Loosening of pedicle screws is a major complication of posterior
spinal stabilisation, especially in the osteoporotic spine. Our
aim was to evaluate the effect of cement augmentation compared with
extended dorsal instrumentation on the stability of posterior spinal
fixation. A total of 12 osteoporotic human cadaveric spines (T11-L3) were
randomised by bone mineral density into two groups and instrumented
with pedicle screws: group I (SHORT) separated T12 or L2 and group
II (EXTENDED) specimen consisting of T11/12 to L2/3. Screws were
augmented with cement unilaterally in each vertebra. Fatigue testing
was performed using a cranial-caudal sinusoidal, cyclic (1.0 Hz)
load with stepwise increasing peak force.Aims
Materials and Methods
We sought to determine whether specific characteristics
of vertebral fractures in elderly men are associated with low bone
mineral density (BMD) and osteoporosis. Mister osteoporosis Sweden is a population based cohort study
involving 3014 men aged 69 to 81 years. Of these, 1427 had readable
lateral radiographs of the thoracic and lumbar spine. Total body
(TB) BMD (g/cm²) and total right hip (TH) BMD were measured by dual
energy x-ray absorptiometry. The proportion of men with osteoporosis
was calculated from TH BMD. There were 215 men (15.1%) with a vertebral
fracture. Those with a fracture had lower TB BMD than those without
(p <
0.001). Among men with a fracture, TB BMD was lower in those
with more than three fractures (p = 0.02), those with biconcave
fractures (p = 0.02) and those with vertebral body compression of
>
42% (worst quartile) (p = 0.03). The mean odds ratio (OR) for
having osteoporosis when having any type of vertebral fracture was
6.1 (95% confidence interval (CI) 3.9 to 9.5) compared with those
without a fracture. A combination of more than three fractures and
compression in the worst quartile had a mean OR of 114.2 (95% CI
6.7 to 1938.3) of having osteoporosis compared with those without
a fracture. We recommend BMD studies to be undertaken in these subcohorts
of elderly men with a vertebral fracture. Cite this article: 2015;97-B:1106–10.
This is a prospective randomised study comparing
the clinical and radiological outcomes of uni- and bipedicular balloon
kyphoplasty for the treatment of osteoporotic vertebral compression
fractures. A total of 44 patients were randomised to undergo either
uni- or bipedicular balloon kyphoplasty. Self-reported clinical
assessment using the Oswestry Disability Index, the Roland-Morris
Disability questionnaire and a visual analogue score for pain was undertaken
pre-operatively, and at three and twelve months post-operatively.
The vertebral height and kyphotic angle were measured from pre-
and post-operative radiographs. Total operating time and the incidence
of cement leakage was recorded for each group. Both uni- and bipedicular kyphoplasty groups showed significant
within-group improvements in all clinical outcomes at three months
and twelve months after surgery. However, there were no significant
differences between the groups in all clinical and radiological
outcomes. Operating time was longer in the bipedicular group (p <
0.001). The incidence of cement leakage was not significantly different
in the two groups (p = 0.09). A unipedicular technique yielded similar clinical and radiological
outcomes as bipedicular balloon kyphoplasty, while reducing the
length of the operation. We therefore encourage the use of a unipedicular
approach as the preferred surgical technique for the treatment of
osteoporotic vertebral compression fractures. Cite this article:
Low