The denticulate ligament: anatomy and functional significance

2001 ◽  
Vol 94 (2) ◽  
pp. 271-275 ◽  
Author(s):  
R. Shane Tubbs ◽  
George Salter ◽  
Paul A. Grabb ◽  
W. Jerry Oakes

Object. The authors conducted a study to examine the detailed anatomy of the denticulate ligaments and to assess their classic role in spinal cord stability within the spinal canal. Methods. Detailed observation of the denticulate ligaments in 12 adult cadavers was performed. Stress was applied in all major planes to discern when the ligaments would become taut, and at the same time, gross motion of the cord was observed at sites distal to the stresses applied. Tension necessary for avulsion of the ligaments in various areas of the spinal cord was also measured. Conclusions. These results show that the denticulate ligaments do not inhibit cord motion to such discrete areas of the cord as was once thought. The authors have determined that the ligaments are stronger in the cervical region and that they decrease in strength as the spinal cord descends. These findings are demonstrative of the denticulate ligaments being more resistant to caudal compared with cephalad stresses in the cord. Anterior and posterior motion is constrained by these ligaments but to a limited degree, especially as one descends inferiorly along the cord. Further embryological and functional studies of these ligaments is needed in non—formalin fixed tissues.

1998 ◽  
Vol 88 (1) ◽  
pp. 122-125 ◽  
Author(s):  
Timothy R. Steel ◽  
James Allibone ◽  
Tamas Revesz ◽  
Corrado D'Arrigo ◽  
H. Alan Crockard

✓ This 54-year-old man with a history of right-sided malignant mesothelioma presented with signs of a partial spinal cord syndrome. The tumor had invaded the lower trunk of the brachial plexus and spread along the T-1 nerve root beneath the arachnoid onto the spinal cord itself. Mesothelioma, despite its known predilection for local spread, is rarely encountered within the spinal canal. Neurotropism is commonly encountered in facial malignancies; however, it has never been reported to affect the brachial plexus and spinal cord.


1973 ◽  
Vol 38 (3) ◽  
pp. 374-378 ◽  
Author(s):  
Chikao Nagashima

✓ The author reports the successful treatment of a case of irreducile atlantoaxial dislocation due to separation of the dens and secondary arthritic changes causing sagittal narrowing of the atlanto-axial spinal canal to 3 mm. Complete myelography obstruction was present. A one-stage posterior decompression of the foramen magnum and atlas was performed and occipito-cervical fixation accomplished by wire encased in acrylic plastic.


1974 ◽  
Vol 40 (1) ◽  
pp. 107-109 ◽  
Author(s):  
P. S. Ramani

✓ A rare case is reported in which a primary chondromyxoid fibroma of the 12th rib spread into the epidural space of the spinal canal to cause spinal cord compression. The benign nature of the tumor is stressed and the only other reported case reviewed.


1999 ◽  
Vol 91 (2) ◽  
pp. 211-215 ◽  
Author(s):  
Saim Kazan ◽  
Özgür Özdemir ◽  
Mahmut Akyüz ◽  
Recai Tuncer

✓ The authors describe two rare occurrences of radiographically, surgically, and pathologically confirmed spinal intradural arachnoid cysts (not associated with additional pathological entities) that were located anterior to the cervical spinal cord. These lesions have been reported previously in only eight patients. The patients described in this report were young adults who presented with progressive spastic tetraparesis shortly after sustaining mild cervical trauma and in whom no neurological deficit or bone fracture was demonstrated. The presence of an intradural arachnoid cyst was detected on postcontrast computerized tomography (CT) myelography and on magnetic resonance imaging; both diagnostic tools correctly characterized the cystic nature of the lesion. Plain radiography, plain tomography, and contrast-enhanced CT scans were not diagnostic. In both cases a laminectomy was performed, and the wall of the cyst was excised and fenestrated with subarachnoid space. Postoperatively, the patients made complete neurological recoveries. Based on a review of the literature, arachnoid cysts of the spinal canal may be classified as either extra- or intradural. Intradural arachnoid cysts usually arise posterior to the spinal cord in the thoracic spine region; however, these cysts very rarely develop in the cervical region. The pathogenesis of arachnoid cysts is unclear, although congenital, traumatic and inflammatory causes have been postulated. The authors believe that the formation of an arachnoid cyst cannot be explained by simply one mechanism because, in some reported cases, there has been accidental or iatrogenic trauma in association with congenital lesions. They also note that an intradural arachnoid cyst located anterior to the cervical spinal cord is an extremely rare disorder that may cause progressive myelopathy; however, the postoperative prognosis is good.


1994 ◽  
Vol 81 (6) ◽  
pp. 941-946 ◽  
Author(s):  
Adam N. Mamelak ◽  
Philip H. Cogen ◽  
A. James Barkovich

✓ This report describes the unique case of a child born with paraplegia and a neurogenic bladder who was found to have a dysplastic, nonossified T-12 vertebral body, midline fusion of the T-12 neural arches, obliteration of the spinal canal at T-12, and an extraspinal thecal sac in the T11—L1 region. Neural tissue was focally absent from T9–12, but neural structures above and below were preserved. Narrowing of the thecal sac on myelograms and sagittal magnetic resonance images signifies in utero focal infarction of the spinal cord after neurulation but before formation of the posterior half of the spinal canal. The infarction resulted in severe focal narrowing of the thecal sac from T10—L1, resembling a premature and duplicated filum terminale; to denote the radiographic appearance of these anomalies, the authors have coined the term “filum intermedium” sign. The extremely unusual radiographic findings in this child illustrate the important interactions between neural tube, neural crest, and somite in the development of the spinal cord and spinal column. Correlation of the radiographic findings with the embryological differentiation and migration of these structures suggests that the spinal anomalies were caused by a focal insult, probably vascular in origin, occurring between the sixth and eighth weeks of gestation. The identification of a focally narrowed thecal sac and spinal cord (the “filum intermedium” sign) localizes the time of the insult to between the first and third month of gestation, and therefore is a useful marker in understanding developmental malformation of the spinal cord.


1989 ◽  
Vol 70 (3) ◽  
pp. 454-462 ◽  
Author(s):  
Roberto Pallini ◽  
Eduardo Fernandez ◽  
Carlo Gangitano ◽  
Aurora Del Fà ◽  
Corrado Olivieri-Sangiacomo ◽  
...  

✓ Spinal cord tissue was obtained from 13- and 14-day embryonic rats and homologously grafted to the completely transected spinal cord of adult rats. Eight and 12 weeks after grafting, clinical, electrophysiological, histological, and neuroanatomical studies were performed. Motor performance of the hosts was assessed by the inclined-plane test. The conduction of nerve impulses across the lesion-transplantation site was evaluated by recording the spinal corticomotor and somatosensory evoked potentials. The survival, growth, differentiation, and parenchymal integration of the graft were documented histologically on semi-thin sections. The axonal interactions between the host spinal cord and the graft as well as the posttraumatic retrograde degeneration of corticospinal axons were investigated using the horseradish peroxidase (HRP) technique. Clinical and electrophysiological assessments did not demonstrate any functional activity of the graft. On histological examination, grafted neurons showed a survival rate of 55%. Such neurons exhibited a limited degree of growth and differentiation. The extent of parenchymal integration between the host spinal cord and the graft varied considerably among different specimens and in the various regions of every specimen. The HRP investigations demonstrated that some axonal interactions between the host spinal cord and the graft had occurred. Regenerated axons arising from both the spinal cord and the dorsal root ganglia of the host entered the graft and elongated in it. Also, axons from the grafted neurons were able to grow for some distance in the host spinal cord. The phenomenon of the posttraumatic retrograde degeneration of corticospinal axons was not affected by this embryonic tissue grafting.


1977 ◽  
Vol 47 (2) ◽  
pp. 290-292 ◽  
Author(s):  
Wolf I. Steudel ◽  
William Ingunza

✓ The authors describe a unique case in which a bullet was lodged in the spinal canal at the C2–3 level. The patient exhibited clinically the syndrome of acute central cervical spinal cord injury. The pathogenesis is discussed with reference to three similar cases in the literature.


1978 ◽  
Vol 48 (6) ◽  
pp. 1008-1014 ◽  
Author(s):  
Athanasios Smokovitis ◽  
Tage Astrup

✓ Fibrinolytic activity (caused by a plasminogen activator) in the spinal cord was highest in the rat, lowest in the rabbit, and intermediate in the guinea pig. In all species the activity was highest in relation to the pia mater. The central spinal canal was active in the rat and the rabbit, but mostly inactive in the guinea pig. Foci of activity were more numerous in the gray matter than in the white matter corresponding to the greater vascularity of the former. In all species ability to inhibit plasmin was related mainly to the gray matter, with an additional area related to the dura mater. The high fibrinolytic activity of the spinal leptomeninges may play a role in the pathogenesis of hemorrhagic processes related to the spinal cord.


1985 ◽  
Vol 63 (4) ◽  
pp. 510-520 ◽  
Author(s):  
Robert L. Allen ◽  
Phanor L. Perot ◽  
Steven K. Gudeman

✓ Computerized tomography metrizamide myelography was performed in 46 patients with acute, nonpenetrating cervical spinal cord injuries. By visualizing the spinal canal, spinal cord, and any compressive lesion, the study proved valuable in the decision as to whether surgical decompression was indicated and what approach should be used. Eleven patients were found to have significant spinal cord compression, 10 of whom were treated surgically. The technique, results, and complications resulting from the study are discussed.


2000 ◽  
Vol 93 (1) ◽  
pp. 15-20 ◽  
Author(s):  
Izumi Koyanagi ◽  
Yoshinobu Iwasaki ◽  
Kazutoshi Hida ◽  
Minoru Akino ◽  
Hiroyuki Imamura ◽  
...  

Object. It is known that the spinal cord can sustain traumatic injury without associated injury of the spinal column in some conditions, such as a flexible spinal column or preexisting narrowed spinal canal. The purpose of this study was to characterize the clinical features and to understand the mechanisms in cases of acute cervical cord injury in which fracture or dislocation of the cervical spine has not occurred. Methods. Eighty-nine patients who sustained an acute cervical cord injury were treated in our hospitals between 1990 and 1998. In 42 patients (47%) no bone injuries of the cervical spine were demonstrated, and this group was retrospectively analyzed. There were 35 men and seven women, aged 19 to 81 years (mean 58.9 years). The initial neurological examination indicated complete injury in five patients, whereas incomplete injury was demonstrated in 37. In the majority of the patients (90%) the authors found degenerative changes of the cervical spine such as spondylosis (22 cases) or ossification of the posterior longitudinal ligament (16 cases). The mean sagittal diameter of the cervical spinal canal, as measured on computerized tomography scans, was significantly narrower than that obtained in the control patients. Magnetic resonance (MR) imaging revealed spinal cord compression in 93% and paravertebral soft-tissue injuries in 58% of the patients. Conclusions. Degenerative changes of the cervical spine and developmental narrowing of the spinal canal are important preexisting factors. In the acute stage MR imaging is useful to understand the level and mechanisms of spinal cord injury. The fact that a significant number of the patients were found to have spinal cord compression despite the absence of bone injuries of the spinal column indicates that future investigations into surgical treatment of this type of injury are necessary.


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