Can Variations in Intervertebral Disc Height Affect the Mechanical Function of the Disc?

Lu, Y M; Hutton, W. C.; Gharpuray, V. M.

doi:10.1097/00007632-199610010-00006

Cited by 110 publications

(47 citation statements)

References 43 publications

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“…Most of the data available relate to the lumbar intervertebral discs. Nonetheless, as discussed in prior work (3), biomechanical modeling (26,27,35) and clinical data (24) suggest that increases in disc height may increase risk of injury to that disc. In line with findings from the lumbar spine of the same subjects (1) and also from another bed rest study (3), the results showed persistence of the thoracic disc morphology changes long term after bed rest.…”

Section: Discussionmentioning

confidence: 92%

Hypertrophy in the cervical muscles and thoracic discs in bed rest?

Belavý

Miokovic

Armbrecht

et al. 2013

Journal of Applied Physiology

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The impact of prolonged bed rest on the cervical and upper thoracic spine is unknown. In the 2nd Berlin BedRest Study (BBR2-2), 24 male subjects underwent 60-day bed rest and performed either no exercise, resistive exercise, or resistive exercise with whole body vibration. Subjects were followed for 2 yr after bed rest. On axial cervical magnetic resonance images from the skull to T3, the volumes of the semispinalis capitis, splenius capitis, spinalis cervicis, longus capitis, longus colli, levator scapulae, sternocleidomastoid, middle and posterior scalenes, and anterior scalenes were measured. Disc height, anteroposterior width, and volume were measured from C2/3 to T6/7 on sagittal images. The volume of all muscles, with the exception of semispinalis capitis, increased during bed rest (P Ͻ 0.025). There were no significant differences between the groups for changes in the muscles. Increased upper and midthoracic spine disc height and volume (P Ͻ 0.001) was seen during bed rest, and disc height increases persisted at least 6 mo after bed rest. Increases in thoracic disc height were greater (P ϭ 0.003) in the resistive vibration exercise group than in control. On radiological review, two subjects showed new injuries to the mid-lower thoracic spine. One of these subjects reported a midthoracic pain incident during maximal strength testing before bed rest and the other after countermeasure exercise on day 3 of bed rest. We conclude that bed rest is associated with increased disc size in the thoracic region and increases in muscle volume at the neck. The exercise device needs to be modified to ensure that load is distributed in a more physiological fashion. morphology; uncovertebral joint; magnetic resonance imaging; spaceflight; microgravity PROLONGED BED REST is a methodology used by space agencies to simulate the deleterious effects of spaceflight on the human body (28) and hence also to trial various types of countermeasures against the detriments that occur in spaceflight. Very little data is available on the effect of bed rest or spaceflight on the cervical spine and its musculature. This is understandable, as the effect of bed rest and spaceflight on the musculoskeletal system is most prominent in the lower half of the body (11), and hence research typically focuses on this area of the body.The 2nd Berlin BedRest Study (BBR2-2) was a 60-day head-down tilt (HDT) bed rest study in which the primary focus was on the impact of exercise countermeasures on bone loss (4). When we initiated the study, we felt it important to also gain a deeper understanding of body regions not typically examined in such bed rest studies, such as the cervical spine. Furthermore, from an ethical point of view, we considered it important to better understand what kinds of changes subjects undergo in such studies. In this vein, it was appropriate to investigate body regions such as the cervical and upper thoracic spine. Also, we were aware of anecdotal reports of headache during HDT bed rest, but to our knowledge, these have never been...

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Section: Discussionmentioning

confidence: 92%

Hypertrophy in the cervical muscles and thoracic discs in bed rest?

Belavý

Miokovic

Armbrecht

et al. 2013

Journal of Applied Physiology

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“…The loss of intervertebral disk height may produce a certain instability in the vertebral segment and a relaxation of the oblique fibers of the fibrous annulus, which may contribute to degeneration of the intervertebral disk [14].…”

Section: Discussionmentioning

confidence: 99%

Low thoracic and lumbar burst fractures: radiographic and functional outcomes

Defino

Canto

2007

Eur Spine J

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Twenty patients with thoracolumbar burst fractures (type A3 in the classification of Magerl et al.) were studied prospectively for the evaluation of clinical, radiographic and functional results. The patients were submitted to surgical treatment by posterior arthrodesis, posterior fixation and autologous transpedicular graft. The patients were followed up for 2 years after surgery and assessed on the basis of clinical (pain, neurologic deficit, postoperative infection), radiographic (load sharing classification, Farcýs sagittal index of the fractured segment, relation between traumatic vertebral body height and the adjacent vertebrae (compression percentage), height of the intervertebral disk proximal and distal to the fractured vertebra, rupture or loosening of the implants) and functional (return to work, SF-36) criteria. Two patients presented a marked loss of correction and required the placement of an anterior support graft. Pain assessment revealed that eight patients (44%) had no pain; four (22%) had occasional pain, three (17%) moderate pain, and three (17%) severe pain. According to the classification of Frankel et al., 17 patients persisted as Frankel E and one patient presented improvement of one degree, becoming Frankel D. The mean value of Farcýs sagittal index of the injured vertebral segment was 20.67°± 6.15°(range 8°-32°) during the preoperative period, 11.22°± 8.09°(range -5°to 21°) during the immediate postoperative period, and 14.22°± 7.37°(range 3°-25°) at late evaluation. There was a statistically significant difference between the immediate postoperative values and the preoperative and late postoperative values. The compression percentage of the fractured vertebral body ranged from 9.1 to 60 (mean 28.81 ± 11.51) during the preoperative period, from 0 to 60 (mean: 15.59 ± 14.49) during the immediate postoperative period, and from 8 to 60 (mean: 25.9 ± 13.02) at late evaluation. There was a statistically significant difference between the preoperative and postoperative values and between the postoperative and late postoperative values. The height of the proximal intervertebral disk ranged from 6 to 14 mm (mean 8.44 ± 2.66) during the preoperative period, from 6 to 15 mm (mean 10 ± 2.30) during the immediate postoperative period, and from 0 to 11 mm (mean 7.22 ± 2.55) during the late postoperative period. A significant difference was observed between the immediate postoperative values and the preoperative and late postoperative values. The height of the intervertebral disk distal to the fractured vertebra ranged from 7 to 16 mm (mean 9.94 ± 2.64) during the preoperative period, from 5 to 18 mm (mean 11.61 ± 3.29) during the immediate postoperative period, and from 2 to 14 mm (mean 9.72 ± 3.17) during the late postoperative period. There was a significant difference between the immediate postoperative values and the preoperative and late postoperative values. Except for the height of the intervertebral disk proximal to the fractured vertebra, no correlation was detected between the c...

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“…Progressive disc degeneration was claimed to be responsible for this phenomenon [9]. The loss of height of the intervertebral disc was shown to produce a significant loss of stability in the segment concerned by relaxing the oblique ring fibres [22,25], an effect that accelerates degeneration again. Kluger et al [18] predicted the amount of kyphosis by measuring the intervertebral disc angles and dividing them by the Cobb angle.…”

Section: Discussionmentioning

confidence: 99%

Traumatic intervertebral disc lesion – magnetic resonance imaging as a criterion for or against intervertebral fusion

et al. 2001

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Lesions of the intervertebral disc accompanying vertebral fractures are the subject of controversy and discussion regarding the extent and manner of surgical intervention. The question of when to perform disc resection and intervertebral fusion, in particular, has not been answered satisfactorily. In order to evaluate short-and medium-term lesions of the discoligamentous complex associated with thoracolumbar burst fractures, magnetic resonance images made after stabilisation and again after implant removal were compared. Between 1997 and 1998, 20 patients who had suffered thoracolumbar burst fractures (AO classification A3 and B1 [26]) underwent posterior reduction and stabilisation using a Universal Spine System (USS, Synthes, Switzerland) titanium internal fixator. The implant was removed after an average of 10 months. Magnetic resonance imaging (MRI) scans were performed 1 week after both operations, allowing the changes in a total of 40 intervertebral discs adjacent to the fractured vertebral body to be investigated. The analysis was based on signal intensity of the intervertebral disc in T 2 -weighted scans and on morphological criteria. A total of 81% of the discs with initially normal T 2 -weighted signal

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Can Variations in Intervertebral Disc Height Affect the Mechanical Function of the Disc?

Abstract: Variations in disc height may compromise the general conclusions reached from experimental work and analytic studies in which geometric parameters (especially disc height and disc cross-sectional area) are not taken into consideration.

Cited by 110 publications

References 43 publications

Hypertrophy in the cervical muscles and thoracic discs in bed rest?

Hypertrophy in the cervical muscles and thoracic discs in bed rest?

Low thoracic and lumbar burst fractures: radiographic and functional outcomes

Traumatic intervertebral disc lesion – magnetic resonance imaging as a criterion for or against intervertebral fusion

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