Leroy S. Lavine

Lumbar intervertebral disk herniation in teenage children: recognition and management of associated anomalies.

Herniated disks in children and adolescents can be extremely disabling and difficult to diagnose because of the paucity of neurologic abnormalities and the consequent suspicions of hysteria. The Laségue sign is often the only consistent positive finding, and when persisting without remission, justifies early diagnostic studies such as CT scanning, and electromyography. Myelography may be avoided if these studies are definitively diagnostic. The almost uniformly good results that follow diskectomy do not justify prolonged conservative care. Management is facilitated by awareness of often unrecognized structural abnormalities found in these patients. These include spinal stenosis, lateral recess narrowing, and transitional vertebra. Spinal fusion, while rarely indicated, should be considered where motion segment instability contributes to persistent backache. The management of 25 patients is recorded. Twenty-one of these presented with an anomaly worthy of record requiring modifications in surgical technique to provide proper decompression and lasting relief of symptoms

Degenerative spondylolisthesis with an intact neural arch: a review of 60 cases with an analysis of clinical findings and the development of surgical management.

The treatment over the past 12 years of 60 patients with degenerative spondylolisthesis with an intact neural arch is reviewed. The patients averaged 65 years of age, with women outnumbering men by a ratio of 2:1. Symptoms in the lower extremities had been present for 3 months to 10 years, although varying back pain had existed for longer periods. Two-thirds showed signs of motor dysfunction. Sensory alterations and a positive Las ègues sign could be demonstrated in only one-half of the patients studied. Four of 5 patients developed intermittent neurogenic claudication, with varying evidence of painful radiculopathy. The marked disability caused by claudication contrasted sharply with the lesser neurological changes, and these patients required early surgical decompression. Diagnostic studies included electromyography, plain x-ray films, tomography, computed tomographic scanning, and myelography. The latter outlined a relative stenosis caused by olisthesis as well as arthrotic and spondylotic changes that determined the extent of decompressive operation required. The L-4, L-5 interspace was involved in 56 patients, L-3, L-4 was involved in 2, and L-5, S-1 was involved in 2. The ideal operation with L-4, L-5 olisthesis included complete laminectomy of L-4 and L-5 with unroofing of the lateral recesses and foraminotomy. This more extensive procedure was justified because of the failures encountered in previous patients in whom inadequate decompression had been performed. Among failures, obesity, diabetes, hyperlordosis, and extensive long-standing dysfunction were prominent. The relief of symptoms of intermittent neurogenic claudication was the most gratifying response observed. There was no unusual morbidity.

On electrical condution in living bone.

Despite the effectiveness of electrical currents in enhancing bone repair, there is little information in the literature on electrical parameters per se. Very little is known about the nature of the conduction mechanism or the current path between the electrodes. Without a better understanding it is difficult to establish meaningful hypotheses at the cellular level and to design relevant experimental protocols. In the present work, a first attempt is made at an in vivo delineation of the current-voltage relationship in the medullary area between two platinum electrodes embedded in the femur, by one of the techniques generally known to stimulate bone growth. At potential differences of less than 1 volt, a rather good ohmic dependence is observed, with an approximate specific resistance of 2 to 5 times 10-5 ohms/cm. At potentials higher than 1 volt, electrolytic processes appear to predominate and there is increasing non-linearity. Experimental techniques involving the adjustment of current through bone tissue assuming an ohmic dependence with little or no associated polarization effects are valid and certainly warrant further investigation.

Treatment of congenital pseudarthrosis of the tibia with direct current.

Bone possesses a bioelectric property that is important in maintaining its structural and architectural integrity. In vivo experiments demonstrate that bone formation can be accelerated by the application of direct current. We hypothesize that bone formation occurs through an electrochemical rather than an electromechanical effect. Two cases of congenital pseudarthrosis of the tibia treated by direct current stimulation are presented. A bone graft may be added to enhance bony union in conjunction with direct current. The implications of this work are that there is need for further fundamental studies including ultrastructural observations.

Qualitative Chemical Composition of the Calcifying Organic Matrix obtained from Cell-free Coccoliths

BIOLOGICAL mineral deposition has been defined as a biphasic process comprised of an organic matrix on which specific minerals are deposited1. Investigations with the euryhaline supralittoral coccolithophorid Hymenomonas Mary Parks 156 have shown that this primitive and ancient protist fulfils all the requirements of biological calcification in its production of calcitic coccoliths2–4. The fact that Hymenomonas extrudes a large number of its coccoliths as it ages and that simple manipulation of the cultures3 permits collection of the extra- and intracellular calcareous bodies makes these organisms exceptional test objects for an investigation of the physiology and intimate chemistry of biological mineral deposition.

CORRELATION BETWEEN THE PRESENCE OF SULFATED POLYSACCHARIDES AND MINERALIZATION IN A MARINE COCCOLITHOPHORID PROTOZOON: HISTOCHEMICAL AND AUTORADIOGRAPHIC STUDIES

The deposition of coccoliths, calcite-calcium carbonate-containing organic structures which align peripherally and are liberated into the environment by the primitive marine coccolithophorid chrysomonad protozoon Hymenomonas Mary Parke 156, follows the pathways of biphasic biologic mineral deposition without biochemical evidence of sulfur-containing polysaccharides. Tinctorial and autoradiographic evidence for the participation of sulfur-containing carbohydrate moieties is presented. Nutritional conditions and addition of inhibitors, which have been shown to interfere with the microscopic, electron microscopic and biochemical demonstration of mineral deposition, also inhibit the staining reactions associated in mammalian systems with acid mucopolysaccharides. These observations suggest that, even at the level of an evolving mechanism, sulfur-containing carbohydrates participate in some manner in the deposition of mineral onto a preformed organic matrix.

Calcification XIX. Calcification of Transplanted Rachitic Bone.

Summary Calcification of the rachitic metaphysis, with typical silver line test, was obtained in tibial slices that were transplanted to rats on a normal diet. Similar transplants to rats on a rachitogenic diet did not calcify. This difference was probably due to the higher Ca x P product in the body fluids of animals on a normal diet as compared to the product of animals on a rachitogenic diet. In vitro calcification was obtained in the sera of normal animals, in the sera of rachitic animals to which phosphate was added to raise the Ca x P product but not in the unmodified sera of rachitic animals. In vitro calcification was obtained in inorganic solutions with a Ca x P product of 50 but not with a Ca x P product of 20. Transplanted deep freeze stored bone slices treated with calcium chloride prior to deep freeze calcified more intensively than deep freeze stored bones not treated with calcium, as measured by the silver line test. Calcification in vitro studies indicated reversible inactivation of calcifiability of stored frozen bone which could be prevented or restored by calcium chloride treatment. While differences existed, calcification of the deep freeze stored bone indicated that there was a partial restoration of the calcifying mechanism or that some unknown ingredient exists in the body fluids which, if present, could have elicited restoration of the calcifying mechanism. Transplantation of rachitic bone, as proposed, may be an additional method for studying the differences of the actual body fluids on calcification of a given rachitic bone, or after treatment of such bone the changes in calcifiability with an actual standard body fluid such as that of an animal on a normal diet.

THE EFFECT OF BONE BANK PRESERVATION ON THE CALCIFYING MECHANISM

1. The influence of various methods of preserving bone on the calcifying mechanism of the tibial epiphysial cartilage of rachitic rats was studied. An in vitro calcification technique was employed. 2. Preservation by deep freezing, aqueous merthiolate, boiling, or acetone inactivated the calcifying mechanism. 3. The inactivation was reversed with calcium ions, most readily in the deep-frozen bones, less readily in the merthiolate treated bones, still less readily in the acetone stored bones, and least in boiled bones. 4. Exposure to calcium ions before preservation in the deep-freeze chest prevented inactivation. 5. The inactivation, reactivation and survival of the calcifying mechanism were confirmed by metachromasia studies. 6. The theory of the mode of action of calcium chloride on reactivation and survival of the calcifying mechanism is presented.