P T Simonian

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Malpositioning of iliosacral screws happens more often when common variations in the morphology of the upper sacral segments are unrecognized. Radiological-anatomic correlations of sacral anatomy were studied in 10 fresh-frozen cadaveric pelvises without evidence of skeletal disease, obtained from six male and four female donors. Eighty consecutive patients(More)
The purpose of this study was to document the effect of muscle fatigue on glenohumeral kinematics. Twelve male volunteers without shoulder disease and with an average age of 27 years were studied. Glenohumeral anteroposterior radiographs were taken at 45 degrees intervals as the arm was abducted in the plane of the scapula from 0 degree to 135 degrees. This(More)
Pelvic ring injuries with associated hemorrhage often require provisional fixation to achieve tamponade. Biomechanics information regarding these provisional fixators is unknown. Six fresh-frozen cadaveric pelvic specimens were physiologically loaded, first intact and then after each of the following modifications: disrupted--unilateral superior and(More)
Seven fresh cadaveric pelvic specimens were biomechanically analyzed. Testing was first performed on intact pelves and then after progressive disruption of the (1) symphysis pubis, (2) unilateral anterior and interosseous sacroiliac ligaments and capsule, (3) ipsilateral sacrospinous and sacrotuberous ligaments; and fixation with a 4.5-mm narrow dynamic(More)
The purpose of this study was to evaluate pubic ramus fracture fixation. This biomechanical evaluation compared standard plating techniques with retrograde medullary screw fixation of a superior pubic ramus fracture in a pelvic fracture model. Six fresh-frozen, cadaveric pelvic specimens with a mean age of 79 years were harvested. These specimens were(More)
In an attempt to understand better the contribution of the anteroinferior and posterosuperior popliteomeniscal fasciculi to lateral meniscus stability, we objectively evaluated the stability of the lateral meniscus before and after sequentially sectioning these fasciculi. In the biomechanical model, we attempted to account for the inherent limitations of(More)
A three-dimensional computer model of a total hip replacement was used to examine the relationship between the position of the components, the range of motion and the prosthetic joint contact area. Horizontal acetabular positions with small amounts of acetabular and femoral anteversion provide the largest contact areas, but result in limited joint movement.(More)
The purpose of this study was to evaluate the stability of different types of internal fixation requiring anterior, posterior, or combined surgical approaches for the T-type acetabular fracture. Eight specimens were loaded 25 times in a cyclic manner to 150 N for each type of fixation construct evaluated. The model attempted to range the hip through an arc(More)
This study examined whether a skeletally fixed prefabricated knee hinge can provide the intact or unstable knee with normal motion through a specific arc of motion. Eight cadaveric knee specimens were used. The amount of motion mismatch between knee and hinge motion was evaluated at six different knee flexion angles. With all knee ligaments intact, addition(More)
A clinical and cadaveric example show the EndoButton (Acufex Microsurgical Inc, Mansfield, MA), used for anterior cruciate ligament endoscopic fixation, flipping outside the extensor mechanism or vastus lateralis rather than flipping directly outside the lateral femoral cortex. This pitfall was caused by overdrilling the femoral socket beyond the(More)