Fluoroscopic imaging guides of the posterior pelvis pertaining to iliosacral screw placement.

BACKGROUND: This study correlates anatomic landmarks with radiographic densities and radiolucencies of the posterior pelvis, which assists in percutaneous iliosacral screw placement. METHODS: Radio-opaque markers were placed on selected surfaces of cadaveric specimens and rotated under a fluoroscopic beam. Identified surfaces were described with angular measurements and anatomic characteristics. RESULTS: The anterior border of the S1 body is not parallel to the anterior border of the S1 ala. The anterior surface of the S1 ala is found on the inlet view ( approximately 49 degrees ) by the superimposition of the S1 and S2 alar ridges. Superior surface of the S1 ala is difficult to visualize fluoroscopically because of the highly oblique outlet angle required by fluoroscopy ( approximately 80 degrees ). The superior ridge of the S1 foramen can best be seen during an outlet view when the projection of the superior pubic symphysis is superimposed on the S2 foraminal image. Posterior bony surfaces of the ilium, foraminal region of sacrum, and sacral body are difficult to identify, as are the bony surfaces of the sacral foramina. During screw placement, the narrowest area of bone occurs in the sacral foraminal region. CONCLUSIONS: Use of predetermined angles for inlet and outlet views may not provide optimal visualization of relevant bony landmarks during iliosacral screw insertion. Because of variable sacral morphologies and lumbosacral lordosis, we propose using inherent landmarks to help visualize important landmarks during screw placement. Altering the fluoroscopic angle to superimpose the anterior S1 and S2 alar opacities allows the best visualization of the anterior boundary of the S1 ala. The superior bony surface of the S1 foramen is best visualized on the outlet view.

Femur fractures and lung complications: a prospective randomized study of reaming.

Reaming the intramedullary canal during fixation of femoral shaft fractures may contribute to pulmonary morbidity in patients with trauma. The purpose of our study was to compare acute and late pulmonary complications after reamed or nonreamed nailing of femur fractures. Patients who had femoral shaft fractures were randomized prospectively to a reamed (n = 41) or nonreamed (n = 41) femoral nailing group. Arterial blood gases were measured before and after femur fixation. Ratios of PaO2/FiO2 and alveolar arterial gradients were calculated. Pulmonary complications (acute respiratory distress syndrome) (ARDS), pneumonia, and respiratory failure) were monitored. Age, gender, fracture site, fracture type, time to nailing, length of operation, Injury Severity Score, and Abbreviated Injury Scale-thorax were similar for the two groups. No significant differences were observed in the ratio of PaO2/FiO2 ratios or alveolar arterial (A-a) gradients before and after nailing. The overall incidence of pulmonary complications was 14.6% (eight patients who had reamed nailing and four patients who had nonreamed nailing), and given the sample size, definitive conclusions could not be reached because of inadequate statistical power. We were unable to document differences in pulmonary physiologic response or clinical outcome between patients having reamed and nonreamed femoral nailing. This study may serve as a pilot investigation for other clinical investigations.

Effect of neoadjuvant chemotherapy on distraction osteogenesis in the goat model.

Neoadjuvant chemotherapy potentially can have an adverse effect on bone healing in distraction osteogenesis whether given before or concomitant with distraction osteogenesis. It was the purpose of the current study to determine if administration of chemotherapy before distraction adversely affects bone generation in distraction osteogenesis. Twenty-four adult dairy goats were divided randomly into two groups: a control group having distraction osteogenesis only and a chemotherapy group, receiving one course of Adriamycin before distraction osteogenesis. The animals were sacrificed at 6 weeks, 12 weeks, or 24 weeks and the lengthened tibias were evaluated by radiologic studies, biomechanical testing, and histologic analysis. All goats receiving chemotherapy showed systemic adverse effects. In a multifactorial analysis of the lengthened bones, there was no statistically significant difference between the control goats versus goats that received chemotherapy; indicating that there was no sustained inhibitory effect on bone formation by the chemotherapy. These findings suggest that a prior course of chemotherapy with Adriamycin may not be a contraindication to limb lengthening for limb salvage after resection of an osteosarcoma.

Treatment of femoral diaphyseal nonunions.

There have been conflicting reports regarding treatment of femoral diaphyseal nonunions using reamed intramedullary nailing. Although high union rates have been reported using this technique, not all orthopaedic surgeons have experienced the same success. A retrospective review of charts and radiographs of 39 adult patients with nonunions of the femoral diaphysis treated at the authors' institution with reamed intramedullary nailing, compression, and with and without interlocking was done. The time from the index procedure to nonunion repair was 4 to 75 months (average, 19 months). Fifteen patients had 18 procedures between the index operation and nonunion repair. The average followup from nonunion repair to the most recent examination was 22.5 months (range, 3-108 months) with a median of 15 months. At the last followup, the overall union rate was 74% after one procedure and 97% after two or more procedures. There were seven complications including two infections, one pulmonary embolus, one occurrence of a deep venous thrombosis, a hematoma, and one case of malrotation. The data support the use of antegrade reamed nailing as a successful technique for treatment of most femoral diaphyseal nonunions.