J. P. LiPuma

Posterior Hip Dislocations: A Cadaveric Angiographic Study

Avascular necrosis (AVN) of the femoral head after a traumatic posterior hip dislocation (Thompson and Epstein type I) has been hypothesized to occur due to changes in blood flow. However, to the best of our knowledge of the English literature, a human cadaveric angiographic study has never been performed to delineate these vascular changes. Six fresh frozen human cadavers were used to examine the effects of posterior hip dislocation on the extraosseous and intraosseous blood supply to the femoral head and neck. After a forceful posterior hip dislocation was performed on the cadavers, the proximal vessels were injected with a radioopaque colored latex liquid polymer (Microfil) and examined under cinefluoroscopy. The contra lateral hips were used as controls and were examined in a similar manner. Both hips of the cadavers were harvested, and a macroscopic and microscopic examination was performed. The cine-fluoroscopic examination delineated the dynamic effects of posterior dislocation on the surrounding vasculature. Filling defects were most notable at the junction of the external iliac and common femoral arteries. Filling defects were also present in the circumflex vessels. Compared to controls, the common femoral and circumflex vessel filling defects were statistically significant (p < 0.004). These defects were secondary to an apparent stretching and twisting of the artery caused by the pull and rotation of the dislocated hip. A number of collateral vessels from the gluteal arteries were also demonstrated on fluoroscopic examination. The macro and microscopic examination did not show a qualitative or a quantitative difference in the amount of latex present in the dislocated and control groups. Based on the results of this study, changes in the extraosseous blood flow to the dislocated hip do occur. The vessels that appear to be most affected by the dislocation are the common femoral and circumflex vessels. However, these extraosseous changes do not consistently result in changes in the intraosseous blood flow possibly due to collateral circulation. Relocating the femoral head in a traumatic posterior hip dislocation may provide earlier blood flow to the femoral head by relieving tension across the femoral and circumflex vessels. Delayed relocation could contribute to the development of AVN in the femoral head by not only inducing immediate ischemia at the time of injury but by also producing a progressive and delayed form of arterial damage in the femoral and circumflex vessels. AVN may not be an absolute outcome of posterior hip dislocations due to preexisting collateral circulation and/or the preservation of the femoral circumflex vessels.

Initial experience with nuclear magnetic resonance (NMR) imaging of the human breast.

Two patients with breast abnormalities, one malignant and one benign, were studied with nuclear magnetic resonance (NMR) imaging utilizing a cryogenic superconducting magnet. Three-dimensional NMR images were obtained in one case and single slice planar images were obtained in the other. The NMR images correlated well with the corresponding mammograms. Although both conditions exhibited a different signal intensity for the area of abnormality compared to adjacent ductal and fatty tissue, the configuration of the abnormal areas allowed distinction between benign and malignant process.

Popliteal artery pseudoaneurysm in a patient with hereditary multiple exostoses : MRI and MRA diagnosis

We describe the MR and MR angiographic findings of a popliteal artery pseudoaneurysm in a patient with hereditary multiple exostoses

Percutaneous Nephrostomy in Neonates and Infants

A total of 8 patients between 2 days and 2 years old underwent 13 percutaneous nephrostomies for treatment of hydronephrosis. No significant complications were encountered.

Lymphangioma of the thymus in a child.

Computed tomographic (CT) evaluation of a rare thymic tumor in a child is described. The CT characteristics, pre- and postcontrast enhancement, are described and correlated with ultrasound and plain radiographic findings. Correlation is made between the CT results and the thymic lymphangioma with a subsequently identified abdominal lymphangioma.

Gall stone removal via a postoperative cholecystotomy catheter tract

A surgical cholecystotomy catheter tract was used to remove multiple residual gallbladder calculi postoperatively. The extractions were carried out employing the Burhenne technique. The approach described offers an attractive alternative to surgery in poor-risk patients.