Douglas D R Naudie

London Health Sciences Centre, London, Ontario, Canada

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Publications (66)124.59 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: We previously demonstrated the feasibility and clinical effectiveness of a web-based assessment following total hip or total knee arthroplasty. The purpose of the present study was to conduct an economic evaluation to compare a web-based assessment with in-person follow-up. Patients who had undergone total joint arthroplasty at least twelve months previously were randomized to complete a web-based follow-up or visit the clinic for the usual follow-up. We recorded travel costs and time associated with each option. We followed patients for one year after the web-based or in-person follow-up evaluation and documented any resource use related to the joint arthroplasty. We conducted cost analyses from the health-care payer (Ontario Ministry of Health and Long-Term Care) and societal perspectives. All costs are presented in 2012 Canadian dollars. A total of 229 patients (118 in the web-based group, 111 in the usual-care group) completed the study. The mean cost of the assessment from the societal perspective was $98 per patient for the web-based assessment and $162 per patient for the usual method of in-person follow-up. The cost for the web-based assessment was significantly lower from the societal perspective (mean difference, $-64; 95% confidence interval [CI], $-79 to $-48; p < 0.01) and also from the health-care payer perspective (mean difference, $-27; 95% CI, $-29 to $-25; p < 0.01). The web-based follow-up assessment had a lower cost per patient compared with in-person follow-up from both societal and health-care payer perspectives. Copyright © 2014 by The Journal of Bone and Joint Surgery, Incorporated.
    The Journal of bone and joint surgery. American volume. 11/2014; 96(22):1910-6.
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    ABSTRACT: Highly crosslinked polyethylene (XLPE) is believed to demonstrate better wear resistance than conventional polyethylene (CPE) in total hip arthroplasty.
    Clinical Orthopaedics and Related Research 08/2014; · 2.79 Impact Factor
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    ABSTRACT: We sought to determine what dimensional changes occurred from wear testing of a total knee implant, as well as whether any changes developed within the polyethylene subsurface. Three fixed bearing implants underwent wear simulator testing to 6.1 million cycles. Gravimetric analysis and micro-CT scans were performed pre-test, mid-test, and post-test. Wear volume and surface deviations were greater during 0-3.2 million cycles (91 ± 12 mm3) than from 3.2-6.1 million cycles (52 ± 18 mm3). Deviations (wear and creep) occurred across all surfaces of the tibial inserts, including the articular surface, backside surface, sides, and locking mechanism. No subsurface changes were found. The micro-CT results were a useful adjunct to gravimetric analysis, better defining the dimensional changes that occurred with testing and ruling out subsurface fatigue.
    The Journal of Arthroplasty 08/2014; · 2.11 Impact Factor
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    ABSTRACT: Increased modularity of total hip arthroplasty components has occurred, with theoretical advantages and disadvantages. Recent literature indicates the potential for elevated revision rates of modular neck systems and the potential for local pseudotumor and metallosis formation at the modular neck/stem site. Retrieval analysis of one modular neck implant design including SEM (Scanning Electron Microscopy) assessment was done and correlated to FEA (Finite Element Analysis) as well as clinical features of patient demographics, implant and laboratory analysis. Correlation of the consistent corrosion locations to FEA indicates that the material and design features of this system may result in a biomechanical reason for failure. The stem aspect of the modular neck/stem junction may be at particular risk.
    The Journal of Arthroplasty 06/2014; · 2.11 Impact Factor
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    ABSTRACT: A web-based followup assessment may be a feasible, cost-saving alternative of tracking patient outcomes after total joint arthroplasty. However, before implementing a web-based program, it is important to determine patient satisfaction levels with the new followup method. Satisfaction with the care received is becoming an increasingly important metric, and we do not know to what degree patients are satisfied with an approach to followup that does not involve an in-person visit with their surgeons. We determined (1) patient satisfaction and (2) patients' preferences for followup method (web-based or in-person) after total joint arthroplasty. We randomized patients who were at least 12 months after primary THA or TKA to complete a web-based followup or to have their appointment at the clinic. There were 410 eligible patients contacted for the study during the recruitment period. Of these, 256 agreed to participate, and a total of 229 patients completed the study (89% of those enrolled, 56% of those potentially eligible; 111 in the usual-care group, 118 in the web-based group). Their mean age was 69 years (range, 38-86 years). There was no crossover between groups. All 229 patients completed a satisfaction questionnaire at the time of their followup appointments. Patients in the web-based group also completed a satisfaction and preference questionnaire 1 year later. Only patients from the web-based group were asked to indicate preference as they had experienced the web-based and in-person followup methods. We used descriptive statistics to summarize the satisfaction questionnaires and compared results using Pearson's chi-square test. Ninety-one patients (82.0%) in the usual-care group indicated that they were either extremely or very satisfied with the followup process compared with 90 patients (75.6%) who were in the web-based group (p < 0.01; odds ratio [OR] = 3.95; 95% CI, 1.79-8.76). Similarly, patients in the usual care group were more satisfied with the care they received from their surgeon, compared with patients in the web-based group (92.8% versus 73.9%; p < 0.01, OR = 1.37; 95% CI, 0.73-2.57). Forty-four percent of patients preferred the web-based method, 36% preferred the usual method, and 16% had no preference (p = 0.01). Our results show moderate to high satisfaction levels with a web-based followup assessment. Patients who completed the usual method of in-person followup assessment reported greater satisfaction; however, the difference was small and may not outweigh the additional cost and time-saving benefits of the web-based followup method. Level I, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.
    Clinical Orthopaedics and Related Research 02/2014; · 2.79 Impact Factor
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    ABSTRACT: Currently, there is a lack of high-level evidence addressing the variety of treatment options available for patients diagnosed with femoroacetabular impingement (FAI). The objective was to determine the current state of practice for FAI in Canada. A questionnaire was developed and pretested to address the current state of knowledge among orthopaedic surgeons regarding FAI treatment using a focus group of experts, reviewing prior surveys, and reviewing online guidelines addressing surgical interventions for FAI. The membership of the Canadian Orthopaedic Association (COA) was surveyed through email and mail in both French and English. Two hundred and two surveys were obtained (20 % response rate), of which 74.3 % of respondents manage patients under age 40 with hip pain. Most surgeons (62 %) considered failure of non-operative management as the most important indication for the surgical management of FAI, usually by treating both bony and soft tissue damage (54.4 %). The majority of surgeons were unsure of the existence of evidence supporting the best clinical test for FAI, the use of a diagnostic intra-articular injection for diagnosis of FAI, and for non-operative management of FAI. One in four respondents supported a sham surgery (24.8 %) control arm for a trial evaluating the impact of surgical intervention on FAI. This survey elucidates areas of research for future studies relevant to FAI and highlights controversial areas of treatment. The results suggest that the current management of FAI by members of the COA is limited by a lack of awareness of high-level evidence. LEVEL OF EVIDENCE: III.
    Knee Surgery Sports Traumatology Arthroscopy 02/2014; · 2.68 Impact Factor
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    ABSTRACT: Study Design Randomized controlled trial. Objectives Examine the efficacy of exercise intervention in patients with knee osteoarthritis (OA) directed by Mechanical Diagnosis and Therapy (MDT) assessment. Secondarily, explore outcomes between MDT assessment-defined subgroups within the exercise group. Background Due to the high physical and economic burden of knee OA, the effectiveness of conservative interventions and determining which patients will respond should be investigated. Methods Patients (n=180) with knee OA were randomized to exercise intervention or control groups. Within the exercise group, patients classified as having knee derangements (MDT-derangement) received MDT directional exercises and those classified as non-responders (MDT-nonresponders) were given evidence based exercises and were compared with controls receiving no exercise intervention. Pain and function were assessed at baseline, two weeks and three months using the P4 pain scale and Knee Injury and Osteoarthritis Outcome Score (KOOS-pain and KOOS-function). Two-way analysis of covariance examined treatment and time effects. Multiple comparisons were examined with mean differences with 95% confidence intervals (CI). Results Exercise intervention group had significantly (P < .01) improved P4 (mean difference=-6, CI=-8 to -3), KOOS-pain (mean difference=9, CI=5 to 13), and KOOS-function (mean difference=11, CI=7 to 15) compared with controls at two weeks. At three months, exercise intervention group had significantly (P < .05) improved KOOS-pain (mean difference=7, CI=3 to 11) and KOOS-function (mean difference=5, CI=1 to 9) compared to controls. Conclusion Patients with knee OA, who were prescribed exercises based on a MDT assessment had superior outcomes compared to waitlist controls. MDT subgroup of knee derangement may warrant further investigation in patients with knee OA. Level of Evidence Therapy, level 1b. J Orthop Sports Phys Ther, Epub 22 January 2014. doi:10.2519/jospt.2014.4791.
    The Journal of orthopaedic and sports physical therapy. 01/2014;
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    ABSTRACT: The purpose of this study was to assess the feasibility, effectiveness and costs of a web-based follow-up compared to in-person assessment following primary total hip or total knee arthroplasty. Patients who were at least 12 months postoperative were randomized to follow-up method. We excluded patients who had revision surgery, osteolysis, complications or identified radiographic issues. 229 patients (118 Web, 111 in-person) completed the study. There were no patients who had an issue missed by the web-based follow-up. Patients in the web-based group travelled less (28.2 km vs 103.7 km, (p < 0.01)), had lower associated costs ($10.45 vs $21.36, (p < 0.01)) and took less time to complete (121.7 min web vs 228.7 min usual). Web-based follow-up is a feasible, clinically effective alternative with lower associated costs than in-person clinic assessment.
    The Journal of Arthroplasty. 01/2014;
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    Matthew G Teeter, James P McAuley, Douglas D Naudie
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    ABSTRACT: Highly cross-linked polyethylene has become the gold standard in total hip replacement for its wear resistance. Moderately crosslinked polyethylene is now available for total knee replacement (TKR), although concerns about reduced mechanical strength have prevented widespread adoption. The purpose of this report is to describe an unusual case where a patient underwent cruciate retaining TKR using a moderately crosslinked polyethylene tibial insert that went on to fracture twice in the same location across the primary and first revision surgery. The first tibial insert was 10 mm thick and was implanted for 16 months. The second tibial insert was 15 mm thick and was implanted for 11 months. Both fractured along the posterior aspect of the medial articular surface. The lack of a specific event leading to these fractures and the fact that they occurred twice in the same location in the same patient suggest that caution is still necessary regarding the introduction of crosslinked polyethylene for TKR surgery.
    Case reports in orthopedics. 01/2014; 2014:491384.
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    ABSTRACT: Background Quantitative measurements of damage and wear in orthopaedic components retrieved from patients during revision surgery can provide valuable information. However, to perform these measurements there needs to be an estimate of the original, unworn geometry of the component, often requiring multiple scans of the various sizes of components that have been retrieved. The objective of this study was to determine whether the articular and backside surfaces could be independently segmented from a micro-CT reconstruction of a tibial insert, such that a tibial insert of one thickness could be used as a reference for a tibial insert of a different thickness. Methods New tibial inserts of a single width but six different thicknesses were obtained and scanned with micro-CT. An automated method was developed to computationally segment the articular and backside surfaces of the components. Variability between intact and extracted components was determined. Results The deviations between the comparisons of the extracted surfaces (range, 0.0004 to 0.010 mm) were less (p < 0.001) than the baseline deviation between the intact surfaces (range, 0.0002 to 0.053 mm). Conclusions An extracted surface from one insert thickness could be used to accurately represent the surface of an insert of a different thickness. This greatly enhances the feasibility of performing retrieval studies using micro-CT as a quantitative tool, by reducing the costs and time associated with acquiring, scanning, and reconstructing multiple reference tibial insert geometries. This will add greater detail to studies of retrieved implants, to better establish how implants are functioning in vivo.
    The Knee 01/2014; · 2.01 Impact Factor
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    ABSTRACT: A novel alternative to conventional instrumentation for femoral component insertion in hip resurfacing is a patient specific, computed tomography based femoral alignment guide. A benchside study using cadaveric femora was performed comparing a custom alignment guide to conventional instrumentation and computer navigation. A clinical series of twenty-five hip resurfacings utilizing a custom alignment guide was conducted by three surgeons experienced in hip resurfacing. Using cadaveric femora, the custom guide was comparable to conventional instrumentation with computer navigation proving superior to both. Clinical femoral component alignment accuracy was 3.7° and measured within ±5° of plan in 20 of 24 cases. Patient specific femoral alignment guides provide a satisfactory level of accuracy and may be a better alternative to conventional instrumentation for initial femoral guidewire placement in hip resurfacing.
    The Journal of arthroplasty 09/2013; · 1.79 Impact Factor
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    ABSTRACT: The purpose of this study was to determine agreement between responses on electronic and paper versions of the WOMAC and SF-12(v2) questionnaires following total hip and total knee arthroplasty. Patients completed both electronic and paper questionnaires with a one week interval in-between. The order in which they completed the two versions was randomly assigned. A total of 53 patients completed the study, with a mean age of 69years (range 50-90years). The intraclass correlation coefficients (ICC) were high, indicating excellent agreement (WOMAC ICC=0.96, 95% CI 0.94-0.98), SF-12 (PCS) ICC=0.95, 95% CI 0.92-0.97; SF-12 (MCS) ICC=0.92, 95%CI 0.86-0.95). Online data collection may be substituted for the traditional paper method with no significant effect on the criterion validity of the questionnaires.
    The Journal of arthroplasty 08/2013; · 1.79 Impact Factor
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    ABSTRACT: Revision total knee arthroplasty (TKA) has been associated with an increased risk of perioperative blood loss. Tranexamic acid (TXA) has been proven to be safe and effective in preventing blood loss in primary TKA. The purpose of this study was to evaluate the effect of TXA on blood loss and transfusion rates in revision TKA. We performed a retrospective comparative study on 424 patients who had undergone revision TKA between January 2006 and March 2010. A total of 178 patients did not receive TXA while 246 patients received one intraoperative dose of 20mg/kg of TXA given prior to tourniquet release. There was a significant reduction in hemoglobin loss (42±16g/L vs 38±15g/L, P=0.005), transfusion rates (30.3% vs 16.7%, P=0.001) and average amount transfused (1.1±1.9units vs 0.5±1.1units, P=0.001) in the TXA group. There was no significant difference in recorded major adverse events with the administration of TXA.
    The Journal of arthroplasty 08/2013; · 1.79 Impact Factor
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    ABSTRACT: Several new porous ingrowth surfaces for acetabular component fixation have recently been developed. The purpose of this study was to compare the in vivo fixation achieved by two different porosity ingrowth surfaces using radiostereometric analysis (RSA). Sixty-two patients undergoing primary total hip arthroplasty (THA) were randomized to receive a cementless acetabular component with either a 61% high porosity asymmetric titanium porous surface (StikTite, Smith and Nephew, TN, USA) or a 45% low porosity sintered bead porous surface (Roughcoat, Smith and Nephew, TN, USA). RSA and clinical follow-up examinations were done post-operatively, 6-weeks, 3-months, 6-months, 1-year and 2-years. Both the high porosity StikTite and lower porosity Roughcoat surfaces provided excellent biologic fixation.
    The Journal of arthroplasty 08/2013; · 1.79 Impact Factor
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    ABSTRACT: A total of 6275 consecutive TKA patients were divided into three groups based on their age: <55, 55-70 and >70years. There was a statistically significant difference in the change in WOMAC score (32 vs 31 vs 26, P<0.001) and Knee Society Score (78.9 vs 76.0 vs 69.0, P<0.001) favoring the younger populations. However, the revision rate was higher in the younger patients with a Kaplan-Meier survivorship at 5years of 95.5%, 97.2% and 98.1% and at 10years of 92.2%, 95.9% and 97.6%. Infection was the most frequent cause for failure in all groups although aseptic loosening and instability accounted for the increased revision rate in the younger patients. Younger patients may experience slightly better clinical outcomes following TKA but lower survivorship, when compared to older patient populations.
    The Journal of arthroplasty 07/2013; · 1.79 Impact Factor
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    ABSTRACT: This was a retrieval analysis of 83 PS inserts to assess the effect of limb alignment, implant position and joint line position on the pattern of wear in posterior stabilized (PS) tibial inserts. The total damage score was significantly higher in knees with postoperative varus alignment more than 3° (P = 0.03). The total damage score to the post was significantly more in knees with joint line elevation more than 5 mm (9.7 ± 3.9, compared to 6.5 ± 3.7 in knees with less joint line elevation) (P = 0.05). Limb malalignment and joint line elevation resulted in more damage in PS inserts. An external rotation subluxation damage pattern was found in joint line elevation.
    The Journal of arthroplasty 06/2013; · 1.79 Impact Factor
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    ABSTRACT: BACKGROUND: High tibial osteotomy (HTO) has long been accepted as an effective treatment for unicompartmental osteoarthritis of the knee in young, active adults. For varus knees, the two most commonly performed valgus-producing HTOs are the lateral closing wedge and the medial opening wedge. Regardless of technique, some HTOs fail and are converted to TKA. To our knowledge, no studies have directly compared TKAs done after lateral closing-wedge osteotomies to those done after medial opening-wedge osteotomies. QUESTIONS/PURPOSES: We compared pain- and function-related outcomes and survivorship of TKAs in patients who previously underwent medial opening-wedge and lateral closing-wedge HTOs. METHODS: We reviewed our institutional database to identify all patients having undergone a HTO with subsequent conversion to TKA and identified 188 lateral closing-wedge HTOs and 77 medial opening-wedge HTOs. Mean followup was 88 months (range, 3-264 months) for the lateral closing-wedge HTO cohort and 59 months (range, 3-180 months) for the medial opening-wedge cohort. SF-12, WOMAC, and Knee Society Scores, as well as survivorship at 5 years, were compared between the two groups. Statistical analysis was completed using the independent-samples t-test. RESULTS: No differences were found between groups in postoperative SF-12 scores (p = 0.77 for the mental component summary score and p = 0.21 for the physical component summary score), WOMAC scores (p = 0.67), or Knee Society Scores (p = 0.80). No difference was found in survivorship between groups at 5 years. CONCLUSIONS: Our results suggest there is no difference in functional outcomes or survivorship of TKA in patients having previously undergone medial opening-wedge and lateral closing-wedge HTOs. LEVEL OF EVIDENCE: Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.
    Clinical Orthopaedics and Related Research 05/2013; · 2.79 Impact Factor
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    ABSTRACT: An in vivo method to measure wear in total knee replacements was developed using dynamic single-plane fluoroscopy. A dynamic, anthropomorphic total knee replacement phantom with interchangeable, custom-fabricated components of known wear volume was created, and dynamic imaging was performed. For each frame of the fluoroscopy data, the relative location of the femoral and tibial components were determined, and the apparent intersection of the femoral component with the tibial insert was used to calculate wear volume, wear depth, and frequency of intersection. No difference was found between the measured and true wear volumes. The precision of the measurements was ±39.7 mm(3) for volume and ±0.126 mm for wear depth. The results suggest the system is capable of tracking wear volume changes across multiple time points in patients. As a dynamic technique, this method can provide both kinematic and wear measurements that may be useful for evaluating new implant designs for total knee replacements.
    Physics in Medicine and Biology 04/2013; 58(9):2751-2767. · 2.70 Impact Factor
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    ABSTRACT: Few biomechanical studies exist on femoral cementless press-fit stems for revision total knee replacement (TKR) surgeries. The aim of this study was to compare the mechanical quality of the femur-stem interface for a series of commercially available press-fit stems, because this interface may be a 'weak link' which could fail earlier than the femur-TKR bond itself. Also, the femur-stem interface may become particularly critical if distal femur bone degeneration, which may necessitate or follow revision TKR, ever weakens the femur-TKR bond itself. The authors implanted five synthetic femurs each with a Sigma Short Stem (SSS), Sigma Long Stem (SLS), Genesis II Short Stem (GSS), or Genesis II Long Stem (GLS). Axial stiffness, lateral stiffness, 'offset load' torsional stiffness, and 'offset load' torsional strength were measured with a mechanical testing system using displacement control. Axial (range = 1047-1461 N/mm, p = 0.106), lateral (range = 415-462 N/mm, p = 0.297), and torsional (range = 115-139 N/mm, p > 0.055) stiffnesses were not different between groups. The SSS had higher torsional strength (863 N) than the other stems (range = 167-197 N, p < 0.001). Torsional failure occurred by femoral 'spin' around the stem's long axis. There was poor linear correlation between the femur-stem interface area versus axial stiffness (R = 0.38) and torsional stiffness (R = 0.38), and there was a moderate linear correlation versus torsional strength (R = 0.55). Yet, there was a high inverse linear correlation between interfacial surface area versus lateral stiffness (R = 0.79), although this did not result in a statistical difference between stem groups (p = 0.297). These press-fit stems provide equivalent stability, except that the SSS has greater torsional strength.
    Proceedings of the Institution of Mechanical Engineers Part H Journal of Engineering in Medicine 11/2012; 226(11):848-57. · 1.42 Impact Factor
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    ABSTRACT: PURPOSE: There is a lack of detailed information about the indications of surgical treatment for femoroacetabular impingement (FAI), particularly using open surgical dislocation. The purpose of this review was to systematically review the reported indications for surgical dislocation of the hip for FAI. METHODS: Two databases (MEDLINE and EMBASE) were screened for clinical studies involving the treatment for FAI with surgical hip dislocation. We conducted a full-text review and the references for each included paper were hand-searched for other eligible studies. Papers published until September 2011 were included in this review. Two individuals reviewed all identified studies independently, and any disagreement was resolved through consensus. RESULTS: Fifteen studies met the eligibility criteria, which included a total of 822 patients. We identified a lack of consensus for clinical and radiographic indications for surgical hip dislocation to treat FAI. The most common clinical indications reported were clinical symptoms such as hip pain in 10 papers (67 %), a positive impingement sign in 9 papers (60 %), painful/reduced range of motion in 9 papers (60 %), activity-related groin pain in 4 papers (27 %), and non-responsive to non-operative treatment in 4 papers (27 %). The most commonly reported radiographic indicators for surgical hip dislocation were a variety of impingement findings from radiographs in all 15 included papers (100 %), a combination of radiographs and MRA in 5 papers (33 %) or radiographs and MRI in 3 papers (20 %). CONCLUSIONS: These results showed that that there was an inconsistency between the clinical and radiographic indications for surgical hip dislocation as a treatment for femoroacetabular impingement. This review suggests that there is a need for the development of standardized clinical and radiological criteria that serve as guidelines for surgical treatment for FAI. LEVEL OF EVIDENCE: Systematic review, Level IV.
    Knee Surgery Sports Traumatology Arthroscopy 10/2012; · 2.68 Impact Factor

Publication Stats

662 Citations
124.59 Total Impact Points


  • 2004–2014
    • London Health Sciences Centre
      • Division of Orthopaedic Surgery
      London, Ontario, Canada
  • 2009–2013
    • Robarts Research Institute
      • Imaging Research Laboratories
      London, Ontario, Canada
  • 1999–2013
    • The University of Western Ontario
      • • Department of Surgery
      • • Division of Orthopaedic Surgery
      • • Department of Anesthesia and Perioperative Medicine
      London, Ontario, Canada
  • 2012
    • St. Michael's Hospital
      Toronto, Ontario, Canada
  • 2008
    • Lakehead University Orillia Campus
      Orillia, Ontario, Canada
    • Kingston General Hospital
      Kingston, Ontario, Canada
  • 2004–2008
    • Anderson Orthopaedic Clinic
      Alexandria, Virginia, United States