Lordotic alignment and posterior migration of the spinal cord following en bloc open-door laminoplasty for cervical myelopathy: a magnetic resonance imaging study.

We investigated lordotic alignment and posterior migration of the spinal cord following en bloc open-door laminoplasty for cervical myelopathy. Fifty-five patients (32 men and 23 women) were studied, with an average follow-up of 2.4 years. Radiological examination included evaluation of lordosis of the cervical spine and spinal cord, degree of enlargement of bony spinal canal, and the magnitude of posterior cord migration. We also correlated these changes with neurological improvement. Postoperatively, there was an average of 5% loss of cervical spine lordosis (P > 0.01) on radiographs and 12% reduction in the lordotic alignment of the spinal cord (P > 0.05) on magnetic resonance imaging. Postoperatively, the size of the bony spinal canal increased by 48%. Posterior cord migration showed a significant correlation with the preoperative cervical spine and spinal cord lordosis (P < 0.05). Thirty-seven (67%) patients with neurological improvement exceeding 50% showed significant posterior cord migration following laminoplasty compared with those demonstrating less than 50% improvement (P = 0.01). Our results suggest that a significant neurological improvement is associated with posterior cord migration after cervical laminoplasty.

The tarsal tunnel syndrome: evaluation of surgical results using multivariate analysis.

Thirty-four patients with the tarsal tunnel syndrome were treated by decompression of the posterior tibial nerve. The condition was bilateral in 3 cases. There were 9 men and 25 women with an average age at operation of 41 years. The average follow up was for 3.8 years. Multivariate analysis showed that the outcome is influenced, in order of importance, by fibrosis around the nerve, the preoperative severity of the condition, a history of sprained ankle, worker's compensation, a long history, and heavy work. The results were favourable when there was a short history, the presence of a ganglion, no sprains, and light work. Measurement of the terminal latency of the medial plantar nerve was valuable in assessing recovery. The precise cause of the syndrome and its effect on treatment should be considered before operation.

A new method for permeabilization of the plasma membrane of cultured mammalian cells. IV. Structural requirement for high molecular weight polymers for potentiation of bleomycin cytotoxicity toward mammalian cells under conditions of vortex-stirring.

As we previously reported, the cytotoxicity of bleomycin (BLM) toward cultured mammalian cells was extraordinarily potentiated when the cells and BLM were vortex-stirred for a few seconds in the presence of high molecular weight polyacrylic acid (PAA). Cationic and nonionic polymers could not take the place of PAA in potentiating BLM cytotoxicity. The present study revealed that potentiation was sharply dependent on the molecular weight of PAA and a molecular weight of over 10(6) daltons seemed to be required. Copolymers of acrylic acid (AA) and acrylamide showed some potentiation which was relative to their AA content. It is worth noting that another type of anionic polymer, polymethacrylic acid, did not show any potentiating capacity at all. Polyacrylic sulfonate derivative showed a marginal capacity. The structural requirement for high molecular weight polymers for potentiation of BLM cytotoxicity was demonstrated by the increased uptake of Lucifer Yellow, a non-permeant material. In addition, the ability of permeabilization was not correlated with kinematic viscosity of anionic polymers.

Posterior limbus vertebral lesions causing lumbosacral radiculopathy and the cauda equina syndrome.

This report reviews our experience with spinal decompression for posterior limbus vertebral lesions or osteocartilaginous vertebral corner defects in the lumbar spine in 29 children and young adults. There were 19 male and 10 female patients with a mean age of 16.5 years (range, 9 to 24 years). Twenty-four patients were involved with various athletic activities. Clinical presentation included low back pain with a variable degree of radiculopathy in 25 patients and a cauda equina syndrome in four. The level of the affected spinal area was L1-2 in one patient, L2-3 in one, L3-4 in seven, L4-5 in 17, and L5-S1 in three. The preoperative imaging workup showed lateralised "non-calcified' or 'calcified' limbus vertebral defects in 13 patients and centrally displaced lesions in 16 patients. All patients underwent posterior spinal decompression with a slightly extended laminotomy, except for three patients who had a subsequent posterolateral fusion. All of the patients consequently returned to practice their favourite preoperative sport and lifestyle, but five discontinued their previous sports. We suggest that patients with posterior limbus vertebral lesions require careful diagnosis and therapy that are different from those with an ordinary lumbar disc herniation.