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Mean metal−ligand bond distances for the coordination ligands isothiocyanate, pyridine, imidazole, water, and chloride, bound to the transition metals Mn, Fe, Co, Ni, Cu, and Zn in their 2+ oxidation states, were collected from searches the Cambridge Structure Database. The metal−ligand bond distances were converted to bond orders through the bond distance-bond order technique, as suggested by Pauling. The mean bond order sums at the 2+ metal centers were found to be independent of coordination number or geometry and to be strongly ligand-dependent; the values (by ligand) are as follows:  isothiocyanate = 2.56 ± 0.13; imidazole = 2.13 ± 0.04; chloride = 2.12 ± 0.07; pyridine 1.95 ± 0.10; water = 1.88 ± 0.10. The bond order sum for Fe(III) bound to chloride was found to be 3.09, approximately one bond order unit larger than for the 2+ metal centers bound to chloride. Division of the ligand-specific bond order sums by coordination number allows prediction of the M−L bond distance to within 0.017 Å, regardless of the specific coordination geometry. The physical basis for the ligand-specific variation in bond order sum is also discussed.

The inherent ability of pediatric metaphyseal radius fractures to heal and remodel made us question the need for immediate anatomic reduction under conscious sedation. We believe that isolated closed distal radius fractures with 15 degrees of angulation and 1 cm of shortening will heal well and remodel completely without clinical or functional sequelae. Time and expense can be decreased by splinting and follow-up without the need for immediate anatomic reduction in the emergency room. In order to answer this question, we retrospectively evaluated 34 pediatric metaphyseal wrist fractures that lost position after attempted reduction and healed in their angulated or shortened position. We looked at the time to healing, time to remodeling and any residual clinical or functional deficits. We then did a comparison cost analysis with time matched patients who had complete but minimally displaced fractures of the distal radius that were treated by immediate splinting with orthopaedic follow-up. Our results showed that skeletally immature patients with open physes, isolated injuries, dorsovolar and radioulnar angulations less than 15 degrees and less than 1 cm of shortening will heal and be out of cast within an average of 6 weeks and completely remodel within an average of 7.5 months. The average time in the emergency room was 2 h less with no reduction. The cost of the emergency room visit with attempted reduction was 50% more than splinting with early referral (US dollars 536 versus US dollars 270). None of our patients had significant clinical deformities or residual functional deficits.

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BACKGROUND AND PURPOSE:Our aim was to determine the patterns of error of radiology residents in the detection of intracranial hemorrhage on head CT examinations while on call. Follow-up studies were reviewed to determine if there was any adverse effect on patient outcome as a result of these preliminary interpretations.

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We report our experience with resident preliminary interpretations given at night on both abdominal and neurological CT scans to quantify the discrepancy rate when compared to the final report. An attempt was also made to document any adverse clinical outcomes as a result of the preliminary interpretation. From January 1, 2004 to December 31, 2004, adult CT examinations were prospectively interpreted by residents at night at a level I trauma center. Both the neurological and body CT scans were reviewed beginning at 7:00 a.m. the following morning by the respective subspecialty staff and discrepancies were noted. Adult CT examinations (6,858) were prospectively interpreted by residents: 5,206 cranial spinal CT examinations and 1,652 body CT examinations. Among the neurological studies, there were six cases identified as major discrepancies (0.1%) and 185 minor discrepancies (3.5%). Among the body CT cases, there were seven cases identified as major discrepancies (0.4%) and 23 cases of minor discrepancies (1.4%). There is a low discrepancy rate (0.2% major and 3.1% minor) in the preliminary resident interpretations from the final report. The process of overnight preliminary CT interpretations should continue as it is not substandard care.

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