A computed tomography (CT) based morphometric study of superior pubic ramus anatomy among Arabs to determine safe intramedullary pubic rami screw insertion.

PURPOSE: To assess the morphometric variables of the superior pubic ramus in an Arab/ Middle Eastern population to establish a safe pubic screw fixation technique. METHODS: Cross-sectional retrospective analysis of computed tomography (CT) pelvic images. Morphometric data were extracted including; on pubic ramus length, insertion angles, potential danger zones and ramus diameters. The correlation between pubic rami diameter and patient demographics was also analyzed. RESULTS: A total of 231 participants were included (45% female). The mean pubic ramus length was 104 mm in females and 127 mm in males. The narrowest canal diameters at the para-symphyseal area were; 7.35 mm (males) and 4.75 mm (females). The mediolateral insertion angle was 49.4° in females and 41.8° in males. The cephalic-caudal angle was 49.9° in males and 42.1° in females. The mean distance from the lateral ilium entry point to the joint articular surface was 23.5 mm in males and 19.9 mm in females. The symphysis pubis to tubercle exit point was higher in females than males (24.2 mm vs 16.6 mm, respectively). There was a significant positive correlation between age and pubic ramus diameters in all age groups. CONCLUSION: The results from this study suggest that percutaneous pubic rami screw fixation using the standard 6.5 or 7.3 mm cannulated screw system may potentially be unsafe in female Arab patients. This subset of patients may require alternative non-cannulated screws (3.5-4.5 mm) or plate options. Further, female patients may have a higher risk of acetabular joint penetration, while males have a potentially higher risk of pudendal nerve injury.

Contrast-enhanced cranial computed tomography in magnetic resonance imaging era.

OBJECTIVE: To evaluate the usefulness of intravenous contrast administration in cranial computed tomography (CT) in a general hospital with a magnetic resonance imaging (MRI) facility, and to establish a protocol to determine which patients would benefit most from using contrast-enhanced cranial CT. SUBJECTS AND METHODS: Five hundred and forty-seven patients who underwent routine nonenhanced CT (NECT) and contrast-enhanced CT (CECT) of the brain between June 1997 and June 2001 were divided into three groups. Group A: 496 patients in whom CECT was done in spite of normal NECT; group B: 16 patients in whom CECT was considered necessary irrespective of NECT findings, and group C: 35 patients in whom NECT was abnormal and CECT was performed. RESULTS: Contrast-enhanced cranial CT changed and/or confirmed the diagnosis in 1 of 496 in group A, 2 of 16 in group B, and 12 of 35 in group C, thereby indicating that CECT was useful in the diagnosis of groups B and C. CONCLUSION: CECT is unlikely to be useful in patients with normal NECT in the appropriate clinical setting. A protocol is presented for the use of contrast media in cranial CT in a general hospital with an MRI facility. Using this protocol only 9.7% of patients for cranial CT would have needed CECT, resulting in considerable cost savings without affecting the quality of the service to the patient in a general hospital.