The aim of this study was to evaluate the feasibility
of using the intact S1 nerve root as a donor nerve to repair an avulsion
of the contralateral lumbosacral plexus. Two cohorts of patients
were recruited. In cohort 1, the L4–S4 nerve roots of 15 patients
with a unilateral fracture of the sacrum and sacral nerve injury
were stimulated during surgery to establish the precise functional
distribution of the S1 nerve root and its proportional contribution
to individual muscles. In cohort 2, the contralateral uninjured
S1 nerve root of six patients with a unilateral lumbosacral plexus
avulsion was transected extradurally and used with a 25 cm segment
of the common peroneal nerve from the injured leg to reconstruct
the avulsed plexus. The results from cohort 1 showed that the innervation of S1 in
each muscle can be compensated for by L4, L5, S2 and S3. Numbness
in the toes and a reduction in strength were found after surgery
in cohort 2, but these symptoms gradually disappeared and strength
recovered. The results of electrophysiological studies of the donor
limb were generally normal. Severing the S1 nerve root does not appear to damage the healthy
limb as far as clinical assessment and electrophysiological testing
can determine. Consequently, the S1 nerve can be considered to be
a suitable donor nerve for reconstruction of an avulsed contralateral
lumbosacral plexus. Cite this article:
Clinical, radiological, and Scoliosis Research
Society-22 questionnaire data were reviewed pre-operatively and
two years post-operatively for patients with thoracolumbar/lumbar
adolescent idiopathic scoliosis treated by posterior spinal fusion
using a unilateral convex segmental pedicle screw technique. A total
of 72 patients were included (67 female, 5 male; mean age at surgery
16.7 years (13 to 23)) and divided into groups: group 1 included
53 patients who underwent fusion between the vertebrae at the limit
of the curve (proximal and distal end vertebrae); group 2 included
19 patients who underwent extension of the fusion distally beyond
the caudal end vertebra. A mean scoliosis correction of 80% (45% to 100%) was achieved.
The mean post-operative lowest instrumented vertebra angle, apical
vertebra translation and trunk shift were less than in previous
studies. A total of five pre-operative radiological parameters differed
significantly between the groups and correlated with the extension
of the fusion distally: the size of the thoracolumbar/lumbar curve,
the lowest instrumented vertebra angle, apical vertebra translation,
the Cobb angle on lumbar convex bending and the size of the compensatory
thoracic curve. Regression analysis allowed an equation incorporating
these parameters to be developed which had a positive predictive
value of 81% in determining whether the lowest instrumented vertebra
should be at the caudal end vertebra or one or two levels more distal.
There were no differences in the Scoliosis Research Society-22 outcome
scores between the two groups (p = 0.17). In conclusion, thoracolumbar/lumbar curves in patients with adolescent
idiopathic scoliosis may be effectively treated by posterior spinal
fusion using a unilateral segmental pedicle screw technique. Five
radiological parameters correlate with the need for distal extension
of the fusion, and an equation incorporating these parameters reliably
informs selection of the lowest instrumented vertebra. Cite this article:
Transarticular screw fixation with autograft
is an established procedure for the surgical treatment of atlantoaxial instability.
Removal of the posterior arch of C1 may affect the rate of fusion.
This study assessed the rate of atlantoaxial fusion using transarticular
screws with or without removal of the posterior arch of C1. We reviewed
30 consecutive patients who underwent atlantoaxial fusion with a
minimum follow-up of two years. In 25 patients (group A) the posterior
arch of C1 was not excised (group A) and in five it was (group B).
Fusion was assessed on static and dynamic radiographs. In selected
patients CT imaging was also used to assess fusion and the position
of the screws. There were 15 men and 15 women with a mean age of
51.2 years (23 to 77) and a mean follow-up of 7.7 years (2 to 11.6).
Stable union with a solid fusion or a stable fibrous union was achieved
in 29 patients (97%). In Group A, 20 patients (80%) achieved a solid
fusion, four (16%) a stable fibrous union and one (4%) a nonunion.
In Group B, stable union was achieved in all patients, three having
a solid fusion and two a stable fibrous union. There was no statistically
significant difference between the status of fusion in the two groups.
Complications were noted in 12 patients (40%); these were mainly
related to the screws, and included malpositioning and breakage.
The presence of an intact or removed posterior arch of C1 did not
affect the rate of fusion in patients with atlantoaxial instability
undergoing C1/C2 fusion using transarticular screws and autograft. Cite this article:
We describe the results of a prospective case series of patients with spondylolysis, evaluating a technique of direct stabilisation of the pars interarticularis with a construct that consists of a pair of pedicle screws connected by a U-shaped modular link passing beneath the spinous process. Tightening the link to the screws compresses bone graft in the defect in the pars, providing rigid intrasegmental fixation. We have carried out this procedure on 20 patients aged between nine and 21 years with a defect of the pars at L5, confirmed on CT. The mean age of the patients was 13.9 years (9 to 21). They had a grade I or less spondylolisthesis and no evidence of intervertebral degeneration on MRI. The mean follow-up was four years (2.3 to 7.3). The patients were assessed by the Oswestry Disability Index (ODI) and a visual analogue scale (VAS). At the latest follow-up, 18 patients had an excellent clinical outcome, with a significant (p <
0.001) improvement in their ODI and VAS scores. The mean ODI score at final follow-up was 8%. Assessment of the defect by CT showed a rate of union of 80%. There were no complications involving the internal fixation. The strength of the construct removes the need for post-operative immobilisation.
