Purpose of the study: The surgical technique for thoracolumbar scoliosis and T11-L3 lumbar scoliosis with a lumbosacral counter curvature (neutral L4) does not raise any particular problem in terms of the length of the instrumentation and the choice of the vertebral bodies to include in the fusion. The strategy is however more difficult to establish when the iliolumbar angle is closed and L4 is included in the curvature.

Material and methods: We report 11 cases of type II scoliosis, all in girls aged 15.5 years on average (range 12–18 years). These girls presented an imbalanced trunk with lumbar asymmetry. Mean lumbar curvature was 51° (range 41–72°), and, for patients with a double curvature, the mean thoracic counter curvature was 28° (range 21–45°). Lateral lumbar displacement was 4.2 cm (3–4.9 cm), and in double curvatures the thoracic displacement was 3.1 cm (1.7–4.2 cm). Mean lumbar lordosis was −41° (range −38° to −46°). Mean thoracic kyphosis was +13° (range −2° to +22°). Anterior instrumentation was used for all curvatures. For six patients, five levels, from T11 to L3 were instrumented and in five patients, four levels from T12 to L3. For the double scoliosis cases, in situ rod bending was necessary to balance the lumbar curvature with the thoracic curvature.

Results: Mean follow-up was 42 months (range 14–79). One revision was required for rupture of a corporeal screw with L4–L5 nonunion. Trunk imbalance was corrected in all patients. The iliolumbar angle was opened with a mean L3–L4 inclination of 11° (range 0–18°). Mean Cobb angle was 22° in the lumbar region (range 17–30°). For the double curvatures, the mean residual thoracic curvature was 27.6° (range 17–44°). Mean residual lateral displacement was 0.2 cm in the lumbar region (range 0–0.3 cm) and 0.8 cm (range 0.3–2.2 cm) in the thoracic region. Mean thoracic kyphosis was 13° (range +10–25°). Mean lumbar lordosis was −51° (range −49° to +44°).

Discussion: In the literature, a posterior approach has been proposed for curvatures with a closed iliolumbar angle and inclusion of L4. The assembly includes L4 and often L5, extending as high as T5–T6 in the cases with double curvatures. We have chosen a completely different strategy and propose short anterior instrumentation. The spinal balance obtained appears to be as good with a better functional result due to the preservation of spinal motion and posterior muscle function. Longer follow-up will be necessary to assess the effect on the discs above and below the fusion.

Anterior stabilisation has been shown to be superior in the treatment of the lumbar and thoraco-lumbar scoliosis, both in regard to the correction of the curves and to the number of fused vertebrae. Since 1995, with the emergence of third-generation locking devices, we have extended the indication of anterior fixation to double major scoliosis with lumbar predominance, operating exclusively on the lumbar curve and allowing the thoracic curve to correct itself. We report this experience with respect to 12 patients.

The patients consisted of 11 girls and one boy, mean age 16.6 years (range 12–29). The mean preoperative Cobb angle was: lumbar: 51° (41–72), dorsal 28° (range 21–45). All patients showed a lateral deviation of the trunk with asymmetry of the lumbar region.

Of the 12 patients, 11 received stabilisation by EUROS instruments from D11 to L3 and one from D10 to L3. The mean follow-up is 44 months (range 15–77 months).

A vertebral fusion was achieved for 94 % of the spaces (46/49). In the fixation zone, a 72% correction rate was achieved, whereas in the non-treated zone of the dorsal rachis, the rate of spontaneous correction was 32 %. In total the angle loss has been on average 4°. The study assessed the horizontal position of the disk underlying the zone of the arthrodesis; in other words the L3 – L4 disk showed the presence of an average gradient angle of 7° with a range from 0° to 17°. No post-operative complications were observed, but 7 of 12 patients have had immediate and transient sympathectomy after-effects, with a modification of the ipsilateral limb temperature at the level of the instrumental access site.

Anterior stabilization of the thoracolumbar curve in double major scoliosis with lumbar predominance seems to be preferred to posterior correction. This technique, by preserving the posterior musculature, makes it possible to save from 1 to 2 disk downwards. In turn, this makes it possible to correct the lateral translation and the realignment of the trunk starting with fusion limited to the lumbar spine. It is imperative to avoid hypercorrection of the thoraco-lumbar curve and even leave a bit of curve in the in situ modelling of the rod. Then the lumbar curve can be balanced with the dorsal curve and avoid an increase in the lumbosacral counter-curve with the risk in of rotatory dislocation in adult age. Since we have started using this technique, we have not had to perform double correction, anterior and posterior, for double major scoliosis with lumbar predominance.