The axial cage. a pilot study for interbody fusion in higher-grade spondylolisthesis.

BACKGROUND CONTEXT: The surgical treatment of high-grade spondylolisthesis is challenging. Posterolateral fusion alone has a high rate of pseudarthrosis. Surgical stabilization of higher-grade lumbar spondylolisthesis with a fibula strut graft is an effective technique but is associated with harvest site morbidity and graft fractures. PURPOSE: We hypothesized that a lumbar interbody fusion with a long, threaded titanium cage, packed with cancellous bone, inserted across the center of the spondylolisthesis, would provide the rigid immobilization necessary for successful arthrodesis. This would, therefore, eliminate the need for fibula harvest and possibly reduce the need for posterior instrumentation. STUDY DESIGN/SETTING: Prospective, study cohort of 11 consecutive patients with a minimum follow-up of 1 year. PATIENT SAMPLE: Patients with higher-grade spondylolisthesis (grade II-IV) were considered eligible. OUTCOME MEASURES: Pain was measured with a 10-point Numerical Rating Score (NRS). The Oswestry Disability Index (OSI) was used to assess patient function. Patients also responded to a satisfaction scale to evaluate satisfaction with their outcome. Radiographs were reviewed 1, 3, 6, 12, and, when available, 24 months after surgery. METHODS: We reviewed our clinical results and technical outcomes in 11 consecutive patients who underwent this unique form of anterior lumbar interbody fusion with a custom axial cage. RESULTS: There were no surgical or postoperative complications. Serial x-rays revealed no implant subsidence or loosening. There have been no implant fractures or reoperation. Clinical results have been excellent with significant pain reduction and improved function. At 1 year after surgery the mean NRS was 3.5 (range, 0-7), a significant average reduction of 5.0 points. (p<.001) All patients have been satisfied with their results. CONCLUSIONS: The axial cage technique appears to be a significant improvement over the fibular strut graft for the treatment of higher-grade spondylolisthesis. It provides significant reduction in pain, significant improvement in function, high patient satisfaction, and avoids the morbidity and fracture risks associated with fibular strut grafting.

Anterior lumbar fusion improves discogenic pain at levels of prior posterolateral fusion.

STUDY DESIGN: A descriptive case review. OBJECTIVES: To assess the outcomes of anterior lumbar interbody fusion for painful discs within a solid posterolateral spinal fusion. SUMMARY OF BACKGROUND DATA: Some patients continue to have pain after posterolateral spinal fusion despite apparently solid arthrodesis. One potential etiology is pain that arises from a disc within the fused levels. METHOD: Retrospective review of 176 patients with anterior interbody fusion, which located 20 who had anterior interbody fusion levels of prior posterolateral spinal fusion. All had low back pain, solid posterolateral spinal fusion, and painful disc(s) at the posterolateral spinal fusion level(s) but not elsewhere. Pain was measured by the Numerical Rating Scale, function by Oswestry Disability Questionnaire, and patient satisfaction by the North American Spine Society Outcome Questionnaire. RESULTS: Follow-up data were available for 18 patients (90%). Mean follow-up was 58 months (25 to 102). There were 10 men and 8 women. Mean age was 45 years (26 to 72). Diagnoses were degenerative discs, herniated nucleus pulposus, spondylolisthesis, and spinal stenosis. Eight patients had injuries after the previous posterolateral spinal fusion that precipitated new symptoms. Two patients had one level fusion, 14 had two levels, and 1 each had three and four levels. Four patients had one prior surgery, 5 had two, and 9 had three or more. All patients had solid anterior interbody fusion by radiograph. Mean Numerical Rating Scale improved from 7.9 before surgery to 4.7 after (P< 0.001). Mean Oswestry Disability Questionnaire improved from 56.3 before surgery to 47.9 after (P = 0.04). Of 15 patients unable to work before anterior interbody fusion, 5 returned to work. Sixteen patients (89%) were satisfied with their results. CONCLUSION: Low back pain that continues or recurs after apparently solid posterolateral spinal fusion may be caused by painful disc(s) at motion segment(s) within the fusion. A solid posterolateral spinal fusion may not protect the residual disc(s) from injury. Anterior interbody fusion can provide significant improvements in pain and function and a high degree of patient satisfaction in this clinical setting.

Patient satisfaction after circumferential lumbar fusion.

STUDY DESIGN: A review of 141 consecutive patients who underwent instrumented circumferential lumbar fusions. Outcome was assessed by an independent third party after a minimum follow-up of 2 years. OBJECTIVES: To evaluate clinical outcomes and assess patient satisfaction with circumferential lumbar fusions. SUMMARY OF BACKGROUND DATA: Circumferential lumbar fusion has been used as a salvage procedure for revision spine surgery. METHODS: Data were collected from patient interviews, patient satisfaction questionnaire, and review of records and radiographs of 141 consecutive patients who underwent circumferential lumbar fusion under a single anesthetic. RESULTS: There were follow-up data in 133 of the 141 patients (92%). Mean duration of follow-up was 37.2 months. There were 41 (31%) primary and 92 (69%) revision surgeries. There were 73 (55%) workers' compensation and 60 (45%) non-workers' compensation patients. There were radiographs available at 12-month follow-up in 86 patients (65%). There was solid radiographic fusion in 85 (99%) of the 86 patients. The overall complication rate was 20%. Clinical outcome was determined by the patient satisfaction questionnaire. There were 14 (11%) who chose the statement, "surgery met my expectations"; 68 (51%) who chose, "surgery improved my condition enough that I would go through it again for the same outcome"; 26 (20%) who chose, "surgery helped me but I would not go through it again for the same outcome"; and 25 (19%) who chose, "I am the same or worse compared with before surgery." There was no statistical difference in patient satisfaction between primary and revision surgeries or between workers' compensation versus non-workers' compensation groups. CONCLUSIONS: Circumferential lumbar fusion is a useful procedure for a patient with difficult reconstructive disease. There is a very high fusion rate. Overall, 62% of patients are satisfied with the result, especially those with a diagnosis of pseudarthrosis or spondylolisthesis with stenosis. Patients who are working before surgery and patients who are not injured workers also tended to progress well.

Paradoxical enhancement of atherosclerosis by probucol treatment in apolipoprotein E-deficient mice.

Dietary administration of probucol (0.5%, wt/wt) efficiently reduced total plasma cholesterol levels in apolipoprotein E-deficient mice (apoE-/-) by 40%, with decreases in high density lipoprotein (HDL) and apoAI by 70 and 50%, respectively. Paradoxically, however, aortic atherosclerotic plaques in the probucol-treated apoE-/- mice formed more rapidly than in the untreated apoE-/- mice, and the lesions were two to four times larger and more mature regardless of sex, age, and genetic background (P < 10(-)6). Histologically, lesions in probucol-treated mice contained increased fibrous materials and cells other than foam cells, and were commonly associated with focal inflammation and aneurysmal dilatation. Probucol treatment also accelerated lesion development in apoE+/- mice fed an atherogenic diet, indicating that the adverse effect is not dependent on the complete absence of apoE. Furthermore, mice lacking apoE and apoAI have plasma lipoprotein profiles very similar to the probucol-treated apoE-/- mice, but do not have accelerated plaque development. Thus, the enhanced atherosclerosis in the probucol-treated animals is unlikely to be caused by the reduction of HDL and apoAI levels. Our data indicate that a reduction in plasma cholesterol caused by probucol does not necessarily lead to an antiatherogenic effect.

In situ arthrodesis without decompression for Grade-III or IV isthmic spondylolisthesis in adults who have severe sciatica.

Eight adults who had back pain and sciatica that was caused by Grade-III or IV isthmic spondylolisthesis of the fifth lumbar vertebra on the sacrum were treated consecutively by in situ arthrodesis without decompression. The anterior displacement of the fifth lumbar vertebra averaged 82 per cent (range, 66 to 118 per cent). The length of follow-up averaged 5.5 years (range, two to fourteen years). All of the arthrodeses resulted in a solid fusion and excellent relief of both the back pain and the sciatica. All of the preoperative neurological deficits resolved, with the exception of a decreased or absent Achilles-tendon reflex in two patients. There were no complications, and all of the patients returned to their preoperative occupations.

Retinal projections in sockeye salmon smolts (Oncorhynchus nerka).

The retinal projections in 2-year-old salmon smolt (Oncorhynchus nerka) are significantly different from those observed in other teleosts examined to date in that the projections are more extensive. Very noticeable are extensive projections to most of the dorsal thalamus, to all layers of the optic tectum, and into the periaqueductal gray of the torus semicircularis. The salmon smolt has bilateral retinal projections to the diencephalon and pretectum. A small retinal projection to the lateral habenular nucleus has not been described previously. Although these findings suggest striking differences in retinal projections among teleosts, this variation may relate to age differences since the previously studied teleosts were adults.

Changes with age in total brain concentrations of biogenic amine neurotransmitters in coho salmon (Oncorhynchus kisutch Walbaum).

Whole brain content of several biogenic amines was determined in two age groups of coho salmon (Oncorhynchus kisutch Walbaum). Brains of presmolt salmon (about 5 months old) were compared to brains of homeward migrants (4 years old). Levels of dopamine and serotonin were significantly higher in the homeward migrants.