Clinical orthopaedics and related research
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Clin. Orthop. Relat. Res. · Feb 1997
ReviewAnterior plate instrumentation for disorders of the subaxial cervical spine.
Anterior cervical plate instrumentation is useful in the maintenance of cervical alignment, the prevention of graft extrusion, and the development of late deformity as well as potentially avoiding the need for a secondary posterior cervical procedure in the setting of cervical trauma. Its role in cervical reconstruction after decompression for cervical spondylosis is evolving. The definite risks of anterior cervical instrumentation should be considered, that is, screw and plate displacement or screw violation of neurologic structures, before the implementation of this form of fixation.
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Clin. Orthop. Relat. Res. · Feb 1997
ReviewAnterior instrumentation in the management of thoracolumbar burst fractures.
Anterior instrumentation in the treatment of thoracolumbar fractures has progressed significantly during the past 2 decades. These fixation systems have evolved to meet the anatomic, biomechanical, and imaging challenges associated with internal fixation of the thoracolumbar spine. The evolution of these devices will be reviewed, and from this, the indications and surgical techniques necessary for the safe and effective use of the device will be discussed. ⋯ There were no neurologic or perioperative complications. Eleven of the 12 patients obtained a good or excellent functional outcome. Anterior arthrodesis using instrumentation stabilization after a 1-stage anterolateral decompression and reduction procedure can yield successful clinical results in the treatment of thoracolumbar burst fractures.
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The surgical treatment of spinal tumors depends on a host of factors that include: the type of tumor and its location within the spine, the presence or absence of neural compression, the portion of the vertebrae involved, the anticipated mode of spinal failure, the biology of the tumor, the anticipated life expectancy of the patient, and the type of prior or subsequent adjuvant treatment. Two thirds of all spinal tumors arise from the vertebral body and only 1/3 originate from the posterior elements. Malignant tumors more commonly involve the vertebral body and benign lesions usually are located posteriorly. ⋯ The surgical treatment of spinal tumors is dictated largely by the location of the tumor within the spine; anterior vertebral body tumors generally should be approached anteriorly, whereas posterior lesions should be approached posteriorly. Because most malignant tumors, whether primary or secondary (metastatic), are located anteriorly within the vertebral body, most surgery for malignant tumors should be approached anteriorly. Anterior decompression should be accompanied by reconstruction with biologic materials such as autogenous bone graft unless life expectancy is certain to be very limited (<6 months).
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Clin. Orthop. Relat. Res. · Feb 1997
Comparative StudyBiomechanical evaluation of tension band placement for the repair of olecranon fractures.
Displaced transverse fractures of the olecranon commonly are treated by open reduction and internal fixation using the AO tension band wiring technique. Reports that the AO technique has a tendency to open the fracture site at the articular surface prompted Rowland and Burkhart to modify placement of the tension band. The present study tested the hypothesis that the modified wire placement provides static compression anteriorly, and hence better reduction at the articular surface of the fracture, than the AO technique under static conditions. ⋯ Because the static behavior of the fixations was tested, no muscle forces were included. Results indicated no significant differences in yield loads or stiffness values between the 2 techniques. Based on the results of this static study, the modified wire placement does not provide increased stability of fracture fixation compared with the AO tension band wiring technique.
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Clin. Orthop. Relat. Res. · Jan 1997
Anatomic considerations for uncovertebral involvement in cervical spondylosis.
Morphometric analysis of 54 dry cervical spines from C3 to C7 (a total of 270 cervical vertebrae) and bilateral dissection of 10 anatomic specimen cervical spines were performed. The uncinate processes were significantly higher at C4 to C6 (5.8 +/- 1.1 mm to 6.1 +/- 1.3 mm) levels than at C3 or C7 levels. ⋯ A combination of higher uncinate process, smaller anteroposterior diameter of intervertebral foramina, and longer course of nerve roots in close proximity of the uncovertebral joints at the C4 to C6 levels may explain the predilection of nerve root compression by uncovertebral osteophytes at these levels. The distance from apex of the uncinate process to medial border of the transverse foramen gradually increased from C3 (1.7 +/- 0.8 mm) to C7 (3.3 +/- 1.0 mm), which may predispose the midcervical level to compression of the vertebral artery by laterally projecting uncovertebral osteophytes.