RESUMEN
During open reduction of an irreducible anterior dislocation of a total hip replacement with an Oxinium femoral head, it was observed that the head had been significantly damaged. Gross and scanning electron microscopic examination revealed cracking, gouging, and delamination of the surface. Because of the risk which this poses for damaging the polyethylene acetabular liner, it is strongly recommended that patients with this type of prosthetic head be carefully monitored after a dislocation.
Asunto(s)
Luxación de la Cadera/patología , Prótesis de Cadera , Falla de Prótesis , Artroplastia de Reemplazo de Cadera , Cabeza Femoral/ultraestructura , Luxación de la Cadera/etiología , Luxación de la Cadera/cirugía , Humanos , Masculino , Microscopía Electrónica de Rastreo , Persona de Mediana Edad , Propiedades de SuperficieRESUMEN
An anatomic study was conducted on 49 dried cadaveric humeri and 24 dried cadaveric scapula to ascertain the variability of the following parameters: humeral neck angle, humeral head retroversion, humeral head medial offset, humeral head posterior offset, humeral head diameter glenoid height, glenoid width, and the glenoid height to width ratio. For verification purposes, the results of this study were found to be within 1.5% to 14.3% of other anatomic studies published in the literature. This observed variability was then compared to that provided by an "anatomic" shoulder prosthesis (Equinoxe, Exactech, Inc.); viewed independently, this prosthesis can restore humeral neck angle in 94% of humeri, "secondary" retroversion in 92% of humeri, medial offset in 100% of humeri, posterior offset in 100% of humeri, and humeral head diameter in 96% of humeri. Additionally, the glenoid prosthesis height to width ratio was found to be within 5% and 10% of 71% and 96% of cadaveric glenoids, respectively. The results of this analysis indicate that a dual-offset "anatomic " shoulder prosthesis has the capability to successfully restore glenohumeral anatomy in this representative population.