Oliver Portner

University of Ottawa, Ottawa, Ontario, Canada

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Publications (3)9.55 Total impact

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    Oliver Portner
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    ABSTRACT: According to the literature, closing and opening wedge high tibial valgus osteotomies can raise or lower the patella, and diffèrent methods of patella height measurement show similarly conflicting results. Clarification of this was thought to be important because there is much literature describing morbidity secondary to patella alta or patella infera (baja). Effects on tibial slope and patellar tendon length are not well delineated and the influence of sex and age is unknown.
    Preview · Article · Jul 2014 · Clinical Orthopaedics and Related Research
  • Kathleen Gartke · Oliver Portner · Monica Taljaard
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    ABSTRACT: Continuous perineural blocks are increasingly popular for postoperative pain control. While the reported incidence of neuropathic symptoms has been low, the experience of the lead author suggested it may be much higher. The objectives of this study were to elucidate the incidence of patient-reported neuropathic symptoms following continuous popliteal block (CPB) for postoperative pain control in patients undergoing foot and ankle surgery, to characterize these symptoms and to identify preoperative risk factors. A prospective cohort study of 147 surgical patients undergoing significant foot and ankle procedures was carried out. Patients were followed for 8 months post-surgery. Preoperative/perioperative questionnaires were completed by anesthesiologists. Patients completed questionnaires at 2, 6, 14, and 34 weeks. Multivariable logistic regression analysis using Generalized Estimating Equations (GEE) was used to examine risk factors for neuropathy. The prevalence of neuropathic symptoms at 2 weeks was 41% (95% CI, 33% to 49%) decreasing to 24% (95% CI, 15.4% to 32.5%) at 34 weeks. Multivariable analyses revealed that tourniquet placement, tourniquet time, use of prophylactic antibiotics, type of anesthesia, level of training in anesthesiology, patient history of chronic pain and patient age were not significantly associated with neuropathy. Smokers were more likely to report neuropathic symptoms (adjusted OR, 2.25; 95% CI, 0.96 to 5.33). The incidence of neuropathic symptoms may be much higher than previously reported. Smoking may be a risk factor for the development of neuropathic symptoms.
    No preview · Article · Apr 2012 · Foot & Ankle International
  • Oliver Portner · Hossein Pakzad
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    ABSTRACT: Patellar height is evaluated with ratios that have been derived from measurements made on lateral radiographs of the knee. The importance of using a ratio is that magnification, physical size, and flexion angle are eliminated as factors that affect the values. The Insall-Salvati index was the first ratio to be described. It remains the most popular, possibly because normal values are easy to remember. As all of the currently accepted methods are cumbersome to use because they require two measurements as well as a calculation, a single angular measurement was devised (the plateau-patella angle) to offer a simpler alternative. The purpose of this study was to introduce the new method and to assess its validity by comparing it with three classic, commonly used ratios. In two groups of patients, after exclusions, 269 lateral radiographs of the knee were evaluated. All measurements required for the Insall-Salvati, the Blackburne-Peel, and the Caton-Deschamps indices plus the plateau-patella angle were recorded, along with basic demographics. For validation, the new method was compared with the established methods, and interobserver and intraobserver reliability were computed. There was excellent correlation between the proposed angle and the three selected indices, especially with the Blackburne-Peel index. Interobserver and intraobserver reliability was high and compared favorably with that reported in the literature for the three classic ratios. The calculated ratios were in line with those described in the literature. The mean plateau-patella angle was 25°. Ninety percent of the measurements fell between 20° and 30°, and one standard deviation above and below was 21° to 29°. The plateau-patella angle, a new method of evaluating patellar height, can be measured rapidly with use of either a goniometer or digital software. Its range is easy to remember, it is reliably reproduced, and it correlates well with traditional methods. It is thus a valid and easy alternative method for the evaluation of patellar height.
    No preview · Article · Jan 2011 · The Journal of Bone and Joint Surgery