Radiological Findings and Curve Progression Twenty Two Years After Treatment for Adolescent Idiopathic Scoliosis: Comparison of Brace and Surgical Treatment and with a Matching Control Group of Straight Individuals
Aina J. Danielsson, MD,
Alf L. Nachemson, MD, PhD
Sahlgrenska University Hospital, Göteborg, Sweden
INTRODUCTION:
A consecutive series of patients with adolescent idiopathic scoliosis,
treated between 1968 and 1977, either with distraction and fusion
using Harrington rods (ST, n=156) or with brace (BT, n=127) were
followed at least twenty years after completion of the treatment.
PURPOSE:
To determine the long–term outcome with regard to radiological
findings and curve progression.
METHODS:
Two hundred and fifty–two patients attended a clinical and
radiological follow–up by an unbiased observer (91% of ST
and 87% of BT). This included chart reviews, validated questionnaires,
clinical examination and full standing frontal and lateral roentgenographs.
Curve size (Cobb method), occurrence of any degenerative changes
and other complications were noted. Repeat lateral radiographs,
independently measured by two observers, were taken to evaluate
lateral curvatures and sagittal balance. An age and sex matched
control group of 100 individuals was randomly selected and subjected
to the same examinations.
RESULTS:
The mean follow–up time was 23 years for ST group and 22
years for the BT group. Curve increase was 3.5 degrees for all
ST curves and 7.9 degrees for all BT curves (p<0.001). The
overall complication rate after surgery was low. Nine of the
patients treated with fusion (5.7%) had undergone some additional
curve–related surgical procedure. Both ST and BT patients
had more degenerative disc changes in the lumbar region (p<0.001)
than the control group. There was no statistically significant
difference in terms of degenerative changes between those who
were fused below L3 or those fused to L3 and above (p=0.22).
The study on intra– and interobserver measurements of kyphosis,
lordosis and sagittal vertical axis on two films on each patient,
demonstrated that the repeatability of measuring sagittal plumbline
on two different lateral radiographs, with patients moving in
between, was unreliable.
DISCUSSION AND CONCLUSION:
Although over twenty years have passed since completion of the
treatment, the majority of the curves did not increase much.
The surgical complication rate was low. Unexpectedly, lumbar
degenerative disc changes were equally common in both patient
groups and significantly more than in the control group. The
earlier shown increased incidence of degenerative changes below
fusion extending to L4 or L5 was not seen. The low repeatability
on lateral radiography for sagittal balance measurements makes
evaluation of single examinations questionable.