D Mayman

Queen's University, Kingston, Ontario, Canada

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Publications (6)3.32 Total impact

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    ABSTRACT: : This study was designed to test in a laboratory setting a novel computer-assisted fluoroscopic technique and a conventional fluoroscopic technique for open reduction and internal fixation (ORIF) of hip fractures. Our hypothesis is that a novel computer-assisted fluoroscopic technique will achieve acceptable guidewire placement in one pass, with decreased fluoroscopic time and with accuracy and precision better than conventional technique. Prospective, randomized trials. Laboratory. Thirty, Sawbone, femur phantoms. Dynamic hip screw guidewires were inserted into 15 femur phantoms under fluoroscopic guidance by using computer-assisted fluoroscopic ORIF technique, and 15 femurs were inserted by using a conventional fluoroscopic-assisted ORIF technique. Ideal guidewire placement was defined as the center of the femoral head, 5 mm from the apical bone edge on anteroposterior and lateral views. Accuracy was measured as distance to ideal placement, and the number of passes and fluoroscopic time were noted for each trial. The computer-assisted technique achieved an average guidewire placement that was as accurate as the conventional technique in fewer passes, 1.1 +/- 0.2 (mean +/- standard deviation) compared with 2.4 +/- 1.1 (P < 0.0001), respectively, and with fewer fluoroscopic images, 2 +/- 0 compared with 13.5 +/- 3 (P < 0.0002), respectively. Guidewire placement in both groups was within the tip-apex distance defined by Baumgaertner et al. The computer-assisted technique was significantly more accurate and precise than conventional technique. It also required fewer drill tracks through the femur and exposed the patient and the surgical team to significantly less ionizing radiation.
    Journal of Orthopaedic Trauma 11/2005; 19(9):610-5. · 1.75 Impact Factor
  • Journal of Orthopaedic Trauma - J ORTHOP TRAUMA. 01/2005; 19(9).
  • D J Mayman, J Rudan, D Watson, R Ellis
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    ABSTRACT: To develop an accurate and reproducible technique for inserting Oxford Unicompartmental arthroplasties. A protocol was developed to accurately position the femoral component of the Oxford Unicompartmental arthroplasty using computer-enhanced techniques. A dynamic reference body (DRB) is inserted into the femur, then antero-posterior (AP) and lateral fluoroscopic images are taken of the proximal femur. These images are digitized and entered into 3D space using a registered fluoroscopy machine. The femoral guide from the Oxford system is then placed on the medial femoral condyle in the standard manner. Holes are drilled directly towards the center of the femoral head using a registered drill. The femoral cuts are then made using the standard instruments from the Oxford set. This procedure was carried out on 15 sawbone femurs. Component position was determined by measuring radiographs after a trial component had been inserted. The average lateral error was 1.2 degrees (standard deviation [SD] = 1.207), compared to 4.1 degrees (SD = 2.875) with the standard technique. The average AP error was 2.5 degrees (SD = 1.767), compared to 5.1 degrees (SD = 2.219) with the standard technique. The differences in accuracy in both planes were statistically significant (p = 0.002 for AP, 0.001 for lateral). Using a Fluoroguide-assisted technique, we were able to insert the femoral component more precisely than when using the standard technique as described by the manufacturer.
    Computer Aided Surgery 02/2004; 9(3):81-5. · 0.78 Impact Factor
  • Jeff Yach, John Rudan, David Mayman, Randy Ellis
    Techniques in Orthopaedics. 01/2003; 18(2):205-208.
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    ABSTRACT: Accuracy and precision of inserting joint implants is essential for successful long-term prosthetic function. Clinical and radiographic assessment of Oxford unicompartmental knee arthroplasty using 3 computer-assisted techniques (CT based, “morphing” and fluoro-based) was undertaken on 17 patients. They were followed for at least one year postoperatively. Clinical outcome assessments: Knee Society Scores, WOMAC and SF-36 all indicated good to excellent results. All methods worked well with the manufacturerÆs tolerance of 10° in both planes. However, CT based and fluoro-based techniques were significantly better than the ômorphingö technique.
    Medical Image Computing and Computer-Assisted Intervention - MICCAI 2003, 6th International Conference, Montréal, Canada, November 15-18, 2003, Proceedings, Part II; 01/2003
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    David J Mayman, John Rudan, Jeff Yach, Randy Ellis
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    ABSTRACT: To develop a new periacetabular osteotomy technique that can be performed safely and reliably using computer-enhanced technology. This technique uses a modified posterior approach with a trochanteric osteotomy. A 3D surface model is generated from CT data. The osteotomy is planned using custom software developed by our team. A dynamic reference body is fixed to the iliac crest and the pelvis is registered using an optically tracked probe (Optotrak, Northern Digital, Ontario, Canada). A tracked probe is used to mark the osteotomies in three dimensions. The posterior column is osteotomized between the sciatic notch and hip joint. The pubic ramus is osteotomized under fluoroscopic guidance. The acetabular fragment is rotated into a more appropriate position and fixed with pelvic reconstruction plates. Subjective and objective data are collected pre- and postoperatively. This procedure has been performed on eight patients. Average center-edge angle correction has been 17 degrees. The computer and optical guidance system has provided accurate information in seven of eight cases, and there have been no complications. This technique has enabled us to perform periacetabular osteotomies with safety and predictability. Using this computer-enhanced technique, periacetabular osteotomy may become a more common procedure in the practice of hip reconstruction surgeons.
    Computer Aided Surgery 02/2002; 7(3):179-86. · 0.78 Impact Factor