Gradual incremental cantilever correction of adolescent vs adult Scheuermanns kyphosis: Technique, outcomes, and complications

2012

Summary

Long-term outcomes were studied on 14 patients (adolescent-11, adult-3) after incremental cantilever correction and posterior instrumented fusion for Scheuermann's kyphosis(SK). Both adolescents and adults achieved good deformity correction without implant failure or neuro deficit. Clinical results showed pain relief and improved function. Uninstrumented lumbar lordosis spontaneously decreased in both age groups after the kyphosis was corrected. Gradual and highly controlled cantilever correction of SK appears safe and produces similar correction as instantaneous application of corrective cantilever force.

Introduction

Surgical correction of Scheuermann's kyphosis (SK) has been accomplished using a cantilever force over a few seconds time. A gradual and incrementally applied cantilever correction technique has been successfully used to correct kyphosis, spreading the highly controlled reduction forces over multiple points of fixation. We studied long term outcomes from this Direct Incremental Segmental Translation (DIST) technique, comparing 2 year posterior fusion results in adult vs adolescent SK.

Methods:

Outcomes from 14 patients with stiff thoracic SK (adolescent-11, adult-3) were reviewed. Age: Adolescent-17years (14-20), Adult-53years (46-62). All had correction using DIST over an average 1-2 hour timespan. Excluded: 3-column osteotomies, TL/L kyphosis. Postop bracing was not used. Kyphosis and sagittal radiographic measurements collected: overall kyphosis, T5-12, T10-L2, T12-S1, pelvic incidence, sagittal balance. Clinical data: Complications, VAS, Oswestry (ODI) were recorded preop, 1 year, 2 years, and latest follow up. Data was statistically analyzed with the sign test.

Results:

Follow up ranged 24-60months. Complications: Adolescent- 1 infection; Adult-0. There were no implant failures or neuro deficits. Deformity correction was similar for both groups. Adolescent SK: preop 82° (range 65-93°) corrected to 41.2°. Adult SK: preop- 86.7° (range 84-91°) corrected to 46°. T5-12: Adolescent preop-73°, 2 year-32°. Adult preop-79°, 2 year-39°. Lumbar lordosis: Adolescents preop:-67°, 2year:-47°. Adult preop:-67°, 2year:-53°. Clinical improvement was also seen in both groups, with functional improvement favoring the adolescents. VAS: Adolescent preop- 6.2, 2 year-1.0. Adult VAS: preop-5.7, 2year- 2.8. ODI: Adolescent pre-op-23.3, 2 year-2.8. Adult ODI: pre-op-38.7, 2year-35.0.

Conclusions:

Although reduction for adult and adolescent SK was similar and both groups improved clinically (VAS), adolescent patients had a better functional outcome(ODI). DIST provided a controlled reduction of stiff deformity without implant failure or neuro deficit in both age groups.