Objectives. Pedicle-lengthening osteotomy is a novel surgery for lumbar spinal stenosis (LSS), which achieves substantial enlargement of the spinal canal by expansion of the bilateral pedicle osteotomy sites. Few studies have evaluated the impact of this new surgery on spinal canal volume (SCV) and neural foramen dimension (NFD) in three different types of LSS patients. Methods. CT scans were performed on 36 LSS patients (12 central canal stenosis (CCS), 12 lateral recess stenosis (LRS), and 12 foraminal stenosis (FS)) at L4-L5, and on 12 normal (control) subjects. Mimics 14.01 workstation was used to reconstruct 3D models of the L4-L5 vertebrae and discs. SCV and NFD were measured after 1 mm, 2 mm, 3 mm, 4 mm, or 5 mm pedicle-lengthening osteotomies at L4 and/or L5. One-way analysis of variance was used to examine between-group differences. Results. In the intact state, SVC and NFD were significantly larger in the control group compared with the LSS groups (P<0.05). After lengthening at L4, the percentage increase in SCV (per millimetre) was LRS>CCS>FS>Control. After lengthening at L5 and L4-L5, the percentage increase in SCV (per millimetre) was LRS>FS>CCS>Control. After lengthening at L4 and L4-L5, the percentage increase in NFD (per millimetre) was FS>CCS>LRS>Control. After lengthening at L5, the percentage increase in NFD (per millimetre) was CCS>LRS>control>FS. Conclusions. LRS patients are the most suitable candidates for treatment with pedicle-lengthening osteotomy.
Aims. 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. Materials and Methods. 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. Results. Augmentation showed no significant increase in the mean cycles
to failure and fatigue force (SHORT p = 0.067; EXTENDED p = 0.239).
Extending the instrumentation resulted in a significantly increased
number of cycles to failure and a significantly higher fatigue force
compared with the SHORT instrumentation (EXTENDED non-augmented
+ 76%, p <
0.001; EXTENDED augmented + 87%, p <
0.001). Conclusion. The stabilising effect of cement augmentation of pedicle screws
might not be as beneficial as expected from biomechanical pull-out
tests.
The aim of this study was to compare the clinical and radiological outcomes of patients with early-onset scoliosis (EOS), who had undergone spinal fusion after distraction-based spinal growth modulation using either traditional growing rods (TGRs) or magnetically controlled growing rods (MCGRs). We undertook a retrospective review of skeletally mature patients who had undergone fusion for an EOS, which had been previously treated using either TGRs or MCGRs. Measured outcomes included sequential coronal T1 to S1 height and major curve (Cobb) angle on plain radiographs and any complications requiring unplanned surgery before final fusion.Aims
Methods
The aim of this study was to compare the outcomes of surgery
using growing rods in patients with severe A review of a multicentre EOS database identified 107 children
with severe EOS (major curve ≥ 90°) treated with growing rods before
the age of ten years with a minimum follow-up of two years and three
or more lengthening procedures. From the same database, 107 matched
controls with moderate EOS were identified.Aims
Patients and Methods
Magnetically controlled growing rod (MCGR) systems use non-invasive
spinal lengthening for the surgical treatment of early-onset scoliosis
(EOS). The primary aim of this study was to evaluate the performance
of these devices in the prevention of progression of the deformity.
A secondary aim was to record the rate of complications. An observational study of 31 consecutive children with EOS, of
whom 15 were male, who were treated between December 2011 and October
2017 was undertaken. Their mean age was 7.7 years (2 to 14). The
mean follow-up was 47 months (24 to 69). Distractions were completed
using the tailgating technique. The primary outcome measure was
correction of the radiographic deformity. Secondary outcomes were
growth, functional outcomes and complication rates.Aims
Patients and Methods
This study aimed to determine the relationship between pedicle-lengthening
distance and bulge-canal volume ratio in cases of lumbar spinal
stenosis, to provide a theoretical basis for the extent of lengthening
in pedicle-lengthening osteotomies. Three-dimensional reconstructions of CT images were performed
for 69 patients (33 men and 36 women) (mean age 49.96 years; 24
to 81). Simulated pedicle-lengthening osteotomies and disc bulge
and spinal canal volume calculations were performed using Mimics
software. Aims
Methods
Conventional growing rods are the most commonly
used distraction-based devices in the treatment of progressive early-onset
scoliosis. This technique requires repeated lengthenings with the
patient anaesthetised in the operating theatre. We describe the
outcomes and complications of using a non-invasive magnetically
controlled growing rod (MCGR) in children with early-onset scoliosis.
Lengthening is performed on an outpatient basis using an external remote
control with the patient awake. Between November 2009 and March 2011, 34 children with a mean
age of eight years (5 to 12) underwent treatment. The mean length
of follow-up was 15 months (12 to 18). In total, 22 children were
treated with dual rod constructs and 12 with a single rod. The mean
number of distractions per patient was 4.8 (3 to 6). The mean pre-operative
Cobb angle was 69° (46° to 108°); this was corrected to a mean 47°
(28° to 91°) post-operatively. The mean Cobb angle at final review
was 41° (27° to 86°). The mean pre-operative distance from T1 to
S1 was 304 mm (243 to 380) and increased to 335 mm (253 to 400)
in the immediate post-operative period. At final review the mean distance
from T1 to S1 had increased to 348 mm (260 to 420). Two patients developed a superficial wound infection and a further
two patients in the single rod group developed a loss of distraction.
In the dual rod group, one patient had pull-out of a hook and one
developed prominent metalwork. Two patients had a rod breakage;
one patient in the single rod group and one patient in the dual
rod group. Our early results show that the MCGR is safe and effective
in the treatment of progressive early-onset scoliosis with the avoidance
of repeated surgical lengthenings. Cite this article:
