Effect of direct vertebral body derotation on the sagittal profile in adolescent idiopathic scoliosis

Abstract

Purpose: We sought to clarify the effect of applying derotation maneuvers in the correction of adolescent idiopathic scoliosis (AIS) on the sagittal plane.

Methods: We retrospectively queried a large, multicenter, prospectively collected database for patients who underwent surgical correction of AIS. All patients had at least 2 years of follow-up and documentation as to whether or not a derotation maneuver was performed during surgery. All patients underwent posterior spinal fusion with pedicle screw constructs. Patients who underwent concurrent anterior procedures were excluded.

Results: A total of 323 patients were identified, of whom 66 did not have direct vertebral body derotation (DVBD) maneuvers applied during the deformity correction. The remaining 257 had a vertebral body derotation maneuver performed during their surgical correction. Although no significant differences were identified between the two groups when comparing pre-op and post-op thoracic kyphosis using T2-12 and T5-12 endplates, the absolute change in angulation measured from T2-12 was significantly different between the two groups. Postoperatively, the derotation group had a mean decrease in thoracic kyphosis of 5.1±15.3° as compared to 10.8±18.9° in the control group, P = 0.03.

Conclusion: Although patients in both groups had decreased mean thoracic kyphosis postoperatively, application of DVBD in the correction of scoliosis did not additionally worsen the sagittal profile.

Fig. 1

Operative picture illustrating segmental derotation. a Initial image prior to derotation; b image after segmental derotation

Fig. 2

Operative image illustrating en bloc derotation. a Initial picture prior to derotation; b image after en bloc derotation

Fig. 3

PA and lateral standing radiographs illustrating the application of segmental derotation maneuvers alone to: a a pre-operative 40° curve, b with 27° of kyphosis from T5–12, c post-operative correction to 15°, d and 19° of post-operative kyphosis

Fig. 4

PA and lateral standing radiographs illustrating the application of en bloc derotation maneuvers alone to: a a pre-operative 58° curve, b with 12° of kyphosis from T5–12, c post-operative correction to 19°, d and 12° of post-operative kyphosis

Fig. 5

PA and lateral standing radiographs illustrating the application of both segmental and en bloc derotation maneuvers to: a a pre-operative 43° curve, b with 23° of kyphosis from T5–12, c post-operative correction to 15°, d and 18° of post-operative kyphosis

Fig. 6

PA and lateral standing radiographs illustrating the control group of no derotation maneuver to: a a pre-operative 53° curve, b with 25° of kyphosis from T5–12, c post-operative correction to 13°, d and 17° of post-operative kyphosis