No abstract

We present the first records of Mesozoic fossil birds to be described from British Columbia. New fossil avians from the Campanian Northumberland Formation on Hornby Island (Strait of Georgia) add to the known distributions of two groups of fossil birds during the latter stage of the Mesozoic. New specimens referred to the clades Ornithurae and Enantiornithes demonstrate the presence of a diverse marine avifauna in Canadian Pacific marine sediments prior to the Cretaceous–Tertiary (K–T) boundary. These new fossil bird remains from coastal rocks on the west coast of British Columbia lend further support to suggestions that ocean-going birds were important constituents of marine ecosystems in the terminal stages of the Mesozoic.

Because significant postoperative blood loss can result in many complications, hemostasis remains a critical part of successful joint replacement outcomes. Advanced techniques, such as electrocautery use after optimally timed tourniquet release, focus on desired patient blood loss outcomes. The purposes of this study were to report the incidence of nerve injury, identify associated risk factors following the use of bipolar electrocautery for hemostasis in the posterior knee during primary total knee arthroplasty, and compare that rate with the rate seen using a standard electrocautery device. Clinical and operative data were retrospectively reviewed for an association with postoperative nerve injury in 241 consecutive patients when using bipolar electrocautery between July 2007 and October 2008. A comparison group of 192 demographically similar consecutive patients between November 2008 and October 2009 was also evaluated to establish a surgeon-specific benchmark when using standard electrocautery. Seven (2.9%) of 241 patients in the bipolar electrocautery group reported documented neuropathies compared with 1 (0.52%) of 192 patients using standard electrocautery. In addition, female sex and rheumatoid arthritis were associated with postoperative nerve injury following bipolar electrocautery. Although the bipolar radiofrequency device is effective in achieving hemostasis, the authors recommend judicious use of this procedure in women or patients with rheumatoid arthritis and cautious, nonaggressive use of posterior compartment bipolar radiofrequency ablation in the remaining patient populations.