Effectiveness of multiple-level decompression in laminoplasty and simultaneous C1 laminectomy for patients with cervical myelopathy.
(25/126)
A retrospective study to investigate the relationship between the surgical levels and decompression effects was performed in patients with cervical myelopathy who had undergone Tension-band laminoplasty (TBL) with/without simultaneous C1 laminectomy. One hundred and sixty-eight patients (115 males, 53 females; age: 31-80 years, average 58.9 years; follow-up period: 12-120 months, average 20 months) were divided into three groups according to the range of the surgical levels: seventy-two patients in group A underwent TBL at the C2-C7 levels with C1 laminectomy; 60 patients in group B underwent TBL at the C2-C7 levels; 36 patients in group C underwent TBL at the C3-C7 levels. Neurological evaluation was performed by using the Japanese Orthopedic Association (JOA) scoring system. The alignment changes of the spinal column and the spinal cord were analyzed using pre- and post-operative roentgenograms and MRIs. The differences in the pre- and post-operative anterior subarachnoid spaces (D-ASAS), the spinal cord diameters (D-CORD), and the dural sleeve diameters (D-DURA) at the C1-C7 levels were also analyzed by using MRIs. The JOA scores improved in all groups. As for the spinal alignment, neither significant changes between pre- and post-operation in any group nor significant differences among the three groups were found. The lordosis of the cervical spinal cord was decreased in all groups. D-ASAS of group A was larger than that of group B at the C1-C5 levels (P<0.05), as were those of D-CORD and D-DURA at the C1-C2 and C4-C5 levels (P<0.05). D-ASAS of group A was larger than that of group C at the C1-C4 levels (P<0.05), as were those of D-CORD and D-DURA at the C1-C5 levels (P<0.05). In conclusion, laminoplasty including the C2-C7 levels with simultaneous C1 laminectomy was proven to allow the most posterior shift of the spinal cord within the widened dural sleeve at C5 or higher levels without significantly changing the spinal alignment. (+info)
Quantitative comparison of AIR, SPM, and the fully deformable model for atlas-based segmentation of functional and structural MR images.
(26/126)
Typical packages used for coregistration in functional image analyses include automated image registration (AIR) and statistical parametric mapping (SPM). However, both methods have limited-dimension deformation models. A fully deformable model, which combines the piecewise linear registration for coarse alignment with demons algorithm for voxel-level refinement, allows a higher degree of spatial deformation. This leads to a more accurate colocalization of the functional signal from different subjects and therefore can produce a more reliable group average signal. We quantitatively compared the performance of the three different registration approaches through a series of experiments and we found that the fully deformable model consistently produces a more accurate structural segmentation and a more reliable functional signal colocalization than does AIR or SPM. (+info)
Lhermitte sign during yawning associated with congenital partial aplasia of the posterior arch of the atlas.
(27/126)
We describe the case of a 26-year-old man who presented with symptoms compatible with Lhermitte sign that occurred during yawning. It was associated with congenital partial aplasia of the posterior arch of the atlas. Cervical multisection-detector CT myelography during yawning showed compression of the upper cervical cord due to the inward mobility of the isolated posterior tubercle. The symptoms completely disappeared following removal of the isolated posterior tubercle. (+info)
Anterior retropharyngeal fixation C1-2 for stabilization of atlantoaxial instabilities: study of feasibility, technical description and preliminary results.
(28/126)
Posterior transarticular screw fixation C1-2 with the Magerl technique is a challenging procedure for stabilization of atlantoaxial instabilities. Although its high primary stability favoured it to sublaminar wire-based techniques, the close merging of the vertebral artery (VA) and its violation during screw passage inside the axis emphasizes its potential risk. Also, posterior approach to the upper cervical spine produces extensive, as well as traumatic soft-tissue stripping. In comparison, anterior transarticular screw fixation C1-2 is an atraumatic technique, but has been neglected in the literature, even though promising results are published and lectured to date. In 2004, anterior screw fixation C1-2 was introduced in our department for the treatment of atlantoaxial instabilities. As it showed convincing results, its general anatomic feasibility was worked up. The distance between mid-sagittal line of C2 and medial border of the VA groove resembles the most important anatomic landmark in anterior transarticular screw fixation C1-2. Therefore, CT based measurements on 42 healthy specimens without pathology of the cervical spine were performed. Our data are compiled in an extended collection of anatomic landmarks relevant for anterior transarticular screw fixation C1-2. Based on anatomic findings, the technique and its feasibility in daily clinical work is depicted and discussed on our preliminary results in seven patients. (+info)
Atlas hypoplasia associated with non-traumatic retro-odontoid mass.
(29/126)
A 38-year-old man presented with progressive cervical myelopathy due to atlas hypoplasia associated with non-traumatic retro-odontoid mass. The neuroimaging findings suggested hypertrophy of the transverse ligament of the atlas. No histological confirmation of the retro-odontoid mass was obtained. Clinical manifestations improved after posterior decompression. Decompressive laminectomy of the atlas with or without fusion can achieve a good outcome in such cases. (+info)
Fracture of the atlas through a synchondrosis of the anterior arch complicated by atlantoaxial rotatory fixation in a four-year-old child.
(30/126)
Fracture of the atlas is rare in children. We report a case of fracture of the atlas through a synchondrosis of the anterior arch complicated by atlantoaxial rotatory fixation in a four-year-old girl. (+info)
Fractures of the atlas: can we rely on the NICE guidelines for imaging the cervical spine after head injury?
(31/126)
We describe a patient who was not thought to fulfil the NICE criteria for imaging the cervical spine after head injury but who had two fractures of the atlas, thus rendering the vertebral ring unstable. The reasons for missing this injury in the emergency department are discussed. (+info)
Functional morphology of the first cervical vertebra in humans and nonhuman primates.
(32/126)
The cervical vertebral column bears or balances the weight of the head supported by the nuchal muscles that partly originate from the cervical vertebrae. The position of the head relative to the vertebral column, and consequently locomotion and posture behavior, could thus be associated with the form of the cervical vertebrae. In spite of this assumption and some empirical indications along these lines, primate vertebral morphologies have been reported to be very similar and not clearly related to locomotion. We therefore study the relationship between the morphology of the first cervical vertebra, the atlas, and the locomotion pattern within primates using a geometric morphometric approach. Our analysis is based on a total of 116 vertebrae of adult Homo sapiens, Gorilla gorilla, Pan troglodytes, Pongo pygmaeus, Hylobates lar, Macaca mulatta, Papio hamadryas, Ateles geoffroyi, and Alouatta palliata. On each atlas, 56 landmarks were digitized and superimposed by Procrustes registration. The resulting shape variables were analyzed by principal component analysis, multivariate regression, and partial least-squares analysis. We found that the nine primate species differ clearly in their atlas morphology and that allometric shape change is distinct between the nonhuman primates and Homo sapiens. We could further identify morphological features that relate to the species' locomotion pattern. Human atlas shape, however, cannot be predicted by an extrapolation of the nonhuman primate model. This implies that either the primate atlas is generalized enough to allow bipedal locomotion or else the human atlas morphology is a unique adaptation different from that in the more orthograde nonhuman primates. (+info)