31P nuclear magnetic resonance spectroscopic evidence that canine nucleus pulposus and anulus fibrosus cells differ in principal organophosphorus biomolecules.

STUDY DESIGN: 31P Nuclear magnetic resonance spectroscopy was used to compare amounts and types of principal organophosphorus biomolecules in canine intervertebral disc tissues ex vivo. OBJECTIVE: The goal of this study was to compare principal organophosphorus biomolecules in nucleus pulposus, anulus fibrosus, and in isolated nucleus pulposus and anulus fibrosus cells. SUMMARY OF BACKGROUND DATA: There is no published information on principal organophosphorus biomolecules in disc tissues for any animal. METHODS: Canine nucleus pulposus and anulus fibrosus were shown by hematoxylin-eosin staining to be healthy tissues characteristic of adult dogs. Viable cells liberated from these disc tissues by sequential protease digestion were directly visualized by light microscopy of wet mounts. 31P nuclear magnetic resonance spectra were recorded at room temperature for 12 hours according to conventional published methods. RESULTS: No resonances were detected for intact nucleus pulposus and anulus fibrosus tissue. 31P nuclear magnetic resonance spectra of viable chondrocyte-like cells from anulus fibrosus featured two distinctive resonance peaks consistent with phosphomonoesters and phosphodiesters. After undigested anulus fibrosus was removed, no resonances were detected. 31P nuclear magnetic resonance spectra of viable chondrocyte-like cells from nucleus pulposus before and after removal of undigested tissue featured only one resonance peak consistent with phosphodiesters. CONCLUSIONS: A phosphomonoester-containing biomolecule is present in healthy canine anulus fibrosus tissue but not in nucleus pulposus tissue, nor in nucleus pulposus cells or anulus fibrosus cells. A phosphodiester-containing biomolecule is present principally in nucleus pulposus cells. This study demonstrated that canine chondrocyte-like cells from nucleus pulposus and anulus fibrosus are phenotypically distinctive in principal organophosphorus biomolecules.

Postsurgical epidural hematoma reproducing a lumbar radiculopathy.

A 24-year-old man presented to the spine service with an epidural hematoma three weeks after a successful decompressive laminectomy. Recurrence of the symptoms correlated with the repeat operative findings of a tenting hematoma over the area of the annular window. On decompression, the S1 nerve root relaxed in the L5-S1 gutter, effectively controlling the patient's symptoms and resulting in complete resolution of his pain. Radiographic and operative findings are discussed.

Factors influencing the cost of chronic low back injuries: An analysis of data from independent medical examinations.

Cost factors were examined in 157 patients with work- related spine injuries who were referred to a second opinion program between 1985 and 1991. The independent medical examination (IME) included a history, physical examination, and review of imaging and other studies. Data on demographic variables, litigation, work, injury history, physical examination, and imaging studies were recorded. A standard measure of psychological status (Low Back Pain Symptom Check List) was filled out. The instrument uses pain language as a clinical marker of psychological disturbance linked to a range of conflictual issues such as suppressed anger, burdensome feeling of inferiority, damaged self- esteem, role confusion, abnormal mentation, fear of responsibility or intimacy, gender issues, sexual concerns, disturbing arousal, and the like. Since it relies exclusively on pain language for diagnosis, it does not identify the specific nature of the psychological conflict. Data on treatment, final resolution, and cost were obtained from computerized files of the insurance company. The total cost incurred was $6,551,139. This averaged to $41,727 per case. More expensive cases were associated with a surgical intervention, psychological disturbance, litigation, motor weakness, and positive radiographs. These five variables accounted for 48% of the cost variance. Surgery accounted for 19.9% of the variance and contained the most expensive cases ($68,310 vs. $31,423). Psychological disturbance was detected in 27% of the sample and accounted for 10.5% of the cost variance. Litigation was present in 72% of the cases and accounted for 9.1% of the cost variance. Motor strength and radiographs taken together accounted for 8.4% of the variance. The usefulness of this information was explored from an actuarial and medical perspective.