Many studies have investigated the kinematics of the lumbar spine and the morphological features of the lumbar discs. However, the segment-dependent immediate changes of the lumbar intervertebral space height during flexion-extension motion are still unclear. This study examined the changes of intervertebral space height during flexion-extension motion of lumbar specimens. First, we validated the accuracy and repeatability of a custom-made mechanical loading equipment set-up. Eight lumbar specimens underwent CT scanning in flexion, neural, and extension positions by using the equipment set-up. The changes in the disc height and distance between adjacent two pedicle screw entry points (DASEP) of the posterior approach at different lumbar levels (L3/4, L4/5 and L5/S1) were examined on three-dimensional lumbar models, which were reconstructed from the CT images.Objectives
Methods
Few studies have examined the order in which
a spinal osteotomy and total hip replacement (THR) are to be performed
for patients with ankylosing spondylitis. We have retrospectively
reviewed 28 consecutive patients with ankylosing spondylitis who
underwent both a spinal osteotomy and a THR from September 2004
to November 2012. In the cohort 22 patients had a spinal osteotomy
before a THR (group 1), and six patients had a THR before a spinal
osteotomy (group 2). The mean duration of follow-up was 3.5 years
(2 to 9). The spinal sagittal Cobb angle of the vertebral osteotomy
segment was corrected from a pre-operative kyphosis angle of 32.4
(SD 15.5°) to a post-operative lordosis 29.6 (SD 11.2°) (p <
0.001). Significant improvements in pain, function and range of
movement were observed following THR. In group 2, two of six patients
had an early anterior dislocation. The spinal osteotomy was performed
two weeks after the THR. At follow-up, no hip has required revision
in either group. Although this non-comparative study only involved
a small number of patients, given our experience, we believe a spinal osteotomy
should be performed prior to a THR, unless the deformity is so severe
that the procedure cannot be performed. Cite this article:
This study assessed the frequency of acute injury to the spinal cord in Irish Rugby over a period of ten years, between 1995 and 2004. There were 12 such injuries; 11 were cervical and one was thoracic. Ten occurred in adults and two in schoolboys. All were males playing Rugby Union and the mean age at injury was 21.6 years (16 to 36). The most common mechanism of injury was hyperflexion of the cervical spine and the players injured most frequently were playing at full back, hooker or on the wing. Most injuries were sustained during the tackle phase of play. Six players felt their injury was preventable. Eight are permanently disabled as a result of their injury.
