Dan M. Spengler

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The anterior approach to the cervical spine, first described 40 years ago, has become a popular and widely used procedure by spine surgeons to expose the anterior vertebral bodies from C3 to T1. A significant complication of this procedure is transient or permanent ipsilateral recurrent laryngeal nerve paralysis. In a previous review at our institution of(More)
STUDY DESIGN Laminectomy was performed on cats to destroy the posterior epidural ligament. Evoked potentials and spinal cord blood flows quantified the spinal cord function before and after cervical flexion. OBJECTIVES This work describes a relationship between the loss of the posterior epidural ligaments and cervical spinal cord injury. SUMMARY OF(More)
STUDY DESIGN Task-specific and subject-specific lumbar trunk muscle function, muscle geometry, and vertebral density data were collected from 16 men. A biomechanical model was used to determine muscle strength and the compressive forces acting on the lumbar spine. OBJECTIVES To develop an anatomic biomechanical model of the low back that could be used to(More)
This article describes regional variations in cancellous bone morphology within the human lumbar spine of a 60-year-old woman. An automated imaging technique, based upon the method of directed secants, was used to quantify variations in bone porosity and trabecular size, distribution, and orientation within serial transverse histological sections of the L1(More)
In order to register pressure changes within the cauda equina, a highly sensitive pressure measuring catheter was inserted through a hole in the dural sac. Its tip was placed among the nerve roots of the cauda equina at levels L2, L3, and L4 in seven freshly removed human specimens. The cross-sectional area of the dural sac then was decreased gradually by(More)
Back injuries occurring during isometric strength testing motivated a statistical analysis to determine if a reduction in the number of exertions during the test was possible without profound influence upon the accuracy of the results. Strength measurements from more than 1,000 volunteers in an industrial back pain study were examined. It was concluded that(More)
The purpose of this article is to clarify one mechanism of muscular atrophy of the distal upper extremity that we attribute to cervical compression (Hirayama-type amyotrophy) by medical imaging and anatomical studies of the cervical spine. Five young male patients (mean age: 22.6 years) with this disorder showed characteristic findings to include an(More)
A new method has been developed for the Department of Orthopaedics of Vanderbilt University Medical Center to access departmental clinical data. Previously this data was stored only in the medical center's mainframe DB2 database, it is now additionally stored in a departmental SQL database. Access to this data is available via any ODBC compliant front-end(More)
This study examines changes in stiffness in a three-level spinal construct utilizing transpedicular Cotrel-Dubousset instrumentation. In addition, we evaluated the effect of adding offset laminar hooks at the same level as the superior transpedicular fixation. Porcine lumbar spines (L-1 to L-5) were tested as: (a) intact spine, (b) intact spine with(More)
A procedure for averaging trunk dynamometric positions, velocities, and torques is described which enables identification and parameterization of kinematic movement patterns. This technique is accurate and presents the data in a very compact way, which is ideal for storage and analysis. It can be applied to many types of movement analyses. Application of(More)