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
The aim of this study was to evaluate the time course of changes
in parameters of diffusion tensor imaging (DTI) such as fractional
anisotropy (FA) and apparent diffusion coefficient (ADC) in patients
with symptomatic lumbar disc herniation. We also investigated the
correlation between the severity of neurological symptoms and these parameters. A total of 13 patients with unilateral radiculopathy due to herniation
of a lumbar disc were investigated with DTI on a 1.5T MR scanner
and underwent micro discectomy. There were nine men and four women,
with a median age of 55.5 years (19 to 79). The changes in the mean
FA and ADC values and the correlation between these changes and the
severity of the neurological symptoms were investigated before and
at six months after surgery. Aims
Patients and Methods
We retrospectively examined the prevalence and
natural history of asymptomatic lumbar canal stenosis in patients treated
surgically for cervical compressive myelopathy in order to assess
the influence of latent lumbar canal stenosis on the recovery after
surgery. Of 214 patients who had undergone cervical laminoplasty
for cervical myelopathy, we identified 69 (32%) with myelographically
documented lumbar canal stenosis. Of these, 28 (13%) patients with
symptomatic lumbar canal stenosis underwent simultaneous cervical
and lumbar decompression. Of the remaining 41 (19%) patients with
asymptomatic lumbar canal stenosis who underwent only cervical surgery,
39 were followed up for ≥ 1 year (mean 4.9 years (1 to 12)) and
were included in the analysis (study group). Patients without myelographic
evidence of lumbar canal stenosis, who had been followed up for ≥ 1
year after the cervical surgery, served as controls (135 patients;
mean follow-up period 6.5 years (1 to 17)). Among the 39 patients
with asymptomatic lumbar canal stenosis, seven had lumbar-related
leg symptoms after the cervical surgery. Kaplan–Meier analysis showed that 89.6% (95% confidence interval
(CI) 75.3 to 96.0) and 76.7% (95% CI 53.7 to 90.3) of the patients
with asymptomatic lumbar canal stenosis were free from leg symptoms
for three and five years, respectively. There were no significant
differences between the study and control groups in the recovery
rate measured by the Japanese Orthopaedic Association score or improvement
in the Nurick score at one year after surgery or at the final follow-up. These results suggest that latent lumbar canal stenosis does
not influence recovery following surgery for cervical myelopathy;
moreover, prophylactic lumbar decompression does not appear to be
warranted as a routine procedure for coexistent asymptomatic lumbar
canal stenosis in patients with cervical myelopathy, when planning
cervical surgery.
