Active Apex Correction With Guided Growth Technique for Controlling Spinal Deformity in Growing Children: A Modified SHILLA Technique

STUDY DESIGN

A retrospective study.

OBJECTIVE

To determine if active remodulation in the apex of the curve is possible in scoliosis and kyphoscoliosis patients, using a modified SHILLA; active apex correction (APC) technique for guided growth.

METHOD

Twenty patients with either scoliosis or kyphoscoliosis underwent a modified SHILLA approach, where instead of apical fusion, APC was applied. In this modified technique, the most wedged vertebra was selected followed by insertion of pedicle screws in the convex side of the vertebrae above and below the wedged one. The convex and concave heights of the wedged and control vertebrae were recorded at the time of the surgery and at follow-up duration, both using computed tomography.

RESULTS

The wedged vertebra demonstrated in average a 17% (P = .00014) increase in the proportion of concave to convex heights ratio, whereas the control vertebra did not show any relative change in the wedged vertebra heights at the follow-ups.

CONCLUSION

APC, instead of apical fusion in SHILLA remodulates the apex vertebra, which may in turn help mitigate loss of correction on long term due to crankshafting and adding-on.

Active Apex Correction (Modified SHILLA Technique) Versus Distraction-Based Growth Rod Fixation: What Do the Correction Parameters Say?

Introduction

SHILLA and growth rods are two main surgical correction techniques for patients with early-onset scoliosis. There have been some comparative studies between the two techniques, where a comparison was made between deformity identifying characteristics such as Cobb angle, apical vertebral translation, coronal balance, spinal length gain, etc. However, the SHILLA procedure experiences loss of correction or the reappearance of deformity through crankshafting or adding-on (e.g., distal migration). The current study identifies a solution with a modified approach to SHILLA (which could help in dynamically remodulating the apex of the deformity and mitigating loss of correction) and presents comparative correction data against the long-established traditional growth rod system.

Methods

The active apex correction (APC) group consisted of 20 patients and the growth rod group consisted of 26 patients, both with the same inclusion and exclusion criteria. The APC surgical procedure involved a modified SHILLA technique, that is, insertion of pedicle screws in the convex side of the vertebrae above and below the wedged one for compression and absence of apical fusion.

Results

There were no statistical differences between the various spinal parameters (namely, Cobb angle, apical vertebral translation, sagittal balance, and spinal length gain) of the two groups. However, significant differences existed for coronal balance, which in part may have been due to differences in its pre-op value between the two groups.

Conclusions

APC and the traditional growth rod system showed similar deformity correction parameters at current follow-ups; however, the latter requires multiple surgeries to regularly distract the spine.

Implant-Related Complications Do Not Interfere with Corrections with the Shilla Technique in Early Onset Scoliosis: Preliminary Results

Growth-preservation techniques are utilized in early onset scoliosis (EOS) cases requiring surgical intervention. The Shilla technique corrects the deformity by reducing additional surgeries with its growth-guidance effect. As with other techniques, various problems can be encountered following the administration of the Shilla technique. The aim of this study was to examine the effect of complications encountered with the Shilla treatment on correction and growth. Sixteen patients with a follow-up period of at least one year after receiving Shilla growth guidance for EOS were included in this retrospective study. No complications occurred, and no unplanned surgery was required in 50% of the cases. Of the remaining eight patients with postoperative implant-related complications (50%), six (37.5%) required unplanned surgery; this consequently caused implant failure in the proximal region in five cases (31.25%) and deep tissue infection around the implant in one case (6.25%). Deformity correction, spine length, and quality-of-life scores significantly improved in EOS through Shilla growth guidance. In terms of spinal growth and deformity correction, there were no significant differences between patients with implant-related problems and individuals without occurrences. Although implant-related problems were detected in our dataset and corresponding unexpected surgeries were necessary, these complications had no significant unfavorable influence on correction and spine growth.

A Prospective Multicenter ≥2 Years Clinical Study of the Active Apex Correction (APC) Technique in Early Onset Scoliosis (EOS) Patients

STUDY DESIGN

prospective multicenter study.

OBJECTIVES

Active apex correction (APC) is posterior tethering technique for correction of early onset scoliosis (EOS) via reverse modulation at the apex. Active apex correction has been increasingly used worldwide. This study aimed to assess short-term outcomes of multicenter study with ≥2 years of APC on spine length, curve correction, complications, unplanned surgeries, and proposed low crankshaft phenomena incidence.

METHODS

Prospective multicenter study including 24 EOS patients treated by APC; involves inserting and compressing pedicle screws on convex side of apex proximal and distal to most wedged vertebra allowing apex modulation according to Hueter-Volkmann law. Excluded patients with <2 years follow-up whom APC was not primary surgery.

RESULTS

Mean age 85.97 ± 32.43 months, 71% congenital scoliosis, mean follow-up 35.54 ± 12.36 months. At final follow-up, statistically significant improvement in Cobbs angle (∆ = 23.96%, P < .0001), spinal length T1-T12 (∆ = 12.83%, P < .0001), T1-L5 (∆ = 13.41%, P < .0001) but not in apical vertebral translation (AVT) albeit clinical improvement (∆ = 7.9%, P = .36) compared to preoperative measurements. Comparing immediate postoperative measurements to >2 years follow-up, statistically significant improvement in spinal length T1-T12 (∆ = 6.03%, P = .0002) and T1-L5 (∆ = 6.26%, P < .0001) but not in Cobbs angle (∆ = 4.93%, P = .3) or AVT (∆ = 14.77%, P = .25). 9 complications requiring 3 unplanned surgeries recorded in all patients including 2 broken rods, 2 adding-on and 4 screw dislodgement.

CONCLUSION

Active apex correction is a novel technique that has been incorporated in several countries as treatment modality for EOS. Short-term outcomes are promising in terms of clinical improvement, complication rates and decreased need for multiple operations or unplanned surgeries.

Controlling the Apex in Early Onset Scoliosis Through Active Apex Correction (APC) Non Fusion Growth Modulating Technique, Is It a Myth?

STUDY DESIGN

A multicenter retrospective study.

OBJECTIVES

To determine the rate of Apex facet fusion in children with Early Onset Scoliosis treated surgically with the Active Apex Correction (APC) technique.

METHODS

Seventeen patients were treated with the APC technique as index surgery for Early Onset Scoliosis with more than 1 year of follow-up. A 3D CT scan was done to determine the facet fusion rate in the deformity's apex controlled with posterior tethering.

RESULTS

The average follow-up time was 26.4 months (12-56), Average age at index surgery was 81.2 months (30-132), and average number of surgeries done 1.3. Apical vertebrae studied for facet fusion were the 3 vertebrae in the apex in each patient that were subjected to posterior tethering according to the APC technique. In total they were 86 apical vertebrae (172 Facets studied with 86 convex side, 86 concave side). Our observations showed that 29 facet joints were fused (16% of the total facets studied),15 were on the convex, 14 on the concave side (no statistically significant difference). Regarding the facet joint distance in the non-fused facets was 0.99 mm on the convex side and 1.08 mm on the concave side with no statistical significance difference.

CONCLUSION

APC for Early Onset Scoliosis achieves apical growth modulation and control utilizing posterior tethering without inducing fusion. This study demonstrated that APC is an effective non-fusion technique through the low incidence of facet fusion levels at the Apex, limiting the crankshaft phenomena seen in cases with apex control through arthrodesis.