Spine
-
The purpose of this study was to examine the mechanical function of the C1-C2 capsular ligaments. Physiologic torques of up to 1.5 Nm were applied to human fresh cadaveric specimens (C0-C1-C2-C3) in three dimensions, and the three-dimensional motion of C1 relative to C2 was recorded. Two groups of cadaveric specimens were used to study the effect of two different sequential ligamentous transections. ⋯ Lateral bending to the left also increased significantly by 1.5 degrees after both ligaments were cut. In the second group, with the nonfunctional alar and transverse ligaments, transection of the left capsular ligament resulted in greater increases in range of motion: 3.3 degrees to the right and 1.3 degrees to the left. Lateral bending to the right also increased significantly by 4.2 degrees.
-
Spinal cord plasticity in 55 patients with cervical compression myelopathy was assessed with magnetic resonance imaging, by which the transverse area of the spinal cord was measured at the site of maximum compression before and after surgery and compared with the conventional modalities of computed tomographic myelography. A high correlation (r = 0.901, P less than 0.01) was observed between the preoperative measurements of magnetic resonance imaging and computed tomographic myelography. The preoperative transverse area was in good correlation with the preoperative Japanese Orthopaedic Association score (r = 0.466, P less than 0.01). In most patients with a spinal cord area of less than 0.45 cm2, the clinical results were poor despite considerable morphologic restoration of the spinal canal obtained after decompression surgery, reflecting an irreversible pathology developed in the spinal cord.
-
Comparative Study
Disability exaggeration as a predictor of functional restoration outcomes for patients with chronic low-back pain.
Many of the individual biological, psychological, and social factors attributed to low-back disability have been tested previously for their ability to predict treatment outcomes. To test the assumption that disability exaggeration affects treatment outcomes, models were developed to quantify this complex characteristic and to test its predictive value. Two hundred fifty-eight patients with chronic back disability entering a program of functional restoration were initially evaluated with a battery of tests, including measurements of trunk flexibility, lifting capacity, cycling endurance, self-assessments of pain and disability, and psychological attributes. ⋯ There were no significant associations between any individual factor and 2-year work status. Only two of the 12 disability exaggeration models distinguished between program graduates and dropouts, and none of the models accurately predicted return to work following treatment. Prescription of intensive multidisciplinary treatment should not be denied on the basis of any individual patient attribute or of disability exaggeration, as measured in this study.(ABSTRACT TRUNCATED AT 250 WORDS)
-
Comparative Study
Comparison of eight psychometric instruments in unselected patients with back pain.
A comparative evaluation of eight psychometric instruments was made in 274 patients who were currently suffering or previously had suffered from low-back pain. The specificity and sensitivity values for detection of psychological disturbance were calculated and optimum cutoff scores determined for each test. The influence of current pain, social group, compensation, migrant status, and unemployment on the accuracy of each test were evaluated. ⋯ The Modified Somatic Perception Questionnaire, the Hospital Anxiety Scale, the Hospital Depression Scale, and the Zung Depression Scale were the most accurate and least affected by the factors examined. The combination of the Modified Somatic Perception Questionnaire and the Zung Depression Scale yielded specificities and sensitivities of 91% and 84% for men and 96% and 85% for women, respectively. This combination is recommended for the assessment of psychological disturbance in patients with low-back pain.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Variability of somatosensory cortical evoked potentials during spinal surgery. Effects of anesthetic technique and high-pass digital filtering.
The effects of anesthetic technique (nitrous oxide or propofol) and high-pass digital filtering on within-patient variability of posterior tibial nerve somatosensory cortical evoked potentials (PTN-SCEP) were compared prospectively in two groups of 20 patients undergoing spinal surgery. Average P1N1 amplitude was significantly higher and P1N1 amplitude variability lower during propofol/alfentanil anesthesia than during nitrous oxide/alfentanil anesthesia. ⋯ This study shows the importance of maintaining the highest possible PTN-SCEP amplitudes during spinal surgery. Propofol/opioid anesthesia may be an alternative anesthetic technique to nitrous oxide/opioid anesthesia during spinal cord function monitoring.