Pelvic fractures: experience of pelvic ring fractures at a major trauma centre.

In this review, we discuss the imaging classification of pelvic ring fractures in the context of our experience of reporting trauma computed tomography (CT) in a major trauma centre. Pelvic ring fractures are potentially significant injuries with risk of significant haemorrhage and morbidity. This review details the use of classification systems in determining the mechanism and severity of injury, with discussion of the features of the Young and Burgess classification system. We demonstrate the different types of pelvic ring fracture with examples from trauma CT, and with reference to the distribution and frequency of these injuries in trauma patients. This review will allow the reader to assess trauma CT for significant pelvic ring injury and identify features of instability.

Mechanical and histological fixation of hydroxylapatite-coated pyrolytic carbon and titanium alloy implants: a report of short-term results.

Historically, pyrolytic carbon has been a material for cardiovascular applications, but it has several properties suited for orthopedic uses as well. Pyrolytic carbon has an elastic modulus similar to bone and is highly fatigue resistant, but has not been used in orthopedics because of poor fixation to bone. Plasma sprayed hydroxylapatite (HA) has significantly improved the bonding of bone to titanium alloy implants. The effect of plasma-sprayed HA on pyrolytic carbon implants was investigated in this study. Cylindrical samples were implanted through a single cortex in Beagle femurs. The animals were sacrificed after 8 weeks, and a mechanical push-out test was performed on the implants immediately after explantation. Samples were microradiographed, stained for histology, and examined histomorphometrically. Interface strength for each type of implant was calculated. Pyrolytic carbon showed almost no attachment strength with an average strength value of 1.59 MPa. HA-coated pyrolytic carbon (8.71 MPa) yielded the same interfacial strength as HA-coated titanium (8.71 MPa). Histology revealed that bone was in direct apposition to all implants, both HA coated and noncoated. Failures occurred between the core material and the coating, or within the coating, but not at the bone/HA interface. Histomorphometry results confirmed that the two types of HA-coated implants had more bone apposition than the uncoated pyrolytic carbon implants. It was concluded that a plasma sprayed HA coating significantly improves the bone fixation of pyrolytic carbon.