Clinical orthopaedics and related research
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Clin. Orthop. Relat. Res. · Sep 1998
Comparative StudyPercutaneous iliosacral screw placement using image guided techniques.
A computer assisted technique of iliosacral screw placement that is applicable to unstable pelvic ring fractures is proposed. The goals are to operate noninvasively with a percutaneous procedure to decrease the complications of surgical exposure and to provide greater accuracy in locating the close neurovascular structures. Preoperative computed tomographic images of the pelvis are provided and a computed tomography three-dimensional model is built. ⋯ Four human anatomic specimen pelves were tested with three screw insertions for each pelvis (12 screws). All of the screws were considered to be placed correctly. The method is safe and encourages the start of clinical application.
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Clin. Orthop. Relat. Res. · Aug 1998
ReviewSurgical management of acute tarsometatarsal fracture dislocation in the adult.
Injuries to the tarsometatarsal joint involving fracture dislocations are uncommon and are often referred to as Lisfranc lesions after the French field surgeon in the Napoleonic Wars. Despite the infrequency of this serious injury, they have the potential for chronic disability and require prompt, accurate diagnosis and precise anatomic reduction to minimize long term disability. A review of the literature shows that opinions differ as to the most appropriate method of treatment for these injuries, be it closed or open reduction, but most authors agree that it is imperative to achieve precise anatomic reduction.
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Clin. Orthop. Relat. Res. · Jul 1998
Comparative StudyPlacement of screws in the sustentaculum tali. A calcaneal fracture model.
Current methods of treating calcaneus fractures vary greatly, and many techniques of internal fixation have been described. The study of these fractures has been limited in part by the lack of a suitable laboratory model. In this study, a new cadaveric model of calcaneus fractures was developed, using a combination of osteotomies and impaction. ⋯ Stiffness and energy to failure were significantly greater and Bohler's angle significantly less compromised in Group B. It was concluded that the position of the articular fragment of comminuted calcaneal fractures will be maintained at higher loads when the screws in the posterior facet are incorporated into the lateral plate. The model of calcaneal fractures described in this study may be suitable for examining other aspects of fixation.
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Clin. Orthop. Relat. Res. · Jul 1998
Comparative StudyBiomechanical evaluation of transverse acetabular fracture fixation.
The purpose of this two-part biomechanical study was to evaluate various fixation methods for transverse acetabular fractures in a synthetic pelvic model. In Part 1, 40 transverse acetabular fractures were repaired with anterior column plating using 10-hole curved reconstructions plates with one of four screw configurations to evaluate the effect of screw placement and number on fracture fixation stiffness. In Part 2, 36 transverse acetabular fractures were repaired with one of six fixation methods using combinations of contoured plates and column screws to stabilize the anterior column, the posterior column, or both. ⋯ The stiffest construct combined a posterior column plate with an anterior column screw. Because no significant change in stiffness occurred with the addition of a third set of screws, two screws on each side of the fracture site appear to provide sufficient stability with acetabular plating. Concurrent fixation of anterior and posterior columns of transverse acetabular fractures provides the greatest resistance to postoperative loss of reduction in this model.
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Clin. Orthop. Relat. Res. · Jun 1998
Comparative StudyPossible mechanism of painful radiculopathy in lumbar disc herniation.
The pathophysiologic mechanisms of painful radiculopathy caused by a herniated intervertebral disc remain unknown. This study sought to determine whether the autologous intervertebral disc produces pain related behavior and whether phospholipase A2 and nitric oxide are involved in the pathophysiologic mechanism producing the behavior. A rat model, in which autologous intervertebral discs were implanted on the nerve root in the lumbar spine, was used to measure hyperalgesia, which is a pain related behavior in the rat. ⋯ Thermal hyperalgesia produced by application of the anulus fibrosus was abated and abolished by epidural injections of saline and one of the inhibitors for nitric oxide synthase, respectively. The authors suggest that chemical mediators such as phospholipase A2 and nitric oxide, induced by extruded or sequestrated intervertebral discs, are involved in the pathophysiologic mechanisms of painful radiculopathy in lumbar disc herniations. This study may be useful in attempting to develop new medical approaches for treatments of lumbar disc herniation.