A reinforced rigid fixation device for unstable intertrochanteric fractures

A 120 degrees blade plate reinforced by a strut is introduced for the treatment of unstable intertrochanteric and proximal subtrochanteric fractures. Mechanical tests showed that the strength of this reinforced resistance device was 11,758 N. This strength is two and three times greater than that of the Gamma nail and sliding hip screw, respectively, and five times greater with the strut than without it. Three hundred fifty-eight patients older than 60 years of age were treated with this method between 1987 and 1991 (mean followup, 16 months). Six months after surgery the fracture had united in 82% of the patients who were walking without aid or using only a cane. Weightbearing began when the patient's general overall condition allowed such activity (average, 5 days; mode, 3 days). A chi squared test showed no difference regarding the results between stable and unstable fractures. Intraoperative and postoperative complication rates were 3% and 7.1%, respectively. The failure of fixation rate was 5.4%. Mechanical tests and clinical results showed that immediate weightbearing can be allowed in all types of intertrochanteric fractures. This reinforced device is effective in treating unstable intertrochanteric fractures and is especially indicated for the most unstable types (Evans' Grades 4 and 5).     

Intimate combination of low- and high-resolution image data: I. Real-space PET and (1)H(2)O MRI, PETAMRI.

Two different types of (co-registered) images of the same slice of tissue will generally have different spatial resolutions. The judicious pixel-by-pixel combination of their data can be accomplished to yield a single image exhibiting properties of both. Here, axial (18)FDG PET and (1)H(2)O MR images of the human brain are used as the low- and high-resolution members of the pair. A color scale is necessary in order to provide for separate intensity parameters from the two image types. However, not all color scales can accommodate this separability. The HSV color model allows one to choose a color scale in which the intensity of the low-resolution image type is coded as hue, while that of the high-resolution type is coded as value, a reasonably independent parameter. Furthermore, the high-resolution image must have high contrast and be quantitative in the same sense as the low-resolution image almost always is. Here, relaxographic MR images (naturally segmented quantitative (1)H(2)O spin-density components) are used. Their essentially complete contrast serves to effect an apparent editing function when encoded as the value of the color scale. Thus, the combination of (18)FDG PET images with gray-matter (GM) relaxographic (1)H(2)O images produces visually "GM-edited" (18)FDG PETAMR (positron emission tomography and magnetic resonance) images. These exhibit the high sensitivity to tracer amounts characteristic of PET along with the high spatial resolution of (1)H(2)O MRI. At the same time, however, they retain the complete quantitative measures of each of their basis images. Magn Reson Med 42:345-360, 1999. Published 1999 Wiley-Liss, Inc.