Three-dimensional motion of the uncovertebral joint during head rotation

Object The uncovertebral joints are peculiar but clinically important anatomical structures of the cervical vertebrae. In the aged or degenerative cervical spine, osteophytes arising from an uncovertebral joint can cause cervical radiculopathy, often necessitating decompression surgery. Although these joints are believed to bear some relationship to head rotation, how the uncovertebral joints work during head rotation remains unclear. The purpose of this study is to elucidate 3D motion of the uncovertebral joints during head rotation. Methods Study participants were 10 healthy volunteers who underwent 3D MRI of the cervical spine in 11 positions during head rotation: neutral (0°) and 15° increments to maximal head rotation on each side (left and right). Relative motions of the cervical spine were calculated by automatically superimposing a segmented 3D MR image of the vertebra in the neutral position over images of each position using the volume registration method. The 3D intervertebral motions of all 10 volunteers were standardized, and the 3D motion of uncovertebral joints was visualized on animations using data for the standardized motion. Inferred contact areas of uncovertebral joints were also calculated using a proximity mapping technique. Results The 3D animation of uncovertebral joints during head rotation showed that the joints alternate between contact and separation. Inferred contact areas of uncovertebral joints were situated directly lateral at the middle cervical spine and dorsolateral at the lower cervical spine. With increasing angle of rotation, inferred contact areas increased in the middle cervical spine, whereas areas in the lower cervical spine slightly decreased. Conclusions In this study, the 3D motions of uncovertebral joints during head rotation were depicted precisely for the first time.

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In vivo 3D kinematic changes in the cervical spine after laminoplasty for cervical spondylotic myelopathy

Journal of Neurosurgery Spine ◽

10.3171/2014.5.spine13702 ◽

2014 ◽

Vol 21 (3) ◽

pp. 417-424 ◽

Cited By ~ 8

Author(s):

Yukitaka Nagamoto ◽

Motoki Iwasaki ◽

Tsuyoshi Sugiura ◽

Takahito Fujimori ◽

Yohei Matsuo ◽

...

Keyword(s):

Cervical Spine ◽

Cervical Spondylotic Myelopathy ◽

Head Rotation ◽

Upper Cervical Spine ◽

Registration Method ◽

Flexion Extension ◽

Upper Cervical ◽

Head Flexion ◽

Age Range

Object Cervical laminoplasty is an effective procedure for decompressing the spinal cord at multiple levels, but restriction of neck motion is one of the well-known complications of the procedure. Although many authors have reported on cervical range of motion (ROM) after laminoplasty, they have focused mainly on 2D flexion and extension on lateral radiographs, not on 3D motion (including coupled motion) nor on precise intervertebral motion. The purpose of this study was to clarify the 3D kinematic changes in the cervical spine after laminoplasty performed to treat cervical spondylotic myelopathy. Methods Eleven consecutive patients (6 men and 5 women, mean age 68.1 years, age range 57–79 years) with cervical spondylotic myelopathy who had undergone laminoplasty were included in the study. All patients underwent 3D CT of the cervical spine in 5 positions (neutral, 45° head rotation left and right, maximum head flexion, and maximum head extension) using supporting devices. The scans were performed preoperatively and at 6 months after laminoplasty. Segmental ROM from Oc–C1 to C7–T1 was calculated both in flexion-extension and in rotation, using a voxel-based registration method. Results Mean C2–7 flexion-extension ROM, equivalent to cervical ROM in all previous studies, was 45.5° ± 7.1° preoperatively and 35.5° ± 8.2° postoperatively, which was a statistically significant 33% decrease. However, mean Oc–T1 flexion-extension ROM, which represented total cervical ROM, was 71.5° ± 8.3° preoperatively and 66.5° ± 8.3° postoperatively, an insignificant 7.0% decrease. In focusing on each motion segment, the authors observed a statistically significant 22.6% decrease in mean segmental ROM at the operated levels during flexion-extension and a statistically insignificant 10.2% decrease during rotation. The most significant decrease was observed at C2–3. Segmental ROM at C2–3 decreased 24.2% during flexion-extension and 21.8% during rotation. However, a statistically insignificant 37.2% increase was observed at the upper cervical spine (Oc–C2) during flexion-extension. The coupling pattern during rotation did not change significantly after laminoplasty. Conclusions In this first accurate documentation of 3D segmental kinematic changes after laminoplasty, Oc–T1 ROM, which represented total cervical ROM, did not change significantly during either flexion-extension or rotation by 6 months after laminoplasty despite a significant decrease in C2–7 flexion-extension ROM. This is thought to be partially because of a compensatory increase in segmental ROM at the upper cervical spine (Oc–C2).

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Figure 12.5 Schematic of the trauma shown in Figures 12.2 and 12.3. The spine starts in a neutral position (NP). The 50 to 75 ms time period illustrates the neck forming an S-shaped curvature (Phase I). During this phase, the lower cervical spine intervertebral joints exhibit hyper-extension, exceeding their physiological limits. In the later phase (Phase II), the spine transforms to a C-shape with complete extension. This phase is associated with a lesser degree of the lower level hyper-extension, and thus a lesser potential for injury.

Biomechanics in Ergonomics ◽

10.4324/9780203016268-66 ◽

1999 ◽

pp. 277-284

Keyword(s):

Cervical Spine ◽

Phase I ◽

Phase Ii ◽

Neutral Position ◽

Lower Cervical Spine ◽

Physiological Limits ◽

Complete Extension ◽

Time Period ◽

Later Phase ◽

Phase Phase

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Discectomies of the lower cervical spine using interbody biopolymer (B.O.P.) implants

Acta Neurochirurgica ◽

10.1007/bf01456164 ◽

1989 ◽

Vol 96 (3-4) ◽

pp. 88-93 ◽

Cited By ~ 23

Author(s):

G. Lozes ◽

A. Fawaz ◽

A. Cama ◽

I. Krivosic ◽

P. Devos ◽

...

Keyword(s):

Cervical Spine ◽

Lower Cervical Spine

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The Effect of Tibiotalar Fixation on Foot Biomechanics

Foot & Ankle International ◽

10.1177/107110079701801207 ◽

1997 ◽

Vol 18 (12) ◽

pp. 792-797 ◽

Cited By ~ 25

Author(s):

Jennifer S. Wayne ◽

Keith W. Lawhorn ◽

Kenneth E. Davis ◽

Karanvir Prakash ◽

Robert S. Adelaar

Keyword(s):

Subtalar Joint ◽

Sagittal Plane ◽

Lower Limbs ◽

Coronal Plane ◽

Neutral Position ◽

Talonavicular Joint ◽

Tibiotalar Joint ◽

Contact Areas ◽

Joint Contact ◽

Peak Pressures

Contact areas and peak pressures in the posterior facet of the subtalar and the talonavicular joints were measured in cadaver lower limbs for both the normal limb and after fixation of the tibiotalar joint. Six joints were fixed in neutral, in 5–7° of varus and of valgus. Ten degrees of equinus angulation was also studied. Each position of fixation was tested independently. Neutral was defined as fixation without coronal or sagittal plane angulation compared with prefixation alignment of the specimen. When compared with normal unfused condition, peak pressures increased, and contact areas decreased in the subtalar joint for specimens fixed in neutral, varus, and valgus. However, the change in peak pressure for neutral fusion compared with normal control was not statistically significant ( P > 0.07). Peak pressures for varus and valgus fixation were significantly different from normal ( P < 0.001). Contact areas for all positions of fixation were significantly different from normal ( P < 0.001). Coronal plane angulation, however, also resulted in significantly lower contact areas compared with neutral fixation ( P < 0.001). Contact areas and peak pressures in the talonavicular joint did not appear to be substantially affected by tibiotalar fixation with coronal plane angulation. Equinus fixation qualitatively increased contact areas and peak pressures in the talonavicular and posterior facet of the subtalar joint. Neutral alignment of the tibiotalar joint in the coronal and sagittal planes altered subtalar and talonavicular joint contact characteristics the least compared with normal controls. Therefore, ankle fusion in the neutral position would be expected to most closely preserve normal joint biomechanics and may limit the progression of degenerative arthrosis of the subtalar joint.

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