. RESULTS: A total of 257 questionnaires were completed. The response rate of the clinical centres was 36.7%. A total of 97.7% of the responses reported that clinical and radiological follow-ups are carried out, and 79.6% undertook metal ion analyses (chromium and cobalt). A large majority (83.6%) of the responders who had who used surface implants, and 70% of those with large-head implants reported peri-operative complications. The most common complication was pain (25% with surface implants and 30.8% with large-head implants). Currently 80.8% of those responding were considering abandoning implanting of these hip replacements. CONCLUSIONS: Despite the many limitations to this study, the survey has allowed us to obtain in a quick first view of the implant scenario of Metal on Metal hip implants in Spain, and to determine the type of patient implanted, the time of implantation, and the experience/expertise of the surgeons, and the type of follow-up carried out.

Prótesis de superficie de cadera en presencia de osteosíntesis femoral proximal / Hip resurfacing in the presence of proximal femoral osteotomy

Describimos un caso de reemplazo de superficie de cadera en un paciente con artrosis posterior a necrosis ósea avascular y material de osteosíntesis femoral proximal de difícil extracción. Con las prótesis de superficie se logran buenos resultados si la indicación y la técnica quirúrgica son las correctas. En este caso, facilitó mucho la artroplastia, con un muy buen resultado funcional; se evita una cirugía con mayor morbilidad y una tasa más alta de complicaciones y revisiones, como ocurre con los reemplazos de cadera convencionales tras el retiro de la osteosíntesis proximal de fémur. Los cirujanos de cadera atendemos a estos pacientes con frecuencia; estamos seguros de que este tipo de cirugías debe incluirse en nuestro arsenal terapéutico. A pesar de las desventajas de esta artroplastia (fricción metal/metal, curva de aprendizaje, fracturas del cuello femoral), consideramos que, en estos casos, dichas complicaciones están compensadas por la simplicidad del procedimiento.

We describe a hip resurfacing case in a patient with arthrosis after avascular necrosis and proximal femoral osteosynthesis material difficult to remove. Hip resurfacing achieves good results when its indication and technique are correct. In this case, it facilitated the arthroplasty achieving an excellent functional result; avoiding a major surgery and the high rate of complications and revisions, as it occurs with conventional hip replacements after osteosynthesis of the proximal femur. Surgeons frequently face this type of patients; therefore we are convinced that this procedure must be in our therapeutic arsenal. Besides the disadvantages of this arthroplasty (metal on metal friction, learning curve, neck fracture) we consider that they are compensated for by the simplicity of the procedure.