J Korean Soc Spine Surg.  1997 Nov;4(2):273-280.

The Influence of Segmental Pedicle Screw Fixation on Distal Fusion Level in KingType I Adolescent Idiopathic Scoliosis(AIS)

• Suk SI
• Kim JH
• Kim WJ
• Kim DS
• Lee SM
• Kim JH

Abstract

STUDY DESIGN: This study analyzes the influence of segmental pedicle screw fixation on distal fusion extent of King type I adolescent Idiopathic scoliosis(AIS).
OBJECTIVES
To verify the efficacy of segmental pedicle screw fixation in preservation of distal lumbar motion segments. SUMMARY OF BACKGROUND DATA: King type I AIS has usually been treated by fusion to L4. However, segmental pedicle screw fixation may shorten the distal fusion extent by reducing the hopi-Bontal tiIt of the lower end vertebra.
MATERIALS AND METHODS
Eighteen King type I AIS subjected to segmental pedicle screw fixation of both curves were analyzed after a minimum follow-up of 2 years. Fourteen were fused to L3(short fusion group, SF) and 4 were fused to L4(long fusion group, LF). They were compared for correction of deformity, spinal balance and L4 tiIt.
RESULTS
In SF group, the thoracic currie showed 71.6% correction. Lumbar curve and L4 tiIt corrections were 76.8% and 75.2% respectiveIY. In LF group, the thoracic currie showed 65.2% correction. Lumbar currie and L4 tilt corrections were 76.8% and 78.4% respectively. There was no significant difference between two groups. Spinal balance was maintained in all patients(SF 14/14; LF 4/4).
CONCLUSIONS
Segmental pedicle screw fixation may shorten the distal fusion extent of King type IAIS to L3, preserving a distal motion segment with a correction of deformity and spinal balance comparable to fusion down to L4. It is attributed to enhanced segmental control of the system enabling horizontalization of L4.

MeSH Terms

Adolescent*
Congenital Abnormalities
Follow-Up Studies
Humans
Spine