Clinical and radiological data were reviewed for all patients
with mucopolysaccharidoses (MPS) with thoracolumbar kyphosis managed
non-operatively or operatively in our institution. In all 16 patients were included (eight female: eight male; 50%
male), of whom nine had Hurler, five Morquio and two Hunter syndrome.
Six patients were treated non-operatively (mean age at presentation
of 6.3 years; 0.4 to 12.9); mean kyphotic progression +1.5o/year;
mean follow-up of 3.1 years (1 to 5.1) and ten patients operatively (mean
age at presentation of 4.7 years; 0.9 to 14.4); mean kyphotic progression
10.8o/year; mean follow-up of 8.2 years; 4.8 to 11.8)
by circumferential arthrodesis with posterior instrumentation in
patients with flexible deformities (n = 6).Aims
Methods
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:
