The InterTan device appears to be a reliable implant for the treatment of intertrochanteric femoral fractures. Its design provides for stability against rotation and minimizes neck malunions (shortening) through linear intraoperative compression of the head/neck segment to the shaft. As a result of the negligible complication rate and improved clinical outcomes, this implant is now the standard treatment for all intertrochanteric fractures at our institution.

Fractures of the humeral head are frequent and will further increase due to demographic changes. Prior to operative fracture treatment, the regional differences of bone quality, especially of elderly people, have to be carefully considered to assure stable implant fixation. However, conclusive data concerning the variation of histomorphometric parameters are still lacking. Consequently, the purpose of this study was to analyze the age-and sex-related changes in bone microarchitecture. For that reason, 60 proximal humeri were harvested from patients at autopsy. Twelve regions of interest (ROI) were defined for each centered coronar humeral head slice and the specimens were subjected to radiographic, histological, and histomorphometric analyses. We could demonstrate that in contrast to men, women over 60 years of age had a significant age-related decrease in bone mass. The most prominent decrease was observed in the region of the greater tuberosity, which represents an osteoporotic fracture site. The most superior and medially located part of the centered coronar humeral head slice showed, independent from age and sex, the highest bone mass and can therefore be considered as the best location for subchondral screw placement. Taken together, our study revealed distinct sex-related changes of the humeral head bone microarchitecture with aging, which should be considered in implant positioning. ß

The best predictive accuracy for presence of TBI was obtained using the GCS components. Pupil reactivity together with the GCS motor component performed best in predicting death.

Our results suggest that (1) none of the tested devices restore a comparable mechanical strength in the fractured specimens compared with the intact femurs, and (2) the "IT" possesses some biomechanical benefits for internal fixation of unstable femoral neck fractures compared with DHS and CS. Because the IT constructs failed with an inferior femoral neck fracture, complicating the mandatory anchorage of a prosthetic stem in a revision operation, more biomechanical experiments using the IT in the presence of a posterior comminution defect are required, along with clinical outcome studies.

I.

In comminuted Pauwels type III fractures, the fixation with the IT provided sufficient postoperative mechanical strength, comparable rate of femoral head displacement, and a similar tolerance of physiological loads compared to fractures without comminution. The absence of the posteromedial support in comminuted fractures tended to reduce the failure load regardless of the fixation method.

No abstract

Correct placement of iliosacral screws remains a surgical challenge. The aim of this retrospective study was to identify parameters which impact the accuracy of this technically demanding procedure. Eighty-two patients with vertically unstable pelvic injuries treated with a total of 147 iliosacral screws were included. Assessment of postoperative CT scans revealed screw misplacement in 13 cases (8%), of which six occurred following insertion of two unilateral screws into S1. Six screw misplacements occurred in patients with dislocation injuries of the posterior pelvis. Comparison of a navigated and the standard technique revealed a decreased screw misplacement rate in the navigated group (15% standard vs. 3% navigation, p<0.05). In addition, the malposition rate was influenced by the surgeon's individual experience (20% for low vs. 3.9% for high volume surgeons, p<0.05). Overall, the accuracy of iliosacral screw placement depends on the number of screws inserted into S1 and the extent of dislocation. In experienced hands, the use of navigation represents a helpful tool to improve the placement accuracy.