Adult scoliosis correction: Clinical and radiographic comparison of techniques

2006

SUMMARY

This study compares outcomes of 60 patients with adult scoliosis surgically treated using either rod derotation and in situ bending versus direct vertebral translation with screws containing pivoting reduction posts, followed at least 2 years. Direct vertebral translation was statistically superior (72% vs. 49%) in achieving deformity correction.

INTRODUCTION

Rod derotation, in situ rod bending, and direct vertebral translation to the rod with sublaminar wires have all been used to correct adult scoliosis. A new implant based method (without cables or wires) of direct vertebral translation has also been developed. The purpose of this study is to compare clinical and radiographic results in patients with adult scoliosis treated with the new direct vertebral translation technique compared to patients treated with rod derotation and in situ bending.

METHODS

Sixty consecutive patients with adult scoliosis treated with posterior correction by one surgeon. The first 17 (control group averaged 48 years, range 20–79 yrs) were corrected by rod derotation and in situ rod bending and followed 5 years (range 3-11 yrs). Twelve were idiopathic and 5 were degenerative curves. The next 43 patients (direct translation group) averaged 60 years (19–85 yrs) were followed 3.5 years, range 24-56 months. Twenty-one were idiopathic (1 thoracic, 3 thoracolumbar, 8 lumbar, 9 double major), 15 were degenerative, 7 were revisions of prior fusion attempts. These curves were corrected by direct vertebral translation by slowly and incrementally pulling the spine to a contoured rod via pivoting reduction posts attached to screws. This technique produced simultaneous correction in both the coronal and sagittal planes. Anterior surgery was required in 15/17 control and 39/43 direct translation patients. Only two patients from each group required osteotomies to mobilize ankylosed segments. Oswestry and Visual Analog pain Scores (VAS), pain medication use, and work status were followed along with radiographs. Clinical and radiographic results were analyzed by curve type.

RESULTS

The direct translation group curves of 49° (range 17–83°) corrected 72% to 14° (4-40°) was better (P<0.01) than control group curves of 55° (25–84°) corrected 48% to 29° (10-59°). Idiopathic scoliosis of 58° (43–83°) in the translation group corrected 69% to 18° (7–40°) compared to 49% correction in the control group. Correction of translation group vs control group by curve type was: degenerative 67% vs 49%, thoracic 70% vs 51% , thoracolumbar 81% vs 44%, lumbar 74% vs 67% , double major 62% vs 34% . Control group complications included 3 nonunions (17%), 2 implant pullout (11%), 1 broken rod, 1 infection (5%). The translation group had 4 nonunions (9%), 2 infections (5%), no cases of screw pullout during reduction. Eleven of 14 patients working pre-op returned to work. Oswestry and VAS score improvements were not statistically different between groups at 1 and 2 years.

CONCLUSION

This study shows statistically improved correction of adult scoliosis by direct vertebral translation using screws with pivoting reduction posts compared to other techniques. The most dramatic improvement was seen in patients with thoracolumbar and lumbar scoliosis. The technique appears to be very promising in patients with adult scoliosis.